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BMW Tech Letters

Aug 13, 2003

Buyer's Guide Clarification/Wheel Offsets
Mike Miller's piece, "Buyer's Guide, BMW E34 5 Series" was thankfully a very well done bit of journalism.

As an owner of a 5 Series Bimmer with those dreadful TRX wheels and tires, I commend Mr. Miller for finally explaining the reasoning behind this horror. No BMW dealer, or aftermarket wheel dealer or manufacturer had a clue as to the reasoning when I was searching out replacements. The tires are indeed available but as to why any clear thinking person would sink U.S. $375 per tire to replace his/her TRXs is unfathomable.

For any reader looking to replace his/her bald TRXs do not go through the agony I put myself through--just go directly to your local wheel and tire outfit and pick out your new set of wheels and tires. I put a wheel/tire package on my car for US $700. Michelin and Coker wanted US $1,500 just for the TRX tires--which as Mr. Miller pointed out, suck.

To clarify however, Mr. Miller claimed that E34 7x15-in. 1989-90 wheels are a direct bolt-on replacement for these damn TRXs however, I urge caution for the offset of the E28 wheel is 20mm and the offset for a 1995 E34 wheel is 45mm. The result is that a wheel from a 1995 car will not fit onto a 1982 car as the wheel will come into contact with the strut tower. Perhaps wheels from the model years 1989-90 will fit and not 1991 and newer. Mr. Miller's paragraph just needs a bit of specific clarification.
Brian Toye
via the Internet

Thank you for the kind words, Brian, but what are you trying to do--give me a heart attack? I just looked at every single E34 5 Series wheel in the BMW parts breakdown. None are 45mm offset. All are between 19mm and 22mm, and the overwhelming majority are 20mm offset. I knew this to be true before, from years of looking up this information for BMW drivers who read my work. E34 wheels are direct bolt-on replacements for E28 wheels, up to the 17-in. sizes found on the E34 M5. However, even these can be made to work with fender and quarter panel modifications.


Tranny Conversion
I have a 1993 325is. I'm planning an engine swap with a European-specification E36 M3

3.0-liter S50 engine next year, but first I want to convert the gearbox from automatic to manual. How difficult would this be and approximately how much does the conversion cost? Because I'm doing an engine swap, would this mean the gearbox and other parts I would have to purchase has to match the S50 engine? If so, would it be better to do the engine swap first?
Thy
via the Internet

The gearbox swap is straightforward except for the pedal assembly and interior trim work. I'd recommend a five-speed manual from as late an M3 or 328i as you can find, as this gearbox went though numerous updates. A recently departed donor car would be the most economical way to go about this job. You'll need the driveshaft, too, of course, and upgraded gearbox mounts are strongly recommended. The cheap way out is to use mounts for an E21 3 Series or E3 sedan, but check out the trick mounts sold by UUC Motorwerks (www.uucmotorwerks.com).

You will also need to remove the 3.91 differential this car came with in favor of a 3.15 or 3.23 limited slip unit, which will be far more compatible with the 1:1 fifth gear in your new manual box. Look for the new diff from a six-cylinder E36 up to 1995 (3.15) or an M3 from 1996-on (3.23).

You can use this drivetrain combination with either your current engine or the "new" engine. Obviously, you will need a great deal more parts than just the engine, but you probably know that. We're talking harnesses, ECU, exhaust, etc.


Tech Help for an 02
First I have to say that your magazine is great! I really like all the project cars. I am currently restoring/modifying a 1975 BMW 2002. In other words I'm having fun with rusted floors, panels, subframes and rotten hoses, etc. I have two questions:

1). My exhaust manifold is cracked, so I thought about a header but all the manufacturers I found couldn't make any claim for increasing power. Would it be a better move to just try to find a 2002tii exhaust manifold?

2). My radiator is pretty much done, and I found it lacking for spirited driving. Because my budget is pretty limited I'm thinking about replacing it with a factory unit from another car. I have freed up some space by relocating the battery and cutting the battery plate. I was wondering if you guys are aware of any radiator that would be a good upgrade and that would have similarly placed outlets. I'm planning on higher compression and aggressive cam so I don't want to risk it with the stock one especially since I don't have knock sensors.

Thanks a lot! I realize these questions won't really interest the main readers of european car and that my car isn't your typical project car so I have pretty slim chance of getting an answer but asking won't hurt. Continue the great work!
Alex Coallier
Montreal, Quebec, Canada

Whaddaya mean, Alex? The BMW 2002 is the quintessential project car! And hey, thanks for all the compliments.

1). You're on the right track with the tii manifold, which is a huge upgrade from the stock North American smog pipe manifold. However, with the cam and higher compression, I'm thinking you really would benefit from a nice 1 3/8-in. primary header. No, no one can tell you exactly how much. Some other considerations: You'll need to use the factory bracket from the downpipe or header to the bottom of the gearbox, or the pipe will crack at the flange. Fresh motor mounts are required with the header, or it will crack anyway. With any 2002 exhaust manifold or header, use an E30 single-cam 318i exhaust manifold gasket, which includes an integral heat shield to protect the plug wires, part number 11 62 1 723 876. Also use new studs and copper exhaust nuts from BMW.

2). Despite popular folklore, there's nothing inherently deficient about the factory 2002 radiator unless you live in the desert, which you clearly do not. So, if you want to use a factory replacement 2002 brass tank radiator, there's no problem with that. Most cooling system deficiencies on old BMWs are more related to aluminum oxidation buildup in the cylinder head coolant passages impeding coolant flow. Other tricks: Use the factory 400mm fan without a shroud, and try a 75-degree or even a 71-degree thermostat in place of the original 80-degree unit.

If you are set on a different radiator, the aluminum and plastic unit from a 1980-1983 320i will work, but you have to use two 320i rubber radiator mounts and drill holes in the nose panel, and fabricate two L-brackets for the bottom. Or you can buy an installation kit with the radiator from BMP Design (www.bmpd.com) for $250, which includes all necessary bits including a new cap. This radiator does have superior cooling capabilities relative to the original unit, but it won't last as long. The key to cooling system integrity and long life is use of original BMW antifreeze and 2-year coolant changes.

Make sure the fan you use has no cracks in the plastic. You'd be amazed what a fan blade looks like sticking out of your head. I'd recommend buying a new one from BMW. Don't forget the fan bolt lock strips.

The 75-degree thermostat is available from BMW. The 71-degree unit is aftermarket only. I get mine from Bavarian Autosport (www.bavauto.com).

3). You may want to order the BMW Mobile Tradition Parts and Repair CDs to help in this project. Part numbers are as follows:

Parts: 72 00 0 147 437
Repair: 01 56 0 004 532


Seeking Information
(Or, Finally! An E-mail from Nigeria Not Asking for Money!)

I have two BMWs: a 1986 525i and a 1991 318is, both in good condition. My problem is I don't have the owners manual for either car. I would appreciate if you could render any help.
Akpo Emmanuel
Nigeria

BMW owners manuals are available for purchase from any BMW dealership. They also come in multiple language formats. However, the ETK is rather cryptic about the part numbers. Here's what I came up with:

01 41 9 783 801
E30 3 Series English owner's manual

01 41 9 699 391
E28 5 Series English owner's manual

Sorry for the quippy subject intro, but for the last 5 years American E-mail has been flooded by some type of Nigerian scam involving electronic funds transfer. it's nice to hear from you, and best of luck with your Bimmers!


Project 325is: Pump Up the Volume
Just have a suggestion for future project for the BMW 325is or other E36s--an audio system upgrade. As owners know, the audio system is very specialized, with amplifier and speakers of different frequency range outputs. So what is the best way to upgrade the speakers?
Russ Liu
Santa Clara, California

Yes, BMW is notorious for its proprietary audio hardware. I'll confess to not knowing much about audio, but I've found that www.crutchfield.com always has what I need including patch cables and fixit kits for late model Bimmers. I refer BMW audio tech questions to them. I've never stumped them. Granted it never involved an E66 7 Series, but there's never been a time when I called Crutchfield with some goofy BMW request that the audio nerd on the other end didn't say something like, "Oh, no problem--we can hook you up with a J-46 space modulator and oompah-woompah air puff system. Of course, you'll need the new nuclear shielded plasma cables, and we'd recommend the...."

This is a good time to point out that one of the problems with aftermarket audio, and one reason BMW went to proprietary hardware, is damage to the vehicles caused by hack installation jobs. On the other hand, there are plenty of master artisans out there working at local sound shops. I suspect Santa Clara has its share of those, and .L.A., too. We'll forward your suggestion to Dan Barnes, who owns Project 325is.


325 Part Fitment
I will be soon converting my 1993 325is automatic to a five-speed manual gearbox. I will be using the gearbox and 3.15 limited-slip differential from a 1995 M3. Will this be a bolt on to my stock engine? Will it be a plug and play to use M3 parts on a 325is or will I be looking into a considerable amount of modifications.
Thy
via the Internet

The parts swap is straightforward. Everything will bolt up, assuming you also use the M3 driveshaft. However, the are electronic issues with what you plan to do. The ECU will need to be either replaced with a 1993 325is manual gearbox ECU, or recoded by a BMW dealership. In order to recode the ECU, you are going to need a patient technician and a 1993 325is five-speed manual so he can read the code off the cover. As a practical matter, is going to be simpler, safer, easier, and faster to simple to simply buy a used ECU for a 1993 325is.

The car will run without this step, but you'll have a perpetual "TRANS PROGRAM" warning in the MID, as the DME eternally searches in vain for signals from a slushbox that's no longer there. It's kind of like phantom pains after amputation of a diseased limb.


Overheating Problem
I live in Germany and own a 1991 BMW 320i with an overheating problem. I have found no coolant leaks, but when I turn on the air conditioning the overheating seems to get worse. I ran the car for 15 minutes with no air conditioning, and the guage stayed steady at the mid-point. After switching on the air conditioning, the coolant temperature began to rise rapidly. I'm leaning toward blaming the thermostat, but I also think it could be a water pump. Could you help me with any ideas or a solution? This is a European-specification model.
Jason
via the Internet

If the coolant only overheats with the air conditioning activated, then the electric auxiliary cooling fan is probably not working. This fan, mounted in front of the radiator, activates either when the coolant temperature reaches higher-than-normal levels, or when the air conditioning is activated. If the fan is not functioning, the problem could be a faulty diode in its wiring harness, its temperature sensor switch, or the fan itself. The problem is easy enough to diagnose and the diode and temperature switch are cheap, but the fan itself is rather pricey.

If the coolant overheats without the air conditioning activated as well (this is unclear from your letter), and if the auxiliary fan is functioning, then I would suspect the thermostat or water pump. However, a faulty water pump on this engine is generally characterized by coolant leakage from the bearing weep hole. Bottom line, you should change coolant every 2 years anyway, draining both the radiator and the engine block, and using only original BMW anti-freeze mixed 50-50 with water. You don't mention how many kilometers are on this engine, but a preventative thermostat and water pump replacement may not be a bad idea.


Valve Adjustment Procedures
I have a one-owner 1987 325es with 55,000 miles. I want to do valve adjustment on it but have not been able to find any book to say how it can be done step by step. If you can direct me to a book that says how it can be done step by step, or if you can instruct me, I'd greatly appreciate it.

Also I asked a mechanic to change my BMW timing belt, and he said I must change the water pump too. I have installed a water pump at 40,000 miles. Do I need to change my water pump any time I change my timing belt?
Ben Nosrati
via the Interent

The best manual for your car, and one with step-by-step valve adjustment procedures, is the Bentley E30 3 Series Service Manual. It is available from many of our advertisers, from the publisher directly (www.bentleypublishers.com), and from your favorite book store. The cool spring-loaded valve adjustment tool sold by Bavarian Autosport (www.bavauto.com) is a good thing to have, although you can use a piece of coat hanger for free. It also helps to have a momentary contact switch to bump over the starter, but this isn't a necessity either.

You don't have to replace the water pump with the timing belt, but along with the thermostat it is a nice attendant service because all the other labor to do the pump and thermostat will be done in the course of the timing belt replacement. BMW timing belts must be replaced every 50,000 miles or five years, whichever comes first. If the belt brakes, the best case scenario is bent valves. The worst is a blown engine.


M43
You keep writing in your article that engines after 1992 are M42'. Yet what I know is that after 1994 they started installing M43s. There is no mention of the M43 in your article.
Farid Wayne Kareem
via the Internet

Actually, the M43 is a low-powered sohc four-cylinder engine that was never imported to the U.S. market. U.S.-specifcation four-cylinder engines transitioned to the M44 designation in 1996.

The primary differences between the M42 and the M44 are that the M44 grew to 1.9 liters up from 1.8, and incorporated the OBD-II emissiosn control systems. In the E36 3 Series, both engines feature BMW's excellent dual resonance intake system (DISA). Early E36 M42 engines (up to 01/94 production) use a combination of two V-belts and one poly-ribbed belt to drive engine accessories. From 01/94-on, a single poly-ribbed belt was used. On the road these two engines are virtually indistinguishable. The slight increase in displacement made up for the more restrictive emission controls on the M44.

You're right, maybe we should have mentioned the M44. However, because there is no practical difference between it and the M42 before it, we felt the distinction was not germane to a buyer's guide article.

Since we're splitting hairs, you may also wish to know that the M42 engine went through two generations. The first M42 generation encompassed the E30 318i, 318is, and 318i convertible. It used three V-belts to drive the alternator, water pump, power steering pump, and air conditioning compressor. The intake manifold incorporated traditional runners, as the ingenious DISA system was still on the drawing board. The E30 M42 timing chain tensioner, tensioning rail, and side guide rail were all improved in the M44, and the new style parts supercede when you order them. There's a good reason for this, too--these parts do wear on high-mileage E30 M42 engines, and can result in timing chain-related engine failures. This is particularly true in engines that have seen severe service.

The second generation M42 was the DISA-equipped, combo V-belt/poly-ribbed belt unit appearing in the E36 318i in 1992. If you want to REALLY split hairs, you can say there is a third generation M42--the one from 01/94-on that uses a single poly-ribbed belt.


M42 to M50 Conversion
I have been searching around forever trying to find the answer to my question. I have a 1995 BMW 318ti and although it is quick, it just tends to be slow in comparison to all the Japanese cars in my area. So I know I can find a 323i, 325i or 328i engine for a pretty good price and I think it would be cool to have a six-cylinder engine in the 318ti model. But I don't know if any of those engines will fit. Can you tell me which six-cylinder engines will fit and where I could get the necessary hardware (engine mounts, adapters, etc).
Matt Jones
Allentown, Pennsylvania

Search no more, Matt. There are no fitment issues with what you want to do. Any of these engines will fit, but it simplifies matters if you stick with a pre-1996 engine. This will allow you to avoid the complications of OBD-II, which would mandate use of pre-1996 fuel injection and engine management on any 1996-on engine. As a practical matter, it's entirely possible that engines this old may need a rebuild. But they'll bolt right up to your four-cylinder manual gearbox, which is a bit smaller, but it will work. Best to use good lubricants, though--Red Line Oil is highly recommended. You will also have to upgrade your front struts, springs, and brakes to six-cylinder E36 parts, and there's no reason not to use M3 parts. I'd recommend a full suspension upgrade with whatever flavor sport shocks and springs you like.

Zionsville Autosport can hook you up with what you need. Visit them at www.zionsvilleautosport.com.


E30 Cabriolet
I have an E30 320i cabriolet and I'm looking for ways to improve power output. If possible, I would like 420 hp with a turbocharger or supercharger. Please tell what kits would be suitable for my car, and me how much it will cost and if I want to ship it to my country, Jordan.
Mohammad Shilbayeh
Jordan

It is not possible to get 420 hp from a 2.0-liter M20 engine and maintain durability and driveability. Some combination of nitrous oxide injection and turbocharging may do it, but there's not kit for this and engine life would probably be measurable in hours.

Korman Autoworks is the only shop I know of that still lists M20 turbo work on its Web site (www.kormanfastbmw.com). Dinan Engineering (www.dinanbmw.com) used to have an M20 turbocharging program that produced 265 hp. That was about the most powerful the M20 ever got to our knowledge, but Dinan no longer has this package available. No one ever made a commerical supercharger kit for the M20, although there may be some one-offs running around out there.

The problem with forced induction on an M20 is that it has no knock sensors to retard ignition timing in the event of detonation (pinging). This means you have to lower the compression ratio to keep the engine damaging itself, and this means a complete rebuild with low compression pistons.

For your purposes, I know that Korman can build a 2.7-liter M20 that uses a Schrick camshaft, triple Weber carburetors, and a host of other trick parts to achieve 230 hp. You'd have to contact them about the cost. They will probably want to simply build you an engine and ship it to Jordan for installation in place of your current 2.0-liter engine. There is also the possibility of shipping your car to the U.S. so the work could be done here.

Good luck with your Bimmer!


Engine Swapping
I have a BMW 328 and it is fun to drive but not enough power. To upgrade to a good turbo or bolt on supercharger costs from $5000 to over $20,000 to get in the 400 hp and up range. Do you know of anyone that has put a small block Chevy in a 3 Series? Who can I contact? I am sure there are going to be issues with the wiring harness.

I have done swaps before and I built my own twin turbo small block with fuel injection and Accell programmable DFI. I would love to put a small block in and according to my measurements there is room with a custom oil pan and special made exhaust. The wiring harness and computer are what scare me!

If I can get it to fit I can make up a 350 or 383 and make over 500 horsepower easily with a cost of less than $10,000.

Thanks for your help! I am not worried about the resale cost of the car but I will not butcher it to put this in!
Gary D. Harper
Fort Collins, Colorado

While we can certainly appreciate the virtues of the small block Chevrolet V8, bolting one into a Bimmer would be kind of like bolting a giant steam engine onboard the USS Ronald Reagan because, you know, those nuclear reactors are so pricey. My feeling is, why not buy a nice Corvette or Camaro with the mouse motor already installed by Chevrolet?

In addition to the electronic concerns you so rightfully raise, this would be a lot more than an engine swap. You'd need a gearbox as well, and I have no idea where you'd find front coil springs to suit all that weight. All that weight would also destroy the handling balance of the car. The car would, in all liklihood, spend the rest of it's days breaking parts like many other cars equipped with 500-hp Chevrolet engines. All in all, there's probably a good reason we don't know anyone who has done this.


E36 325is
I own a 1993 325is five-speed with 170,000 miles. I want to rebuild the motor and I want more power. The suspension has already been taken care of, and I have the chip, intake, and exhaust system. Would S50 M3 camshafts, headers, flywheel and a rebuilt motor with slightly oversized Wiseco piston heads create power? Also, what about the 3.46 differential? I drove a 1995 M3 and loved it. I want to make more juice for my baby and I'm willing to tune this motor to try and make it as quick as a E36 M3. An engine swap was ruled out because of DMV and Insurance costs but I am ready to put the big bucks down for naturally aspirated power and let my little car serve me for more years to come. Any ideas would help.
Eugene Lee
Pomona, California

Yours is a common question, because California insurance companies are thrown all adither by any BMW with an "M" in it's name. Elsewhere, an engine swap would be no problem, but California gets you there, too, this time with it's draconian emissions bureaucracy. Unfortunately, to a certain extent you are up against displacement in extracting the torque you want. But that doesn't mean all is lost, and you are smart to look at the back of the car--the differential--in addition to the front.

Another very common question from non-VANOS E36 owners is, "can I install M3 camshafts in my cylinder head, and if so, what will it do for me?" We consulted BMW engine builder and parts swap specialist Pete McHenry of Precision Performance in Winston-Salem, North Carolina. His reply: "You can install an intake cam from a 1992 M50 on the exhaust side. Check the beginning of valve lift of the stock cam, then set the timing so that the swapped cam has the same starting point. This will give you a 240-degree cam with 9.7 lift vs. 9.0. Buy a Schrick non-VANOS 252 for the intake and you'll have the same timing as an M3." However, neither McHenry nor I will promise anything regarding the California emissions police. Same is true with respect to headers. The M3 flywheel is the same as the one you have now. A lightweight flywheel would certainly help things, though.

I am not familiar with Wiseco pistons, but generally speaking I recommend using original equipment manufacturer Mahle pistons where they are still available, which I believe they are for your car. If you rebuild this engine, there's little doubt you'll need to bore out the block and use oversize pistons. But I'd be careful with increasing your stock 10.5:1 compression ratio. It is already pretty high for California, where even "premium" gasoline has a pretty paltry octane rating of only 91. I suspect your knock sensors are already retarding timing, especially with a performance chip. Higher compression ratios may overcome the knock sensor operational parameters and lead to detonation--pinging. For all the cool cars there, California is no longer the place to be for automotive enthusiasts.

A 3.46 differential is pretty low (numerically high) in combination with your 1:1 fifth gear, but it will certainly increase acceleration. Most people go with a 3.23 differential from a 1996-on M3. Your current differential is a 3.15.


E30 Freshening or What Not to Do
I have a 1987 325i convertible. It is a wonderful car and I am considering updating it. Could you advise as to who I might contact about a complete update. Thanks.
Steve Fix
via the Internet

We're posting Steve's note as an example of what not to do. Please don't send in vague open-ended questions and leave us sitting here trying to figure out what you want. What sort of updates interest you? Body? Suspension? Wheels and tires? Brakes? Drivetrain? Interior? Factory BMW updates? All of the above? What sort of contact are you looking for--a shop to install parts, or a vendor who sells parts? And you haven't provided any information on the car itself or the way you drive it. What do you hope to achieve with this car? How do you drive it, and where? Is it a daily driver, or a fun car? How many miles are on it? What is its shift configuration--manual or automatic? What is its present condition?

So, while we wait for Steve to narrow things down a little bit, we'll whittle away the time with a discussion of BMW convertibles.

(The 1987 325i convertible is in fact a wonderful car. One thing that makes it wonderful is that it does NOT have a power top. Power tops are extremely problematic on many BMWs, especially the E30. There was actually a factory retrofit kit that would allow you to turn a reliable and durable manual top into a persnickety trouble-prone power top. Unfortunately, many early E30 cabriolets have it.

Even today, BMW technicians continue to wrestle with E36 and E46 power tops. But the Z3 manual top? It's practically a no brainer. This is actually a common theme with BMW, which is that the company makes an outstanding basic vehicle. The chassis, brakes and suspension are without equal. Then marketing and engineering add their "features and benefits" and the reliability and durability problems start. I think the situation has improved incrementally since the electronics revolution with the E34 5 Series in the late 1980s, but they still have not matched the reliability and durability of, say, the E30 3 Series--except for E30 convertibles with the power top retrofit!

The actual tops themselves are made from wonderfully durable canvass material. However, wonderful as it is, this material does not hold up very well to winter use in the salt belt. This is why BMW makes fantastic hardtops. If you drive a BMW convertible in winter weather, get one. There are also some very good factory canvass top care products to keep your top looking and working great. They are included in the BMW Soft Top Maintenance Set, part number 83 14 1 467 134. The shampoo is great for the whole car, and each item may be ordered individually using part numbers on the containers. In particular, the "Impregnation Spray" works well. I guess we're supposed to keep it away from girlfriends, though. German doesn't always translate well.

BMW's much-maligned convertible plastic rear windows can actually be maintained in perfect condition indefinitely by using two simple and inexpensive factory products: Plastic Window Polish, pn 82 14 1 467 129, and Plastic Window Cleaner, pn 82 14 1 467 128. Fail to use this stuff, and your plastic rear window will deteriorate rather quickly. Bowing to pressure from the elite automotive press and milquetoast owners, BMW convertibles now have glass rear windows.)

We're waiting, Steve...


...E30 Freshening (Redux)
I didn't realize we needed to get quite so intimate. I don't have answers to many of the questions you pose. I am looking in the first instance to get a plan together for the project. Perhaps it is best to begin with basics and then try to formulate my vision.

I am the cars third owner and it is in excellent shape. It has 240,000km. on the clock--it is a Canadian Car and I am in Canada. It has been serviced at bmw always except for approximately 40,000 km. when in the care of the second owner. It has never been driven in the winter. I use it in the summer as a daily driver with qualifications. That is, it competes with my motorcycle and it is the only drop top in the fleet so often gets scooped by my wife or one of my children.

That said I envision a sleeper. No modifications that do not enhance performance and as few as possible that are visible. The car has lovely lines and, at least where I am from, is much more exclusive than an E36 or 46 rag. I like to do my own work and can do most of it. I can not, however, shoehorn an M50 into it. My difficulty is that I get busy with work/family, etc., and my projects get delayed/abandoned first. I am desirous, therefore, of having a plan I can implement in stages and I can do individual stages myself or farm them out.

The question that needs to be answered first is how much horsepower? That of course effects brakes, suspension and body work. I do not want to do brake and exhaust/intake upgrades now and find out later they are insufficient for the horsepower I end up with. I am happy to spend money but not keen to waste it. The manual says it puts out 175 ponies with 169 lb-ft of torque. It is by no means slow but can you ever have enough?. I am convinced I can get another 25 horses with intake/exhaust and chip but is that enough?

How much can be messaged out of that engine before it looses driveability? I don't mind a lumpy idle but I still need to be able to let my daughter drive it. If we imagine more significant work like a turbo/supercharger what are my options? I did actually read in your publication about a shop that stuffs M50s in. How much can the horsepower be increased before we need to make driveline modifications? Am I limited buy the chassis' inherent lack of rigidity?

Once I figure out how much horsepower I need, I then have some questions about the rest of the project. How much stiffer can/should the car be? Does it do any good to brace the strut towers given the lack of a roof? I don't think I want a rollcage in my car. I would like to upgrade the suspension even though the stock stuff shows no signs of wearing out. The stock wheels are in excellent shape but do look a bit dated. I am not convinced I like the look of 17-in. wheels if it will leave only wafer thin tires given the cars current configuration. I still prefer the look of some rubber, so maybe 15- or 16-in. wheels, unless of course we decide on enough horses to require bigger rubber overall. I don't think I want to start flaring fender wells at this point.

This has been rather therapeutic. If I stick just to upgrades in the suspension, brakes and wheels and message as much as I can out of the mill what will I end up with. I am all for more fun but not at the price of additional headaches nor do I want to have to sort out a story about the car failing as the reason for my daughter being several hours late coming home.
Thanks,
Steve

Initially, with 249,000 Km (149,000+ miles), we need to take into account the condition of this engine. After all, if you take your grandfather and make him run sprints he may be able to do it, but whether he'll survive it is another question. I'd recommend you do cylinder compression and leakdown testing to gauge the condition of the bottom end. If this engine has never had a valve job, I can almost guarantee it needs one now unless it has been driven very sedately. Also, basic issues like air and fuel filters, spark plugs, cap and rotor, valve adjustment, fuel injectors, water pump, timing belt, cooling system service need to be verified or addressed before any thought of increasing power on a mature engine. At this mileage, catalytic converter and oxygen sensor condition are also in question.

The standard bolt-on modifications for the M20 engine include a chip, cone-type intake, and a performance exhaust system. I would say you're looking at bolting on a good 25 hp with these items assuming you can get fuel good enough to satisfy the chip and assuming the engine is in good condition. That's about all you're going to get without removing the engine for a complete rebuild using high-compression pistons and a Schrick camshaft, along with lightening and balancing of the reciprocating mass. There are no superchargers or turbochargers available for the M20 engine, and even when turbos were available, they requried low-compression "turbo" pistons due to this engines lack of knock sensors.

Bear in mind the maintenance requirements of an oiled cotton gauze air filter.

These bolt-ons will not affect driveability as long as the engine is maintained in good tune and good high-octane gasoline is used. Engine longevity depends far more on maintenance and severity of service than what performance modifications are bolted employed. Make sure you use good motor oil, BMW filters, and bear in mind that today's ultra-low-viscosity 5W-30 has no place in an E30 except during Canadian winters. The rest of the time, you should be running 20W-50.

Yes, the M50-into-E30 is a popular conversion, but as with all conversions one should not enter into it expecting to save money over a performance engine rebuild--it'll probably cost more.

The best speed secret for an E30 six-cylinder with a five-speed overdrive manual gearbox is a 4.10 limited-slip differential from an E30 M3. While not exactly falling off trees, especially in Canada, these components can be found on the used parts market, and it will greatly increase acceleration and top speed (due to the increased pulling power against wind resistance), at the cost of a bit more rpm at any given road speed. It is a direct bolt-in.

As always, Red Line MTL and 75W-90 are recommended for the gearbox and differential.

The robust E30 drivetrain and chassis is capable of handling a great deal of power, upwards of 300 hp in my opinion. There are E30s running around with M6 engines and even M60 V8s, although this makes them very nose-heavy. Nothing you can bolt-on to an M20 is going to overtax your brakes, but again at this mileage I would be concerned with the basics--condition of the hydraulics if the brake fluid was never changed, rotor and pad condition, swelled rubber brake hoses, etc. A standard rehab of these parts, good brake fluid change, and use of new rotors and performance brake pads will be all you need.

As with any BMW, the fun quotient is best increased with suspension improvements. The E30 can be made to handle like a slot car if you are willing to put up with lower ride height and firmer ride quality. Again, we want to make sure the basics are sound--steering parts, ball joints, rear suspension carrier bushings, trailing arm bushings, etc. The hot setup is Bilstein Sport shocks, the performance coil springs of your choice--Eibach, H&R, and Racing Dynamics are popular--E30 M3 offset front control arm bushings, and a set of large sway bars with mounting reinforcements from www.turnermotorsport.com. You can also run E30 M3 aluminum front control arms for a 4.4-lb. weight savings at each side--nice especially when fitting heavier wheels and tires. A plethora of factory and aftermarket 15-inch wheels are available, on which you will want to mount 205/55-15 tires. The 225/50-15 size is also correct, but added clearance may have to be worked into the fenders and quarter panels. For your purposes with this car, 205/55-15 ultra-high performance tires such as my new favorites, the Yokohama AVS ES100, will be more tire than the car will know what to do with.

Normally, I would say that a strut brace isn't going to function except under extremely hard cornering forces, however on a convertible I think there may be other benefits. Bear in mind that the more you firm up any convertible, the more cowl shake you will get over rough road surfaces. Unless you want to add a roll bar, that's just the way it is.

None of these mods are going to affect reliability. If the car breaks, it's unlikely to be because of anything you did to it. Here's a tip: Replace the main relay, fuel pump relay, and the fuel pump preventatively. Just bite the bullet. I was once stranded in at the base of the Dempster Highway outside Dawson City, Yukon Territory, in an 120,000-mile E30 rally car with a dead fuel pump. Trust me on this.

If your daughter comes home late, it probably won't be due to the car. One other bit of advice: In my humble and decidedly non-sexist experience, the average life of a front air dam on a lowered BMW with a female driver is approximately one week. They are not wired to think of this kind of thing, just as men are not wired to remember dates and anniversaries. School your daughter in the perils of speed bumps, inhospitable driveways, and especially parking curbs. A label maker sticker on the instrument cluster that says, "Remember: 5 Inches of Ground Clearance," may help, too.


E30 BMW M3
I've been an avid reader of your mag for over 10 years, now, and it's always been a real pleasure. There is a black E30 BMW M3 in my neighborhood, and I think the guy wants to sell it. I would really like to build a true club racer out of it, but this will be my first project. At 26, I'm a late bloomer, but I haven't had a lot of money until now. Can you drop me a line on where I could shop for great parts on the internet for this car? I know the possibilities are endless with the E30, and I've always been a big fan. Thanks for any assistance, and keep it up with your fantastic magazine.
Jonathan Dorsey
Vancouver, Washington

Thank you for the compliments, Jonathan!

The E30 M3 ranks right up there with BMW's premier enthusiast road cars over the years. With characteristic E30 durability, a spot-on suspension right from the factor, and a sweet high-revving S14 engine, there's nothing not to like about the E30 M3. However, it's probably not the best choice for a club racer, even though it is highly competitive.

The reason it's not a good choice has to do with money and rarity. First, you can have just as much fun if not more racing an E30 325i or 325e, which will have the same functional suspension and brake parts as the M3 by the time you are done building it for the track. Parts and the cars themselves are half the price. Second, the E30 M3 is a very rare BMW, and a wonderful street car. It's a shame, in my opinion, to cut one up for the track. And this ties into a final reason: Club racing is for fun. There is no prize money, no winners' circle, no champagne spray, not even a kiss from a pretty girl.

I don't want to talk you out of the E30 M3, I just hate to see you cut it up for the track. Consider other E30s instead--God made lots of them, you know.

For E30 performance parts, check out these places:
www.activeautowerk.com
www.bavauto.com
www.bmpd.com
www.turnermotorsport.com
www.kormanfastbmw.com


Carbon-fiber Hood
Do you know where I might find a carbon-fiber hood for my 2003 M3? I do not plan to have it painted.
Scott Oakley
Howard, Pennsylvania

The E46 3 Series has not yet wrought the full panoply of aftermarket carbon-fiber body parts as did its predecessor, the E36. Our hope was that the new Europe-only M3 CSL would have a carbon-fiber hood. As it turns out, the hood is one of the few body parts on the car that is not carbon fiber--at least, not as of this writing.

There's no doubt that the aftermarket will step in and make carbon-fiber hoods for the E46, and in fact we may be missing a source now. But while we admire your plans to keep the hood naked, the problem with that is most carbon-fiber pieces are not really finished very nicely--not nice enough to leave naked. It would be kind of like a thong bikini on the wrong person, if you know what we mean. If BMW built a carbon-fiber hood, it would be but a part number away. More likely, we'll see some of the esoteric German tuners come out with very nice pieces that don't need to finish work, although at great expense.


Buying a BMW E34 or E39
My wife and I are planning to buy a 1995 E34 525i or a 1997 E39 528i in the next six to nine months. Can you tell discuss the reliability and maintenance history of these cars? What are the potential problems that are expensive to repair? Are there other things to look out for? What are the key differences between the E34 and the E39 (regarding reliability, safety, performance)? Any advise or reference that you can provide will be greatly appreciated!Noel Hwang
Austin, Texas

Pick up the August 2003 issue and read the E34 Buyers Guide article, which answers your questions regarding the E34 5 Series. The same concerns apply to the E39, however electronically the E39 seems to be proving easier to diagnose and repair due to improved diagnostic technology.

Essentially, there is no difference in maintenance between the E34 and the E39 except in the realm of the M5 in both body styles. In terms of reliability, the chief concerns with any modern BMW are electronic. There's not much you can do to bolster electronic reliability in terms of maintenance other than to make sure the charging system is in good condition, and don't pull a boneheaded maneuver like reverse polarity at the battery.

If you are concerned with long-term durability and minimizing repair and parts replacement costs, my best advice is to avoid automatic transmissions and V8 engines. Also, generally speaking, the fewer doo-dads the car has the fewer electronic problems you are likely to encounter over the long haul. The E39 is still pretty new so it's difficult to get the clear big picture of long-term durability. But we mentioned your question to a few BMW technicians, and the general feeling is the E39 is going to have the same problems as the E34, but the E39 will be easier to diagnose and repair.

I assume you are referring to passive safety--the ability of a car to protect occupants in a collision, as opposed to active safety or driver safety, which in my opinion are light years more important. There is no question that the latest passive safety technology is the best technology, and the latest passive safety technology is found on the latest cars. To a certain extent, the same is true of performance--newer is always better.


Desperately Seeking M3
I am a faithful european car reader. You have a great magazine. I have a 1994 318is to which I have added a few modifications. However, I recently test drove a 1997 M3. I must have one! I was hoping to find a Cosmos Black 1997 sedan with luxury package--and a manual gearbox of course. I have been perusing e-bay and my local classifieds in search. Would you recommend any other on or off line sources that could help. Any information would be greatly appreciated.
Justin Barnes
via the Internet
P.S. Project M3 kicks ass!

I've always been fond of the classifieds posted at www.roadfly.org. It seems to be populated by genuine enthusiasts who are more likely to have well maintained cars than the average driver. The BMW Car Club of America publishes a slick monthly magazine, Roundel, which is crammed full of BMW classified ads each month. To get Roundel, you have to join the club. Check out www.bmwcca.org. Membership also gets you a local chapter newsletter, which will likely have even more classified ads.

A bit of advice: Plan on traveling for the car you want, and before you do that, plan on finding a local technician or dealership to check the car out for you. Also plan on paying for that service, but do ask the seller to split the cost with you. The worst he can say is no.

Yes, Project M3 does kick some ass. We're glad you like it!


E36 Fuel Leak
I recently purchased a 1994 BMW 325is and have been eagerly following your 325i project car's progress. One problem that I have encountered with my Bimmer that has not been mentioned, and so I assume is not common, is a fuel system leak. Every time I park the car in the garage with a full tank of gas, the garage has a very strong odor of gasoline shortly after. The tank must be loosing pressure, because the new gas cap never has pressure when I open it. The garage only smells when the tank is very full, otherwise it is slight to none. Any suggestions would be appreciated.
Chris Reynolds
Tucson, Arizona

I suspect you have a fuel leak, perhaps more than one, in the area of the fuel tank level sensors. The E36 3 Series uses a large dual-lobe fuel tank, with a fuel level sensor for each lobe. Fill your tank to capacity, remove the rear seat cushion, lift up the insulation, and remove the two fuel level sensor access hatches. My guess is you'll find leakage under one or both of them. In particular, check the fuel hoses and the O-ring seals on the fuel level sensors.

This problem is not common, and seems to occur mainly in desert environments where dry rotting is accentuated by heat and low humidity. Use only factory BMW fuel 8mm hose--not the crappy 3/8-in. stuff sold at the local auto store, or you'll be in there replacing it again in a year.


E36 Rear Floor Failure Brought on by Collision
I love your magazine! Please keep up the good work. Let me tell you about my car. I got my 1993 325is five months ago. This is my dream car since I was 13 years old. It has Eibach Pro Kit springs and 18-in. wheels. Last Friday I got rear ended by a motorcycle. The bike hit my passenger rear wheel at 45 mph, this hit make the rear suspension mounts tear out of the body. I did some research and find out that the E36 is really weak in this area.

To make a long story sort, the money is coming out of my pocket. The dealer estimates the repair at $2,900.00, so I have to go to my friend's shop. He's not a BMW technician but he's going to give me a break on the price. Also he knows that my second dream is to race my car on SCCA ITS so he wants to know what will be the best way to fix it so it will take any hard driving on the track in a near future. My heart it been broken; I've lost my baby--please help me out!

Also, I've heard that an E36 four door automatic differential should be the next step to getting my car ready for the track. Is this true?
Rafael Torres Jr.
Atlanta, Georgia

This variation on the notorious E36 rear floor failure was brought about by the collision, no doubt, but it is possible the area could have been cracking to begin with. A bit of rust in the area is a sure sign that it was. The sheet metal in the rear floor area around the mounting points for the rear suspension carrier actually breaks, allowing the entire rear suspension to basically dangle, for lack of a better term.

The only way to totally guard against E36 rear floor failures is to install a full roll cage in the car, and tie it in to the rear suspension carrier mounting points. One company, Turner Motorsport (www.turnermotorsport.com) sells reinforcements for the E36 rear floor. However, installation requires all of the disassembly and corrosion protection work required to repair the actual failure itself, and there are no guarantees the reinforcements will prevent the failure. Clearly, once a failure has occurred, it would be folly not to install the Turner Motorsport reinforcements during the restoration process. For your SCCA aspirations, the rollcage is a requirement anyway.

The first step in the repair process is to support the body on four jack stands or a lift, and remove the exhaust system and entire rear suspension. You can't just weld up the floor and spray goopy black tar "undercoating" all over everything. Depending on the damage, patching may or may not be required, but you'll have to grind the welds, etch the metal with zinc phosphate, use specific zinc primers, seam sealers, factory-specification "underbody schutz" (we prefer Wurth products--www.wurthusa.com), and then paint the repair area body color. This repair is more in the nature of automotive restoration work than just bodywork or welding. The problem is compounded by the fact that it's a forced purchase--people don't think about or want to use a restoration shop because of cost. Then you wind up with a situation where the welder doesn't do body work or have the necessary products to finish the job, so the car gets flat bedded to a body shop. Chances are the body shop doesn't do restoration work either--just quick and dirty collision repair--and they don't have the right stuff either. It's a tough job.

E36 automatics have lower differential ratios that can provide greater acceleration to manual gearbox cars, but not all drivers favor the higher engine speeds on the street. And before you buy a diff, make sure you read the SCCA rule book to make sure it's legal in your class.


M42 Replacement
I have a 1991 318i with a blown engine. Can you tell me what all I would need to install a 1996 318i engine? I assume it is a 1.9-liter engine. My car has a five-speed manual gearbox. Will the bell housing and flywheel from my 1.8-liter fit? What about the engine control unit?
Gene Ketcum
via the Internet

I'll bet you snapped your timing chain on that 1991 318i didn't you Gene? Members are well advised not to ignore timing chain noises coming from an M42 engine. Many of these parts, including the tensioner, tensioner rail, guide rail and crankshaft sprocket have been updated in the BMW parts system. Also, there is an idler sprocket in there with a ball bearing inside it. This bearing has been known to fail on high-mileage M42s.

When replacing an M42 with a used engine, we're confronted with the fact that it's essentially unique in the 1991 model year. M42 engines in 1992-1995 model year BMWs are direct bolt-ins incorporating BMW's ingenious DISA intake manifold, and depending on model year, poly ribbed drive belts. But you'll need all the ancillaries (alternator, air conditioning compressor, etc.), the engine harness, and the ECU. Now, what you want to do is less than advisable--replace an M42 with an OBD-II engine. Everything will physically bolt right up--that's no problem. But the 1996-on OBD-II system will probably code due to the difference in the exhaust system, and you'll be running around with a perpetual check engine light. Best to use a 1992-1995 engine if you can't find a suitable 1991 unit and you don't want to rebuild the existing engine.


1996 Euro-spec M3
Okay, first I just wanted to say thanks for the advice on the install of my 1996 European-specification M3 motor in my 1996 328is. Here is a list of mods since the install:

1996 European-specification M3 motor swap (S50B32)
Eurosport Evo II carbon-fiber Conforti intake system
European-specification cooling system
European-specification ellipsoid headlights with angel eyes
Remapped ECU
Heavy-duty oil cooler
Remus DTM exhaust
Custom stainless-steel straight-through pipes
Brembo cross-drilled and slotted rotors
EBC Green Stuff track pads
M3 LTW chassis brace
Eibach three-way adjustable anti-roll lit
Eibach Sportline springs
Eibach Pro-Dampers
17-in. Fittipaldi rims wrapped with Toyo Proxes
Zender rear wing with LCD
Clear front/side/rear markers
Hyper white show-off bulbs all the way around
Autometer dual gauge pod oil pressure/oil temp
Built-in K40 radar
MOMO shift knob
Alpine alarm
Alpine mobile multimedia station
Alpine Sound Field Processor
Alpine 12-disk changer
Alpine V12 amp
Four crossovers
Three JL Audio subs

So, on to the point: I was wondering if you know anybody that makes or that can make a turbo kit for my European-specification M3 engine. My turbo of choice would be the T04b Hi Fi by Garrett. Any advice on this would be helpful.
Justin
via the Internet

Sounds like a wild ride just like it is, Justin.

The acknowledged BMW turbocharging expert in the United States is Active Autowerke in Florida (www.activeautowerke.com). Their systems are legendary amongst the U.S.-specification M3 engine crowd, but we don't know if they've ever tackled the European-specification M3 engine--they probably have. Best to get in touch with them on this. However, be ready to pull that engine again for a rebuild using lower compression pistons, fresh bearings and a new timing chain. Also be ready to pull that spiffy exhaust system off the car in favor of a complete Active Autowerke turbo exhaust system.


Lamenting the Demise of the BMW Limited-slip Differential
I have a 2000 540i six-speed manual, and I've been looking for a limited-slip differential. I can't believe they sell the car without one. The only options I can find is a Dinan unit (M5 internals, I believe) and a custom built unit from Koala Motorsport. I thought I had read that a E36 M3 unit would fit. Is that possible? Are there any other parts you would recommend for the car, especially ones that fit from other BMWs? The E39 is a tough car to get performance parts for.
Don Kurelich
via the Internet

In the 1990s, BMW phased out the limited-slip differential in all but their M cars as part of their stated goal to replace mechanical systems with electronics. The theory is that dynamic stability control (DSC)--BMW's marketing name for traction control--takes the functional place of the traditional limited slip differential on low-traction surfaces. Contemporaneously, BMW deleted most internal differential parts from the parts system so that independent rebuilding is now extremely difficult and expensive. This came directly on the heels of an article published in european car, which delineated ring and pinion gear set part numbers for the E30 3 Series. Coincidence? Maybe, but I doubt it.

In reality, and you can take this from someone who drives an E30 318is in northeast winters on four 175/70-14 snow tires, the 25% limited-slip differential is far, far superior on low-traction surfaces than DSC. In fact, if anything, I often have to switch off DSC when driving a press car in snow, especially when ascending a hill, where a little wheel spin is desirable. Snow tires, of course, are still the most important winter driving aid on any car.

The other aspect is performance driving, where the limited slip differential transfers power mechanically to the rear wheel with the most traction as that traction is constantly affected by weight transfer in cornering transitions. DSC merely stops the other wheel from spinning, and can also step in to limit throttle input. Limiting throttle input is a good idea for saving an unskilled driver getting in over his or her head. Skilled drivers limited their own throttle input using their decidedly non-electronic right foot. Once again, DSC gets switched off. Apparently, BMW thinks people like us need to buy M cars. Unfortunately, people like us can't always afford to buy M cars.

Amazingly, there was no hue and cry from the BMW enthusiast community when they killed the limited-slip differential. Even more amazingly, the elite automotive press gave the issue short shrift at best, and went on to discuss DSC in the next paragraph. This, perhaps, is the downside of staffing a magazine with engineers.

On some models, notably the 3 Series and the six-cylinder 5 Series cars, you can use an M3 differential, which is still a limited slip unit. However, on the V8-powered 5 Series, your only choices for a limited slip differential are as you noted--Dinan Engineering (www.dinanbmw.com) and Koala Motorsport (www.koalamotorsport.com). Don, you already know what you have to do. In either case, give your VISA card a good facial scrub, hair cut and backrub--she'll need it.


1995 BMW 525i Touring
I just acquired a 1995 525i wagon and I'm interested in making some modifications. I was very glad to see your current article on buying the BMW 5 series, but I have some questions. As you know, the touring models only come with an automatic transmission, which is quite disappointing. I'm interested in switching to a manual and it was mentioned in the article that it's a relatively easy conversion. I'd like to know who to talk to about converting the car but I don't really know where to start. Any information you can provide would be helpful.
PFC Sheldon, Donald M.
U.S. Army

It comes down to, "relatively easy for whom?" If you're a do-it-yourselfer with low or no BMW knowledge, then an automatic to manual gearbox conversion is not a good way to get your feet wet on any car. You should probably find a good local independent BMW shop for this job.

The most economical way to go about it is to find a 1991-1995 525i manual (not a pre-1991 manual, as these don't have the gearbox you want) at a BMW dismantler or other scrap yard. You'll need the gearbox, driveshaft, clutch hydraulics, pedal linkages, shifter and console parts. I'd recommend using new clutch parts from SACHS, including the release bearing. While the gearbox is out, it's a good time to reseal it and replace the rear crankshafts seal on the engine. You will also want the differential, because your current 4.10 unit will be way too low (numerically high) for use with the 1:1 fifth gear in the manual gearbox. The 1991-1995 525i manual sedans use a 3.23 differential. Limited slip was optional. You'll also need the ECU, otherwise the car will always have a "TRANS PROGRAM" message in the MID as it searches in vain for a slushbox that's no longer there--kind of like phantom pain after amputation.

The problem with finding a donor car is that everyone else has the same idea, and of course manual gearbox BMWs are rare to begin with and often owned by enthusiasts who do not wreck or neglect them.

It's also possible to use parts from an E36 3 Series, and for specifics here I'd refer you to the BMW drivetrain swap specialists at www.zionsvilleautosport.com.


1994 325i Thinks it's a 1964 Cadillac
My 1994 325i automatic gets really poor mileage, like 10 mpg. I drive mostly around town and I was wondering if you have any ideas regarding what the problem might be. Thank you.
David Rabie
via the Internet

Even with the automatic transmission and lack of highway driving, you should be seeing fuel economy at least in the low 20-mpg range. You haven't told us how many miles are on this car or what its maintenance history is like. But I can tell you that most fuel economy problems result from the need for simple tune-up, often combined with an oxygen sensor replacement. How many miles have your spark plugs, air filter, and fuel filter been in service? Regular BMW spark plugs in cars of this era have a 30,000 to 60,000-mile service life. The air and fuel filters should be replaced every 30,000 miles. The oxygen sensor used in this car has a 100,000-mile service life. Other factors that can contribute to low fuel economy include partially clogged catalytic converters, gasoline choice, dirty fuel systems, poor fuel injector spray pattern, and, of course, fuel leakage.


Socket Size for a 1987 325e
What size socket fits the spindle nut on the front of my 1987 325e? Thank you!
Wydell K. Conley
via the Internet

Wydell, you get the "Simplest Question of the Month" Award. There's no prize but if there were, you'd have won it. You need a 36mm socket. Recommend Sears Craftsman part number 44248, which is a 1/2in. drive unit with relatively thin walls so it fits into the hub. Cost is about seven bucks.


1985 BMW 325e
I have a U.S.-specification 1985 BMW 325e. Does my engine have a timing belt or a timing chain? It has 236,000 miles and runs great, but do I need to change the belt or chain? Can I convert to a cold air intake to add more horsepower and add a little more throaty intake sound?
Francis
via the Internet

The 1985 325e, along with all "e" models, and the E30 325i, and the E34 525i up to 1992, has an M20 engine that uses a timing belt. This timing belt must be changed every 50,000 miles or every 5 years, whichever comes first. Attendant services include the tensioner pulley, camshaft seal, and, if you want, the water pump every other belt. Failure to replace the timing belt can result in timing belt failure, which means bent valves at best and a blown engine at worst.

Sure, you can add a cone-type air intake system that eliminates the airbox, and it will sound throatier. But you need to be ready for the maintenance inherent in an oiled cotton gauze air filter. Frankly, a performance chip does a great deal more for this engine, but at your mileage I would forget about performance mods and concentrate on maintenance and repair of any deficient areas on the car.


Another 1985 325e
I have a 1985 325e that is giving me a fits. It will start when cold, but when it gets hot it will not start again. When you try to start it while hot, it wants to start but want, but has no spark or fuel. I have tried almost everything, but now I am at a standstill. If possible, could you steer me in the right direction?
moto2
via the Internet

Only three things can cause this car to lose spark and fuel pump power: The main relay, the onboard computer control (OBC) module, and the digital motor electronics control unit (ECU).

The main relay sends power for all digital motronics function, and it is known to fail when old. You didn't say how many miles are on this car, but if it is much more than 120,000 miles, the problem is most likely the main relay. I would recommend preventative fuel pump relay replacement at this mileage as well.

The OBC module has an anti-theft feature, which can be programmed to cut power to the main relay. The module can develop hairline cracks in solder joints inside it, which can cause the problem you are expereincing. If you smack the module and the car starts, then this is the problem. You can open the module and reflow fresh solder over the joints, or replace the unit. This problem is relatively rare.

The last and most remote possibility is a faulty ECU. Contrary to urban legend, BMW ECUs rarely fail. More often they are killed by water, static electricity or, sometimes, sheer stupidity!

Location of these components is detailed in the Bentley E30 Repair Manual. Please don't E-mail us asking how to program the OBC anti-theft function--the procedure is in the owner's manual. If you don't have one, order one from BMW.


Aussie 318i Seeks Spiritual Motivation
I own a 1982 318i and I was wondering what engine conversions I can do or, what "go fast bits" can make the car go faster. It has a five-speed manual gearbox and, I think, the M42 engine. What does this mean? Any information would be a great help. My mum also has a 1982 325is imported over from England, but the wiring harness has shit itself. What is the best and cheapest way to go?
Carl Archer
Australia

I'm not sure if both these cars are early E30 3 Series cars or if your 1982 318i is actually an E21. If they look different, then the 318i is an E21. If they look the same, then they're both E30s. There were no E21 325i's, but there were E30 318i's. Either way, recognize than while engine swaps are viable upgrades, they are never the cheapest way out--it's always less expensive to buy a BMW with the engine you want already installed. Nor is it a job for the novice tinkerer--professional skills are required to successfully transplant an engine, along with the electronics and other drivetrain components that often go along with the swap.

Your engine is an M10, not an M42. The E21 body will accept an S14 E30 M3 engine and M20 six-cylinder, and even the M30 six-cylinder. All will require different gearboxes and custom driveshafts. The versatile E30 body will accept virtually any BMW engine. The only one I haven't seen in an E30 is a V12, and it probably exists somewhere.

There's not much you can do to a 1.8-liter M10 engine in terms of bolt-on modifications that make a difference. A rebuild with higher compression pistons (not sure what you have now, though) and a mild camshaft upgrade can make a big difference, but it's not what I'd call fast especially in the heavier E30 body. And by the time you're done spending that money, you could buy a nice 325i.

The best and only place for you to get that wiring harness is from BMW. However, I'd be concerned with exactly what went wrong because BMW wiring harnesses don't simply die--they get killed by something.


Bought a '93 E36 325i and Looking to Give it Wings
Six years ago when I was 15, my parents were nice enough to buy me a 1981 320i for $800. Other than some turn signal problems and a needed paint job everything was okay. Well, in my reckless youth I hit a tree. So I moved to a 1985 325e, and after the 230,000-mile mark the trip odometer stopped working and the engine finally would just not stop over heating--suspected blown head gasket. So I decided to save the money for a new car. I still have the 325e, though--just couldn't let her go, just waiting for a new engine one day.

Well anyway, as luck would have it, I found a 1993 325i, black with black leather interior, which I purchased for $5,500. It needed an ECU for $1,000 and an exhaust system, but I haven't done the latter yet. My ultimate plan is to have a car that thinks it has wings and rides on rails. For the engine I want to get a used E36 M3 engine and bore sleeve charge for street tracks, shoot it up with NOS for the strip, and all performance internals, but like most I can't break the piggy bank and pay with cobwebs So I plan to start off with the purchase of an engine and have the work done or buy the parts piece by piece until it's ready to drop in. Is there a particular year M3 engine I should look for and how much of the engine should I buy. For now I just want any information I can get on the engine block I should use and hopefully you'll still be as generous with information when I'll probably need your help once again.

Jason Purdy--May all 1/4-miles last less than 10 sec., and may all roads be twisted
via the Internet

For a novice do-it-yourselfer, I would say the S50 3.0-liter engine from the 1995 M3 would be your best choice. This way you can avoid the complications involved in defeating the OBD-II emissions control system on the later S52 3.2-liter engine. You will also need the engine wiring harness, the ECU, and air intake parts. Your existing manual gearbox will work, but the M3's is larger. If you did go with the S52 engine, you'd still need an intake manifold, wiring harness, ECU, and myriad other parts from an S50. And you'd need to drill and tap the cylinder head for a sensor--not a novice operation.

The thing about this conversion is, everyone wants to do it and God only made so many 1995 M3s so you may find it difficult to obtain parts on the used market. Also, we have to bear in mind that a 1995 M3 engine is now seven years old. Normal mileage would be 105,000 miles. Now, this is no problem if the engine was well-maintained, but well-maintained engines are relatively rare, Jason. In other words, as the 1995 M3 slips further toward it's Grecian Formula days, we need to recognize the likelihood that we'll be buying worn out parts to do this conversion--including an engine in need of a rebuild.


Manual Gearbox Conversions: Mo Money
I am a complete novice. I was wondering if it is feasible to convert a 328i from automatic to manual. What parts would I need? What would be the cost for labor and parts?
Mo
via the Internet

The cost of a manual gearbox conversion is always more than a replacement automatic transmission, so depending on your intentions and situation, you might want to bear in mind that caveat. It is always best to get the car with the shift configuration we want rather than try to build it ourselves later.

The most economical way to go about it is to find a 1998-1999 328i or M3 manual at a BMW dismantler or other scrap yard. You'll need the gearbox, driveshaft, clutch hydraulics, pedal linkages, shifter and console parts. I'd recommend using new clutch parts from SACHS, including the release bearing. While the gearbox is out, it's a good time to reseal it and replace the rear crankshafts seal on the engine. You will also want the differential, because your current 3.91 unit will be way too low (numerically high) for use with the 1:1 fifth gear in the manual gearbox. The 1998-1999 328i manual uses a 2.93 differential, while the M3 uses a 3.23. Limited slip was standard in the M3, not available in the 328i. You'll also need the ECU, otherwise the car will always have a "TRANS PROGRAM" message in the MID as it searches in vain for a slushbox that's no longer there--kind of like phantom pain after amputation.

The gearbox is different in older E36 cars, but it will work. I'd refer you to the BMW drivetrain swap specialists at www.zionsvilleautosport.com.

The problem with finding a donor car is that everyone else has the same idea, and of course manual gearbox BMWs are rare to begin with and often owned by enthusiasts who do not wreck or neglect them.


Project M3: Brace Yourself
I would like to know, were you purchased the undercarriage brace used on project M3, as seen in part 18, while changing the oil pan sensors. It has not been mentioned in any of the project parts. Does it make a big torsional rigidity difference?
Mike Czok
via the Internet

As used by BMW on the M3 Lightweight and M-powered Z3s, the Motorsport X Brace, as it is more frequently referred to, will stiffen up the front chassis and reduce body flex. The difference probably won't be noticed much on the street, but under extreme driving conditions--especially with R-compound tires--the driver should be able to tell the difference in rigidity and steering response. Something I've found to compliment the X brace well is a rear shock tower bar, which tightens up the rear. Both products can be ordered from Active Autowerke, BMP Design or Turner Motorsport. The X-brace itself can also be ordered through your local BMW dealer. Make sure to ask the sales rep to use the M Coupe or M Roadster as a guide to finding the right part number.

Active Autowerke
(305) 213-8050
www.aatuning.com

BMP Design
(800) 648-7278
www.bmpdesign.com

Turner Motorsport
(800) 280-6966
www.turnermotorsport.com


Project M3: Intake Systems and Exhaust
I read with interest your article on exhaust systems. I own a 98 M3 and an considering some changes from my stock setup. In the opening paragraphs, you mentioned the importance of upgrading the intake system, noting that "it's practically the best horsepower bang for the buck on an M3." Are there significant differences in the systems offered by BMP, Bavarian Autosport, etc.? Are there any that stand out?

Also, in the article about exhausts, you note that the BB Tri-Flow became "noisy and less desirable at full throttle." Yet your box score gave it a 4/5 in "sound quality at WOT," and a 5 in "loudness at WOT." Although you list 5 as "best, perhaps in these cases a higher number simply means louder? In contrast, the Supersprint received a 3 under "sound quality at WOT" and "loudness at WOT." Is it quieter or less obtrusive than the BB at these levels? Does it sound better? Or does 3 mean it doesn't sound as good?

Finally, you mentioned fit and finish problems with the UUC exhaust. Have these been addressed by the factory?
Doug
Oregon

We've tested intake systems from East Coast Induction Systems (www.ecisbmw.com), Active Autowerke (www.aatuning.com) and Turner Motorsport (www.turnermotorsport.com) with significant results, and for half the price of most of these exhaust systems. But like the exhaust tests all of the intake systems seem to yield similar gains as well.

In the exhaust test the B&B Tri Flo exhaust was indeed the loudest, with the UUC exhausts at a close 2nd, which is why the units got a rating of 5 and 4, respectively. The Supersprint received a 5 for sound quality at idle because we really liked the deep rumble it makes. However, after revving it up the rumble turned into a slight buzz in the higher rev range, which is why we decided gave it a lower score. But it's not nearly as loud as the previously mentioned units at idle or WOT, which is why it got a score of 3 for each of those categories.

As for the subjective ratings, don't take it from us--log on to www.europeancarweb.com and download the sounds for each system and decide for yourself which system sounds better.

The UUCs were difficult to align and we are uncertain as to whether this was taken care of by the company. You may want to contact UUC to see if anything else was done to better the alignment. You can go through its website at www.uucmotorwerks.com, or call (732) 398-0001.

Another alternative is to use a few washers on one side of the exhaust hangers to pivot the exhaust a bit more to the right or left, which is not difficult to do.

In the exhaust test, each unit seemed to have its own advantages and disadvantages over the rest, which is why it was so difficult to choose a winner. But we hope it provided some help to our readers in deciding which system, if any, is best for what they want get out of their E36 BMW. We wish you the best of luck in your aftermarket endeavors.

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