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BMW Tech Letters

Mar 19, 2004

M42/M44 Lightweight Flywheel
I love project 325is -- thats exactly what a daily driver project car is supposed to be like. I've been following it because I have a 1992 318is daily driver, but it has a 1997 318is engine, the M44, supercharged by a Downing Atlanta. I have installed Blistien Sport shocks, H&R springs, wider tires, an M3 bodykit and bushings all around, amoung other things. What I really need is a light weight flywheel and a new clutch kit. In the January Issue on project 325is a lightened flywheel, E34 clutch, and short shifter were installed. It's exactly what I wanted for my car, but iI have yet to find a lightened flywheel for a this engine. I really need some help here because locally there is no one who knows BMW's in my area and my father and I do all the work on my car. I was wondering, will an M3 clutch and lightened flywheel bolt up to the four-cylender engine? If not could you point me to the right people to find a way to get a new clutch and light flywheel on my car? Thank you and i know you guys are the real professionals so I trust you opinion and knowledge.
Paul Bonfilio

The aftermarket doesn't support the M42/M44 engines with a lightweight flywheel kit essentially because the most popular performance modification for an E36 318i is to replace it with a 325i. The M3 parts will not work. However, we have heard of a solution. We have not tested this system, nor do we know anyone who has. There is rumored to be a certain idle hiccup or off the line hesitation that may accompany it. No warranties are given or implied. Being that you and your dad like to tinker, here's the parts list and half-hearted notes we received from, well, somebody:

1- 11-22-1-262-827 late E30 325i retainer plate
8- 11-22-1-717-840 late E30 325i crank bolts loctite
6- 07-11-9-919-939 late E30 325i? clutch cover bolts
1- 21-21-1-223-026 E30 325i press plate or M3
1- 21-21-1-223-174 E30 325i disc or M3
1- 11-22-1-706-575 late E30 325i flywheel (should be almost no part of flywheel extending past ring gear, if sticks out almost 1/2" will lock up on oil pan support ribs it's the wrong part. Weight is 8.4 lbs.) 1987-91
1- 21-51-1-204-525 release bearing E21 323i (?) catches low to floor, new set up is shorter, so this is longer
1- 21-51-1-204-229 318iS release fork
1- 21-51-1-202-659 318iS release fork pivot pin
1- 24-41-1-722-844 late model gear reduction starter E30 325i '87-91
1- 11-21-1-271-403 M42 pilot bearing
1- 23-41-1-466-118 selector coupling washer.

May want to replace rear trans seals. Check guibo & nose bushing in driveshaft & center support brg.

E39 523i
Hey european car people, your magazine is GREAT! I am American and I live and work in Germany. I have a 1999 European-specification BMW 523i with the M sport package and M-sport fahrwerk II. What type of engine is this, beyond the fact that it is a 2.5-liter six-cylinder? Is it the same engine as in the 99/00 323i? What type of engine mods can I do to it to increase HP safely and cleanly? I already have upgraded my exhaust system to a REMUS muffler system. Can I use the REM SRS for the 323i on my car too? Thanks for your answers in advance. I hope you run this letter because I have never seen ANYTHING on the 523i or 520i in your magazine. I would like to be the first!
Marc Mason
Mannheim, Germany

Hi Marc, thanks for your interest and kind words. When we delve into European models for feature articles, we tend to focus on performance cars that aren't available in the United States, such as the new BMW M3 CSL. That's where the meat lies for us, rather than more pedestrian models that have counterparts sold here. In the US, the 523i was the 525i. The difference with your car, apart from the M-sport bodywork, is that the suspension is slightly firmer and slightly lower, and the engine is more powerful due to the lack of US-mandated emission control systems. In particular US versions have an air-injection exhaust gas recirculation (EGR) system built into the exhaust manifolds. EGR came back to us with the dreaded OBD-II emissions control legislation. Other than that, your engine is essentially the same as ours. I don't know what REM SRS is. SRS means supplemental restraint system -- the airbags. Airbags are generally not transferable from one car to another. Because you have a German-version car and are living in Germany, your best bet is to stick with German tuners. Personally, my favorite tuner is AC Schnitzer. But check into others such as Hamann and Hartge as well. In my opinion, Alpina has degraded from a performance car manufacturer to an exclusive luxury car manufacturer whose offerings epitomize the boulevardier concept. However, as a manufacturer, Alpina was never willingly part of the bolt-on world anyway.
Best regards,
Mike Miller

1995 325is Electrical Challenges
My onboard computer showed taillight out. I replaced the bulb but it still did not work. Then I replaced a bad fuse. Now the tailight works, but the interior light will not go out. When they did go out, the car restarted. The next morning the car had a dead battery. I jumpstarted the car properly and again the interior lights and now the radio will not turn off when ignition is turned off. I took the car to the dealer, who rebuilt an electrical harness, that was cooked. They stated that BMW no longer made the harness that went into the main interior light. I had to wait for new interior light to be ordered, but while I was waiting the taillight always worked. Two hours after installing new intrior light, the taillight failed again. Any ideas?

This problem requires hands-on diagnosis. The first thing the technician should do is verify electrical system function by testing the battery and alternator outputs, so he knows he has a baseline functioning system. My feeling is the electrical harness they repaired has a short somewhere else, and will need to be replaced. I seriously doubt the part is unavailable, as this car isn't even ten years old. Moreover, electrical problems are not unusual on the problematic E36 3 Series. The tech probably just didn't want to replace the entire harness, which can be a big job.

Men of Few Words
Would an E39 M5 V8 engine somehow fit in an E30 325e?

Somehow, yes. In fact, it's been done somehow, although not with the S62 engine specifically. Plan on replacing the rest of the drivetrain as well, along with the suspension and brake systems. Also plan on spending a great deal of money.

540i HFM for 325is? Nope.
Recently I've been searching the Internet for intake options for a 1995 325is. I found a lot of people saying that you should replace the stock HFM for a 540i HFM on the E36 M3s, but when you do, you need a Jim Conforti chip that is tuned for the 540i HFM. Since there are no modification-specific Conforti chips for the 325is, would this mean that the 540i HFM doesn't work on my car, or that I shouldn't even bother with it?
David Lu

We posed your question to Doug Mahar at Turner Motorsport ( His reply: The U.S.-specification M3 benefits from the larger European-specification HFM because it is a 3.0 engine running an HFM from a 325i (2.5L engine). The HFM on the 325i was designed for the 325i, but when BMW made the U.S. M3, they apparently cut costs by running a 325i meter, therefore there is a potential for more power on the M3 and not the 325i. A larger HFM on the 325i would be an expensive upgrade for only a very small amount of power, if any.

Quest for the Holy Grail
Do you know where I can buy a European-specification 3.2l M3 engine, ECU, and harness? I want so swap these into my E36 325i. I dont know if i can use the US M3 5-speed gearbox. I'm looking for get like +400 hp with supercharger or turbo.
Cristian Diaz Arata

Whoa now -- just hold on there, Hoss! First, you might as well be looking for the Holy Grail in terms of used parts. Sure, I know where you can buy this stuff -- your local BMW dealership. Just bring about $23,000 with you. In terms of used parts, these items are rarely seen even on the street in the U.S., let alone for sale. Your best bet would be, along with Internet searches including Europe. By the time you're done paying, you'd be able to have yourself a nice E36 M3. Second, there are no turbo or supercharger kits available for the multiple-throttle body European specification engine, at least not readily available in the U.S. For the U.S. spec engines, check out Third, you can use a U.S. M3 5-speed gearbox with any M3 or M50/S50 engine. The benefits of the 6-speed overdrive unit are largely marketing for BMW and bragging rights for enthusiasts, unless you want to swap in a lower differential.
Best regards,
Mike Miller

Euro M3
I own a 1995 European-specification M3 S50 motor. Are there any superchargers or turbochargers available for this motor?
Kevin Scarlett

To the European tuners, a 1995 S50 engine is ancient history. My best advice is to contact Active Autowerke in Florida and see what they can do for you.
Best regards,
Mike Miller

Suspension Revamp Fur Der Neder Bimmer
First, a big pat on your back for European Car magazine. I buy it from an American book shop in Amsterdam, so you have European readers who appreciate the mag. My reason for writing is my E36 325i Coup, built 05/1992. I have two areas on my car I want to ask you about: 1. Suspension: Conversion to BMW M-Technic Suspension My car is completely original, with standard BMW 15-inch alloys and 205/60-15 tyres. I like my Bimmer to look as original as possible and meant to keep it that way, until I realised I wanted to improve handling a bit. I am a very sporty driver, and though the standard handling is not bad, I would really enjoy getting a bit more from the car. I want to lower my car, but not in an extreme way. I don't want to spoil the looks or E36 core handling characteristics, I want to enhance it. Do you recommend a BMW M-Technic kit, or an aftermarket setup? As I have an original BMW fixation, I enquired about fitting an official M-Technic suspension kit (springs, dampers, anti-roll bars), but I have to admit the price from BMW was quite steep -- approx 1,500-2,000 Euros. I know there are numerous non-BMW lowering sets, but they often focus solely on springs/dampers, without upgrading sway bars. I am afraid those are more for the people who want to lower their cars primarily for the looks, not so much for a well balanced handling package that improves the handling. Are my concerns justified? Also, if I go for a kit that lowers my car no further than the M-Technic suspension would, what size of wheels and tyres do you recommend? I wouldn't mind keeping my original BMW 15" rims, and change the tyres maybe from 205/60-15 to 205/50-15 with lower sidewalls, but I am not sure the 15" wheels would look right on a slightly lowered car. (I hate 'undertyred' cars as much as 'overtyred' cars.) Finally, on this subject: when I go for larger wheels (16- or 17-inch), does that cause problems with the speedometer, ABS and gearing, for which I need to make adjustments?
2. Engine: Vanos and Oil Cooler I read all kinds of conflicting information about which E36 325i engines have Vanos, or even Double Vanos. Is there a way to tell from my car's engine/chassis number, or it's birth date, 15/05/1992? Also, can you recommend what oil is best for my engine and would you recommend using different oils for the winter and summer? I always use full synthetic oils (0W40, Shell Helix Ultra), but wonder what the best viscosity is. The mileage on the car is about 98,000. Also on this point, I sometimes play with my car at driving schools, making some slides, burning some rubber when my tyres are due for replacement, etc. When doing this I was recently shocked to experience a very rattly engine, as if the valves were making themselves heard. A BMW specialist told me my oil goes very hot when I do that, resulting in the valve rockers sinking down lower due to the oil being too thin. He recommended fitting a small oil cooler. What do you think? Will this not keep the oil to cool in wintertime? I hope I didn't ask too many questions at once!! Feel free to answer just point 1 or 2, though you would make me sleep better if you have time answer them all!
Philip Hofman
Haarlem, Netherlands

No problem, Philip. Thanks for writing in. From your driving habits I can see that you would certainly benefit from a performance suspension upgrade, especially at this mileage when you probably need to replace shock absorbers anyway due to normal wear. You're laboring under some misconceptions that we'll try to clear up. First, springs, shocks, sway bars, suspension bushings, and alignment geometry all work together to facilitate vehicle handling. With respect to body roll in general, yes, sway bars are big part of the equation but they are not the only part. Center of gravity, shock damping, and particularly coil spring rate also affect body roll resistance. However, it is true that European tuners and car manufacturers traditionally prefer to rely upon spring rates to control body roll, but this has to do with the possibility of significantly larger sway bars tearing loose from their bar-to-frame mounts, which possibility would never be allowed by TUV in Germany. In the U.S. various reinforcement kits are available from Turner Motorsport ( to counteract this possibility, which is really only a factor in autocrossing or driving schools. That said, the E36 chassis is inherently weak compared to other Bimmers, so I wouldn't take any chances -- if I were going to upgrade sway bars to aftermarket units, I'd want the reinforcements as well as the E36 cabriolet front X-brace between the frame rails under the car. Second, regarding tire sizes, the 205/60-15 size is the only performance tire size you can use on these wheels while still maintaining acceptable overall tire height. 205/50-15s would be far outside the industry standard tire height deviation of one-half-inch for plus or minus fitments -- they would be over 1.5 inches too short. This industry standard exists so you won't have to worry about speedometer and odometer readings, gearing, or fitment issues. To upgrade your tires, you have a choice between buying higher performance tires in your stock size, or upgrading to 16-inch wheels and 225/50-16 tires, which is a factory-approved tire and wheel size upgrade. Seventeen-inch sizes are also possible and approved, specifically 225/45-17 tires. However, my feeling is that 16-inch wheels and tires are, depending upon tire choice, probably more tire than a 325i knows what to do with. Now, regarding the factory BMW M-Technic suspension upgrade versus an aftermarket setup with performance shock absorber (Bilstein Sports, most likely), shorter, stiffer coil springs, larger sway bars, and M3 front and rear control arm and shock mount bushing upgrade. The factory M-Technic system includes many of the same parts, tuned specifically to maintain good ride quality and factory-like handling qualities. I can't advise you on ride height, except to say that the M-Technic system generally lowers the car about 10mm or so from stock height. But stock BMW ride height varies from country-to-country, and I have no way of knowing where you're at now in terms of ride height. Aftermarket tuned suspension setups take the car to the next level in terms of handling performance. They are lower, firmer, increase shock damping a great deal, and provide a higher level of body roll resistance and cornering ability. They are also less expensive -- much less expensive. But whether this would constitute, "spoiling the looks or E36 core handling characteristics," is largely a subjective question. In my opinion, no. But one person's too low or too firm is always someone else's just right. People who lower a car just for looks can be identified by one determining factor, which is that they only want to buy coil springs without upgrading any other parts. This is a mistake they pay for later. Your M50 engine does not have VANOS, which can be either good or bad depending upon your point of view. While VANOS technology affords a nice flat torque curve, allowing for retarded timing at low engine speeds for good idle and advanced timing for high rpm power, the system has a number of downsides as well. The biggest is that one day it is entirely likely that you'll have to replace the VANOS unit at significant expense. Another is an increase in the general complexity from which all modern Bimmers suffer when they mature. Plus, your engine has wonderful high rpm camshafts and sexy double valve springs. It revs like crazy -- much better than VANOS versions of the M50 engine family. There is much to be said for sticking with the motor oil to which a mature engine has grown accustomed. Shell makes great motor oil in Europe, and for the U.S. market as well. In particular, I've always liked their 15W-40 Rotella fleet oil here. But for your purposes I'd stick with what you're doing. If you want to switch between, say, a 10W-40 in winter and a 15W-40 or 20W-50 in summer, that wouldn't be a bad idea but I know motor oil is very expensive in Europe. One thing I'd definitely recommend is, replace your water pump and thermostat preventatively every 60,000 miles, as both are problematic on the twin-cam six cylidner engines as well as the V8s. Oil coolers, including the factory M3 oil cooler that your tech would probably want to fit, are thermostatically controlled, so there is no problem with oil temperatures remaining too cold in winter. If you are in fact experiencing high oil temperatures, it would be a good idea. However, I'm not convinced that's the problem. You might want to install a set of VDO gauges including an oil temperature gauge to keep track of it and discuss the readings with your tech. BMP Design ( is our one-stop shop for BMW gauges and gauge housings. I hope this helps!
Best regards,
Mike Miller

Very Short Question Dept.
I am trying to locate a turbo chargeer for my 1999 528i. Any suggestions?
Jeff McClintock


Product of a 1,200 rpm Society
First, thank you for years of great material. There is no better magazine than European Car. I have a 1995 M3 with many mods including a turbocharger, but like most all US M3 owners I am tired of not having an overdriven fifth gear in the gas guzzling 5-speed. My question is: where can I get a European-specification 6-speed, and will it bolt up to the US 3.0-litre. Also, would I need to change the differential, and to what would you suggest for good acceleration with a descent top end for tracks like Road America. Thank you in advance for any help you can provide.
Ryan Marzec
Libertyville, Illinois
Thank you for the kind words, Ryan! No better magazine, eh? Not even Playboy? Not even Pizza Today? Not even Martha Stewart's Living in Jail? That's quite the accolade. Ryan, it is not your gearbox that guzzles fuel, but your turbocharged S50 engine in conjunction with your right foot. With a 1:1 fifth gear in combination with a 3.15 limited slip differential, your turbocharged M3 is geared perfectly for both street and track. Repeat after me three times: A 3.15 final drive ratio is not low. I don't need an overdriven gearbox. I can go about my business. However, to answer your question specifically, you can use the 6-speed overdrive manual gearbox from the E46 M3. You will also need the driveshaft for a European-specification E36 M3. The gearbox you may find used in the US. The driveshaft would likely have to be special ordered from BMW, and you would have to pay a core charge. Your 3.15 differential that is so well-suited to the car now would become hopelessly long-legged with the 6-speed's intergalactic overdrive. Unless you want to downshift into fifth to grab the boost for every pass under 100 mph, you'd need about a 3.64. Guess where that's going to put you at normal Interstate speeds? Yes, right about where you are now, which is perfect. The problem here is, we have become a 1,200 rpm society. Lumbering V8s, gearing for corporate average fuel economy at the expense of performance, and the demise of the screaming four-cylinder engine has lulled even enthusiasts into thinking that 80 miles per hour in top gear must come at 300 rpm over idle speed. Come for a ride in my 1976 2002, with a 4-speed manual and a 3.90 differential, and I will show you the meaning of high rpm driving -- while still getting 26 mpg in the process. Live a little, Ryan. High octane gasoline is still relatively cheap in the US. Let's enjoy it while we can, until the lefties triple the price with taxes like in most of the world.
Best regards,
Mike Miller

There, There, It's Not So Bad...
Nearly two years ago my 1989 735i started acting up as follows:
When coming off the freeway or approaching a red light, the engine would suddenly die as if someone had thrown the main electrical switch. The carwould immediately restart by turning the key. After six months of this problem, a new variation occurred. During the summer of 2002, I topped off my gas tank the day after we had had very severe thunderstorms. My car was running fine at the time and within a block of the gas station, the red, check engine light came on and the car began "surging" like someone was shutting off the main electrical switch! I was able to drive the car since when you accelerated, it went from a running mode to an off mode and back again, which meant the car would go about 25 mph. After cleaning the throttle valve and replacing all vacuum lines, the problem mysteriously went away. Nobody seemed to have a clue what was happening, including the dealer. When he inspect the car, he said his computer couldn't get any read-out from mine, but since they had just downloaded new software on his diagnostic computer, they might have a problem. I put in a can of dry gas and the car ran fine (no stalling or surging for 18 months). Last week the surging problem came back and the dealer wants $700 to install a new engine ECU. What do you think? Does this sound like a engine ECU problem? In my opinion, the symptoms indicate that the entire electrical supply to the ignition is (1) prone to cut out, causing all dash gauges to light up, or (2) cutting out intermittently, causing the surging. Could this be due to a faulty coil, or a bad ground? I know the engine doesn't have a main electrical switch. I use this figure of speech to describe what is happening. If there was a switch and I kept turning it off or on/off, you'd have the condition I am experiencing. Just love those BMW electrical problems!
W.A. Kopper

Initially, I'm wondering how you could drive this car for two years without solving this problem. But it should be relatively easy to solve. The kid working on this car was probably ten years old when it was built. Dealer techs these days tend to rely too much on their diagnostic computer and not enough on good old fashioned snooping. Even with an OBD-II car, not everything sets a trouble code. Your car is OBD-1. You have not told us how many miles are on this car or what it's maintenance history is like. However, the "on/off" condition you describe sounds exactly like a faulty main relay. This part is cheap. Replace the main relay as well as the fuel pump relay. The main relay controls power to the fuel pump relay, and also supplies power for all digital motronic functions including the engine ECU, so it's a prime suspect. As both the main and fuel pump relays are prone to failure north of 100,000 miles on this car, preventative replacement is in order anyway. Now, if the problem still occurs, then there is only one other thing it could be besides the ECU -- the on-board computer (OBC) control module. The OBC has an anti-theft function, where the driver programs in a code and the car will not start without that code being re-entered. The OBC does this by cutting power the ECU. When OBC modules mature, sometimes hairline cracks develop in the internal solder joints. You can open them up and flow fresh solder, or replace the unit. (Readers, please do not flood us with e-mails asking how to use the anti-theft function. Read the owner's manual.) The ECU is the absolute last thing I would suspect, but it's a possibility if nothing else pans out. Your "surging" problem is different. That is most likely caused by a dirty or faulty idle control valve. You can remove it and clean it out with carburetor cleaner and sometimes it will work for a while, but eventually you'll have to replace the part.
Best regards,
Mike Miller

Reinventing the Wheel -- Again
I want to turn my 1992 318 is into a powerful racing machine. I know that the engine I have now won't make much more power. So, what engines will fit and produce more power?
Joseph Hamilton

Well, the short answer is, any E36 six-cylinder engine, and preferably the stroker engine frm a U.S.-specification M3. But it's a lot more complicated than that, Joseph. First, you run into OBD-II problems after 1996, which leaves you with the 1995 model year, unless you want to use a 1996-on engine with 1995 fuel injection -- lots of parts to buy from BMW. You're also going to need the rest of the drivetrain -- gearbox, driveshaft, and differential. Then you'll need to upgrade your brakes to handle the extra power. Ditto the suspension. Then you run into the inherent weakness of the E36 rear floor, and fitting the reinforcement kit from Turnner Motorsport ( When you're all finished, you'll basically have the same M3 you could have simply purchased in the first place for less money, already built by BMW. So why reinvent the wheel? Well, there's really only one justification, which is cost of insurance. It's underhanded, and if you ever have a claim you'll probably get caught and possibly charged with insurance fraud. But there's no doubt that 318is insurance is less expensive than M3 insurance.

Camshafts: Regrind vs. New
What are the advantages of using a camshaft made from blanks such as a Schrick cam, versus using a regrind? I'm considering cams for my E36 M3.
D'juan M. Williams

Excellent question, D'juan. Reground camshafts have a big price advantage over new billet cams: They are also cut on factory billets, retaining the factory lobe centers so there's no need for indexing. If you've ever tried to find a tech who can index cams, you'll recognize the benefit in this. Regrinds also benefit from factory hardness. In the minus column, regrinds are typically created by reducing the base circle of the camshaft, thus reducing the heal area to add valve lift. The total amount of lift you wind up with is limited to the amount of material that can be removed. Remove too much material and the hydraulic lifters will wear trying to reach the cam, which can lead to premature lifter failure. Obviously, this is not a problem in BMW engines that do not have hydraulic lifters. In general, reground camshafts are entirely dependent upon the skill of the regrinder. There are good ones, and their are terrible ones. You want to avoid radical profiles due to lifter wear on this car. By contrast, Schrick cams are a no-brainer except for the price and the need for indexing in some cases. Schrick as been creating performance BMW camshafts for decades, and their quality and workmanship is beyond reproach. This leads to certain bragging rights, and there is no question that, at resale time, "Schrick cam" listed in a classified ad can have a very salutary affect on an enthusiast purchaser.

Monaco Seats: RIP
I was looking for a set of Monaco RS seats for my 1988 BMW 325is. The only relevant link I can find for these was Part 6 of Bidrawn's 16V GTI. I asked on, but most of the links have turned up dead. Monaco's US web site ( is no longer active. Could you provide me with any information as to acquiring a set of these seats for my car?
Jared "Chapel" Robinson
Beverly. Mass.

Chapel, our searches yielded the same results as yours. Almost anything can be found with, but when it returns results listing restaurants in Bosnia-Herzogovinia it's probably safe to say what you're looking for is no more. I am copying Les Bidrawn on this e-mail to see if he has any ideas. Assuming the Monacos really are gone, I suggest you check into Cobra, Corbeau, MOMO, Recaro, and Sparco seating instead.
Best regards,
Mike Miller

M3 Engine Swap
First, I would like to thank you for taking the time to look at and respond to this email. I have a 1995 M3. I purchased this car as a shell, the engine was destroyed by the previous owner, so as a result the selling price was very very reasonable. Which means i have an ample amount of money to upgrade the car. The first thing i want to do is upgrade the engine, I have been told of three possiblities: an S54 M3 engine, an S62 M5 engine, and one person mentioned a S38 M5 engine. My question is which of these options are feasible and which would you suggest? Again, thanks for your time.
Mr. X
Jerry Martinez

Anything is possible with enough time and money, X. The further you stray from the S50 engine with which the car was born the more of both you will spend. Any engine later than a 1995 model year will require you to deal with OBDII complications. Moreover, I hope you realize that unless you are a professional BMW technician who is very good with fabrication and electronics, in which case you wouldn't be e-mailing us, then you will be paying someone who is. If it were my car, it would get a freshly built S50 engine. If I wanted to spend the money, it would get an Active Autowerke turbocharging system (, or a supercharger. For the price of making an S62 engine work, you could have an S62 engine with the rest of the M5 wrapped around it. Now, an S38 would be cool and less expensive, but would require no small amount of fabrication as well. It would involve another gearbox, a custom built driveshaft, and a larger differential to efficiently use the overdriven 5th gear unless your budget also included a new Getrag close-ratio E34 M5 gearbox from BMW.
Best regards,
Mike Miller

S38 into a E36 M3
Please knock some sense into me! I want to swap a rebuilt 378-hp S38 engine into a E36 M3. Is the swap even possible? If so, how hard is it and will I have to spend tons of money to make it happen? Please help!
Steve Lucchese
Moraga, California

Some sense, coming right up. Anything is possible with enough time and money, Steve. The real question is, why would you want to do this? You could just supercharge or turbocharge the exisitng engine, get the same power at a lot less weight. And you'd save yourself a lot of grief, aggravation, and probably money. Visit for more information. That said, the S38 is one of my favorite BMW Motorsport engines. However, it is heavier than the S50/S52 engine, and will not bolt to the E36 M3 gearbox. You'd have to use an M5 or M6 gearbox, which, if it's a US-specification version, will have an overdriven 5th gear. Then your differential ratio will be too high (numerically low). You'd wind up replacing the entire drivetrain, with untold fabrication. And if your car is a 1996-on E36 M3, you'd have OBD-II complications to worry about as well. After all that, you'd be confronted with all that weight in the front. You'd need coil over front shocks, so you could find an appropriate set of coil springs. Of course, your current brakes are too small. Then, after all is said and done, and you've spent enough money to get an E46 M3, you might just rip the rear suspension out of the weak E36 rear floor. How's that?
Best regards,
Mike Miller

Oil for BMW
Can I use Tranself TRX 75W-80 oil in my 1985 BMW 318i manual gearbox?

I've never heard of that product. I use and recommend only Red Line 75W-90 Synthetic Gear OIl ( in all BMW differentials. Red Line products are ultra-high end lubricants that are almost never available locally, and has to be ordered through the web site or by telephone.
Best regards,
Mike Miller

Gasoline Freezing?
Every day for the past week we here in Kalamazoo, MI, have had below freezing nights, and every day I have frozen fuel lines. It pains me to see my Bimmer parked immobile for hours like that. Please, if you have any tips on how I can get my Bavarian hot rod up and running again, contact me. Thank you
Joe Kuilema
Kalamazoo, Michigan

Anything will freeze if you get it cold enough, and gasoline is no exception. While the freeze point of gasoline varies according to chemical composition, in this case it is not the gasoline that is freezing, it is the water in the gasoline. The water gets into the fuel system due to filling station storage tank contamination and also by condensation inside the car's fuel tank(s). Flat bed the car to a heated garage to defrost the water, then add Red Line Fuel System Anti-Freeze and Water Eliminator ( You can try a locally-sold similar product, but the best I've ever used for this problem is the Red Line product. If the problem is contamination of your local fuel, you may have to use this product periodically as a preventative measure.
Best regards,
Mike Miller

Production Numbers: Why Care?
Do you haved any idea how I can find production numbers for the 1988 BMW 750iL?

The Germans cannot fathom why anyone would want to know such information, so it is very difficult for us to find the person who has it. This is the best we could do, courtesy of BMW of North America and BMW AG: The total number of 750iLs imported into the US was 12,959, from model year 1988 through 1994. Production information broken down by USA versus rest of the world production and model year is typically covered in factory publications such as the BMW Mobile Tradition Profile series. However, these books do not yet extend to the E32 7 Series. The BMW Mobile Tradition Profile and other Mobile Tradition books, CDs, lifestyle articles and collectors' items are listed in the BMW Mobile Tradition 2003 Catalog, which is available free of charge under BMW part number 01 20 0 301 785. Many dealers have them in stock. As the parts department.
Best regards,
Mike Miller

Turbo Timers: WTF?
What are turbo timers, what do they do, and should I get one? I live in Southern California, drive hard most of the time, and it often gets in the triple digit temperatures here. So, what's the story? Are there any downsides?
Jim Cassidy
Southern California

Turbo timers facilitate engine idle for a preset amount of time after the ignition has been switched off. The purpose is to aid turbocharger longevity. In turbocharged vehicles that have an engine oil lubricated turbocharger bearing, this prevents hot engine oil in the engine from superheating and "coking" inside the turbocharger bearing. Hard driving and high ambient temperatures can raise engine oil temperatures to levels where coking is possible depending upon the oil in question. Proper cool down time is essential for a healthy turbo bearing, and a turbo timer saves the driver from having to sit in the car idling while the turbo cools down. However, the better way to cool down a turbo is to drive for a while without spinning it up to boost levels. This way, the cooling air circulating around the engine and the cooler oil circulating in the system is doing most of the work for you, rather than time. If you have a turbocharged car in Southern California, and you're a hotshoe, and you are not inclined to cool down the turbo manually -- either by driving gently before shutting down the engine or idling or a while, then a turbo timer may be a good idea for you. The downside of a turbo timer on a BMW is that it introduces yet more electronics into an already electronically dicey equation, further complicating the factory's less-than-ideal electronic integrity and raising the specter of unintended consequences either as a result of installation foibles or some sort of systems conflict.
Best regards,
Mike Miller

318Ti Motivation
I recently purchased a 1998 E36 318 TI, and I would like to swap the engine with something more powerful. I am concerned about putting to much power in such a small car though. A friend recommended a Chevy LS1 engine, but it seems a little large to put in a hatchback. Also, will such a swap be problematic with the manual gearbox or suspension? Any advice would be helpful. This is my first car that I plan to tune to perfection, and I want to do it right. Thank you.
Cullen Nice
Ft. Bragg, North Carolina

First, forget about the small block Chevy engine. It's not necessary to build a car like that because you can buy one already built by the experts. Chevrolet calls it a Camaro. Stick with BMW power for your new friend. An engine swap is eminently doable in this car, but you should recognize at the start that for what it would cost you can easily sell the 318ti and buy a BMW with a larger engine. You have two eminently viable choices. First, you can simply bolt a Downing Atlanta supercharger ( onto the existing engine and wind up with about 215 very easy horsepower, up from your existing 139. You may wish to upgrade your suspension to firmer shock absorbers from Bilstein or Koni, along with larger E36 325i front rotors and calipers behind the wheels. Or, if you want to spend more than the $4,000 a supercharger will cost, you can install an E36 M3 engine, which will bolt directly to your existing manual gearbox. This will mandate installation of E36 M3 front strut assemblies, a full supension upgrade with springs, shocks, and preferably larger sway bars, along with E36 M3 front brakes. Not to pitch the competition, but in the spirit of BMW comradeship, there is a full article on this exact transplant appearing in Bimmer magazine, issue 9, May 1999. Now, if you want the whole enchilada, you can supercharge the M3 engine as well. Check out At that point you'll be up to Pablo Escobar-level expenditures, but you'll definitely have a rockin' 318ti!
Best regards,
Mike Miller

Wheel Spacers: Friend or Foe?
Hi, great magazine and website. I wanted to know about wheel adapter spacers. I heard they can mess up your suspension geometry. Is this true? Thanks.
David Waters

Now, see this guys? The best questions are one liners -- and have NOTHING to do with engine swaps! Wheel spacers are sometimes employed by aftermarket manufacturers or retailers to broaden the fitment applications of a given wheel. The spacers change wheel offset, allowing one wheel to fit multiple cars. Sounds great, right? Well, there are some other considerations. First and foremost, wheel spacers change only wheel offset not supension geometry. That sounds like a classic Internet myth. The primary consideration with wheel spacers is hubcentricity, or the ability of the spacer, through its design, to center the wheel on the hub. This involves various spacer designs depending upon the car and the wheel, but the general idea is to have a little lip on the spacer which fits into the hub area of the wheel. Without hubcentricity, you have the wheel being located by the lug bolts or nuts, and that is a surefire prescription for suspension vibrations. Other considerations: You want to avoid enormous wheel spacers -- anything over 10 or certainly 15mm -- especially on cars like BMWs which are incredibly sensitive to wheel balancing. You'll also need lug bolts or studs that are longer than stock by the same width as the spacers. Unless your spare tire is mounted on the same type of wheel you have on the hubs, you'll need to carry one set of compatible lug bolts or nuts in a bag in the trunk. Finally, wheel spacers do give wheel installers one more way to screw up the job. At the end of the day, I try to avoid using wheel spacers. If at all possible, I prefer to buy wheels in the correct offset for the car so they don't require spacers. The smaller the spacers are, the less apprehensive I feel about them especially if I know the installer is savvy. Thanks for the compliments!
Best regards,
Mike Miller



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