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Project BMW M3 Part 12: Track days

Pablo Mazlumian
Nov 21, 2002 SHARE

My goals for Project M3 evolved, as do most projects, over the past months. I initially wanted to build a moderately powered street car/weekend track car, and then I envisioned building a normally aspirated club racer, and finally I settled on a turbocharged speed demon, although not a full race car. It will, however, be run at various track events and time-trialing for some weekend fun. To that end, I configured the car with a number of new items, beginning with the running gear.

Although I love the Fikse wheels fitted to the car, I wanted an additional set of wheels for the track so I could use track-specific tires. Again I wanted a set of lightweight, multi-piece forged wheels--and, yes, they had to be black. With its history of racing excellence in SCCA, Grand Am and American Le Mans, Forgeline wheels perfectly fit the description of true racing rims.

Forgeline offers both two- and three-piece wheels for street or racing, all made of high-strength forged 6061-T6 aluminum and featuring a true forged center--created by a 6,000-ton press--and aircraft-quality bolts. Forgeline also offers custom offsets, titanium bolts, custom center colors and polished or powder-coated finishes. For the true racer, Forgeline also offers center-lock wheels. For track use, Project M3 sports Forgeline's WC3 three-piece wheels, which currently are offered only in 18-in. sizes--and I need 18s to clear the massive brakes. If you want a 17-in. wheel, Forgeline offers its sexy RS model (which I had initially chosen to go with before I made the big jump to 14-in. brakes). In anticipation of using 245/35-18 race tires, I opted to go with a width of 8.5-in., which will also allow me, as I become more acquainted with the car, to try out some of the entry-level R-compound rubber offered as 225/40-18s. And although a staggered set would have made the most sense with the amount of torque from the turbocharged engine, I decided to go with the same size all the way around in order to be able to rotate the tires for maximum wear. To clear the large Brembo calipers up front, I ordered a set of H&R's 5mm wheel spacers. Known for its wide range of performance suspension systems, H&R also offers spacers for almost any application. These vibration-free spacers are made from an aluminum/magnesium alloy and offer up to a 70% weight savings over steel spacers.

In order to avoid chewing up my S-03s on the track, I got hold of a set of Toyo Proxes RA1s for track testing. In Part 6 I tested these tires against the street Pirelli 7000s I was using earlier at Willow Springs Raceway, and the results were staggering. I was able to get an extra 5 mph per corner, and the braking grip was improved as well (see european car, 01/01).

The Toyo RA1's two-ply rayon casing construction and free-floating steel-cord side ply was designed to provide superior steering response and thermal stability. Additionally, Toyo engineers cooked up what it calls a Solution SBR compound, said to offer excellent wet and dry grip as well as uniform wear. These tires have an "A" rating in both traction and temperature and a treadwear rating of 40--they'll last you several track days, and you can drive them to and from the event if you reside within a few hundred miles.

The RA1s were mounted at Big O Tires in Colton, Calif., on a Hunter TC-3500 machine, good for wheel sizes up to 23-in. diameter. Although I anticipate graduating to full slicks in the future, these RA1s are perfect as I get to know the car more on the track. They offer superior grip to any of the street tires out there but at the same time are very predictable--and their durability gives them a cost advantage over many of the other R-compound tires out there.

But a track tire's life is determined by several outside factors, one of which is camber alignment. Up front, Project M3 already has the Ground Control adjustable camber and caster plates, which help tremendously in dialing out understeer and promoting use of the front tires' full tread for maximum wear and grip. But in the rear, Project M3 gets only 0.8 degrees of negative camber with the factory adjusters.

To remedy this, I ordered a set of adjustable rear lower control arms from BMP Design. Unlike the factory units, which are made from pressed sheetmetal, the BMP rear control arms are constructed of high-grade tubular steel with a hardened-steel aircraft-quality turnbuckle, allowing for the lengthening or shortening of the control arm by up to 1 in. The bushed end of the control arm is fitted with a high-quality urethane bushing with a steel inner sleeve. (evosport installed these units without any problems, but it was after the track event--I'll report back with results later.)

Changing wheels on your own BMW can be a big pain because of having to align the stud bolts; and it's even worse if you have to use a wheel spacer. Since I knew I would be switching back and forth between my Fikse and Forgeline wheels, I called up evosport and ordered a wheel-stud conversion kit, which included 20 German-made studs and nuts.

Installing them is easy: Dismount your wheels, apply some Loc-Tite(TM) to the stud and screw it in. Tighten them down with a 6mm Allen socket and let cure overnight. By the next morning, your wheel-swapping chores will be twice as simple.

My morning was made even easier thanks to a heavy-duty jack from Griot's Garage. If you're still changing wheels or working under the car using a factory jack, stop right now and get a good jack and heavy-duty jack stands. Twice already I've had the factory jack slip on the floor (I jack my car up a lot), and I must have gone through three or four of the $30 jacks by now. Also, with a lowered car, all of these cheap jacks required a 2-in. pre-lift with my factory jack or the car to be on a couple of 2x4s for the jacks to get under--they can't get much lower than 5 in. But the 2-ton ultra-low-profile floor jack from Griot's Garage has a lifting clearance of just 1 1/2-in. (2 1/2 with rubber saddle). You also can quickly raise the saddle point to a lift point with the foot-controlled pump, and then use the conveniently tall T-bar from there. Thanks to the Advance Design shocks and quick pumps from this jack, I can get two wheels from the same side off the ground in just seven pumps.

The only downside to this jack is its weight-- 90 lb. For a couple hundred more bucks, Griot's Garage offers a 1-ton aluminum floor jack that weighs just 35 lb, has a saddle clearance of just 3.5 in., and gets to its 17.5-in. limit in just six pumps. (Use caution when checking out Griot's Garage's catalog--you'll find yourself painfully addicted.)

Now that I had a nice track wheel and tire setup, I was in the hunt for seats that would help keep me from hitting my head against the window Chris Kattan-style during hard cornering--I turned to MOMO. The name MOMO is synonymous with racing. It's the largest steering wheel manufacturer in the world, and it offers other products like shift knobs, seats, harnesses, racing pedals, strut bars, exhausts, driving suits, gloves and shoes. A MOMO steering wheel is found in most if not all CART Champ cars, as well as in the hands of superstar Michael Schumacher in his F1 Ferrari. Car manufacturers such as Ferrari, Lamborghini and Maserati use MOMO products in their lineup as well.

I ordered a pair of its Street Racer seats. Unlike MOMO's true racing seats, the Street Racers are easier to get in and out of and offer seat-back release and reclining adjustment on both sides. The tubular frame and cloth material offer a super comfortable fit for the road course, as well as everyday driving. The suede-like Alcantara on the shoulder supports offer excellent grip during high-g cornering.

Aside from the added comfort and interior styling these seats offer, an additional weight savings benefit is realized as well. With the O.E. M3 "Vader" seats weighing 64 lb each (non-electric, heated), Project M3 lost 22 lb per side, including brackets--expect a much greater weight savings if your seats are electric. And if you desire additional weight savings, try a pair of MOMO's fiberglass or carbon-fiber race seats--you'll save an additional 25 lb per side (a total minimum weight savings of almost 100 lb), but these seats don't have reclining adjustments.

Getting rid of the factory seats was an easy decision for me, as I'm not a big fan of leather--it gets too hot in the summer and too cold in the winter. These MOMO Street Racers don't.

After the seats were installed, I sat a little to the left and too high for my taste, so I had Wedge Engineering in Long Beach--the manufacturers for virtually all aftermarket seat brackets--custom build a bracket to site the seat an inch lower and more centered. This assured that I'd fit into my car with a helmet on. (By the time you read this, MOMO should have these improved seat brackets available.)

Some of the time-trial events I run require a five-point harness. In my last M3 I liked the street-legal, four-point Schroth harnesses I'd ordered from BMP Design, so I called again for a pair of the German-made Schroths, this time in five-point setups. Unlike many of the harnesses on the market today, the Schroth belts have a quick-release mechanism for easy operation, and the belts are FIA approved. Schroth harnesses are available in various colors and come in either four- , five- or six-point setups. For the street, anything over a five-point is illegal to use, so I made sure I could still use my three-point factory safety belts when I'm not on public roads. But I'll really enjoy being "strapped" to my seat for track use.

I was aching to get Project M3 back out on the track. Once again, I joined in with the Alfa Romeo Owners Club of Southern California (AROSC) during its time-trial event held at Buttonwillow Raceway Park. I like running with the Alfa Club--its down-to-earth members are great to be around, and some of the cars that come out to play are pretty spectacular. This time there were about five other BMW M3s with speedy and very smooth drivers behind the wheel. While in Buttonwillow, AROSC usually runs race configuration number 14 clockwise (see www.buttonwillowraceway.com).

AROSC offers schooling to anyone with a valid driver's license. However, your car must pass a strict tech inspection, and a five-point harness and fire extinguisher are required to run the time-trial class (no upgrades are needed for the school class). The entire two-day event is only about $170 for non-AROSC members, so these events are more than a bargain when compared to some other schools and clubs that charge $300 to $550 per weekend. Races are held for those who are qualified as well.

It was going to be a hot couple of days, so in order to save the motor from any pinging, I chose to run the AA turbo at only 8 psi all weekend. Lap after lap the motor generates a lot of heat, so I contacted Downs Oil in Corona, Calif., and picked up several 5-gal. pails of Sunoco 112-octane leaded race gas. After the successful testing of Sunoco's GT Plus Unleaded 104 (see european car 05/02), I was confident in using its 112-octane race gas for this track test to avoid detonation.

The 112-octane race gas has a research octane rating of 114 and a motor octane rating of 110 (11 more than the GT Plus Unleaded 104's motor octane of 99). However, this gas contains lead, so for this event I swapped out the catalytic converters and replaced them with one big straight pipe--talk about helping the turbo spool faster! Lead also harms oxygen sensors. I put back an old sensor I 'd earlier fried to plug the hole up for these two days.

With the blue 112-octane fuel in the tank, the car performed admirably--no hesitations all day whatsoever, and at just 8 psi my M3 was still more than I could handle. Exiting the second-gear radius of turn 2's Off Ramp was a hoot, trying to "feather" out of the apex without power oversteering. And on more than one occasion I nearly missed the left turn after the Riverside sweeper, leading to the Lost Hill turn also known as Magic Mountain--yeah, that left turn before Magic Mountain where we all go flat out. The car pulled with such fury exiting Riverside in fourth gear, a couple of times I almost had to bypass the left-turn dogleg to Magic Mountain and rip through the coned-off, West-Loop straight where the dragstrip is located. Although this track is not known to be a super high-speed track, I was still seeing speeds in excess of 125 mph.

The big Brembo brakes seemed to be the star of the show at the AROSC event. Most people's first question after walking up to the car was, "Whoa! Are those like 14s or what!" They performed extremely well throughout the weekend, even with the street/sport pads I was using. I know they stayed cool, because my pedal was firm the entire time. Next time I'll install some race pads and test the difference.

To test the differences using BMP Design's brake ducts, I kept the driver's-side air duct installed and took out the passenger side. Even though my ducts are routed differently than ultimately desired because of the intercooler piping being in the way, I still saw around a 35*F drop in rotor hat temperatures with the brake duct fitted. Without the intercooler piping there, I'm sure I could get a much more direct flow and much cooler temperatures.

Before I did any laps with my Forgeline/RA1 combo, I went out with my street Fikse/Bridgestone S-03 setup to work up to speed and to see if there was a noticeable difference with the RA1s. I was extremely impressed with the S-03s' performance. Even though the fronts were only 225s, the excellent turn-in feel was further amplified with a little trail-braking, which was safe--the large rear wing and 255/35-18 S-03s out back helped the rear stay firmly planted. But when I put the RA1s on, the difference was intoxicating. I saw an increase of up to 4 to 5 mph on the Riverside sweeper, and the switchback turns of 3 and 4 (AKA the "Cotton Corners") were so much more exhilarating. Braking performance was noticeably improved throughout the course thanks to the extra grip of the RA1s.

Trail-braking with this setup was a little touchier, since I had the same 225s on the rear as I did in the front. Coming in too hot into Turns 3 and 4 (I was well into fourth gear before entering the Cotton Corners) caused the rear to kick out a few times under trail-braking, more so than I am comfortable with. But I think the BMP Design rear lower control arms will help with that when I crank down the rear's camber a bit to balance out with the front's, which was set at about -2.8 degrees thanks to the Ground Control camber plates.

Even though the weekend saw temperatures well in excess of 90*F, the water temp stayed at just below half the entire time. The oil temp, on the other hand (I'll talk about my gauges later) was getting warm after a few laps--remember, the turbo is oil-cooled. Even though it's reportedly good for 300*F, I made sure the Redline Oil stayed under 260. Still, this car needs an oil cooler before I get back out in this summer heat.

So, how did I do in the time-trial? Not too badly. I placed second in my class behind a trailered, 450-bhp Dodge Viper with 335/35-17 Hoosier slicks and performance parts to boot--he beat me by less than a second, so I wasn't too upset. One of these days I'll have Project M3's suspension all dialed in, and, with a little more practice, it will be a different story. For the time being, I'll keep the boost at 8 psi on the track, which is good for about 300 to 340 wheel horsepower, depending on the weather--plenty of juice for me.

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By Pablo Mazlumian
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