Project BMW M3 Part 6: Cams, header and pulleys

My previous M3, a 1997 3.2-liter sedan, dynoed 221 hp at 6200 rpm and 224.7 lb-ft of torque at 3950 rpm. There wasn't much left to do unless I was going to spend the mega bucks for real engine tuning. Because of the OBD-II computer, at that time I couldn't easily put in higher-lift cams or the freer-flowing '95 M3 intake manifold or the even European mass air sensor without going back to OBD-I--and that would have been a federal offense! So I never got past a good intake, cat-back exhaust and ECU upgrade. After reading this write-up you'll see why I opted to go with the smaller displacement '95 M3 3.0L this time around. Where was I in my project in terms of power? From Part 4, I registered 234.4 hp at 6570 rpm and 217 lb-ft from 4320 to 4880 rpm. That's a lot of juice for a normally aspirated 3.0-liter motor. Could we get more? Denon Performance was sure I could. As the North American distributor for Dr. Schrick's products, Denon helped me procure a pair of hotter cams. The stock cams have an intake and exhaust duration of 252 and 244 degrees, respectively, with 10.2mm of lift. The Schrick cam duration is 264* for the intake side and 256* for the exhaust side, with 11.2mm lift. Yeah, the lobes are pretty damn big.

To properly operate with these cams, the M3 was going to need larger injectors and the proper chip tuning. Turner Motorsport sells a package for the '95 M3 that consists of the Schrick cams, 24-lb injectors, a larger Euro-spec air mass sensor, an intake kit with an ITG filter, heat shield and the proper Conforti-tuned chip to go with it. (Turner Motorsport is also in the process of working on a cam upgrade kit, which will also use a larger air mass meter, for OBD-II M3s).

Will Turner, founder of Turner Motorsport in 1993, has been racing in the Speedvision Touring Car series with great success. Since the company's inception, Will has teamed up with chip tuner Jim Conforti to put out high-performance chips and intakes for the BMW M3. Turner Motorsport specializes in high-performance streetcar upgrades and race fabrication as well.

I got the Denon/Schrick and Turner stuff and eagerly took it to evosport for installation (you didn't think I'd tune the VANOS myself, did you?). Ron Inchausti, one of evosport's technicians and who's skilled at working with BMW's variable cam timing, found evidence that the heads had previously been opened up. Apparently, he could tell the bolts had once been removed, and the valve cover gasket was not O.E. I gave him the thumbs-up to continue anyway. (evosport advises to change the spark plugs and valve cover gasket when doing a camshaft installation.) The factory muffler was bolted back on to show the gains of the cams and intake in kit form, as Turner sells it. The keys were handed to me, and I fired her up--wow, she was quiet again. I missed the sound of the AA exhaust. But now there was a new rumble coming from inside engine compartment. "Yep, there are definitely cams in there," Ron said. It wasn't a rumble like you'd hear from a hot rod, but you could still tell a difference. Off I went for my test drive.

The car felt strong. Though not particularly a great deal faster than with the last setup, it just felt really strong. At idle the car felt as smooth as ever. But once the tach needle hit 5000 rpm, that intake noise sure got real loud! I drove it around for a few days to give the chip its proper adaptation period, and brought it back to our tech center, where Dominic Conti put it through some dyno runs on our Dynojet 248C. Sure enough, the car made power--good power: 242.5 hp at the wheels, with a stock exhaust!

As you might have guessed, it was time to change that. I needed to see how much power I could get out of this 3.0-liter motor while staying within a reasonable budget. Supersprint North America was the source for stainless-steel headers, a center resonator and a cat-back exhaust.

Supersprint has been manufacturing high-performance exhaust systems for European cars since 1955, each system engineered for that particular vehicle. Because the company believes in only improving performance, each system is engineered and dyno-tested to offer horsepower and torque increases without violating any noise level ordinances. All Supersprint exhausts are TUeV-approved for sound and quality. Since this setup involves the substitution of the center resonator for the catalytic converter, it is for off-road purposes only. In addition, these headers will not fit the factory's stock catalytic converter.

The car went back to evosport for installation. If you've never installed headers before, get ready for a serious test of patience--24 nuts never looked more difficult to put on than these. Give yourself about 3 to 4 hours for this part alone. evosport technician Frank Lopez didn't have any trouble. The exhausts went on and everything fit perfectly. I anxiously jumped in the car and turned the key--it was pretty quiet, but the exhaust had a nice, deep burble at idle speed, very characteristic of Supersprint exhausts. As I pressed the throttle the exhaust didn't get very loud, even without the cats, but still it sounded awesome.

I anxiously went back out for a test drive to see if there would be any difference with my butt-dyno, and there was. My favorite was accelerating from around 2000 rpm in second gear, sort of like a slow street-start. The extra torque of this new exhaust system was truly evident here, and the top-end power was smoothed out even more. Happily, the car continued to furiously pull through redline, showing no sign of letting up no matter which gear I was in. Yes, this car will easily pull past 7000 rpm in fifth gear. How do I know? No comment.

Given the right gearing or more rpm, I was certain this car had the power to reach 170 mph. But Turner wisely set the rev limiter at a hair past 7100 rpm--good for an easy 162 mph with the U.S.-spec gearbox. I was back at the McMullen Argus Tech Center for another dyno session. When I first outlined my goals for this project, I had hoped to put together an M3 that would pull 250 hp at the wheels, without forced induction. With the cams and now the exhaust, Project M3 pulled 252.4 hp at 6830 rpm and 225 lb-ft of torque from 4650-4900 rpm--a very usable range indeed! My goal had been achieved.

Not only did the car gain a substantial amount of horsepower and high-end torque; it lost some weight as well. The entire Supersprint exhaust system weighed in at only 72.75 lb compared to 100.75 lb for stock--a 28-lb loss in vehicular weight.

Since the project M3 had been running a lightweight flywheel, I decided to stay away from a crank pulley upgrade in order not to upset the crankshaft balance too much, as mentioned in Part 3. evosport, however, came up with a much better idea: reducing load on the engine with its aftermarket power steering, alternator and waterpump pulleys. These pulleys are made from T-6061 aluminum and are hard anodized--and, according to Vadim Fedorovsky of evosport, these pulleys give a 10- to 20-percent decrease in accessory speeds, therefore reducing the load on the engine. In addition, these pulleys can be used with the flywheel because the stock crank pulley is retained. "We don't have an aftermarket pulley for the crank, because you don't want to unsettle the crankshaft, especially a long one like that found in the inline six," Vadim said.

After evosport installed the pulleys, just like that I saw another 10.7 hp peak gain at 6960 rpm and 8.1 lb-ft of torque at 5560 and 6960 rpm. The final peak numbers were 262.4 hp at 6940 rpm with a whopping 233.3 lb-ft of twist at 4750 rpm! In addition, the M3 was now maintaining over 202 lb-ft of torque--which is more than the peak baseline torque was--all the way past 6800 rpm! Suffice to say my 250-rear-wheel-hp goal was now well surpassed.

To the average 3.2-liter M3 owner, 233 lb-ft of torque may not sound like a lot, considering most 3.2s are dynoing between 210 and 220 lb-ft of maximum torque when stock. But we must realize the importance of where in the powerband this happens. The higher up you can get this kind of torque, the more horsepower you will be making. As an example, my previous, modified '97 M3 mentioned earlier was making 224.7 lb-ft of torque at a low 3950 rpm, or only 8.6 lb-ft less than the new peak numbers of our Project 95 M3. An 8.6 lb-ft difference doesn't sound like a lot, does it?

Now let's compare what happens at around, say, a pretty important engine speed of 6000 rpm: 192 lb-ft of torque for the 3.2-liter vs. 221 lb-ft for the Project M3--a difference of 29 lb-ft of torque (and a lot more when compared to a stock 3.2-liter)! Not such a little 8.6 lb-ft difference anymore, is it? A lot of low-end torque and not a lot in the upper range costs us horsepower in the end, but it's always nice to have more of both!

With this in mind, I was absolutely pleased with every modification in this part of the project. Denon and Turner's not-too-radical Schrick cams and cold-air intake setup made substantial horsepower up top and awesome mid-range torque, without sacrificing any torque down low, even over the last AA/ECIS setup, which included an aftermarket exhaust. This makes the setup ideal for the street or track.

The Supersprint exhaust system made both, a lot of low-end torque and high-end horsepower. This makes them ideal for powering out of slow turns, where low-end torque is desired, sometimes avoiding the need for a downshift. In addition, the engine still continued to breathe better all the way through redline! And after all of these substantial gains, evosport's pulleys bumped up the graph by yet another 2 to 4 percent throughout the entire rev range, without any loss in power, also making them ideal for street or track use.

In the end, Project M3 got an incredible gain at the wheels of 51.1 hp and 40.7 lb-ft of torque over stock at 6580 rpm with these upgrades. With horsepower now peaking at over 6900 rpm, the power curve is too high up in the rev range to fully compare it to stock, because the stock figures were limited to 6600 rpm by the factory governor. Who knows how much the gains really would have been if I had more stock rpm to compare it to. In any case, horsepower gains never dropped below 11 and torque gains never dropped below 23 lb-ft. With these cams, exhaust and pulley upgrades, Project M3 absolutely got the best of both worlds--lots of torque and lots of horsepower...everywhere.

Next up the Project M3 will receive much bigger brakes and high-performance wheels.

Author's note: It is absolutely important to check and see if your M3 has had previous cylinder-headwork done before doing a camshaft install. The Schrick setup is to be used on a factory-spec E36 M3. If the head had been previously milled, or if there was a thinner head gasket installed to raise compression, the higher-lift cams can bring the valves in contact with the pistons (especially if the valves float at high rpm), which in most cases could be detrimental. Before doing cams make sure your engine has not been changed from O.E. specs.

Also, like the AA flywheel, most aftermarket flywheels do not come with a TDC (top dead center) alignment hole, which allows for the engine to be locked at TDC. If you have an aftermarket flywheel and want to install cams, make sure your mechanic is capable of manually aligning the cams and VANOS.

Denon Performance Products Inc.
1160 Yew Ave.
Blaine, WA 98230
(888) 468-0688 or (604) 464-4401
Fax: (604) 944-1670

evosport inc.
(714) 731-6040
(888) 520-9971 (orders)
Fax: (888) 520-9972
E-mail: info@evosport.com
www.evosport.com

Supersprint NA
3208 Park Center Dr.
Tyler, Tx 75701
(800) 239-7232
www.supersprintna.com

Turner Motorsport
207 Elm Street
Amesbury, MA 01913
(978) 388-7769
Fax: 978 388-4202
E-mail: info@turnermotorsport.com
www.turnermotorsport.com