The previous installment of this seemingly endless project covered the new 3.2-liter motor and larger Active Autowerke's turbo installation. Not surprisingly, the engine has even more power, but with more horsepower comes more heat, a problem I tackled next.
Last time I tested Cool Ride Products' heat-shielding wraps for the exhaust manifold and intake pipe. I was thrilled with the results, so I asked the company to make some custom wraps for the car's turbocharger and intake manifold. Tony Anthon has been wrapping turbochargers on select CART turbo V8s and has found it keeps internal temps high, thus helping turbo spool-up. The wrapping also blocks the glowing-red turbo's heat from increasing underhood temperatures.
This is not to say that the temps under the hood stay as low as they were when the car was stock. For this reason Cool Ride also provided a heat shield for the underside of the intake manifold, preventing heat from the block coming up against the intake plenum and warming the intake air. I also took it a step further and got some of the leftover sticky heat shielding I had from wrapping the intercooler piping (ec 12/02) and wrapped the entire intake manifold. Then I reinforced it with a couple of large rolls of aluminum tape I bought at Home Depot. The engine bay might now look like something out of NASA, but I know the temps are staying as low as possible, helping prevent detonation, which is much more important than aesthetics. According to our pyrometer gun, the underside of the intake plenum is now reading up to 50*F cooler thanks to these wrappings.
The stock BMW radiator is good--the factory temperature gauge has yet to creep past the halfway mark, even on the track. But the factory gauge doesn't tell the whole story. Many times a 20* increase, say from 200- to 220*F, won't cause the needle to move from the middle. Yet I've seen white spots around the engine bay from coolant that's boiled over and dried after a track session. It was time to contact Fluidyne High Performance for a solution.
Probably the biggest name in automotive cooling, Fluidyne offers a wide variety of applications for street and race cars, ranging from high-output fans to all-aluminum radiators, water-to-oil heat exchangers to rear-end and transmission coolers.
Although the firm didn't offer an E36-specific radiator when I called, Fluidyne subsequently decided to make one up as a direct replacement for E36s. When the first one was completed, I put it on Project M3. It was a perfect fit (thanks to Jon Caldito of M Performance for the installation), no modifications to the engine bay were needed and it uses O.E. hoses.
According to John Castro of Fluidyne, in addition to 25% extra fluid capacity, the Fluidyne E36 radiator cooling fins are more efficient than the stock Behr unit's, and as a result I should expect to run about 20*F cooler. I haven't tested the radiator on the racetrack yet (my marriage and honeymoon put track events on hold for a short while), but I'll report back with results in the near future.
The most critical fluid, which heats up quickly after only a few laps, is the motor oil. Now I can monitor it thanks to an AutoMeter oil temperature gauge. However, in a preemptive move to help matters before the gauge gets into the red zone, I procured a B&M oil cooler. Although it looked rather small, B&M assured me it would do the trick. If I can keep my oil temp below 240*F after 10 laps on the track, I'll be happy. Again, I won't find out until the next track event. In the meantime, I'll take the car to my favorite shop, evosport, to get oil cooler installed.
The last visit to evosport was for fitment of a finned differential cover from Rogue Engineering. Rogue offers BMW enthusiasts a wide range of products ranging from suspension systems and brakes to short shifters and driveline products. Its Web site also offers helpful technical tips for the do-it-yourselfer.
It took evosport a few hours to install, because technician Josh Rickards needed to drop the subframe as part of the procedure. Thankfully, after all that work, it fit perfectly. Not only does the diff cover give the back of the M3 a very aggressive look, it helps keep differential fluid temps down during hard runs or track driving.
According to Rogue, by doubling the fluid capacity to 3 qt, as well as adding much needed cooling fins, the differential cover helps keep the diff within factory-spec temperatures. For a turbocharged M3 or an M3 race car, this product is very important.
One of the most important methods of avoiding detonation in a boosted motor is intercooling. In addition to the intercooler, I've added water injection to further chill Project M3's intake charge, just to be on the safer side.
The Aquamist water-injection system is sold through George's Imports in Kansas City. After testing this system and being extremely pleased with the results, the M3 turbo gurus at AA made some modifications to the system and converted it into a BMW-specific application. Now AA offers it for both super- and turbocharged M3s. It's not an easy installation; allow six hours.
The Aquamist water-injection system's main function is to suppress detonation caused by high temperature and pressure developed within the combustion chamber when the effective compression ratio has been taken beyond the auto-ignition point by either a turbo or a supercharger. It does this by spraying a mist of water and alcohol through the intake, making the charged intake air temperature drop significantly to reduce detonation. Also, the engine doesn't get "heat soaked" as easily, helping maintain power even after repeated runs.
Heat soak has always been a problem for turbocharged cars. For example, after three dyno runs just one minute apart, european car's Project Audi S4 lost more than 10 hp each time at even the stock boost level (ec 08/02). On the dyno, even Project M3 gets heat soaked, needing a cool-down period after only two hard fourth-gear pulls. With water-injection, however, intake temperatures are reduced so much that heat soak is almost completely eliminated.
The water-injection system comes with a factory-set pressure switch (75 psi). But I would first test the system on the dyno to make sure the horsepower numbers are not less than with a dry, cold run. If the horsepower figure drops, this could be an indication of too much water, effectively "blowing out" the spark. At this point the pressure switch can be easily adjusted with a screwdriver. I recommend doing this in quarter-turn intervals until you get a pressure that maintains horsepower after repeated runs. This process shouldn't take longer than half an hour.
Soon Project M3 will go through a series of dyno tests using the AA/Aquamist water-injection system to see how many runs in a row it will take for heat soak to affect the power significantly, and I'll report back with the performance of the new radiator and B&M's oil cooler on the racetrack.
and Performance Products LLC
Cool Ride Products Inc.
19565 Montana Lane
Boca Raton, FL 33434
Fax: (561) 482-1127
Order: (888) 520-9971
Fluidyne High Performance
East Coast: (888) 358-3963)
Fax: (704) 662-8120
West Coast: (800) 358-3963
Fax: (909) 923-9797
George's Imports Ltd.
8011 State Line Rd.
Kansas City, MO 64114
3500-A 20th St. E.
Tacoma, WA 98424
Rogue Engineering Inc.