Over the last month we finally decided on our engine program. The M54 we had planned to install is pushed into the corner, we are going to use BMW’s S52. This often misunderstood motor is perfect for our build. It was drastically detuned to meet US standards and produces power that is in the window we are looking for. In fact we will detune it even more. Running enduros will put a strain on our equipment, a detuned motor will last much longer as it is never having to work near its limits. And the torque will make for some happy drivers.
Was everything perfect, no. But we had made it after months of thrashing. Since last October we have been playing the 2 steps forward, one step back game with this car. Between body repairs and essentially replacing every significant piece of the car except brakes we finally just about finished. No longer was the #25 the clown car we bought last year and tested at Buttonwillow in October. Granted we won both events with the funny looking car, but after that event there was a list that just kept growing, in short replace everything on the car, including the motor.
Well in February it was time to drop in a motor that can let us compete, in went the S52 from a ’97 M3,but there was a catch. How do we get this OBD2 motor to talk to our OBD1 computer? Less than a week ago we were desperately looking for an answer. Thanks to Wyatt at Bimmerworld, I was on the phone later that day with Epic and a chip was sent overnight for us to try. Not yet perfect, but after a quick tuning session we were able to restrict the engine down to a declared 209 avg hp. It ran safely and with significant restriction and a bit of ballast and were able to make class rules. In reality, we were a bit lower than that, but compared to the 170hp we had at Buttonwillow we were excited to see what we had. We were coming to the track with a reasonably complete package.
We are ready for our first true race weekend with the car we had designed last summer. On the schedule we have 2 ST5 races and a 3.5 hour WERC enduro with NASA SoCal at the fastest track in the west, Willow Springs.
Friday practice went ok, lap times were very good but we had a huge problem with understeer. One of the current compromises on our backup car here is the shock package is just a street set. They just aren’t up to the task but it’s what the car came with so we were dealing with it. One thing we didn’t really think about was that most of the day we were using our backup wheels that were 17×9, same tires but ½” narrower wheels than our new forged race wheels from APEX. After lunch we decided we needed more data so we chose to burn a new set of TOYO RR’s on the correct 17×9.5” APEX EC7R wheels.
What a difference. Immediately the car became much more balanced, still a trend towards understeer, but nowhere near the dump truck push the boys were fighting earlier. Time to rest and get ready for a big day Saturday.