Dave drove down with his fully prepped e34 535i. Dave is running a stock ( and tired) motor with a S2 setup and his own alcohol injection system. He ran between 10-14psi all weekend. This were his 10th and 11th track days of this year so his car is truly tested! He is also a great driver and drove solo the entire second day. He and his car had no issues and enjoyed the perfect weather conditions and really awesome track.
Now me and the "Buzz Bomb" are a totally different story. These were the 3rd and 4th track days of my life. My only other weekend occuring 5 years ago in a slow e12 at CMP in SC. The "Buzz Bomb" had only been running 6 days and had a total of 212 miles on the new motor when I pulled on to the track.
Sweeney and I rebuilt the motor at the TCD World Headquarters last month. I then installed the motor, new clutch kit, bigger front brakes, track pads, new gauges and a few other things. Car was in an untested state! I set the rev limit to 6000rpm and the boost to 7psi. When it was time to hit the track I was quite nervous.
The first day I put 75 miles on the car on the track. The car perfromed flawlessly! Zero issues. The power was fabulous. The handling was great with mild underteer. The brakes were flawless. I used Carbotech race pads. The clutch, tranny and diff had no issues. The engine ran 182-183F the entire time.
I had read over and over that a water/air intercooler would heat soak immediately on the track. I was really worried about it. The last session I ran 28 miles. I pulled into the paddock and immediately popped the hood and put my had on the intercooler. It barely felt above ambient temp. I put the infared temp gauge on the intercooler outlet tank and it measured 83F! The water tank on the ontercooler measured 75F. I had no way to measure the actual temp of the water but I suspect it was very close to ambient! Without a doubt the intercooler system had worked wonderfully with NO heatsoak. Same was true with Dave's car. Another internet myth goes down!
The second day, I bumped the boost to 9psi and removed the 6k rev limit. Wow, another 25rwhp makes a big difference. I ran 121-122mph down the back straight for anyone who knows the track. During the morning session (temps were ~45F) the car felt great. It all came together for me driving and my instructor signed off on me to driver solo the last session but my tie rods took a dump and the front end was a mess under heavy braking. I didn't run the last session.
So two turbo BMWs with a combined stock HP of 349bhp and combined turbo power of 680bhp survived a weekend of thrashing at Mid-Ohio. Pretty cool stuff.
As most of you, I have read many times on the internet about the difficulty of driving a turbo car on the track. Many SC guys say they perfer the SC because of the linear power delivery and ease of control.
Well my experience was very different from all the internet gossip. The 325i running a modest 9psi was so easy to drive it was amazing. The power delivery was so linear that it felt like a n/a car. Step on the throttle and full boost was immediately available. The boost delivery was immediate and with NO drama. The only clue that the car was turbocharged is that it accelerated quicker than almost everything else in the run group.
I ran full throttle through turn 1 at full boost at fairly low RPM. I never had any fear of anything goofy happening.
Have no fear of driving your turbo car on the track. Do it. It was fun.
RussC, did you have similar experience?
Todd
[Edit by TCD on [TIME]1130969970[/TIME]]
