Well, I could not resist the temptation to do a bit of validation testing on this M3 during Volunteer Day. In preparation, I cleaned up a slight interference issue between the front dust shields and the calipers, and loaded up the Hawk DTC-60s.
Next, I took the strut tower brace off my 330i and put it on the M3. I also adjusted the rear Konis which, as anticipated, was a huge pain in the ass. I adjusted them to 2 turns stiff out of 2.5 total which seemed about right. Finally, I had used 10mm spacers on the front which produced a very small gap between the wheel and the caliper (leaving very little flex room between the caliper and rim) so I changed these to 12.5mm (yes I got new longer bolts).
For this test, I stuck with my road Conti DW tires (340 rated thread wear) because I did not wanted to buy a new set of wheels and tires this late in the season and also, this served as an effective G limiter because I have not have the sub-frames welded yet.
Results:
Initial Impressions: I did not think the additional 80 90 rear-wheel hp would be so significant (stupid me) that and the street tires made the gas pedal into a grenade. My test session turned into a great exercise in car control and smooth driving and managing the very limited grip. I got so that I could get the tires to scream consistently on every turn, the best that could be accomplished. I really had to watch the gas in third rear because it would spin the tires on the straight and exiting turns was walking a knife-edge. I also had to get use to the additional 20 25 mph into turn one. I never even considered turning off the DSC.
Motor: The engine held together very well after my rod-bolt changed and I was surprised how little, if any oil it used, like maybe a 1/3 quart including the drive up there. This engine seems to be in great shape for 160k. More evidence that this car was not abused.
Cooling: The coolant temp never went above the first tic on the track. Yes I know that it was only 70 75 degrees but the results are encouraging. Although it is counter intuitive, I think the Turner Pulleys I added (slowing the WP, alternator, and PS Pump) actually improved cooling at higher rpm levels. Basically the WP was not cavitating and losing efficiency until a much higher rpm. The engine oil temp did go up to 230 240 so a bigger oil cooler is on the list of winter projects.
Suspension: Need a bigger front sway-bar. This is an e46 and they like heavier front sway bars (and soft rears bars) otherwise it felt good. I also had a rather tame alignment on it so it needs a lot more camber, both front and back.
Brakes: They felt horrible the first session (pulsing, etc) great the second and third just needed to be broken in. As for the projected increase in rear bias (found out about this doing some research) was not an issue. The car seemed to be very flat, consistent, and controlled under braking.
Conclusion: I would consider this project a great success thus far. Got some winter projects coming up.