Well, Dr Ron has spoken... We had a chance to catch up the other day after he reviewed all of the detailed post race data I sent him.
Basically we made a front spring rate adjustment to (1) try to help keep the front tires off the fenders and (2) work on a loose condition post apex.
Those of you that were lucky enough to attend part 3 of his seminars knows that the majority of the track day tuning we learned about involved increasing or decreasing the amount of grip the inside rear tire has to adjust to conditions. This is assuming you have the rest of the geometry optimized of course which we did.
This spring rate change worked for #1 and helped #2 in braking turns but hurt slalom turns because the inside rear now had too much grip when not in pitch. I hate driving a car with a push, this was reiterated to me again at the last event.
The correct cure is multi-faceted...and will take me some time to implement. The good thing is I completely understand the whys and hows because I have a good teacher. This is just another part of the evolution of me as a driver and a tuner. 4 years ago when Ron and I started down this path, this would have been too much for me to comprehend, today though...I am ready for it.
#1 Mill 1/4" of hub of wheels to put them back where they were before the spindle change
#2 Put the 600# springs back in the front and put ride height in front back to where it was before to fix slalom turns
#3 Install bump stops in the front to limit travel to exactly where it is needed to fix balance in braking turns and use shims to tune these on race day.
#4 Ron thinks I have a little too much brake now and wants me to investigate MC sizing (or other options like manual MC or a driver mod).
Thankfully I'm pretty certain I have plenty of wheel hub material so taking 1/4" off of them shouldn't cause me any other issues. This will however correct the tire\fender contact issues the new spindles created and allow us to put the geometry back where it worked best. Difficult part of this is finding the time to dismount my pretty new rubber and then finding a machinist I trust here in the valley to love on the wheels a bit. This might not happen right away but I am aware it won't handle properly until this is done.
Meanwhile, I'll make whatever shock adjustments I can and lower the front ride height just a bit and race it next Saturday as is. With now understanding exactly what is going on maybe I can adjust the driver mod and get the most out of it I can until I can fix it properly.
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Lance
1985 Monte Carlo SS Street Car
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