A version of part of this was buried in a strut-rub thread...but since it, in fact, had nothing to do with strut rub I've decided to make another thread piling together all I know now...I figure the more detail we give as to each others suspension tweaks the more we'll all learn. That's why we post and read here, right?
Background- My goal is to build a true BMW M3 slayer for a fraction of the Bavarian's price. We already have the power- I want the handling now. Regardless of the track, I want the poise to tackle an E46 M3. (Obviously, my next major mod will be brakes as the ones on the '04 are only slightly better than sticking your arm out of the window.)
In pursuit of this goal, my '04 M6 had a full suspension revamp about 20k miles ago, with a full Pedders / Prothane bushing kit, Yellow Koni struts, and Hotchkis sways fore and aft. I had Corvette suspension guru Dick Guldstrand's shop do the install and setup. I'm unsure as to my 18" wheel offset- I'll measure that this weekend.
My typical daily drive is ~230 mile round trip- mostly over mountain highways but ~1/4 of it in LA traffic. I throw that in because if you don't pile on the miles like I do, you may not care much about heavier tire wear.
OK. So much for back story.
Came in to work Monday morning through a raging downpour on the Grapevine, and was rather freaked out by the fact that in order to keep the front tires from hydroplaning, I had to keep my speed under 40 mph. I knew my tires were getting to the point where I need to think about replacing this set (I had ~33k miles on the Dunlop FM901 245/40Z18s), but I had no idea.
When I got to work, inspection showed that the extreme inner edge of my front left tire was badly trashed - down to cord and metal in places- while the rest of the tread was at least serviceable. Pix later.
I'm glad I saw it, but it made my heart hammer in my chest. Just that morning, on the other side of the mountain (where it wasn't raining) I had gotten her up in to the 120 mph range. Dumb.
I had just been under the car about 4000 miles before as I changed the oil...and gave the car a good once over and they seemed fine. I was more concerned about the fact that the damned B&M was leaking again- maybe that distracted me. But I digress...not preflighting my car more often and more carefully makes me guilty of the High Crime and Misdemeanor of Dumbassery.
My alignment was set very
aggressively at around 9 degrees of caster and 2-1/4 degrees of negative camber. This is bitchen for the track, but Doom City for street tires and long drives.
I've replaced the Dunlops for Goodyear F1 GS-D3s (great tires, BTW) and went back to the Vette gurus to get my alignment dialed back a bit. Got it dialed back to -1/4 deg camber, leaving the caster where it was at at 9 deg right, 8 left.
Problem with screwing around with the alignment is that it takes a good high-speed run to figure out what effect your adjustments will make...which is why they have warm-up days in racing. In this case, pulling it in that much has definitely dulled the sharp "Bimmer-esque" steering response. It's still better than stock, but after having it at -2+ deg it's a little like screwing while wearing a rubber. Think I'll set it to -1.25 deg as tire-wear / handling response compromise, as I obviously cannot afford to pop for $1k+ worth of tires every 5-6 months.
Obviously, the optimum solution is a decent strut tower top caster adjustment plate & bushing- this would enable me to make the tweaks easily and when needed- dialed way back for everyday use, extreme for track day. The Noltek appears to be the only one out there. However, it looks cheap compared to some of the nice ones available for Bimmers...a billet block with settings engraved in the top for easy and more precise setting. Anyone know of such an animal?