My baby needs new shoes...

[BigBrother]

Just got home from a late-night autocross (that's how we do it in the summer, here in the land of 110+ degrees in the shade)...

My Hoosier's have good tread left, but methinks they're about done, cycled out. I came to this conclusion twice tonight - once while telling myself the course is awefully dusty or something 'cuz grip isn't what it should be, then overhearing a couple other drivers talk about how sticky it was, lol. Second and more definate time, while pulling out of a 3k or so RPM in 2nd gear right hander into a long (by Solo II standards) straight; more wheelspin than I'd like and STILL spinning at over 45 mph with the wheel straight, LMAO. I can't do that on the stock 'lops!!! Insult to injury: My align,ent's off, and the shop that did it couldn't get me in yesterday or today. Grrr.

Finished 2 seconds behind where I needed to be and over 1 second off the time I thought I could pull. I could have done better under different conditions even with these tires, but not 2 seconds better, wheras with new A6's, I bet I could have found over a second even under the substandard conditions. She was pushing like crazy even with heavy trailbraking all night. Best STS time (national-level driver) was a 40.3xx, I needed to be within .170 of him to beat him in PAX, and would've been ecstatic coming within 1 second of him. Best run was a 42.571 no matter what I did, got into the 42's and that was all she wrote for the night, even with a re-run (downed cone right before the finish, gotta love it - on what would have been my worst run, too, LMAO). I'll be lucky to make top 20 PAX with that, much less the top 10 I always shoot for here (I've been as high as 5th).

*sigh* - Koni Yellows, $650. 245/45/17 A6's or similar, approx $230 EACH. I'd throw in another $1500-1600 for lighter wheels, too - IF ANYONE MADE ANY! Still - $1,800 that I can't spare for shocks and tires and mount/balance, etc, is gonna hurt.

[scottherbert]

Believe me..., you have my sympathy.

BTW, you're very right about the rear swaybar. I got the car back from the shop yesterday (with 1.5 degrees of negative camber on both rears and 2.0 degrees of negative up front) and added the 'progress' swaybar. Very dramatic changes.

I can throw the rear end around at will (with the steet rubber) and I'm not seeing as much front wheel spin. I also moved my Hoosiers from the 7" wheels to the 7.5" wheels and 'flipped' the tires, and they seem to stick better based on a short drive in the housing area (they're relatively fresh). I think I should 'soften-up' the rear Konis (they're almost full-stiff), but I'm going to see how the current setup works first.

I haven't added the URaceCars frame connectors yet. I plan to run in DSP this coming Saturday and see how the present changes work. I'll probably add the frame connectors the next weekend.

I'm emailing Panasport to see what they can do for me with custom wheels (I'll probably ping Enkei too). The widest I can find, for now, is 17x8" (American Racing - ugly -- but I don't care), and you could use spacers to deal with the offset issue, and squeeze a 275/40 x 17 on an 8" rim (Hoosier recommends a minimum of 9"). Kumho wants even wider rims for their 710s. If you don't want to mess with the camber, the 710 would be the best answer.

Scott

[BigBrother]

I've found plenty of wider rims, just no light ones. Some a few pounds lighter than stock, but not the sub-17 pounders that everyone else gets (FN01CR's, Trak-Lite's, TE37's, SSR anythings, Kosei K1's, etc, etc, etc). I would kill for a set of 17x8" 15 lb Trak Lites like we have on the MX-6, or 17x7 if I stay in DS (not likley though).

To do with discussion in the other thread - temp readings on a drivers-side abusive course were 128 inside, 130 middle, 133 outside on the drivers side front. And that's with -2.7 degrees on that wheel and 44-45 psi running pressure - and still coming dangerously close to rolling it too much. My grease pencil marks were inderterminate; they wore off further down than they should but only on runs where I botched a corner and pushed too much - and every time I marked the tires (3 runs out of 6) I ended up doing that, LMAO. The temp readings were consistant though, 5 to 8 degree spread from inside to outside on that wheel. Passenger side was unreliable data; the finish left me with the passenger wheel inside and spinning wildly, so the inside edge was consistantly reading 8 or 10 degrees over the middle and outside 'cuz it got heated up right at the finish. Grr. Anyway - I still say these cars need -3* in the front with DOT slicks. Everything says so, pyrometer, wear, everything. I can't believe it's worth giving up that grip to have a little less wheelspin under exit IMHO. :shrugs: We'll see, when I go to get the alignment fixed I'm gonna go for -3 even on each side.

[scottherbert]

Originally Posted by BigBrother

To do with discussion in the other thread - temp readings on a drivers-side abusive course were 128 inside, 130 middle, 133 outside on the drivers side front. And that's with -2.7 degrees on that wheel and 44-45 psi running pressure - and still coming dangerously close to rolling it too much. My grease pencil marks were inderterminate; they wore off further down than they should but only on runs where I botched a corner and pushed too much - and every time I marked the tires (3 runs out of 6) I ended up doing that, LMAO. The temp readings were consistant though, 5 to 8 degree spread from inside to outside on that wheel. Passenger side was unreliable data; the finish left me with the passenger wheel inside and spinning wildly, so the inside edge was consistantly reading 8 or 10 degrees over the middle and outside 'cuz it got heated up right at the finish. Grr. Anyway - I still say these cars need -3* in the front with DOT slicks. Everything says so, pyrometer, wear, everything. I can't believe it's worth giving up that grip to have a little less wheelspin under exit IMHO. :shrugs: We'll see, when I go to get the alignment fixed I'm gonna go for -3 even on each side.

I've run 3.0 degrees of negative and it certainly helped in the corners. The problem I've had at the higher negative settings, in DS, is that the inside front only has a very small strip of rubber on the ground in a hard corner (almost no torque), so I was able to spin the fronts more easily and couldn't get on the gas as quickly at exit. Result, I was slower. I pulled way back to -1.5 as an experiment and I've been a little quicker -- but I changed my driving style to accommodate -- I braked late, coasted through the entry of the corner (no power, no brakes), tried to make almost a 90 degree turn out of everything, and was then able to accellerate hard coming out of most corners. Result, faster than before.

BTW, I bought a pair of used 225/45 x 17 Hoosier A6s from a guy a couple of years ago -- supposed to have some life left -- I ran them on the rear to save some money (because I was trying to be cheap after I'd won two new A6s from Hoosier after a National Tour Event win in DS) -- so... I swapped ends on the very first hard corner. The tires corded after one run -- but thay only cost $10 so I couldn't really complain, and he had no way of knowing how little life was left. So much for being cheap!

Scott

[BigBrother]

Rather than ditch the camber, I'd try for the following:

Less front sway bar, to reduce the unloading of the inside wheel.

Stiffer front springs, to compress the outside corner less and therefor keep a tad more weight on the inside wheel.

Rear sway bar, which as we all know will apply torque to the front of the car and keep the wheels better planted.

FE5 arms - increase castor a smidge, which will help as well, and these are stiffer with less front to rear flex to reduce wheel hop AND they're 25% (2.2 lbs) lighter.

Try that setup with -3* and I bet you change your mind. That's my plan, but on 245/40/17 Star Specs (245/45/16 if they'll fit over upgraded calipers/rotors) for STX. That plus slicks in DSP = woohoo! Of course, you know your shit too, so I am curious to see your results as well.

[Cat Ion]

I was certain that Centerline made a 5X110 wheel for our rides that weighed ~16 lbs? If you're that determined, check them out. They aren't cheap though. $450ish per wheel.

[BigBrother]

Centerline does. In fact, I could have got a brand new set of 4 from them for $1,000 shipped. But Centerline pissed me off something fierce, so I don't want to deal with them. If another option doesn't arise by next season, I may have to deal with them after all.

[qwikredline11]

Originally Posted by BigBrother

Rather than ditch the camber, I'd try for the following:

Less front sway bar, to reduce the unloading of the inside wheel.

Stiffer front springs, to compress the outside corner less and therefor keep a tad more weight on the inside wheel.

Rear sway bar, which as we all know will apply torque to the front of the car and keep the wheels better planted.

FE5 arms - increase castor a smidge, which will help as well, and these are stiffer with less front to rear flex to reduce wheel hop AND they're 25% (2.2 lbs) lighter.

Try that setup with -3* and I bet you change your mind. That's my plan, but on 245/40/17 Star Specs (245/45/16 if they'll fit over upgraded calipers/rotors) for STX. That plus slicks in DSP = woohoo! Of course, you know your shit too, so I am curious to see your results as well.

you simply have to put a spherical joint in the flca thats where your camber is disappearing to, and why the outer rib gets rubbished....there is nothing amde by anyone in a DOT tire that can even come close to the A6 ..245 is the one, i use a 9.0 or 9.5 inch rim, currently 9.0 .go directly to Hoosier...dont even think of anything else unless you want to go slow....he he

[qwikredline11]

Originally Posted by BigBrother

Rather than ditch the camber, I'd try for the following:

Less front sway bar, to reduce the unloading of the inside wheel.

Stiffer front springs, to compress the outside corner less and therefor keep a tad more weight on the inside wheel.

Rear sway bar, which as we all know will apply torque to the front of the car and keep the wheels better planted.

FE5 arms - increase castor a smidge, which will help as well, and these are stiffer with less front to rear flex to reduce wheel hop AND they're 25% (2.2 lbs) lighter.

Try that setup with -3* and I bet you change your mind. That's my plan, but on 245/40/17 Star Specs (245/45/16 if they'll fit over upgraded calipers/rotors) for STX. That plus slicks in DSP = woohoo! Of course, you know your shit too, so I am curious to see your results as well.

oh and for wheel hop, while surely better control arms can help, the root cause is the impossible angle from the output shaft of the transmission to the center line of the front hub; GM latest information suggests that assymetrically stiffer axle shafts will help reduce hop ( I guess that means buying one stage 2 shaft off the aftermarket if you believe that) but the GM build book says rotate the motor and thats been my experience . I have done the rotation both with UHMW (works but vibration is awful) or with shims, stock rear mount and revised front mount with a UHMW offest bushing with a smaller rubber joint...both methods work 100% i settled for no vibration... .

[BigBrother]

...none of which is legal in either D-Stock or STX, lol. Of course, he's is DSP, so he should be able to IIRC.

When I make the move to STX, I'll be going the FE5 arms w/ poly motor/trans mounts route, I think that'll just about do it. We'll see - that doesn't get to the root cause, but it should be an effective band-aid. Not that I deal with hop much anyway, since I don't street race or drag race anymore. More a precaution and something that might matter at a ProSolo, lol.