Hi,
I recently purchased a low mileage 93 6spd with the following mods to replace my stolen porsche 944 which i finally got all the bugs out of. And the car was infested!

Hypertech chip
Callaway honker air box
MSD spark enhancer

Hotchkis strut brace
lingenfelter sways and trailing arms
slp springs and 17x9 rims
Doug Rippie revalved bilsteins

I plan on putting the stock 16" rims with whats left on the original goodyears and taking the car to the next PCA autocross next month, and evolution next season.

with the solid axle and overabundance of power i think i will get plenty of oversteer.

does anyone have a similar suspension setup? what pressures are you running? im thinking 40 in the front and maybe 30 in the rear. should i be running less?

the temperature should be in the low 50s high 40s.

Is the setup i have considered "balanced"? i think the rear is a little too stiff. I haven't driven a stock Z28 to compare mine to so im a little in the dark.

TIA

 

I can't remember which sway bars Lingenfelter uses. I know they sell Hotchkis 1 7/16" inch bars but they also sell a hollow front bar too.

 

Steve,
when i bought the car i quickly reviewed the sellers receipts. I was supposed to get them, but somehow that didnt happen. I will try to get them when i pick up the original parts one of these weeks.

how can i check and report back to you which ones I have? Im guessing he bought a kit for the suspension, then bought the shocks directly from doug rippie.

I used to short shift into second in the porsche but think its probably better to start in second with the camaro. any other tricks?

 

I have an A4 but I know Tommy Pulliam (Evo instructor here) has a six speed in his and he REALLY uses (abuses?) first gear. That's probably something you'll have to get a feel for. I use mine quite a bit, depending on the size and type of course.

 

just checked out your site. i will send you a link to some pics i took of my car the day after i picked it up, as well as the 68 firebird convertible ive owned since 76. guess im coming back to my roots.

im probably gonna stick with the porsche clubs autocrosses since i got to know the guys there, and the season is almost over. we have a bunch of scca guys that come out.

i know im toast as far as times go for three reasons. first is i suck, but thats another story. second is i would be in x class which is all non porsche cars, and a guy with a very worked griffith often comes very close to FTD. third is the guys at PCA love really tight chicago boxes.

how different is the tire pressure between your front and rear tires?

 

Well, I run Hoosier A3S03 so....

I run about 40-43 front and 35-38 rear. I've tried higher and lower and this range seems to work the best.

 

i'll try the factory goodyears (now close to slicks) with 7-8 lbs difference between front and rear and go from there.

I think im gonna drop the rears of the 17" dailys a pound or two and see if it cuts down on the hop.

 

Axle hop??? Under hard breaking??

 

steve,
its more like the rear end is stiffer than the front. seems the rear is bouncing over bumps while the front is soaking them. not much different than my 68.

maybe its just a solid rear over an irs.

i had a lot of rx7s, and the first generations had a solid axle. when i would go over certain bumps the rear would hop up and move a bit. the camaro does this, only not as dramatically.

i think the spring is bouncing like what was mentioned in the FAQs. i also think i have the lower springs because i hit driveways at low speeds.

i guess a quick drive is worth a thousand words.

the car has the slp17" rims with 275/40 comp ta Zrated tires.

my sellers dad just had bypass so i dont want to call him to ask more questions for a few weeks.

 

Steve I assume you have not gone this low but I am finding that 35 front and 31 rear works great. That is with the 315 Hoosiers. Tire temps are about 5-10 degrees warmer on the inside (I run 3/16 toe out so this has some to do with it) and in the rear the spread is no more than a degree or two.

Our cars are basically the same.


Tom your setup may not be too bad. The rear bar may be big it may not. One trick is if the rear is just a little too stiff put the stock rear springs in and leave out the rubber isolator. You will have a softer rear spring and still lowered.

 

The other day when the course seemed to go away, I dropped my pressure three runs in a row andI couldn't tell any difference in feel or times. I think I got down to 35/30 on the last run. You've seen what Hoosier recommends??

 

yeah Hoosier recomends a bit higher pressures. At least according to a guy at Hoosier, not from the sidewall.

But my guess is that Hoosier tire will tell you a general temp for their tires and not really size specific. I know for me 35 and 31 work the best. And temps even say so.

Another rather un-scientific way of thinking is this. Bigger tire will end up running higher pressures. So lets increase from 35psi and go to a 275 tire. Say 3 pounds to 38. Then another 3 or 4 to 41lbs or so for the 245's. Wich I think is right around where the FS guys are at.

Another thing is I saw a guy with a Global West car (stiff springs small bars) adjusting his pressures and according to hig gauge he was only running 33lbs.

 

Here's what Hoosier recommends:
------------------- Hot -----Cold
1800-2200 lbs 39-42+ 31-36
2200-2600 lbs 40-43+ 32-37
2600-3000 lbs 42-46+ 32-37
over 3000 lbs 43-48+ 32-38

Most of the F Stock guys here run in the low 40's. I've run 44 in front but dropping down to 35 just didn't affect my times at all. Go figure.

 

played around with tire pressures this weekend.

it seemed ok with 34 and 31. i bumped it up to 35 and 33 and the back is bouncing again.

i will try 35 and 32 and see what happens. my numbers may be 1.5lb high, or my other gage is 1.5 low

 

Give me some more info on "the back is bouncing again...". Under what conditions does it bounce? Those pressures are pretty close for street tires though.