Next suspension step for more AX performance
 

I've done some searching, but can't decide what to do...I'm trying to plan my next suspension move to hopefully improve autocross performance in my 85 carrera coupe...I drive my car @ 5k miles on the street a year and try to hit 8 or so AXs (this coming season will be my 3rd)...

Here is my current setup:

ERP ploybronze bushings front and back
22/29 torsion bars
Bilstien sports all around
stock carrera sway bars with new bushings
polygraphite strut tower bushings
new ball joints
ERP shock tower brace
replaced cat with bypass, M&K muffler, SW chip
Remove some wieght - AC, rear seats, ect...took about 250lbs total from stock
1.75 front camber, 2.0 in rear (i do my own alignment with string)
running around Euro height (can't go lower, drive scrapes:(
stainless brake lines with normal street brake pads with lots of life, but most rotors are @ 22mm (limit i think)

I autocross with 7x8x15 fuchs and R888s (225s, 245s i think) - probably 1/2 or 3/4season of AX time left on the tires...the 15" wheels see good for hole shot.

What should be my next focus? budget is @ $1200-1500

do i get more camber somehow, invest in adj sway bars, add more aggressive brake pads(replace rotors since they are getting close?), or should I invest the $ in more aggressive AX wheels/tires (larger wheels, real ax tires)??....or?

Thanks much in advance
http://forums.pelicanparts.com/uploa...1260736156.jpg

Spend the money on a good driving school.

You do not need more brakes for AutoX. If you have lock up on one side a lot, that would need to be corrected for.

Your current set up is more a street/DE set up and would be on the front stiff side. To compensate you might try a larger adjustable rear sway bar . Try a 25mm size, 23mm rate Taget / Rebel Racing / ER rear sway bar or if you have the dollars concider a Smart Raceing Products 23 or 27mm rear bar.

225/235' 15's are good. R888's are not the best AutoX tire. Try a set of A6's or Kumho V710's. 225/225 seems to work well for AutoX.

AutoX calls for a lot of camber. Shoot for as much as you can get in the back up to about -3. Elongating the bottom arm hole may help.

The front is more a challenge as you will not get close w the stock set up. Smart Racing Products Camber King strut top and bar can get you close to -3 if you remove the shock hat. Otherwise you would have to have the A arms lengthened or the struts decambered to get more neg camber. Elephant Racing has offset ball joints that can get about another .75 of camber. ER also has a quick change strut top that makes it easy to bump your camber for the week end and pull it back for street driving.

So camber, rear stiffness, tires, and mostly just work on you skills.

Our setups and driving needs are very similar except I'm using a wevo camber king with about the same camber you have. I probably could get close to 3 degrees if needed.

I wouldn't sacrifice brake noise and dust on the street for more bite. You won't really get the pads up to temp to take advantage on most courses.

If your not using your 15s on the street, you could try a lower profile tire to improve gearing/acceleration. I've thought about getting 15x8 instead of my 16s because they're lighter. As a second set I could use dedicated R compound that are shorter in diameter.

I've thought about having my bilsteins re-valved to match my 22/28 bars. I'm not sure how much performance would be added here.

Sways bars could be in my future, but I haven't wanted to introduce another variable yet.

Someone mentioned driving school. I've done an Evolution auto x school and it's good. Really good instructors, but probably won't be helpful regarding a 911. I usually grab the quick guy at my local PCA events for some constructive criticism

i looked and my stock sway bars are 20mm front, 18mm rear...so 911t, you think i can possibly start with a rear adj sway only?...I like the thinking from a $ standpoint.... wonder how long I can get away with the stock sway bar mounts? :rolleyes:

for another cost effective try, I think i will try and trim my front stock camber plate to get more camber like in this thread...

http://forums.pelicanparts.com/porsche-911-technical-forum/298923-more-front-camber-tricks.html

will tweak my rear camber in a bit more too...

also when my R888s wear out, i'll replace them with stickier AX rubber...

other thoughts?

Beside more seat time and good instruction, nothing will do more for your times than tires. The fastest SC/Carrera cars in our region are running 8 & 10 x 15" rims with Hoosier A6 tires in 225/45 and 275/35-15. Since this requires custom rims, with perfect offsets for the rear (and clearancing mods), it may be outside your stated budget. The tires alone would be almost $1,000 delivered, and they don't last as long as your Toyos. They also need a LOT of negative camber (-3 degrees would not be too much).

If you are allowed to run non-DOT tires in your class, a cheaper but less effective alternative is to run the 15" Goodyear or Hoosier cantilever slicks. They don't come in as soft of a compound as the A6 and won't heat up as fast, but the cost advantage is that they will fit on cheap 7" rims (cookie cutters or phone dials) and you can buy good used castoffs from John Berget for cheap money. Your tire guy will hate you, though--they are a b!tch to mount and dismount. Since they are bias ply, they take very little negative camber to work but have a larger slip angle.

Have fun,
TT

Is the 225/275 for track work or AutoX?

I knew they were having some success in PCA track racing with that combo, did not know they have popped up in AutoX and had turned out to be a proven combo?

Hire Terry Zaccone to instruct you a coupe of times a year.

Frank

I agree with the recommendation for good instruction. I believe the V710's are more tolerant of camber-challenged suspension than the A6's, and will last longer, though your 888's are a great compromise for AX, DE and wet courses. Adjustable sway bars will transform your car when you have the skills to use the extra performance. Corner balance wouldn't hurt either.

I would get a good sport seat and harness with harness bar and also get a sport steering wheel (I like the suede Momos). This will connect you closely to the car and ultimately the road as it will avoid any slipping around in the seat. Sport seats w/ harness made a huge difference in my performance driving.

George

Have someone that's really fast ride with you in the car and tell you where you can find improvement.

I would upgrade the sway bar to an adjustable type. I'm running a Smart Racing front and rear adjustable in my SC and it's make a world of difference. If I'm at the track and I'm pushing, I can adjust to the front and get more traction, same goes for the back end.

Question for you: I see guys running 15's and guys running 16's. Did you run 16's before the 15's and what is the advantage disadvantage. We're running our cars on tight courses and I'm curious as to what you've experienced.

the 15s are great at hole shot in AX because of gearing..I can tell a difference versus my 16s....

FWIW, the late Carrera rear bar on my car had enough flat area where the link attaches to drill another hole on each side. Take a look at yours. If they are like mine, you just need some adjustable links to have two more positions, both stiffer.

+1 here...

Thanks everyone for your advice...given the input I think i will forgo sway bars this winter, and work on getting some more camber for the AX season....will concentrate on improving my driving skills until my R888s wear out, then consider getting some Kuhmo or Hoosier sticky tires...

thanks again!

Don't forget that Chuck (Elephant Racing) has a software dodad that gives you a step by step progression on suspension improvements. It includes costs too. Pretty handy.
Just my .02c.

Good deal.

Once you are getting to the fine points of suspention set up, adjustable sway bars are the prime way one sets the front to rear ballance.

After tires, I would say that adding lightness is a key to any good AX car. The less weight you have to move around, the better. Sounds like you have done some already, but more weight saving is always better. Especially from the rear.