I have an 01 996TT with a few mods (stage 2) and stock suspension. I'm getting into PCA autocrossing but I'm getting smoked by GT3s (and even 914s!). My car understeers horribly and the brakes don't seem great. Otherthan more seat time and instruction, could anyone recommend any upgrades to improve handling and reduce understeer? What is camber and how could it help?

Thanks

Ron

Come by the shop we set up most of the front running PCA AutoCross cars around So Cal.

We do all the work in house!!


Feel free to drop me a line.

996TT is a heavy car for autocross to begin with. I would at least throw few light weight mods on the car before starting anything else(GT3 seats/light weight Battery/lighter exhaust) ,also a camber adjustable suspension with high spring rate (recommand -3 in the front ,-2 in the rear for camber),pagid orange or Ferrado 2500 pads,Kumho v700 R-compound tires( they heat up faster than other R compund tires) will all help

If you consider a vertical line and put the outside edge of your wheel at that line with top and bottom of wheel right on the line, that would be 0 degrees of camber. What you want is for the top of the wheel to be to the inside of that line ( or bottom out, whichever way you prefer to think of it) When that is done on your car, you will have negative camber and that is desirable for better handing on the autocross track. I agree with the camber numbers posted above except that I would go -2.5 for rear. A lot of negative camber will wear the inside edges of your tires heavier than the outside.

Putting more air in the front tires or less in the rear will also help reduce understeer. Anti-roll bar installation and adjustment will also help. Go soft in the front. A good coil-over suspension will help. increased spring rates will also help. the heavier springs will degrade your ride on the street. If you go with new coil-overs, lower the car all the way around. The ride height I run on the street is 110mm front and 120mm rear. I have to be careful with deviations in the driving surface or I will scrape the nose piece in the front, but I rarely do so.

As for tires, the best I know of for pure autocross would be the Hoosier A6 compound. They are very sticky and will not last very long.

Changing brake pads will help. Pagid black will give good initial bite but will be harder on rotors than stock pads. I don't think they are a good choice for street driving. Try to drive your car down the street before your run group comes up. Do a lot of braking and build some heat in the rotors and pads. this has helped me in the past. If you have heat, the stock brake system should be adequate for autocrossing.

A properly set up turbo will hold its own with the other clases pretty well. Go get 'em.

Coilovers
Auto X Tires
Alignment with lots of neg camber
H&R Rear sway, FULL STIFF
Driving Skill

Is all you need.

it can be done. As above. Alignment, lower and stiffer, and sticky tires.
Kumho 710s for best times, and Yokohama Advan Neovas for truely
streetable performance tires.

Joe

I've auto-x my car and it sux.

have you ever seen an elephant with rollerskates?


Well, I have a pretty good idea about what it would look like...



If your car is set up at all for tracking (ehem...like moi), then going to the autox course is great if you like getting killed by 325is...haha. (I know autox is an equalizer, but...there are certain cars that just arent meant for it...haha. Youll find the front pushing so much, its not even comical...

I have the road atlanta auto-x lap record, the tt is very capable.

In the Peachstate Region of PCA (Atlanta area) there is a 996tt that only attended 2 of the 6 events last season and won fastest time of the day each time on Nitto NT-01's which are very streetable tires.

Dont be so modest there Al !!!!!!!!!!!!

Joe,

Do you think the Kumho 710 is really a quicker tire than the Hoosier A6? I think the A compound is designed for autocross. I have no experience with either. Just passing on what I have read. Enlighten me. Thanks

what event ? and what your laptime ?

[quote=sechsgang;1508841]have you ever seen an elephant with rollerskates?[quote]

That's funny but appropriate.

Road Atlanta has a auto-x that is an actual course not cones. They use it for big events like the year one experience and lots of people show up every year to see what their cars can do on the auto-x and the big track and they were taking the panoz race cars over there (before skip barber took over ) and allowing race school students to set laps. I ran a 22.6 I think, I cant remember, but it was the fastest lap on the course when I ran it. I couldnt match it though because I was on hoosiers and they kept making us park in a dirt parking lot between runs, so my tires were cold and dirty. Then I blew a radiator hose and had to call it quits.