I'm another new 996TT owner here. The car is basically stock with stock sized wheels and Pirelli Assymetrico 18" tires with about 50% tread. I'm a fan of the "80/20 rule", saying 'You can get 80% of the results with 20% of the effort'. That said, I'm looking for the bang-for-the-buck modification to help correct the car's understeer (without converting to RWD). Researching has shown the following as good suggestions. What have you guys had good results with? What would be the recommended best first choice?

1. Check and setup car's alignment settings (specific settings?)
2. Larger rear sway bar
3. Larger front and rear sway bars
4. Wider front tires
5. Wider front and rear tires
6. Wider front track (wheel spacers)
7. Wider front and rear track (wheel spacers)
8. Replace all 4 tires with 'something better'
9. Adjustable shocks (via coilovers)
10. Upgrade differential
11. Replace suspension bushings
12. Lowering springs only

 

stiffen the rear sway bar, or soften front(assuming GT2/GT3/adjustable bars installed)
of course alignment is 110% important and should be checked first..

 

GT2 Kussmaul/ Motorsports settings...aim towards them(won't be able to get full adjustability with a TT unless GT or aftermarket parts are installed) :

Front Camber - 2.5 degrees
Front toe 2 mins per side
Caster 8 degrees -0+.5

Rear Camber -2.4 degrees
Rear Toe 14 mins per side -0+2. 28-32 mins total

Loaded ride height 112mm front, 130 mm rear

 

I've run Pirellis on my previous 996 and on our Boxster. I've notiiced if they are not real new and fresh they want to push and feel a bit hard. New front tires may help a lot. I did a stiffer rear sway on my 996 C2 and it made the handling a lot more neutral. My Turbo has Sumi HTRZ lls in a 225 F and 285 R and pushes less than with the Michelin PS2 in OE sizing. On a hot day (near 100+) after a few hard turns the Sumis will start to get a bit greasy, so I wouldn't recommend them for track. My car handles to my liking and is an '04 Cab, low miles stock in every way. I have H&R lowering springs but haven't installed them yet. If I do I'll add a bigger adjustable rear bar.

I almost ordered PSS10, then Ohlins coilovers a few times but resisted temptation and held off. I know I could easily spend $6K+ and still not be satisfied, maybe even less so than stock. More and more money, just keeps pushing the horizon and the reality is the car will do things better, but in the end, the overall ownership is about the same.

Welcome, enjoy, and good luck!

 

Get a set of Eibach adjustable sway bars. $350 gets you the pair. Then adjust until you get your desired effect. I like mine in the middle setting front and rear.

 

Increase your corner entry speed and trailbrake deeper thus loading up the front tires as you smoothly apply steering input which will aid in rotating the car. Maximum bang for zero buck...

 

I have the Eibach sways, I set the rear 1 setting harder than the front, I also run 1" lower and harder on the shocks, it turns in nicely.

Careful until you get to know the car better on the limit, it's a big pendulum back there. It gets much livelier without the PSM

 

Use oem swaybars. My recm only change rear at your entry level/budget.
Yes alingment. Yes wider front and wider rear. I would go 245/35 front..315/30 rear for street...toss all rubber out of rear suspension... Lose some weight of car and you will be good starting point.

 

Some good information on the topic.

http://rogerkrausracing.com/pages/moreinfo.html then click on oversteer/understeer

 

Great info there!

thanks for posting, should be a sticky as this gets asked over and over

 

Don't forget not all info applies to our awd. Like playing much with tire height.

Now when anyone wants to change to a certain type of sway bar or go to different tire widths you don't just buy into it because it sound goods. Drive your car, better yet take a few track lessons so you get to know your car and then make changes one at a time, testing to see what changed and if it changed as you expected.

 

+1 what Chad said. Take some track lessons from a pro and learn the car. Everyone *****es about these cars under steering a bunch and they do if you brake hard in a straight line and then enter a corner under throttle unloading the front causing it to plow. If you carry more speed into the turn and make the front tires bite under braking while turning then understeer is not an issue. Some of the fastest set ups are geared towards understeer as it forces you to elevate your minimum speed on turn entry. I have over 30 track days in my car this year alone and I'm just now starting to figure it out after spending some time with a pro cup driver both in my car and his Cup. I used to spew my knowledge (or lack there of) on these forums thinking I had a balanced car. Boy was I wrong. He completely changed my set up towards much more understeer. I hated it at first but it forced me to drive the car in a completely different way but the end result was a much much faster car, on the order of 4 seconds quicker on a 2 min lap. The byproduct was also a car much less hairy and more predictable at the limit. Long story short, spend some money on driving lessons at the track from someone with a Porsche racing background and learn the car. If I'd do anything to start I would put a rear GT3 4 way sway on the car to allow for some fine tuning. Good luck and have fun out there..

 

A decade of motorcycle roadracing helped me. A lot of same handling characteristics apply to rear weight bias 911s.