Need help with track setup: Stock 997 GT3 with OEM Michelins, used 90% track car. I have not seen any recent posts on what is working.

Currently running
Front -2.6 with 0 toe, sway bar full soft
Rear -2.15 with 1/16 toe in, sway bar full stiff

Still pushes too much with wearing outsides of tires

 

first...make sure your alignment hasn't changed..especially rear toe...if you can't get your understeer within the tuning range of the sways your only choice is to do it with other options i.e. tire pressures, tire size, toe setting, front caster, sways or springs...here is a chart that will give you some other areas to look at...another solution is a softer front sway or a stiffer rear...since you have wear on the outside edges you may have the fronts under inflated, with zero front toe they shouldn't be wearing that way...mine wear pretty evenly...if none of these other options work you may need a softer spring in front...the only other thing to consider is driving style...does it oversteer throughout the corner or just on entry and oversteers mid corner to exit...you may be overdriving corner entry and scrubbing the tires...good luck, it is frustrating when you can't get it dialed in with the bars

 

Another popular upgrade is to switch the rear sway bar with a GT2 bar (stiffer).

 

Correct me if I am wrong, but I thought the GT3/RS is compatible with any race spring such as a Eibach Race Spring (ERS). I am not sure about the stock GT3 spring ID or length, my guess is it's 2.25" or 2.5" ID, which you can buy in virtually any rate or length from Eibach.

Going to a linear race spring would be the first thing I would do, as I feel if offers more consistent handling. By stiffening the rear via a spring, as opposed to the swaybar, will help your LSD work better and last longer. (The 2010 GT3 uses linear race springs now too). By sticking with softer springs and then using a huge rear swaybar you will overstress your LSD because as you corner hard and weight up the outside wheel, the big bar will be trying to pick up the inside wheel all the time...which you don't want. You want to try and resist roll with stiffer springs, that way when you weight up more of the outside, the spring rate will be doing more of the work, not the big bar.

Just look at what the stock spring rates are (I don't know what they are), then bump up both front and rear, but increase the spread in rate from front to rear even more than stock rates (in no less than 100# increments, you'll likely not feel anything less than that). Then use the stock swaybar as a fine tuning method.

So for example, increase your front rate by say 100#, then increase the rear by 200#. Then play with swaybar and tire pressure settings for fine tuning. Then if it's still not enough, then increase the rear by 300#, while keeping the front still at the 100# increase rate.

That's how the pro's tune their race cars, it works. And springs are only $120/pair.

 

All of the input above is good advice. However, the root of your problem is simply the OEM MPSC's. Get rid of them, and miraculously, your problem is solved. Also, consider a stiffer front bar as compared to the back once you switch tires.

 

+1 on the MPSC's being the source of the problem. Tried two sets of them, and felt like they were a down grade from the other R Comp's that I have tried. Next track day I will be on R6's, from what I have heard these tires are a lot of fun!

 

You won't believe how much improvement until you try the R6's. Beware, there is no going back.

 

Swithing to different tires doesn't solve the handling problem because you will still be increasing grip at both ends by the same amount. That doesn't miraculously solve anything.....In order to solve the handling issue you need to increase grip at the front, decrease grip at the rear, or both. NOT just increase total grip. If you slap on a set of R6's, then you just increase the limits but don't change the handling balance.

Like I said, no need to go out and drop $1500 on a set up R6's when the problem can be solved with $240 springs, and free bar adjustments and tire pressures.

The problem is the setup. The owner didn't complain that his grip level was too low, or that he wants stickier tires for faster lap times, he said he was having understeer problems and excessive wear on his outside front tires. You can't solve that with new tires. The driver also should examine his technique to make sure his inputs aren't making the understeer worse. None of us are Pat Long.

 

Feel free to drop me a line happy to help... We have done a few dozen of these


I would highly recommend our sway bar upgrade for all GT3's and RS... Its by far one of the best bangs for the buck on the market today.

http://www.gmgracing.com/porsche_suspension.shtml

 

what car are you coming from? the 997-3 is always going to have some understeer. I think -2.6 camber on the front is on the high end. I start this process with a pyrometer and checking the tire temps. that will help with a camber issue. as far as the getting the understeer out. Can you tell me the kind of corners, is it tight in, middle or out. Tires can be a big factor, for example when I first put on a set of R888's full tread, they scared the crap out of me. Loose in, tight out of the corner.
I have learned how to drive the 3 with a slightly tight set up. trailbrake in slower corners and modulate the throttle of faster ones. Good luck as this is just as much about your personal preference and feel as it is with the car.