pbu

Thanks for the update Mvez. I'm interested on your feedback after you had a chance to run it on the track. Do you have data acquisition to compare before/after?

997gt3north

As I already posted, that was my exact feeling - it is a stunning difference on turn in and as you say still perfectly streetable.

My car is in this week to put my re-valved rears (#900) on. I'm hoping for a similar result (ie still very streetable). I will have a track update assuming all goes well on the install - I'm at Mosport next Wednesday.

Unfortunately, my 600# springs have been lost in the mail so I will be trying my 450/900 setup (both are revalves). I will then have my second set of revalved fronts installed with 600# fronts to see which I prefer. I have a set of 730# rears that I can also try should 900 be too high as a combo street / track setup.

I am going with the rear spring hat that I got from Dan Jacobs (will know shortly if everything fits) - but when the Tarrett Engineering part is done that will be my solution.

TrackDays247.com

Good to hear actual numbers - this one's a keeper.

997gt3north

Update

Customs found my 600# springs so I will be trying at Mosport on the 22nd re-valved OE shocks with 600f/900r springs.

And,

I will be using Ira of Tarrett Engineering's new prototype upper rear spring hat that he just received back from prototyping that fits both the OE and his Monoball upper strut mount. This solution should be available very shortly for everyone that wants to try more rear spring - in readily available 60mm diameters. We spoke over the phone today - it fits, I will be trying out the non pretty version.

More updates to follow post trackday.

Paul

NJ-GT

On my 2007 GT3 RS I found -3.5 front and -2.5 rear perfect on Hoosiers 265/345 x 19. I also ran Cup slicks with same alignment, but they needed another 0.5 degree to be on the spot. I ran these same specs on my MPSC 265/345x19.

Car had GMG sway bars (a must if you use stock suspension for a 2007 GT3), and a few monoballs here and there, nothing crazy.

Reter and Randy run -1.0 camber at the back, they are going to regret once I show up in a Beetle with proper alignment.

Mvez

Well, I finished up an awesome first weekend with the car and have lots to post, including an incredible sequence of pictures of me driving through T10 at Putnam Park (coming soon, with a full explanation). Having John Lewis and Cass Whitehead around all weekend to discuss setup, advanced driving techniques, and some in-car instruction was invaluable. Big thanks to them both, and Randy from Bluegrass Motorsport.

On topic first: The tire wear ended up being virtually perfect. John commented on how responsive the front end (and rear end) felt, no doubt because of higher front spring rate and bars. Weight transfer from front to rear, and side to side was very super crisp. Front dive under hard braking was never an issue with with new front spring, and you can really lean on the front end

I went out with -3.1 front, and -2.45 rear camber with 4 year old Toyo RA1's (245/305 sizes) and although the tire wear ended up being virtually perfect, I think a couple of changes would have given me more rear grip, which was definitely needed. Traction control was turned "off" all weekend, which allowed for some ridiculous slip angles....

My GMG bars were set in the middle, both front and rear. The front was fine, perhaps maybe a tiny bit less as well, in the range of -2.9 to -3 would work too, but I don't need to make any changes to the front. I definitely did not need to soften the front bar, as the car was very neutral at turn-in.

With alot more rear bar, the transition from trail brake to throttle, at the limit, induced too much oversteer, and although it was unbelievable fun, it was adding too much unecessary heat to the rear tires and leaving grip on the table. At first, alot of it was caused by my inputs, but as I began to re-calibrate my input rates and became smoother, it still needed a bit more rear grip. I don't want to use Hoosiers (315 or 335), but I think if I would have been on those, the rear setup would have been just about perfect as it would have allowed the rear to take more of a "set", on the transition, instead of overpowering the rear tire grip, as discussed with Cass and John. Since I am trying to use RA1 type grip, I think by softening the rear bar by 1 hole, and perhaps a fraction less rear camber (-2.2 to -2.3 or so) would have been ideal for the 305 size tire.

All in all, I'm blown away by this car. With just a few simple mods, I have a car that I can spend literally years learning how to drive it faster and faster. What I though were super smooth inputs for my M3, are now like being a bull in a china shop, so it's deeply rewarding to learn to drive even smoother, as everything is magnified in this car. Steering, braking, throttle, everything seems 10X more sensitive, truly exhilarating on track. After 2 sessions, I was already pushing the car as hard as I could, which is a testament to the confidence this car inspires.

TRAKCAR

Patiently awaiting for you to bring it on..

-1 rear with Toyo, -2.8 Hoosier, both wear even. I will cord inside RA1 in one day with -2.5 rear. I tried.
Bar middle rear 1 from full soft front, or maybe full soft, don't remember. But that is .2RS with 335...

Mvez, Glad to read you are having so much fun, but that is to be expected. I went from Mustang to GT3 being really worried about rear weight bias, but i was giddy with fun and confidence pushing harder then ever after 2 sessions :-)

997gt3north

With a 245 ra1 type grip, anything beyound -2.6-2.7 in the front and you are just giving up braking ability - I suggest that you reduce the front when you are bringing the rear back to -2.2 (-2.7f, -2-3r) is where I ended up on an mk1 as a combo setup that would work for OEs & R6s - I have since dialed it back to (-2.3f,-1.75r) for my PSS experiment.

You are definitely correct on the rear bar - it might be correct for a 325 R6 but get it to full soft for RA1s. Since it sounds like you enjoy trail braking, you may even find that stiffening the front bar 1 hole, in addition to softening the rear by 1, will be an even faster setup.

I received Ira's new rear spring hat today and it is exactly what you need - it is a perfect piece on very quick analysis - the actual install starts this afternoon. 600/900 on revalved OE dampers with full RSS rear suspension (dog bones, LCA) and Tarrett rear strut monball will hopeful get it's maiden voyage Thursday. I'm going to start with Front OE sway in middle of 5 holes and uprated GT2 rear bar on soft- tires will be new, but scrubbed PSS. Car will be lowered 5mm all around because of the stiffer springs.

Izzone

had entire rear changed to monoball

when to Sebring this weekend

1.6 camber rear

corded the outside of both rears

I think with monoball you need more camber

mdrums

Randy I'm running -2 rear...although only got 4 laps in and not all fast laps either it looks like -2 in the rear at least on my car is good.

utkinpol

i had same issue with 1.5 deg in rear, now with 2.5 deg i had rear 335 RA1 tires for almost half season, started them at full tread, now it`s about of 40% of tread left, wear in rear is virtually perfect. i had a guy to drive with me at lime rock 2 events ago who has '07 gt3 rs car, and to his feel my car had better grip than his. i got to say the feel of driving on 275/335 rubber with proper setup is pretty awesome.

ArcticGT3

Mvez,

It's great to read that you are enjoying the car so much. I'm very impressed by the changes you've been making. Somebody should have told me I could do that! I'm looking forward to the pictures. Also, remember that the car came with a camera mount on the rollbar!

Armando

Mvez

haha, I had the mods planned before I even bought the car. I must have way too much free time on my hands. I would kill to have recorded that entire session, it was intense. The instructors from the Porsche NA Driving School at Barber are awesome.....in only my 6th session in the car, John Lewis had me doing things at Putnam Park I'd never done before, and I know that track like the back of my hand. I have much to learn.