if you are thinking 19" on GT3, you clearly have bought the wrong car.

 

I totally disagree!!!!

The GT3 is fine to run 19"s I tracked mine for a year with 19" wheels the only thing you give up is R compound tires. I build these two style light weight 19" wheels. The front 19x8.5 weigh 19lbs and the rear 19x11 weigh 22lbs compared to stock wheels 18x8.5 @ 25lbs and 18x11 @ 27lbs. Thats a 32lbs weight reduction in unsprung weight and then multiply for rotatiing mass.

So the big thing is GT3 purest feel 19's are a sin, do not listen to them as long as you are not increasing your weight from stock your performance will be fine and you already have 18's for the track so go ahead and run 19" I can give you the offsets so you don't rub and if you want to go aggressive I can tell you those offsets as well.

As stated before the overall diameter will stay the same if you use the correct tire sizes.

19x8.5 front +41mm 235/35/19
19x11 rear +55 - +58mm 315/25/19

19x11 rear @ +51mm is very aggressive and you will need to roll the fender just about flat but they will work as well.

Yes you can run 315's on a narrow body no problem.( Just not Michelin as they have a very square and blocky side wall)

Use Conti, Yokohama AVS Sport if you can find them or Toyo now has thes sizes in the T1R.

GOOD LUCK GO FOR IT!!!!!

 

perfect! i went ahead and got 19" with those exact sizes of tires in toyo t1r's. i also ordered a set of 18" volks TE37's for the track with slicks. should be great!!!

btw... i did not know that the stock wheel weights are that high! damn.

 

Amen Brother!

 

The small sidewalls required to run the same rolling diameter WILL affect your suspension dynamics. Breakaway characteristics and ride quality of the car, as well as the way it behaves under bumpsteering or extreme lateral loads will be affected. Then of course, you also have the problem of not having any proper R-compound tires available.

Do what you want, it's your car... but I don't see any 996 race cars running 19's... coincidence?

Bill, you may be right on your points, but then again, if you're not even running R-compounds on your car, are you really pushing it anywhere near the limits on the track?

People use the example of Cargraphic's GT3 RSC all the time, but it is a flawed comparison, because we did not see it perform better than if it had 18" race wheels with MPSC tires. Of course that probably wouldn't happen, because Cargraphic has a co-sponsorship agreement with Dunlop, and they have discountinued their R-compound tire, the Super Sport Race, for Porsche fitment. Now all they offer is their mediocre Sport Maxx tire, which is not anywhere close to an R-compound tire.

The GT3-RSC handles well because it is based on a GT3-RS. But I would be willing to the bet the same car performs better with 18" wheels and Cup tires.

 

i am with hamman on this one.
if you want the look, sure 19" 20" 22" 40" wheels on your car.
if you want to lap as quick as you can , 18" is the way to go. you will have lots of trouble finding r compounds or slick at 19". of course that will change in 12 months when 997gt3 is out wiht 19". but then i dont keep my cars that long.

 

Hmmm..........

Some points we have already discussed and some new one's-

-This is a street car that uses 18's for the track. The 19's are strickly for looks. I don't believe you will need "R" compound for the street.

-The Cargraphic 996GT3 RSC has bested every previous years time, except for 2005 when it rained. It has improved by more than a second any of the times from 2004 and previous when it was using 18" tires and wheels. It used Dunlop SP Sport Maxx street tires every year including this year. This car beat cars that were running on 18's with MPSC plus an additional 200hp! So I don't believe stating that a race car is faster on 18's, 19's or even 20's is important. Race cars are race cars and street cars are street cars and should not be confused. You will find very few race cars with their race setup that make good street cars. These race suspensions are designed for the specific loads generated by the tire/ wheel combination used and the surfaces they race on. Believe me, if this car was faster on 18's it would be on 18's. That competition carries alot of weight over there! Having bling and getting spanked, does nothing for your reputation and sales!

-z

 

Right on...I am with you on all of that. Why go with a set of wheels that you can not buy R compounds for?

 

Zona,

Your analysis is flawed and simplistic to say the least.

You did not take into account that Cargraphic increased displacement to 3.8L this year thanks to a new tuning package by RS Tuning which now gives it 435hp and 339 lb. ft. of torque. Obviously the larger displacement also give it more low end punch that would help at a track like Hockenheim. That power made a huge difference. Also, you cannot say that the Cargraphic RSC setup is optimal when the car has not been publicly tested or timed with MPSC instead of the Sport Maxx. There is no way you can compare these two tires on the track, period. End of story. Again, this will not happen because Cargraphic has a long standing sponsorship and co-marketing agreement with Dunlop. This does not mean that Dunlop makes the best tire.

The GT3 RSC is also a very stiff car... every test review says it is barely a street car, and extremely stiff. So really, it seems to be close to a race setup than a street one.

In addition, just because it beat other cars with more than a 200hp advantage only says so much. Even a stock GT3-RS can make better lap times than cars with much, much more power... The advantage is in the revised suspension geometry.

If the Tuner Grand Prix had taken place on the Nordschliefe, there is no way the Cargraphic car would beat cars like the EDO GT2-RS. In other words, there is no way a GT3-RSC on Sport Maxx tires would beat 7:15 around the Ring, or 13 seconds better than a Carrera GT with Walter Rohrl behind the wheel.

It should also be noted that many of the Tuner Grand Prix cars are based on 996TT's and GT2's with modified suspensions. However, even the EDO car does not have the optimized geometry that the GT3-RS has. They use a KW sport suspension with the standard GT2 geometry, which is nowhere near as advanced as the RS. The RS suspension was, if you remember, optimized to homologate for the GT3-RSR. Therefore, the pickup points and geometry are optimized for the lower ride height, and this is what makes the big difference. If the EDO car had a proper suspension with ERP A-Arm links, RSR wheel carriers, etc. it would be an even faster car.

What I'm saying is that the fact that the GT3-RSC uses 19's does not prove than 19's are as good as 18's. It just means that the GT3-RS is an awesome platform to start with.

Cargraphic is a marketing driven company, and the decision to use 19's was definitely partially marketing. There is no doubt the car would be faster with 18's and Cup tires, period. To say otherwise is completely foolish.

What do you think would happen if the GT3-RSC ran against the Manthey GT3-MR??? The answer is that it would get SPANKED.

 

I use 19's on my Benz...Porsche Gets 18's..

That's just me..
I'm just saying..

 

I just sold my 19" Champion RG5B's with MPSII's today. I can't speak in technical terms, but simply put the 19's made the car nervous towards the limit. I originally bought the wheels for my 996C2 and although I did notice increased bump steer, the back felt planted and I felt the car was stable enough for the street. When I got my GT3, I immediately noticed that the 19's felt very darty and didn't give me any warning before letting go. Further, in braking from high speed the 19's tended to shimmy and cause the ABS to kick in right away. The 18's just feel as if they aren't stressing the suspension. The GT3 appears to be more sensitive to changing away from the 18's than my old C2. Again, simply subjective feelings.

So although I never intended for the 19's to be anything more than bling (the 18's are the only thing I would use at the track), the disadvantages were enough that I didn't want them for the street either. I will miss the look, but quite frankly as a novice GT3 driver, I actually had some safety concerns.

 

19"s are not inherently bad, but from a performance standpoint on a 996 GT3 they are, unless you're willing to noticeably increase overall diameter of the tire. Keeping the overall tire diameter while switching to 19s shortens the sidewall, which effects break-away characteristics, tire rebound and compression. The shorter sidewall may improve turn-in at the front, but will also cause the rear to break-away quicker, giving a twitchy nervous handling. And any wheel that's super light weight as a 19" will be even lighter in an 18".

The only real reason to put 19"s on a 996 GT3 is for bling; and if bling is your thing then the GT3 may be the wrong car...

One trick, if you're looking for the look, is to get an 18" wheel that looks like a 19" - no stepped lip.

 

I run 19"x10" 265/30R19 and 19"x11.5" 315/25R19 MPS2.

I get better feeback from the 19" with street tires than with 18" and street tires. The tall side walls 18" street tires are floppy.

The suspension on the stock GT3 is designed for 18". If you want to run 19" wheels, it is recommended to change the shocks for adjustable ones, so you can adjust the bump and rebound according to the stiffer tires/wheels package.

My 19" are 2 lbs heavier than the stock ones per corner, but I replaced the steel brakes with PCCB saving 13 lbs per corner at the front and 9 lbs per corner at the back, a total of 34 lbs reduction on unsprung weight compared to a stock GT3 with steel brakes and stock 18" wheels.

Funny thing is that my 18" Kumho V710 are much stiffer than my low profile 19" MPS2.

We competed on the 19" at the 2006 SCCA NorthEast Solo National Tour on day 1.

 

Let me see if this foolish, simplistic mind can respond to some of your points.............

1) The GT3RSC 3.6 w/ 19's was faster than the GT3RS w/18's do some research and compare the laptimes through the years! The 3.8 only improved the lap times by a second!

2) Lets look at the facts, this race only happens at Hockenheim, so bringing in another "if this would have happened at this track" is wishful thinking.

3) I don't really care how fast the car would be on MPSC, BECAUSE ITS NOT USING THEM!

4) This is a race car used basiclly for one event a year-enough said!

5) All your othe comments are really comparing apples to rocks, different cars, tracks, setups, tires conditions...........wishful thinking again!

For a street car 19's are fine and in the near future 19's will be fine for racing!

 

I am assuming that this GT3 is being used like many others. Limited driving during the week on the street, typically as a 2nd or 3rd car. Used for DE and open track days on the weekends, typically with Michellin PS Cups or some other R compound tire on 18's. Correct?

If that is the case, then going with a lightweight forged 19" wheel for the street with the proper tire combo is not the mortal sin everyone says it is. If on the other hand, your daily commute is timed and you are looking for a personal best, then stick with the 18's.