Kinda new here but wanted to get some opinions on running 18" vs 19" wheels performance, looks, tech issues, etc.... Also anyone have pics of 997 GT3 with 18" wheels?
ast78

 

Serious track drivers will use 18". For street, I'd stick with 19".

 

CCW makes the C14's in 18" for the 997 GT3.

 

CCW's look pretty nice, also reasonably priced. Have any experience on the track with these?

 

I would go with the lightest & strongest 18" wheel you are willing to pay for. BBS (E88 or similar) or HRE (Cup Racing or "C" Series). Here's why:

1.) For same wheel, 18" will be marginally lighter than 19". Regardless, you want the lightest possible wheel, as this will give you an immediate performance boost from reduced unsprung weight: Better acceleration, braking and handling.

2.) 18" wheel will effectively increase the final drive ratio, improving acceleration in all gears. This is key, as the gearing in 3rd and 4th is a bit too long. I think it will shave a few 10th's of a second to 60mph.

3.) If you want to eventually move on to slicks for track, 18" offers best selection. However, more 19" options are becoming available.

4.) If you get 18", you should also, corner-balance, re-align (aggressive street will work) and lower the car as well. Another benefit is the car can be set lower on 18"s, lowering the center of gravity and improving handling as well.

Here are pics of my RS with 18" HRE Cup Racing Wheels:
http://www.gmgracing.com/dave_gt3rs.shtml

Same wheel as the GMG HRE Wheel, but offset/sized for the RS. The GMG HRE Cup is sized for the GT3.

 

you forgot 18 inch tires are cheaper. haha

 

counter point. the 997 3 was designed for use with 19 inch wheels. the lower profile 19 inch wheel will have a different driving dynamic. Now I am not saying that the average person would take notice, and its true that you will have many more choices of rubber by going to 18. the 18 inch tire will be a bit smaller in diameter which gives you better acceleration, but depending on the track different shift points because of the smaller tire.

 

what tire height do you use for your 18 wheels on 997 gt3.

Im going to be getting 18" for the track and I not sure if im supposed to keep the same profile height, or go bigger.

My current set up:

235/35/19
295/30/19

 

toad, you can get the same profile on an 18" wheel. I would recommend it. All tracks are different, some require shorter gearing, others longer. The stock setup, IMO is a hair too long in 3 & 4. 1st and 2nd are perfect. The cars are raced with 18's. You have to remember, the GT3/RS are designed for racing and simply sold to meet racing requirements. The 19's IMO, were put on to follow the trend of larger wheels on street cars for the perceived "aggressive" look. Regardless, 18 or 19, go light. That's were the bulk of the performance boost comes from. The rest is minor. For me, major downside is that Michelin doesn't offer 18" PSC's in the sizes I need (they used to). They have a larger selection in 19". So I am forced to use Pirelli's, which, IMO, aren't as sticky.

mobonic, Pirelli Corsa's: 235/40/18 in front, 315/30/18 in rear. The front has slightly higher profile. This does "softens" the tire slightly, which improves front grip (fights understeer) and surprisingly has no noticeable loss of responsiveness/feel.

 

Laguna,

Your RS looks great. Off topic, but who did your winshield decal?

 

Thanks OmahaGT. I bought the car back in Sept. from Steve B. (he is a forum member) in San Diego. I believe he had it done at Stuttgart Performance in Costa Mesa, CA, but not 100% sure. I owe Steve a call and will confirm and post the details for you.

 

Laguna_Dude,
Thanks for the descriptive insight! Your wheels look great. I guess depending on how much i track i may just have to get a set of 18".

 

I agree.

 

hey if you like pics i have done alot of Gt3 on 18" and 19" i can send your pics pm me your email address .. thanks ben

 

I currently have a GT3 RS and I had a GT3 and I have driven both cars on multiple whell and tire combos on the street and track. Without question, both cars drive and perform better on 18" wheels and tires. The 19's are for looks.