Hi guys been reading abit but pardon me.



So my qn is is it possible to use a 305 fatter tires when originally mine came with 295? is there a need for spacers? does that improve or affect handling?

I went to tire shop and was told that i can even use 285 or 275..?

just like to hear from you guys.

 

if the wheel is 11 you can use 305

 

305 actually is better suited to a 11" wheel over a 12" which is a little stretch.

 

Yes, the 997.1 C2S has 11" rears so you should be fine, but why do people like to do this? I guess I'm just different but 1) the 305's are more expensive, and 2) it makes it harder to kick the rear end loose and have some fun! Isn't that the point of rear wheel drive?

 

Are you running wide body offset Turbo wheels?

 

i run 305 on the street - no problems (with PSM/ABS) despite the slightly taller measurements, and i do so basically for looks. for track, i run 295/stock size which i feel are a better balance for performance.

 

Have 2005 C2S Launch Edition with PCCBs and went to RE-11s and 305's on the rear on stock 11" rims. Had PS2 295s previously and yes the 305s are harder to break loose. Granted the PS2 were a bit worn. The 305's fit fine.

 

many thank you for those who replied me.

I did some research elsewhere and found this..

http://www.renntech.org/forums/index...-tires-on-c2s/

anyway seems my TURBO WHEELS are 11 inches wide.

So it seems they should fit.

Thank God as most of the SS tires I am looking come in ...305s

Been looking at the following

Michelin Sport Cup 305!
Michellin Pilot Super Sport 295 but Non N Spec?( is this a problem!)
Bridgestone RE 11 305 !



But i just wonder if using a fatter tire means less performance.

Any comments?

 

define "performance"? since the 305's are slightly taller than 295's, technically you will be slower to accelerate but you will move a bit farther for each tire revolution. i doubt that you can notice either, but just quoting physics.

more noticeable - in terms of cornering it all depends on how you have the car set up. if you have adjustable sways and suspension, you can change settings and alignment to accommodate the 10mm extra in the rear (i.e. compensating that it has more grip, breaks loose later, etc). on a totally stock chassis/susp i dont think you have much leeway besides alignment.

 

And 305's create more unsprung mass at each rear corner, but now we're splitting hairs...

My preference is to mimic stock setup as much as possible, this is how Porsche preformed all their R&D testing and is the standard the car's suspension, brakes, and chassis were designed to.

 

305's are stock on the turbo and the wheels on an S and a turbo are both 11" wide in the rear. The difference in handling between the 2 is really pretty small. The 305's can also be quite a bit more expensive. The Super Sports are the newest Michelin offering and should be hot. Even if not N spec.

 

Techincally speaking the 305 is slightly taller than the 295 so you can suffer some loss in acceleration but nothing you will ever notice.

Ignore the N spec rating on the tires you are looking at. The Michelin Super Sports have been reviewed and tested over on Rennlist. The Bridgestone RE11 are very nice too. I running Toyo Proxes1 on my 09 Carrera S on the street and I like them better than the Michelin PS2's I had.

 

thanks guys.

Been very informative this thread.

Hope it helps other people who might query this when the change for tires beckons!


Here is somthing i found out and hopefully it is more clear to anyone who wants to know.

I got this from Pistonheads,

"Correct - the Carrera Sport wheels are 1/2 inch wider both front an rear 8.5" F / 11.5" R vs 8" F / 11" R for the standard Carrera / Carrera S wheels and Sport Design option. For narrow body cars, the rear offset is the same at 67 mm whilst the front offset is reduced very slightly to 55mm from 57mm (to move the wheel slightly outboard). For wide body cars, the rear offset is reduced from 51 mm to 50mm; the front offset being reduced to 55mm from 57mm like the narrow body cars. As well as allowing for the fitment of wider rear rubber (305/30 vs 295/30) the combination of wider rims and different offsets bring the outer edges of the rims closer to 'flush' with the bodywork and give an appearance of better filling the wheel arches. They look even better with the Porsche 5 mm spacers (or aftermarket 6 mm or 7 mm). Any more and the rear wheels start to sit outside the line of the arch.

305s can be fitted to the standard 11" rear rim size (as they are on wide body cars as standard) but 295s will be slightly 'overstretched' on an 11.5" rim and consequently aren't recommended.

Ian

"
http://www.pistonheads.com/gassing/t...Michelin&mid=0