Potomac-Greg

Depends on whether he is buying them for the track and if so what the rest of his setup is. He could go 235/235 if that was a concern. It will look very nice. 944s look great with fat rear tires, even if they're not needed!

I have the same wheels with 235/255s -RA1s- (not optimum but they came with the wheels) and while understeer might be the ultimate result, the car is very "workable" with the throttle. It's been a good learning tool; and when I wear these RA1s out, my phone dials will become my track wheels.

harrisonrick

you may need an 7-8mm spacer on the fronts to clear the bearing caps....

Tom R.

235/255 is the same as 225/245, which is different than 225/255.

dont forget longer studs.

TRWright

He does NOT need spacers. I have run those same wheels on 2 different late 944s, so this is firsthand information.

Those tire sizes are not ideal, as Tom says.

PorscheDude1

I think you need the spacer for the center cap to clear the bearing cap. Otherwise no spacer needed.

harrisonrick

you really don't need longer studs for up to an 8mm spacer.

JohnKoaWood

Well, I believe I have chased down the squirrel, so next on to the wheels, I am planing on going 225-45-17 on front and 255-40-17 on the rear.

This will have a .325mm difference in the sidewall from the front to rear, and will maintain the stock front tire width with the nice FAT rear tire look, I use the car for a daily driver and while I would love to track it, I simply do not have the time....And for daily driving I want form over function, but the additional traction in the rear will be fabulous as I quite frequently end up sideways due to loss of traction in the rear.....

I was thinking Eagle F1s, anyone have any experience with these for daily driving? Suggestions? Ideas? Recommendations?

Tom R.

you will get form over function for sure.

you dont have to track a car to get understeer. all you have to do is turn the wheel.

i use 225s all around and have 50 more hp than you in my S2 and dont get sidways on the street unless i am doing something stupid. dome to think of it, the only times i got sideways on the track was when i did something stupid as well.

Potomac-Greg

True, but the size of the front tires will determine WHEN you get that understeer. Understeer is just the dynamic that occurs when the fronts run out of grip before the rear. If the fronts are grippy, but narrower than the rears, you'll still understeer, but at a substantially higher speed. And if you have good tires in 225 width, and you're understeering on the streets, then you're probably better off taking it to the track.

JohnKoaWood

With a good alignment, stock suspension setup, and mild changes to the engine I seem to have little issue with breaking loose the rear in 2nd and can slide the rear on wet pavement in 3rd as well, have to take care in 1st and 2nd when the pavement is wet, or it will definitely spin the rears, but this is with POS continental tires that came on the car when I bought it a year ago, 225 width front and rear now hence I am going to put on the same width fronts, same offset on the wheels should retain my front end setup as is..

The rears 225 is allot narrow to put on a 8.5inch wheel don't you think? I think the 255 would look much better and should provide me more contact area to prevent the slippage, granted I will have to watch out for hydroplaning, but then I have to do that now...

Like I said this is my daily driver, not a track car, were I using it for the track I would have 4 corner adjustable coil overs, soft compound track radials, solid bushings, and anti sway bars, no torsion bars adjustable camber plates, strut tower bars, a full cage...and then there is lightening, but that is a different thread.... For now I am looking for a set of tires to make the new rims get on my car, but then I guess bald Pirelli P Zeros might hold better than the POS tires on the car now...

on a side note tire spin is caused by torque not horse power, horse power determines the top speed, torque determines how fast you can reach the top speed...or how easy it is to spin your drive tires.

Mike Buck

what aspect ratio's Tom? 245/40 is shorter than stock, 245/45 taller. what will that do to the handling with a rearend sitting lower or higher than the front.
225/45 and 255/40 preserves the correct diameter front and rear. the understeer/handling issue is moot. my $.02

you don't need a spacer to clear the bearing cap with those wheels. other style boxster or 996 wheels yes, but not those

JohnKoaWood

Hence my intent to use 255/40 rears and 225/45 fronts....keep within .5mm of the stock height and only pick up 6 rotations of the rears per mile...

Tom R.

no, you are incorrect.

the 225/255 setup you described will have more understeer than a 225/245 setup.

the most neutral for our cars is the same size all around. the greater the difference in width the more understeer.

this has been debated ad nauseum here and on other sites. ROW cars had the same size tire on all four wheels. the factory staggered the wheels and tires for the us maket because they didnt feel like getting sued by the dentist trying to impress his receptionist....

the reason i suggested 225/245 in my first post is because 225 is about as wide as you should go on a 7, and 245 is about as narrow as you should go on a 8.5.

the 225/245 setup will have less understeer than a 225/255 setup with all four tires the same height.

JohnKoaWood

My only reservation is the rear end kicking out now is an indication of oversteer correct? hence the wider tire will introduce understeer, and just might get me to the place I want to be...neutral for street use...not track use...and for the record my car has the same size tires on all four corners right now (225/50/15 on OEM phone dials) I will be sure to follow up with before/after/use notes as we go.... Right now I have wicked oversteer...hence corners are not much fun because with little effort my rear end is coming around and while drifting has its place, it doesn't belong on my daily commute...

Tom R.

you shouldnt have oversteer with four tires the same size unless there are other modifications to your suspension, or something else is out of whack.

going 225/245 will add some understeer, going 225/255 will add some more understeer.

what you and another poster are ignoring is if it understeers on the track it will understeer on the street. what do you want? neutral or understeer? understeer feels like a plow. my brother likes the feeling. makes him feel secure. i dont, makes me feel like im driving a plow.