Will a 255/40/17 Fit the front of a 88 944?

[Racerbvd]

I'm about to order track tires for my 88 944 with coil overs. I ha9x17" Cupids, 55et.
Will the 255/40/17s fit up front?

[Racerbvd]

[walfreyydo]

On the inner side, harder to tell, but it looks like by your photos you have like at least 1" additional backspacing clearance to the spring seat with your current wheel/tires. Not sure how much additional distance you have to the outer fender.

If possible, measure where your current tire sits, both inside to the spring seat and outside to the fender. Figure out the width/offset of your new tire/wheel and determine how much more the tire/wheel will sit inward and outward. Then you can understand how much room you have and how much room you will need and make your assumptions based on that, leaving an additional 5 to 10mm of contingency..

If you know you have 1" of backspacing available with the same wheels but at a 225 width tire, moving to a 255 tire will require approx 15mm on each side additional (which is about 0.6") which means youll likely have enough backspacing to fit. Now do the same calculations on the outer fender. If those photos are different wheels with different offset/width, then the calculation gets more complex but still doable. Its important to fully understand how wheel offset works to do these calculations, because a 8" wheel and 9" wheel with the same offset wont sit in the same place (forgive me if you already know this).

Sorry I cant be more helpful but I havent run that tire/wheel combo before. When looking at whether wheels/tires will fit, I always make those decisions based on my current wheel/tire combo (as a baseline) and run calculations based on what the projected size will be based on wheel/tire width, offset differences from that baseline, understanding how much further out or in the tire will move. I then compare the changes from baseline to the current gap between fender and spring seat that I currently have to determine if it will fit, and how close it will potentially be. After that, look at spacers or camber adjustments if needed. Too close to spring seat but plenty of space to outer fender? Run spacers. Too far out to tuck inside the fender? Run more camber (to a limit of course).

[Racerbvd]

Thanks, I took the risk, as I bought the set of 4 9x17s for the 968, and the guy I got them from was running them on a 951, but I couldn't remember if he said he was running 245s or 255s. Since he was running the same coil overs I had on the 968, 944S and 88 944, I figured there wouldn't be a problem.
So I ordered a set of 255/40/17s, and told them that I want to make sure of the clearance before removing the other 3 wheels. Well, since they hadn't mounted the tires when I got back for my appointment (I dropped the wheels off yesterday, and actually stopped by earlier to have the spare for the Featherlite checked) I went across the street to Ruby Tuesday for lunch. The tech called and said that they are hitting the fender liner, so I walked back to check it out, he didn't notice that I had 1" spacers on the front to kick the 7s out. So after they removed the spacers, they fit with no issues, even at full lock. Glad they worked as now I don't have to brea the street set up for 225s
Again, 255/40/17 993 Cup II 9x17, 55 et, does fit the front of a 87 and newer 944, but mine do have coil overs and I am sure the smaller diameter of the springs help.


No rubbing on the inside.

[Racerbvd]

Day number 1 in the books, and no tire or any other issues at the track.




Great day so far.