I will be installing the ROW M030 supsension on my 99- C2 coupe mostlikely next weekend.

I plan on getting new tires and a alignment too, but can't decide which size I should run on the back... (I have 18" stock rims)

1. Which would you choose and why?
2. Do you have any suggestions on alignment specs as well?

Paul

 

Mine came with 265s and I replaced them with 265s twice. The 3rd time I went with 285s and I will never get 265s again. The 285s look nicer on the rim and instead of being too narrow for the rim they look just right. If you ever look at the front and rear tires on your car you will know what I mean. The 265s look like they are too narrow and appear stretched onto the rim. The 285s fit right and also allow the rim protector bead to actually protect the rim.

There is a slight problem though. The issue is with the front wheels. If your car came with 265s then you are supposed to only replace them with 265s. Not because of the rear rim but because your front tires and rims are matched to the 265 rears. Installing 285s will upset the handling characteristics of the car. In order to upgrade to the 285s properly, you are supposed to change the front rims to a 1/2 inch wider version. I didn't bother because I don't track my car. Just be aware that there is more to it than just changing to the wider rear tire.

 

I went to a 285 after my first set wore out on my 2000, it would be good to upgrade the front wheels to 8" as they are only 7.5" for 1999-2000..this way even though you will be wearing the same tire size in the front you will expose more tread to the road on a wider rim and even out the f/r size difference to avoid understeer issues...

 

Hmmmmm,
Is there a way to measure my front rims with out taking them off?

 

The size is stamped on the outside '8J' means 8 ", when I put my snows on 265 rear down from 295, my cars handling is off the wall, the awd is constantly correcting itself front to rear, it's a weird feeling.

 

Paul,
If you have stock wheels, the fronts are 7.5", rears 10". The sizes are listed in your owners manual.
I have standard Turbo Looks on my car and the wheel size and offsets are not stamped in a visible area (as they are on many Porsche wheels). I measured my wheels with a carpenter's tape to confirm that I have 7.5's in the front. I kept 265's on my rears. 285's cost about $30 more per tire also (for Pilot Sports). I suppose 285's coupled with the 7.5's on front might increase understeer slightly, but you could probably compensate by reducing rear tire pressures. I am currently running 36f/40r anyway to help with understeer until I get the Row installed. Then, of course, will have to re-evaluate front/rear pressure stagger.

Have you recieved any shipping info on our group buy Row 030 from Rick @ Suncoast?

 

Rick only charrged me $47.33 to ship to San Diego, California.

 

Go with the 285. If understeer is a problem, either change out the fronts to 8 or 8.5 inch rims and put 245-35's on them or get a larger sway bar. I can't imagine increased understeer being a problem with a rear-engined car; the Boxsters are more sensitve to understeer-oversteer changes.

FYI, here's a pic of mine with 285-30 in the rear and 245-35 in the front. The Dunlops run very wide, so the the 285's measure out to a 295 tire section width and the fronts measure out to a 255 section width.



Bruinbro