New Rims..dove head first off cliff

[SleeperZ]

Tire width is not the governing factor in grip. Tire compound is. The Z nuts I know that regularly run around the road course usually use 205 or 225 width on all 4 corners. The tires they use are sticky - BFG R1 or Toyo Proxes. A 205 width R1 will rule over any street compound no matter what the width.

 

If you go too wide you may lose traction because the tire compound will not heat to it's optimal temperature. There is an optimal width for whatever tire compund you decide to use, depending on the weight of your car, and the type of racing you do.

 

Of course, this is MO.

[ZR8ED]

I agree SleeperZ. The R1's are the way to go, but this thread has gotten a bit mixed up tho.. I do take this car on the track, but it sees most of its use on the street. I even drive it work when the weather is perfect.

 

I do run the Victoracer 700's on the back, but I do this because it is the widest low profile 16" tire I can find. I only bought them to fill my deep flares. It happens that they grab the pavement something fierce, but they are not suited for driving regularly...They are terrible for picking up stones, sand, etc and chipping my new paint job. let alone the short tread life.

 

I need/want street tires to be able to drive the car more regularly. Thats why i'm going for such a wide street radial..also for looks...my flares are mighty big, and are not easy to fill up.. 8)

 

I figure the Yokohama AVS sports will do well in the dry and the rain, and will do well on the track...I don't believe I will maintain that wicked hookup I enjoyed with the track tires out back.

 

But its a compromise..performance always is..

[Mudge]

My point is that going too wide for the wheel will cause sidewall rollover and cause loss of grip versus a smaller width wheel. The most serious road racers I know, and setups I come across all follow this rule. The older Supra racers likewise go from thier stock 225 to a 205 tire because of this rollover, on a 7" wide wheel.

 

I would love 225s but wont do it without more wheel. Some people try to compensate by running very high PSI, like the Camaro Mustang Challenge guys running 44 PSI I believe on 255/50 on a 16x8" wheel, they wont last as long as if they were on a 9" wide wheel either of course.

 

I am not an expert, and I am quite positive Ed you have more experience than I do, I just wanted to understand why. I wanted 225s also but was told to avoid it for these reasons, and I have a lengthy explanation from an SCCA/NASA/Open Road racer if you'd like me to post it.

[ZR8ED]

I understand what your getting at.. "Proper width tire/width of rim ratio"

 

Following the mfg ratings for range of widths of tires for rims is critical.

 

As far as pressures go for street tires, if your running on the track you would like to see the proper width of tire for the rim, so you can run max pressures to prevent tire rollover.

 

I have typically run max or very near max pressures on the track. Heck I used to run 40psi on the street with my Yokohama AVS 225/50/16's... never saw roll over. I still mark the tire with a bit of white shoe polish to measure tire roll over. Though I do it to protect my tires, as they must last several summers, not always for maximizing my contact patch.

 

 

I have used a set of slicks from a friend with 275/35/15's on an 8" rim no probs.. hang on like a SOB.

 

You can run up to a 245 on a 7" rim..depending on the profile/tire type... though I agree not a good ratio for track use.

 

My 9" rears said no smaller than a 245.

 

Again different tire mfgs have different specs as well..

 

I checked my tire/wheel combo well before I purchased this set of rims. Its been tough finding a tire to match a particular rim width... I had to find a rim width that would fit the size of tire that would fit in my car.. (width and total diameter)... even the fronts were not easy.. Diameter of the tire has been my biggest stumbling block. anything over 26" WILL NOT FIT. I'm running pretty close, and I can see myself tweeking the suspension or flares a "tich" thats how close its gonna be.

My front tires miss my front edge of the wheel well/airdam by approx 1/8" at rest.. obviously under compression there is more room...oh and this is during turning. when going straight, they are inside the wheel well completely.

[Mudge]

I'm glad you know what your doing then I wish I could stick some 275s on the car, man that would be some serious STICK I'm worried about breaking stuff, which is why at one point I thought C4 stuff front/rear, but who knows if/what and when will happen. I will be stuck with 15x7" for awhile.