Got the pics of the 17x10, 315 wide setup

[Mikelly]

But Clifton, think about it for a second... Doing an autoX, where the loads on the tire/bead are much lower than you'll experience at 110MPH on an offramp, or and 100MPH hammering 3rd/4th shifts, you won't have nearly the "risk" of a tire breaking a bead and coming off the wheel.

Add to that the less than optomised feel from sidewall deflection and you have other issues... Can you run that tire? Sure. Should he? I wouldn't let anyone I car about do it.

 

Over on another BB right now there are guys having serious problems with a specific brand of tire rotating on the rim under braking and acceleration during track days. There is some discussion as to if it is a tire to rim fitment issue or something more. And these guys are experiencing this at above 150MPH...

 

When it comes to tires, I tend not to want to experiment to much beyond manufacturers guidelines.

 

 

Mike

[Clifton]

I think there's quite a bit of lateral force on a tire/bead at auto X. The lateral force would pull a bead if anything but I don't know if running a wider tire increases that chance.

 

I would agree that running a tire within the recomended width gives the best contact patch though.

[Mikelly]

Ask the manufacturers of your current tires and wheels and see what they tell you...

 

Mike

[Gollum]

I would like to see video of an 85 mph wheel spin with only 305 lbs/tq.

 

I've seen turbo honda spin tires at 100mph, and with only 2 liters of displacement I seriously doubt they have more than 300 torque. But thanks to RPM they have 500+ hp, and very low weight on their tires.

 

Remember, HP does mean something. If it was only torque that spin tires and RX7 (without an LS1 ) would never be able to do a burnout.

 

Get an engine that's more RPM based than Torque based up to it's redline, and with a strong clutch those tires WILL experience a ton of load.

 

But lets get our facts straight though. When 1 fast z was at 17 pounds pushing 475hp, he was at 402 torque. If he's talking about how the car is feeling as good at 12psi as it used to at 17, then I'm betting he's in the same torque/HP range.

 

This isn't a torqueless motor, and he's using turbos that the engine should have no problem spooling. I think spinning the tires at 85mph shouldn't be a testement to the amazing torque, RPM, or lack of tire, but rather a good strong clutch that makes it all happen.

[Daeron]

It all comes down to this, with emphasis added to the two important points.

 

Can you run that tire? Sure. Should he?

 

....

 

When it comes to tires, I tend not to want to experiment to much beyond manufacturers guidelines.

 

 

Mike

 

and that is the wisest advice ever given by a car guy.

 

I look at tires in the exact same light I look fishing line. These things are the definition of "by the book" selection. "What am I trying to do, with what equipment, and how do I want it to perform?" Given the answers to those questions, there is a precise numerical designation for your selection. Using my 7 foot medium light baitcaster with an Ambassadeur 5500 on it, I opt for 12# test in high wind or low lure/target fish weight conditions, and opt up to 14# test if I plan on bait fishing or potentially meeting up with a tarpon. Tire size should be decided based on A: desired outside circumference B sub1: Desired tread section width Bsub2: wheel width C: wheel diameter (for sidewall sizing considerations) then D: tread compound.

 

Will the tires work? Frequently. However, there is only a narrow range proper selection given the wheel size. Anyone who doesn't understand why would do well to learn more about it, because it is a fairly simple topic. The reason I made the fishing analogy above is because there are more similarities.. My fishing line is a thin bit of plastic that connects me and my expensive tackle, to the fish I so desire. It is the weakest link, and it is in fact tiny; so it needs to be sized appropriately and used in the right manner. The four little contact patches underneath your car, transferring all of your power and control, are equally tiny bits of rubber. Every effort should be made to maximize their performance, or you might lose contact not with some stinky fish... but with the asphalt. That can leave you in very close contact with cement, or other tires, or orange barrels, or other vehicles... depending on venue. It is a risk not worth taking ignorantly. If you take it, you should be fully aware of what you are doing.

 

 

for the record, at this point a post like this is no longer directed AT the OP of this thread; its more for anyone who might be reading it through for the first time and failing to understand Mikelly's warnings.

[1 fast z]

Tires have thousands of miles on them. DEFINITLY no rubbing, there are some Videos of the car at MSA autocross floating around somewhere, that can show that. I actually have room on the inside to move them in if I desire, but I wanted to fill the flares. Am I saying they are perfect width to width ratio, no. Am I saying they work perfectly, and hook nice for what I paid, yes. Car has seen 165+ MPH, with no ill effects.

[JustinOlson]

Car has seen 165+ MPH, with no ill effects.

 

Is that why you're not driving?

[Mikelly]

Car has seen 165+ MPH, with no ill effects, YET.

(tick tick tick tick tick)

 

Fixed that for you...

[1 fast z]

Since the thread is alive from the dead, Ill update the photos.

 

 

 

 

 

 

 

BTW, I Have found some 10.5" wheels, that I might by now, so that will give me a .25" per side

[1 fast z]

No, I am still driving, for another month or so, till sentecing comes . I was in a z car though, but was not speed related, and my lawyer wont let me say much more to the public, untill after I am finished with my case.

[JustinOlson]

What style wheel are you looking at?

[1 fast z]

 

[Mikelly]

Those look very similar to the TSW I'm running...

Mike

[johnc]

Doing an autoX, where the loads on the tire/bead are much lower than you'll experience at 110MPH on an offramp, or and 100MPH hammering 3rd/4th shifts, you won't have nearly the "risk" of a tire breaking a bead and coming off the wheel.

 

Actually, not entirely true. Autocross cars will typically see higher transient lateral G loads then cars on a road race track. Because of this its not unusual for autocross cars to bicycle in certain situations. Road race cars will see slightly lower lateral G loads but for a longer duration. Both situations can lead to tire/rim separation but its actually a very rare event in both disciplines.

 

Regarding tire and rim width recommendations. Tire manufacturers "offcially" recommend rim widths based on a DOT regulation/formula. These recommendations are required by federal regulation for street driven vehicles.

 

Both Hoosier and Kumho race support trucks will mount 285/30-18 tires on 8.5" wide wheels at autocross and road race events. Hoosier will mount the same size tire on 8" wide wheels but you better give the tire busters a C-note or your stack will always be "the next one" to get done. You're not getting the most out of the tire and your own testing is needed to prove its worth a little bit of time.

 

FYI... Jason Isley's three time BS champ RX8 runs 245 V710s on his car, not the 285s. His testing (and he's done a lot) shows that the 285 Hoosier on a narrow rim doesn't work for his car and driving style.

[AkumaNoZeta]

I have a question regarding this. Would an ET Drag Radial such as this http://store.summitracing.com/partdetail.asp?autofilter=1&part=MTT%2D3795R&N=700+4294923107+4294922134+4294921520+4294757567+115&autoview=sku have a higher chance of unbeading itself from the wheel in a corner?

[1 fast z]

I have had numerous autocrosses and track days, and lots of hard driving, and NEVER had a de-bead.