[Z06] 315 on 9.5s
05-23-2016, 10:27 PM
#1
Intermediate
Thread Starter
315 on 9.5s
To all who are running 315/35r17 Hoosiers on c5z fronts. How do they handle at higher speeds? I've only read one thread where someone said it got a little unnerving. My car is around 600 whp thinking they would be the better option?
05-23-2016, 10:38 PM
#2
Pro Mechanic
Pro Mechanic
A 9.5-in wheel is not wide enough for a 315/35ZR17. You need 11-in or better.
With 600 at the wheels, you need the Z07/ZR1 tire package.
With 600 at the wheels, you need the Z07/ZR1 tire package.
Last edited by Hib Halverson; 05-23-2016 at 10:39 PM.
05-24-2016, 01:00 AM
#3
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I assume you're only running the Hoosiers at the track, so the speed will likely never get to 140. Yes, they won't be as stable as 275's, but you're going straight. Since it seems that 600hp is the point where most make the change in width, they also drop the pressure a couple pounds to maintain the footprint shape and that's what causes them to be less stable. If you can still hook with 275's, there's no need to switch.
05-24-2016, 08:59 AM
#5
Lots of people run this combo. I ran 315/35s on 9.5" myself until I swapped to 335/35 on 11". I wouldn't want to be shifting to 5th gear on this combo (155+mph) but it works great at the track.
Last edited by Hanlon's Law; 05-24-2016 at 12:03 PM.
05-24-2016, 11:54 AM
#6
I'm running this combo at the track and on the street. Been 150 on the street and felt fine to me. See video below
Just make sure they put the wheel weights on the lip of the rim. The stick on ones would hit my brakes.
Just make sure they put the wheel weights on the lip of the rim. The stick on ones would hit my brakes.
Last edited by BOTTLE FEDvette; 05-24-2016 at 12:10 PM.
05-24-2016, 02:51 PM
#7
Supporting Vendor
05-25-2016, 02:01 AM
#10
05-25-2016, 01:24 PM
#12
I've done as low as 16psi hot in the hoosiers. It did feel a little unstable at the end of the track at that pressure.
05-25-2016, 01:47 PM
#13
05-25-2016, 03:53 PM
#14
Supporting Vendor
05-25-2016, 05:01 PM
#15
Racer
I had that exact same combo on the C5Z front rims. It trapped at 139 and they felt great. I realize that this is not the ideal rim width but it worked on my combo.
I ran about 18 psi on them.
I ran about 18 psi on them.
05-25-2016, 10:31 PM
#17
Does this tire combination actually use all the contact patch on the 315? Or is the 9.5 wide rim to narrow meaning were only really using like a 295 or 305 of the 315 tire?
05-26-2016, 01:50 AM
#18
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However, the shape of the patch will change. It gets wider as the tire gets wider. Traction is greatest in the same direction as the longest side of the patch. A long front to rear patch provides better straight line traction, while a long side to side patch provides better traction sideways.
What happens when you launch at the dragstrip, is the weight transfers to the rear and therefore the patch shape gets a little longer front to back, since the tire width won't change. Reducing the pressure also increases the front to rear patch shape. Increasing the tire sidewall allows the tire to flex, aka wrinklewalls, which adds even more front to rear length.
The bottom line is to run the narrowest tire with the tallest sidewall at the highest pressure that will still hook. Light weight and sticky compounds are bonuses.
05-26-2016, 09:58 AM
#19
With little exception, the contact patch will remain the same regardless of the tire size as long as the pressure and the car weight doesn't change.
However, the shape of the patch will change. It gets wider as the tire gets wider. Traction is greatest in the same direction as the longest side of the patch. A long front to rear patch provides better straight line traction, while a long side to side patch provides better traction sideways.
What happens when you launch at the dragstrip, is the weight transfers to the rear and therefore the patch shape gets a little longer front to back, since the tire width won't change. Reducing the pressure also increases the front to rear patch shape. Increasing the tire sidewall allows the tire to flex, aka wrinklewalls, which adds even more front to rear length.
The bottom line is to run the narrowest tire with the tallest sidewall at the highest pressure that will still hook. Light weight and sticky compounds are bonuses.
However, the shape of the patch will change. It gets wider as the tire gets wider. Traction is greatest in the same direction as the longest side of the patch. A long front to rear patch provides better straight line traction, while a long side to side patch provides better traction sideways.
What happens when you launch at the dragstrip, is the weight transfers to the rear and therefore the patch shape gets a little longer front to back, since the tire width won't change. Reducing the pressure also increases the front to rear patch shape. Increasing the tire sidewall allows the tire to flex, aka wrinklewalls, which adds even more front to rear length.
The bottom line is to run the narrowest tire with the tallest sidewall at the highest pressure that will still hook. Light weight and sticky compounds are bonuses.