dekan513

im wanting to run a 315/35/17 on my car its base fenders still. has anyone ran the 50mm offset zr1 wheels. ive looked and found a few but the info is confusing as hell. lol

HOXXOH

Without knowing a little more about your car and the reason you want to use those tires, it's hard to respond. Your profile shows nothing.

Year, trans, HP, tire brand and model, and intended use are just the main things to get started. More info never hurts either.

dekan513

i just need to know if they fit. i need a wider tire cause im blowing off et street bias plys . 26x11.5x16. i do alot unprepped races so a bigger foot print would help.

175 shot cammed stall ls3 2008 base body panels.
making 65x/69x , stock trans. headers cai . 2.56 gear.

but i just need to know if anyone has ran a 17x11 zr1 wheel on a base car. or fit a 315 on a 9.5

HOXXOH

A 315 will fit on a 9.5, but if you intend to drive it on the street, those who have tried it, say it'll rub the fenders. It'll get by at the dragstrip, since there are no bumps and no curves.

Wide tires have the same size footprint as narrow ones of similar construction and pressure, but the shape is different. The maximum traction is in the same direction as the shape. If you want sideways traction, go wide. If you want forward traction, stay narrow.
You can get a bigger or smaller footprint by adjusting pressure, which lengthens or shortens the forward traction footprint shape.

You might be better off using a 295/45R17 on a 9.5 wheel. It's taller and you have the HP to turn it. It has a taller sidewall to flex and create an even longer footprint at the launch. You won't need to lower the pressure as much to get good results and it'll extend your 3rd gear speed into the high 130's or low 140's depending on the shift RPM.

This stuff is covered under the tire size selection chapter in Racing 101. Tire compounds are discussed in the second semester. JK

dekan513

right now with a 26.2 tire i shifting to 4th @ 140. car should trap 142 or now so i need a 27" tall tire really
but i really like to run a 315 for the no prep airport races and stuff. then get new tires for my 16" wheels and keep that setup for the track

HOXXOH

140 MPH in 3rd with 26.2 tires is a taste over 7K RPM. If you don't want the 3-4 shift (the weak link for A6 trans) to happen, taller tires or more RPM is required. Christopher Martin can tell you more about the A6 strength and HP.

A 315 at 142 MPH in 4th gear means you'll finish at barely 5400 RPM, which is at the low end of your power band and the traction will still be limited by the footprint direction. Stock tires on a Hellcat are 275's for a reason and that's for forward traction, not auto-X.

Do whatever you want, but at least investigate the science and math to get the right stuff for your application.

dekan513

shift point is about 6800 right now. but ill spin harder if needed. but what im getting at is for unprep u need all the tire u can get. no worried about the track i have 16" for that.

HOXXOH

And what I'm saying is that wide gives you the same square inches of footprint as narrow. The direction of the shape is what's important.

It's physics, but think of it this way. If you want to run, do you point your feet forward or sideways?

Plaincoupe

Not mine but those are 17x11s....

subfloor@centurytrans

It is/was mine.

The 17x11 will fit great on the track and not rub, but don't try driving them on the street as it won't take much of a pothole or dip in the road for them to hit the fender.

dekan513

if i want traction sideways lol.
i just went ahead and ordered race stars 9.5 . and gonna run a 275 or 295 tire. cause some of the places i race is got some humps and bumps. airports and such.

Petr702

what offset are/were those?

subfloor@centurytrans

Not sure, but it's whatever the offset is for a 95 ZR1.

Petr702

the offset for those is +50 .. I asked on the general section and people were saying you can’t run 17x11 with a +50 offset on a base C6 lol but here there are people running them . Did you have to do anything special to have them fit? Your set up is what I’m aiming for

subfloor@centurytrans

Nope, just bolt on and go.

The 17x9.5 works just as well as I was cutting 1.33 60ft times with them a couple weeks ago.

Petr702

between those two sizes, which would you recommend for some street driving as well?

subfloor@centurytrans

Probably the 17x9.5 but the 315 tire width is gonna cause you problems regardless of the rim width.

fashcham

Hey man, I was looking at options - is this similar to what you have in that photo?
Corvette Wheel - ZR1 Rim - CV01 17x11 Silver Machined Corvette Rim (oewheelsllc.com)

When you say there would be issues on the street running 315s for the base, where would the rubbing be? Is it because it's too tall for the fender or too wide and will be rubbing against things on the inside of the wheel well? I'm only planning to run these at the track.

subfloor@centurytrans

It's a little too wide to fit completely inside the rear quarter panel. You'd be fine at the track but the lip of the panel would make contact with the tire if you hit a pothole or dip in the road.

fashcham

I see, ok that makes sense. Is that even with the 1.2” smaller total diameter on the 315/35s? I guess if you hit dips and potholes the extra room wouldn’t matter if the tire is outside of the fender.

Would a 17x9.5 and 275/40 offer comparable traction? I would imagine a setup like that would still be inside the fender?

Thanks so much for your feedback.