Anybody run 17x11 and 315s on a 94 'vert?

I keep hearing "You can't/yes you can.....You can't/yes you can." Can anybody help a brutha out here with some absolute facts? Thanks.

 

I'm not sure about that one. Find someone who knows what they are doing at your local tireshop (good luck) and see if they can tell you.

 

AFAIK, the differences between the coupes and verts is over-blown, and many guys with Z28 'verts have installed 17x11 (+50mm) ZR1s with no more modification than guys have to do for their coupes.

I used a little hammer action to gain clearance in a few critical spots on the inner fenderwell, and ground off a chunk of the bumpstop+bracket. I'm waiting on an adjustable Panhard rod to centre the rear end now, 'cause it ended up being out by a little bit - that was never apparent with the 16x8-245's but looks a little goofy with the 315's.

Check out this thread and especially this thread. Fred (Injuneer) knows his stuff... pay attention to his posts in those threads.

From everything I've read, though, there seems to be quite a bit of production variance from car to car... so your results may vary.

 

If somebody is telling you NO then my car must just be a figment of my imagination. LOL!

Not only am I running 17x11s with 315s but the car is lowered about 1.5 to 2" as well!

94Z convertible...

http://www.brentfranker.com/gallery/album80

 

Ditto.... a friend of mine had a 30th SS Convertible with genuine GM Grand Sport 17x11 wheels, and he had LESS problems with fitment than I had with my coupe. We were both running BFG 315 DR's.

I spent a lot of time under the 97 convertible, including pounding the wheel wells for 28x10.5-15W slicks, and there was no difference in the external dimensions of the wheel wells. There was some added reinforcing in some spots, but it was BEHIND the fender liners, not in the wheel wells.

I will agree with Brent 100%.... 17x11 50mm offset wheels will fit on your convertible with no more problems than on a coupe. Of course that means either a coupe or a convertible MAY require some inner panel pounding, cutting the edge off the jounce bumper bracket, recentering with an adjustable panhard rod, and rolling the edge of the fender lips..... its a crap shoot that varies from car to car, but its not dependent on whether its a convertible or coupe.

 

Brent & Fred...

Do you guys know why all these wheel manufacturers keep perpetuating this myth????

I realise that (at least initially) the convertable SS's and WS6's didn't get the bigger 17x9-275's from the factory like their coupe counterparts - due to chassis flex concerns on GM's part. Are the wheel makers just assuming they won't fit?

 

I don't know??? I have seen this information on the AFS website. However, they also give a "special procedure" on how to install the 17x11 wheels to avoid the wheel from contacting the bump stop bracket. While I know many people do this, it just seems like a "bad idea" because you could go over a hill or bump or something too fast and cause your rear end to become light/airborne and then you have the same problem... your wheel contacts this metal bracket and, well, yuck!

 

Was this due to chassis flex or ride comfort? I had always thought the reason the 16" wheels (on IROCs) and from what you are saying the 17" wheels on SSs weren't available on the convertibles was due to what GM considered too "harsh" of a ride (less sidewall) when combining these larger wheels with the stiffer convertible "frame". By having a larger sidewall they thought the ride was improved. I could have just had a dream about that though and am talking out my buttocks.

 

I'm with Brent on this one too... I thought the issure was ride comfort. But I guess you could extrapolate the larger sidewall idea into putting less stress on the chassis as well.

Just to ease your concerns, the 30th SS convertible in question had no problems with excessive chassis flex, and it was running 8.60@160mph with 1.30 60-ft times, and more than once was dropped hard from a 4-foot wheelstand.....

 

Well, just slap me if I don't love you guys! It sounds like the dreaded "Oh, you CAN'T put 315s on a 94 vert" is jive. Seriously, thanks a ton for the clarification.

My car was just on a lift and I was walking around under the rear wheelwells thinking, "Man, what's the deal......looks like at least as much clearance under here as a coupe." Sounds like I was right.

So while we're at it, anybody have experience with the Cragars, or should I just get the Torq Thrust IIs and be done with it? Retro-muscle, baby!

BTW, did I ever tell you guys that my first car was a '68 Shelby GT500 vert 4 speed? Ford 427 LeMans motor with serious mods. Learned to drive in that car. Basically, my current project is to make my Z feel like that big block. I'm gettin' there.

 

One more thing. Would you guys with 315s on a 94-97 vert mind giving me your exact offset and backspace, or just what wheels you run/ran and tirebrand and I'll find the numbers myself. I'm thinking the slight variations in offset, backspace and tire dimensions might explain why some say "yes" and some say "no". Thanks a ton for the help.

 

Mine are the AFS wheels...

2-17" x 9.5" (+56mm, 7.4" backspace) front and 2-17"x11" (+50mm, 7.93" backspace) rear. They are 5-lug (5x120.65mm).

 

Yeah... I think ride quality sounds a lot more intelligent than chassis flex, as the reason GM didn't use the 17"s on the convertable. I do seem to remember that 3rd gens had limited tire/engine/suspension choices, when you went with T-tops though, and chassis flex was the (supposed) reason. That's probably where I came up with the chassis flex theory. I don't think the 3rd gen T-top versions got the same frame stiffening (X-brace?) that the 'verts did.

 

My AFS's have some slight damage to the insides because the guy I bought them from didn't grind enough off his bump stop brackets. I made sure that I took plenty off of mine. It's easy to get enough clearance without compromising the strength/function of the bumpstop, so I don't know why anyone wouldn't do it.

 

I agree.... seems like common sense.

A little rubberized undercoat and you'll never know its been ground down....
http://cjcfo.fbody.com/members/injun...A/FendMas2.jpg