Anybody know the specs on these wheels. I know they are 17" diameter and I know they are directional to the left or right side of the car, but I was just wondering if they all 4 the same or do they differ size wise front-to-back? Also, I know they make reproductions of this wheel to fit f-bodies perfectly, but will these OE Chevrolet wheels fit either/both/neither my 3rd or 4th gen cars?

I like these wheels, found a nice set at a $$$$$ too good to pass up so I am getting them tomorrow and just trying to see what I may run into. One way or another, they are hopefully rolling on the '98 T/A this weekend!

I believe C4 up will direct bolt to an Fbody from 90 up. I am not 100%, but pretty sure they will fit. I do not know if they were larger in the rear or not.

Matt

I've come across this - it seems there are at least 2 styles of C4 "sawblade" wheels, the standard issue and the ZR1. It seems all 4 of the standard issue as well as the front ZR1s are 17" X 9.5" while the rear ZR1s are 17" X 11". Also, read the backspacing is the same on all four standard issue "sawblades" but didn't find any backspace info on the ZR1 specifics. It has been a little bit since I saw a C4 ZR1 but I seem to remember perhaps a deeper wheel lip inset on the wider rear wheels, that seem right to anybody else? I can't say for sure which these are I'm getting, had forgotten that ZR1 had the same style wheel when I looked at these a week ago. However the guy selling them was really firm disclosing to me that all 4 of these are NOT the same size(he wasn't specific, and I played dumb and unexcitied so as to hopefully keep the price as low as possible) so maybe I am getting the ZR1 fat daddy 11" rears.

Good luck trying to drift on those! LOL

Yeah, right! The drifting will be relegated to the smaller and cheaper to replace 16"s, that is if any drift at all. I seem to have a hard enough time keeping the car on the road driving in straight lines ...

Guess this update is due now anyway - the purchase is off for now. Found what appears to be a bent wheel(not horrible, but the tire doesn't hold air) near the wheel lip/tire bead area. Anybody know anything about straightening alloy wheels? May still buy 3 good wheels from him and keep an eye out for the matching one I need going forward if this one can't be fixed.

Oh yeah, they are all 17" x 9.5", no fat 11s

If you are going to wait for another ZR1 wheel, you could be waiting a long time--they are very rare and hard to find (every Corvette owner wants a set). The rears are indeed 11 inches wide and the fronts are 9.5 inches wide. The Corvette ZR1 had a fatter fender flares to handle the width increase. The back spacing is indeed correct for your car and the front spacing is offset the correct amt. I see no reason why you cannot fit these to the Firebird. However, that said, bear in mind that the increased tire size and cornering loads (who ever heard of driving something like this slowly?) will wear out the rear wheel bearings and axles a whole lot faster. Also, you will have some problems with the tires (315ZR35s) fitting in your wheelwells. For this to work properly, install a Watts Link and throw the Panhard bar away. Once the rear axle is centered, the Watts Link will keep it that way, no matter what the car is doing.

Yes, that rear wheel lip can be fixed. In the back pages of any of the sports car magazines--like Road & Track, there are always a few companies advertising that they can fix a bent alloy wheel and repaint like new for about $100. Good luck.

Ive got 11 inch wide ZR1 rims on the back of my bird.-check out my latest pics in my gallery and theres a few shots, they look good, but are not necessary in any way. They bolt on no problem...every person/car has diiferent experiences

rubbing outerfender lip, solution-roll the lip. This can be done using a channel lock if you really wanna go cheap, or you can pay someone to do it or use a fender roller(google it, it's an actual tool )

rubbing inner fender well-depending upon suspension condition it may rub the inner well. Solution-beat it in with a hammer (its not much area at all usually) and recoat it the well.

some people have many problems, others have a few, others dont have any. Depends on the condition of the vehicle.
good luck



Me too, whats this about a watts link? ive never heard of it.

I'm gonna repeat this MT so please don't forget it. Don't beat in the inner fender of your car. If you already have, shame on you. That area is a major structural element for the rear of the car and the LCA pickup point. If it is beat in, that "work hardens" the inner fender and it will split after a period of time ruining the car body. In order to repair, welding will have to be done. If the tire you have chosen hits the inner or outer fenders, then it is too big for the car and is not safe. Please don't advise others to beat in their inner fenders.

You are risking not only your own life but some innocent person in the other car that you are gonna take out when something breaks.

If you absolutely insist on doing this, then get a Watts Link and bolt it in to permanently locate the rear axle properly. You will also need to buy and X brace to strengthen whole car to prevent damage to the inner fender.

Yeah, I know the C4 ZR1 sawblade wheels are like hardly ever for sale because of rarity and demand. That is why I was excited to think I may have found a set because as I saw them stacked it was obvious 2 tires were no doubt wider than the other 2. As I unstacked and inspected closer, I saw that they are normal C4 sawblades(all 9.5" wide) but the difference was in the different tires. 2 tires are 225/17s and 2 tires are 275/17s, both mounted on 17x9.5 wheels. Anyway, when I say "wait on another single wheel" I meant just another 17x9.5, making sure it was for the correct side of the car(these wheels are directional, the single biggest reason I want them). They are not as clean as the guy stated to me that they were, so I'm gonna hold out for another good set or a reduced price to cover repair or replacement of the 1 bent wheel.

Just to cover an earlier question too, a watts link is somewhere between a torque arm/panhard bar style suspension and a 4 link style suspension. Basically the Watts link centers the rear end by using 2 control arms, both with one end mounted at the center of rear diff then extending out towards each wheel from there. Variations are seen on some heavy duty production trucks and vans currently. This is only good for lateral movement stabilization, the torque arm (adjustable aftermarket preferred) must remain in the system in order to set the pinion angle correctly.

I've heard and seen all kinds of different theories and methods for 10.5" wide and wider wheels under the back of 3rd and 4th gen. F-bodies(on a side note, has anybody heard what the single letter code for the new 7 series BMW is going to be? You guessed it - F-body! Go figure...). MeToo is right, this is a hugely structural part of the car however the inner fender are towards the front of the car is the most common place that clearance is needed to fit a wide Corvette wheel on the back of a Camaro or Firebird. I've seen plenty that have been altered and have yet to see/hear about a vehicle so modified coming apart in such a drastic way. Personally, I don't care about banging on any Firebird body/structure with a hammer in any sort of way, but if it has to be done to a minor manor to fit a set of these beautiful ZR1 wheels, then I believe that'd be OK. The ones I've seen only needed clearance in the fractions of an inch range and I consider that minor. Plus my car already has the X cross bracing welded in so rigidity should be there.

The 11" wide wheels look PERFECT on the back of 4th gens., and I want that look. To make it right and safe, my aging OEM suspension will have to be upgraded across the board(as a system people, that's the key!) but it will not be a track ready car at that point. I honestly don't care anything about the added cornering and overall traction benefits of the wider Corvette wheels/tires, I like the look and stance. Since I'm dealing with an automatic tranny car, all my racing, if any at, will be done in a straight line and the 16s with stickies will go back on the rear. I don't want an all out track or dragstrip car either way, so the suspension will always be something that falls somewhere in the middle.

Each to their own, it's your car but ''a pair of channel locks and a hammer'' sounds like butchering to me. Never do that to my Bird, but if it is actually comprimising the stucture/safety of the unibody of the car, that's a whole different matter.

The problem is what is called "work hardening" of the steel in this area, and it is precisely the area where the F body fails when put under very high stresses such way too much hp and big tires. There is all kinds of info on this on the Internet and various solutions for making it stronger. In fact, I first heard about this on this forum and then immediately checked up on it. I think it was Doug that first brought it up. Any pounding with a hammer in this area will stretch the steel (that's what you are doing by beating it inwards for clearance), harden it, make it brittle and seriously decrease the strength.

The other problem with tires this size is that the suspension was never engineered for it. This size tire needs an independent suspension to keep it from wearing out in the center. Everyone knows how unevenly the 245/16 tires will wear-- the center goes first...well, it gets a whole lot worse with a 315 series tire. In fact, that center wear is what keeps the Firebird from putting the max rubber on the road for good traction in a straight line drag race. The owner will always be better off with lowering the tire pressure a bit and keeping the tires relatively skinny (but the correct height) and getting the stickiest set possible (like Drag TA's). My best tire pressure when the car ran a 12.54 1/4 mile at 113 was with 26 psi rear and 28 psi front.

I talked extensively with Goodyear about this problem. They state that GM went to the limit with the 275/17s and they would not recommend anything larger. Also, lowering the tire pressure to counter the center wear problem becomes counter-productive. If the tire pressure is lowered too much, then the rim becomes vulnerable to damage from potholes and the tire could be pinch flatted. Also, a low pressure tire of that size becomes pretty darn squirrely. The bottom line is that it is the wrong size for the car.

Another problem with this big donut on the rear of the car is that the 315/35/17 is exactly the same height and diameter as the 245/50/16s and that means that it has nearly the same volume--that also means that at the same tire pressure, it will put exactly the same contact patch on the road (Newton's Law here). However, the usable contact patch will be smaller than the tread width, becuz most of the force will be exerted on the center of the tread.

The Watts Link is a partial solution to the problem, becuz it positively locates the rear axle side to side and lowers the roll center. A Torque Arm must still be used. Here is a website for those interested:

http://www.fays2.net/fays2_watts_link_21_.html

This is a good one in that it is a true bolt on, just bolt on, adjust and go.

Blackbird,
Another option for a wider look and stance is some quality 1" wheel adapters for the rear.(the narrowest ones you can get) Not slide on wheel spacers...bolt on ADAPTERS!
Mine can be seen in my FQuick link below.
http://www.fquick.com/UsualSuspect

Here's the result -
Using the stock 17" WS6 wheels with the stock 275/17 tires you get about the same outer edge of the rear tires stanced, as with a 315/17 tire.
The inner edge is also moved outwards too(logically) and thus causes no inner tire rubbing at all. The difference in viewing underneath and from behind is pretty close to 315s and the overall look and stance is much "tougher" than stock.

But...as with 315s you may have to roll the fender lip under. I did. I didnt rent a roller machine but I didnt "butcher" it either.
With the tires off I used a razor blade and cut a line along the under edge so that when the fender edge was turned up it wouldn't stress the paint and crack out to the front and be visible. That step is important.
Then, using crude instruments such as a short pliers and a rag for softness I started rolling up. If you start at one end and take small increments it goes evenly. If you take too big of gaps it WILL look lumpy and butchered.

This wider stance is best when the car is lowered IMO. I just installed an adjustable panhard bar and perfectly centered the body over the tires. The stance is low and PHAT and it can be done without 315s. It's not for everyone but when going to the store or gas station I get ALOT of compliments on the look and stance.
And it's simply lowered with 1" wheel adapters.

Just another option to pricey 315s and requires no inner fender modification.

yea, everyone I realize the "risks" in doing this, I made the same decision thousands of other people have made and wouldnt have made it if it really wasnt such a miniscule amount of hammering I had to do. The area on the inner fender was an area about the size of half my pinky in length and it was barely rubbing. So i doubt my car will implode anytime soon...

As for a channel lock, yeah...you CAN use one, that doesn't mean id reccomend it or thats the best option I just thought Id mention it because some people do in fact do that. If somebody asked about options for oil You COULD use a gas station's brand of conventional oil too if u want, but I wouldn't do that either....

I have heard people talk about "risking your life" by puttin on 315's, but has anybody ever seen an fbody get totalled from this? has anybody witnessed this damage themselves? I'd actually like to know if you have...


chances are your probably way far more likely to die in your car by speeding or street racing, or getting into an accident when using your cell phone. And yur probably more likely to damage your car by not doing proper oil changes and maintenance than you would if you where to hit your fenders in a little...

when modifying a vehicle in any way shape or form from the original specs you have what is called an assumed risk...

Disagree with me, shame on me...whatever, I respect everyone's concerns, thoughts, and opinions but people run 315's all the time...




Im not trying to attack anyone here, and if you do feel like I am I apoligize. I am simply trying to give my .02 based on my experiences and from what I've heard...



ScrmnWs6 beat his inner fender wells in a tad too and had well over 400hp in his 96 ws6...

Lemme see if I've got this right...it's OK to hammer on the inner fender, it's OK to run a tire too big for the car and one that is incompatible with the rear suspension? And, it is safe to do so? The problem is, the tire does rub. The problem is...it is too big for the rear wheelwell. The problem is...the car body is the frame and a stressed member. The damaged inner fender probably won't fail tomorrow, maybe not in a year from now, but it will fail, and the problem is YOU don't know when it will fail. Failed parts usually pick the worst possible time. Maybe it will fail 10 years from now when some unsuspecting owner didn't know you beat the crap out of the inner fender. Like I said before, your first clue should be that the tires are rubbing on the body.

It's like running boxed LCAs. GM designed them to flex, becuz they have to flex. So, people install boxed LCAs all the time, several on this forum probably have them on right now. However, does that make it right? Nope, it doesn't, and one day they will try to remove them, becuz the poly bushings are squawking so loudly, they can't hear their girlfriend/wife talking in the car (maybe that is a good thing?). Problem is, the fwd pickup point will be so bent that the owner will have a hard time removing it and a harder time straightening the flanges. It happened to me (had to use a torch to heat them up), and that is where the inner fender starts the failure, right at the pickup point.

You don't modify a car for the here and now, you take care of it for the lifetime of the car so that it doesn't fail when least expected. It's called being safe and keeping others safe who don't deserve to be mixed up in your accident.

And, the one thing your argument fails to consider is this....the large tires do absolutely nothing for the performance of the car. You installed those tires, becuz you think the correct size looks dorky.

I dont think I ever claimed taht they did do anything for performance...I know they don't...they probably make it a bit worse actually, the hweels are heavier and like was said eariler, the center of the tire wears quickly at normal Psi...I put them on because it looks better and I got a good deal on them...nothing more...

Ok guys. Let's try and keep it to a small uproar or take it to PM. Anymore and the topic will be closed.

Matt