i posted in the autocross forum to no avail.. was hopin somebody would be able to shine some light on the subject..

first off, i have a 97 camaro z28 convertible...

i have 18x10 enkei v1's with +45 offset which should work out to 6.77 backspacing.. i am looking to throw 285/35 18 tires on all 4 corners, but may throw 275/40's on there temporarily.. i am planning on buying the slp level one supension package within a week..

my question for you guys is will there be clearance problems? its a wide wheel, its an offset that will push the wheels out a little farther than usual, and the slp level one package should lower the car about .75 inches from stock..

i am wondering if this will require me to roll the fenders or take any other precautions...

i have bought kyb agx shocks and was just gonna get some stock sprngs to have clearance for the 18's (i have sportlines now and they will not work with the wheels and the longtubes i am installing) but i would rather the slp package..

any input would be great, thanks...

josh

 

I have the "John Ames" autoX springs and 17x11s in the back. My car is about as low as any but I am not sure about the offset on the wheels. I got an adj. panhard rod and haven't had any problems hitting the inside fenders. I do however rub the top of the fender lips which would most likely be fixed if I roll the fenders but I don't trust myself to do it. I would highly reccomend the adj. panhard rod and if you autoX or road race you might look into getting one with spherical rod ends on both sides. OTher than that I am not sure if convertibles are different underneath but if not I don't think you will have a problem.

 

thats the kind of info i was looking for... although i am not sure how low your car is... maybe someone with the slp level one package?

 

The level one package only lowers the car .5-.75" from stock. The John Ames kit is WAY lower than that. Probably around 2" lower than stock. Another reference point is the regular Eibach spring kit, that kit lowers the car about 1.5" from stock.

 

You calculated the backspace incorrectly.... you forgot about the width of the wheel's tire retention flange.... typically in the range of 0.45-0.50". 1/2 wheel width + offset + flange width = backspace.

5 + 1.77 + .45 = 7.22"

This corresponds to a 3.68" "frontspace". That means the wheel/tire edge will be moved about 1.35" further toward the outside of the fender than the stock wheel (2.33" frontspace). You have to decide if you can live with that in the front. I've run a 3.32" frontspace with OZ Monte Carlos 17x9.5 and that puts the tire near the edge of the fender. The Torque Thrust II 17x9.5 has a 3.52" "frontspace".... you might want to look at a pic of those on an F-Body to see how you like them.... very aggressive in my mind. But will that work with a lowered car?

I can give you a link to pic's the OZ's and the TT II's if you want.

In the back it isn't a problem.... you have 3/4" less backspace than my 17x11's, and about 1/4" less frontspace.

 

injuneer, as always, you have been a great help

i was aware that the tire would be farther out than the norm... but you put it into a much easier way for me to visualize.

as a matter of fact, my next door neighbor had 17x9.5 tt2's on his camaro.. i liked the way they looked quite nicely..gave it a squared off look in my opinion.. when you say 1.35" farther out than the stock wheel, are you referring to the 16x8's? or the 17x9's?

as for tires i have decided on 275/35-18s for the front and 285/35-18's on the back... i am hoping that the slightly narrower tires on the front will not only make the wheels look like they arent as far out, but also i wont have to wrestle as much with the steering as i would with a 285 series tire on the front..

also, i think that with the slp package only lowering the car .5-.75 inches from stock height i will have a decent amount of room between the tires and the fenders.. (but will they be ok for spirited driving/cornering?)

thanks guys so far, but keep any opinions or experiences coming..whichever...

 

With the OZ's and 275's, and the front end lowered 1.8" in the front, I had some rubbing inside the fenders with the wheels at "full lock".... and just riding along with the wheels straight ahead, a sharp bump would produce some rubbing inside the wheel wells. All the rubbing appeared to be on the plastic fender liner, so it wasn't a problem. If you only drop .75" you shouldn't have a similar problem.

My reference to the "stock" wheels was the 16x8's. The "stock" 17x9's already stick out 1/2" more than the 16x8's.

17x9.5 TT II's on the front of a late model T/A (17x11 in the back):

Kelly Drown's T/A

 

<insert sigh of relief here>

excellant info, that was exactly what i was looking for...

thanks again injuneer!!