hey guys,

im about to pick up a set of custom rims for my 89 iroc and i wanted something thats going to fill up the wheel wells nicely, but at the same time i want to run 275's up front and (if i can) 315's out back. i know a 17x9.5" and 17x11" combo will fit and allow me to run the tire combo that i want (im not afraid to hammer the wells a bit or roll the fender lip), but i was wondering if a 18" wheel will fill up the wheel well perfectly, or is a 17" enough?

also, i have an eibach prokit installed and koni yellows at all 4 corners. i thought since i could make the konis rock hard, an 18" wheel might be feasible, but i was concerned that i wouldnt be able to run as wide a tire with 18's....is any amount of hammereing/rolling going to get the 18's with a 315 in the back to fit??? anyone done this???

 

You should talk to RedRocket over on the SoCal Board. He is the suspension guru of 3rd gens. He is personally running 245/40/18s in the front and 295/35/18s in the back on a 18x10" rim. He said that the 10" rim is capable of a 315 tire, but that an 11 inch rim is best. IMO, if you go with a 315, go with an 18" rim, that way you will get less rolling of the side wall of the tire. I know someone with the 17x11 ZR1s on the back with a 305 tire and it has lots of side wall roll going on. Cant imagine it with a 315. Most important deal with something that wide isnt just rolling or hammering the fender lips, but having an adjustable Pan Hard Rod and having it properly adjusted. This is RedRockets car below...

 

I personally think 17's look too small. The only reason I can see for running them is to have Drag Radials. If you don't drag get the 18's. The 18's work well for road racing too.

 

18’s are the only way to go. 17’s are ok too but I’m not the type of person that accepts ok. They will totally change the dynamic of the car. You will achieve cornering ability never imagined or let alone attempted. As far as esthetics go your vehicle will command the attention of every enthusiast you pass on the road. I will put it in the simplest terms possible 18’s, suspension, and a nice size nut sack you will dominate any late model sports car (except the 996TT) dressed in factory attire you encounter.

 

jason92z: i already have a slotcar racing adjust. panhard rod installed. ill pm Redrocket though. thx!

rallyred: unfortunately, i DO want to run drag radials in a 315/35 size. i think i may go with 18's out back, but who makes a 315/35/r18 drag radial???

 

sup guys

I just bougt a 1992 Z28 ragtop. I put the 17x9.5 chrome Zr1 wheels wit 275x40 tires from my other thirdgen on it. Right now the springs on the passenger side have sagged almost 1 inch. I am going to put an Eibach prokit on it with new kyb shocks and struts. I do not want to have a problem with rubbing saying that i have a custom sub box back there making it bottom out. I am trying to find someone who knows where i can get my hands on a fender rollr or if you kow what i can use to do it. Down the line i am going to put the 18x9.5 C5 weels on it and i dont want to have a rubbing problem. I would say 18's all the way.
thanks

doug