LS4 Front-Drives 2005-2009 - Wider rear tires for GXP...for the look

So I am gonna need new rear tires soon on my 06. I already replaced the fronts with BFG KDW's (oem size)

I was wondering if there is a tire out there that is the same hight/has same amount of sidewall as oem but is wider and will fit the stock wheels no prob? If so what size/brand. I am coming from a C4 vette and a 00 SS both with 315/35/17 rears, so I want the look of more meat out back. To me, the tires out back on the GXP are too narrow and whimpy:emb: I know it's FWD, but I am looking for the look. Even if it's like 1/2"...at least it's something

Thanks!!

The rear wheels are narrower than the fronts but put the same size tires on the rear. I have 255/45/18's on my 06 GXP all the way around and it looks and handles great.

Yeah...I know that they are narrower. I like the concept, but think the fronts should be even wider from the factory, and the rears as well. They just seem to damn skinny

If I went with the same size as the fronts for the rear, would that screw up the ride height or anything (I don't want the back to sit too high or low) Also it would fit the rim W/O any buldging?

buy another set of front wheels and use the 255/45's all around... they should really be on 8's anyway...

Hmmm.....Thats an idea, but not looking for another 2 wheels. how about 235/50/18s for the rear. Shouldn't be too much taller, and I think they should be wider than stock rears. Would I loose alot of sidewall?

whats stock? 225/50x18?
225/50 = 4.43" sidewall, 26.86" overall
235/50 = 4.63" sidewall, 27.26" overall
245/45 = 4.34" sidewall, 26.68" overall
255/45 = 4.52" sidewall, 27.03" overall

The rear wheels are narrower than the fronts but put the same size tires on the rear. I have 255/45/18's on my 06 GXP all the way around and it looks and handles great.

I have the same...oem front potenzas all the way around...I am lowered though and would rub on the fender over large bumps. I modified some spring blockers and run them all the time.

I have the same...oem front potenzas all the way around...I am lowered though and would rub on the fender over large bumps. I modified some spring blockers and run them all the time.

any chance you could get chance of the spring blocks?

any chance you could get chance of the spring blocks?

call me up and i can explain...I dont feel like taking them off...basicly i took the sprink blocker....cut the top part off...so it only touches 2 parts of the spring instead of 3.....it was way 2 harsh with 3.

309 453 6328

just remember for every lb of unsprung rotating weight you lose its like losing 8lb off the car and that goes both ways in addition pontiac did the staggered sizing to achieve the performance handling objective in my opinion and experience taking it to autocross they are not skinny enough breaking traction in the rear is a chore with the 225s

just remember for every lb of unsprung rotating weight you lose its like losing 8lb off the car and that goes both ways in addition pontiac did the staggered sizing to achieve the performance handling objective in my opinion and experience taking it to autocross they are not skinny enough breaking traction in the rear is a chore with the 225s

most dont autocross in their GXP..and the fat rear look much better. I have yet 2 break the rear lose in either set up.

Anyone with their front Alcoas that they'd want to sell/trade?

Where do you get spring blockers from?

my car looks, rides, handles just fine with 255's all the way around. not a lot of bulging on the sidewall and just makes the car look "right". having narrower tires in the rear is just backwards to me as well so thats why i put 255's all the way around.

Narrow tires are better for going through snow, but that's about it.

Where do you get spring blockers from?

i found mine off a new england GP club...you might be able to find some if you post a wanted thread in the for sale section here.

dp can you post a pic of your spring blockers for me so i can see what i should be looking for?

here ya go. i think there may be different versions on them but these are what i came up with when i was looking.

http://i447.photobucket.com/albums/qq194/DPUofF/DSCF0784.jpg

http://i447.photobucket.com/albums/qq194/DPUofF/DSCF0785.jpg

u run 2 on each spring? and do you just squeeze them in? thanks for the pics.

u run 2 on each spring? and do you just squeeze them in? thanks for the pics.

yep 2 go on each spring. doesnt really matter where as long as they are across from each other. you will have to jack up the car so the spring isnt compressed then pop them on and lower the car....once the spring loads they will make a nice fit.

cool did you notice a difference? sorry about jackin this thread.

i only use them at the track..it would be a harsh ass ride because once the blocks are on the rear doesnt move at all. i dont know if they would break either? i used them once and it was a lot easier to launch the car because the power stayed on the front wheels. after they are on if you try and push down on the car it doesnt budge...with our launching issues with FWD this is a good idea because they cost me $35 shipped and it helped a lot.

I ran 245's on the rear to go with a different company (federal tires) I had no issues.