15-20 pounds per side of unsprung weight is a rather large amount. You would definitely change how the tire follows the dips and bumps in the road, as your springs and shocks now have to fight that additional momentum. Under normal driving conditions though- I would have to agree that the difference in weight wouldn't effect drivability.


If you wanted to bump them out a bit and keep all 4 wheels the same width for rotation purposes, you could always do a spacer. You wouldn't get 1.5", but it would make the gap a bit less drastic.

Also, be careful how close you're getting the edge of the tire to the body. It is one thing to take measurements with the car in a static position, but quite another when performing a hard turn (ie emergency maneuver, fast on-ramp, etc) while articulating the suspension (from bumps, potholes, road debris, etc). The tire contact patch will move laterally in relation to the wheel, and the whole wheel/hub assembly will also move as a result of deflection in the bushings.

I'm not trying to say that bringing the tire out 1.5" is dangerous for your car and this wheel and tire setup since I don't really know, just something to consider.


Why would putting wider tires up front be any different than the rear? Actually- it would be better since the LS4 is so traction limited on acceleration. The more grip you can get up front, the better the car will perform (since the front is doing so much of the work) in all aspects of driving at the limit.


Obviously we're talking way outside what the OP intends to do with his car (cruising / normal driving), but when looking at this from racing on a curvy road- putting wider rear tires on isn't really a good thing for us. Due to the weight distribution and design of these cars, they understeer rather hard with 4 matched size tires.

Increasing traction in the rear only isn't going to help you go any faster through a corner- the front tires will still break loose first at the limit in a corner, and the car will still push into the corner.

To try and bring the car to a more 'neutral' balance, you'd ideally want the rear tires to be narrower than the fronts (again, we're specifically talking these cars). That would lower the grip available to the rear tires, and would bring the point where they break loose closer to the fronts- and would allow the car to rotate better.

GM actually proved this point in the GP GXP- virtually the same car as the OP- they run a narrower wheel/tire out back, and a wider wheel/tire up front to do just this.


I think that says it all there- if you don't care at all about the performance of the car, and it's just for cruising and commuting- then just buy whatever you think looks best. (that is as long as you don't create a dangerous situation like getting the tires too close to the bodywork that they rub during emergency maneuvers or something like that)

 

...I currently have 1.5" spacers on the rear. The tires do not rub with my normal passenger configuration and semi-aggressive driving habits...I thought about using spacers on the 19x8, but if I can get a 19x9.5 wheel that creates the same width, that would be a safer bet.

...Of course I care about the performance of the car. I explained that I do not expect a drastic change in the performance. The setup is really not that extreme...just a bit wider, but no taller, and no closer to the the suspension than the stock setup.

I've done this custom wheel thing a few times, Kids. Watch and learn...

 

Any updates?

 

I like em... I always likes that step lip alittle better though

 

Can't believe I haven't seen this one.

I think the TSW Tremblant would look good on yours Scott. I thought an 8.5" wide was pushing it but 9.5" wide!? If you can get offsets to position them in the right spot, like you said, then I don't see why not. The wider tire, with the outer sidewall sitting right at the fender lip, would look mean. I want to see this though, and I say that because I may do wheels at some point and it would be nice to see (and hear) how the wider wheels work, look, feel, etc.

I know you lowered your previous silver SS but this red one is at stock ride height currently, correct? Do you see yourself lowering this one at some point as well?

 

Scott Im looking forward to seeing this done as well, ive been thinking about rims with either lowering springs or coilovers, Coilovers more i guess.

 

Sorry for the late replies, kids. I've not been on the site lately.


Until Chicago digs out of the 6 feet of snow we've received, I'm just sitting here waiting for spring.


I can't wait to get the setup installed. I always measure multiple times, I use a wheel/tire measuring calculator, and have used spacers extensively on many cars, so I've become pretty good at figuring offsets and such. I did have 18x9" Torq Thrust Ms on my '06 at one point, so I am certain this will work.


Matt - I do not plan on lowering this car. I did not like the ride on my lowered '06 as you know...


Income tax refund should be arriving tomorrow, so....

 

Yeah I remember.

Well, like you, I'm waiting for spring as well. Looking forward to updates.

 

...as Spring slowly approaches, I am getting closer to ordering my wheels & tires. I have whittled the total cost down to $1700 for the complete set...

Pictures should be coming soon, but not until the snow has disappeared

 

Good, looking forward to it. Hope everything goes well.