1LE Rear Tire Size

[L99CAMA2011]

Originally Posted by pr3dict

I'll take what you said as a

I got some 19" non forged made with MAT technology wheels that are like 9lbs lighter but 19x9.5" want them, 2 are for sale.

[L99CAMA2011]

Originally Posted by natmad

There's some truth in all the posts above, I believe.

After much reading , I'm convinced that after much testing , the engineers (I'm using this term in a positive light) found that the 1LE handled the best with the current tire and wheel setup.

While the wider 305 rear tires would ultimately give the rear end more grip, they found that the stretched 285 rear tires, near the limit, allowed the 1LE to rotate slightly better in the turns with more nuetral handling, making it faster and more fun. If you can get a car to rotate in the turn, you can get back on the gas sooner than if the car is pushing. Of course, too much rotation--loose as hell--is slower too. If anything, the 1LE is balanced.

On the ZL1, the wider rear tire tires are necessary because of the extra weight and especially the extra power. Powah!!

Sooooooo wrong. I just actually experimented with this even as soon as just last week. Tighter fitment of a tire in the rear leads to increased understeer. Like I said not a 305 but a 295 rear would have been better. However that brand tire they used doesn't have a 295 option. "I guarantee if you put a ZL1 rear tire on a 1LE that handling would be better not worse." This is very correct. It would decrease rear end stability and the tight feel a bit but in return would increase rear end traction therefore giving the driver more confidence and increase cornering ability. I still like the 295 on an 11" rim option though, not as loose as a 305 and a tad more neutral feel over the 285.

[Norm Peterson]

Originally Posted by L99CAMA2011

This car with a 20x11 should have 295s back there . . .

Not with this car being close to 50-50 weight distribution and specifically intended to have only minimal understeer. Keep in mind that the 1LE was intended for about 2% of buyers, and that some of the differences from the SS that put it there obviously won't appeal to everybody (and consciously were not intended to). This is one of the big things.

Unless you're going to run 295's all around, which would probably call for 10.5" front wheels.


A 285/35 tire is a legitimate size to be fit to 11" wide wheels. Yes, 11" is the max recommended width for them, but what that means is that there are no technical reasons for not running that combination on this car.

Appearance preferences and prejudices do not count as "technical" reasons. They're valid as far as how you'd build up your own car from the SS level, but not for the way the 1LE should be built generally.


Norm

[L99CAMA2011]

Originally Posted by cornerspeed92

Cody, im not sure what you're problem is,but would you like to settle this at the track? I will be at Fontana Aug. 11th So bring what ever set up you want,and we will see what the correct set up is. Here is a little video of why C5 gave me homepage(thanks C5) March 2013.This isn't because the tire set up is wrong!

4:17 you can't pass spec Miatas, not allowed .

[Cody6.2]

Originally Posted by snickerdoodle

Size isn't everything on the grille or tire.

Really?

[Cody6.2]

Originally Posted by L99CAMA2011

Sooooooo wrong. I just actually experimented with this even as soon as just last week. Tighter fitment of a tire in the rear leads to increased understeer. Like I said not a 305 but a 295 rear would have been better. However that brand tire they used doesn't have a 295 option. "I guarantee if you put a ZL1 rear tire on a 1LE that handling would be better not worse." This is very correct. It would decrease rear end stability and the tight feel a bit but in return would increase rear end traction therefore giving the driver more confidence and increase cornering ability. I still like the 295 on an 11" rim option though, not as loose as a 305 and a tad more neutral feel over the 285.

At the end of the day you still don't tune a cars handling by stretching tires. But I guess this is what happens when a manufacture designs so much understeer into a chassis from the get go. With intended purpose vs actual usage in 90% of situations they could've ran 295's or even 305's and tuned out understeer with a larger rear swaybar.

[Norm Peterson]

Originally Posted by L99CAMA2011

Sooooooo wrong. I just actually experimented with this even as soon as just last week. Tighter fitment of a tire in the rear leads to increased understeer. Like I said not a 305 but a 295 rear would have been better. However that brand tire they used doesn't have a 295 option.

Unless you ran this comparison on a real 1LE or on an SS that was completely updated to 1LE specs for wheels and suspension tuning, any comparison is of rather limited value.

Sure, the wider rear wheels provide a minimal understeer effect (it's a relative rear vs front slip angle thing). But the basic grip of identical front and rear tires remains essentially constant. Staggering the tire sizes on a normally aspirated car without doing anything else is a recipe for increasing understeer. Period.

"I guarantee if you put a ZL1 rear tire on a 1LE that handling would be better not worse." This is very correct. It would decrease rear end stability and the tight feel a bit but in return would increase rear end traction therefore giving the driver more confidence and increase cornering ability. I still like the 295 on an 11" rim option though, not as loose as a 305 and a tad more neutral feel over the 285.

"Handling" isn't exactly an absolute measure - it's partly dependent on driver preferences and driving style. Some people either want or need a little more straight line stability or cushion against oversteer than others. What I'm hearing is that you'd rather have the front end push a little more as long as it gives you a bigger cushion against too much throttle on corner exit giving you too much throttle (over)steer. That's fine that it suits you better.

Neither a 295-wide or a 305-wide tire on 11" will have as direct a feeling of response as the 285/35; relatively speaking there will be slightly less 'crisp' response to cornering or changes in conditions while cornering. This can be seen as a disadvantage. That you can add power a little sooner is the Band-Aid that tries to cover it up.

Up-sized rear tires are under-utilized for most of the corner, which probably does suit a "point and shoot/stab and steer" driving style a little better than driving styles that more smoothly add throttle, just like staggered tires or tires and wheels has been an appropriate crutch for the big power forced-induction cars. Probably turns people even more into becoming P&S/S&S drivers.


With quite a bit less power than a 1LE and somewhat less tire, it's still easy enough for me to get to where throttle steering can be felt. Mostly it's felt on tighter turns, but every once in a while I get the opportunity to run a higher speed sweeper hard enough to be on the edges of throttle steer. I find it easy enough to modulate the throttle to where I really wouldn't want more understeer getting in the way on turn-in and mid-corner.


I was up in the Norton/Foxboro/Bridgewater vicinity earlier this week on family business. That anywhere near you?


Norm

[Norm Peterson]

Originally Posted by Cody6.2

At the end of the day you still don't tune a cars handling by stretching tires.

Why not? It's just another tool in the handling tuning toolbox and just as valid as shifting the distribution of lateral load transfer via springs/bars/shocks or compliance steer effects with different bushings. Sometimes, maybe it's the best tool.

But I guess this is what happens when a manufacture designs so much understeer into a chassis from the get go. With intended purpose vs actual usage in 90% of situations they could've ran 295's or even 305's and tuned out understeer with a larger rear swaybar.

Mildly stretching the rear tires past their "measuring width" isn't there to minimize understeer.

Relying too heavily on the rear bar (or rear springs, for that matter) to tune out understeer tends to make it harder to add throttle on corner exit, as those tweaks unload the inside rear tire more. Balancing an understeerish tire effect with an oversteerish amount of rear bar isn't going to provide the same net handling balance all the time. Perhaps this happens above the actual use that you're visualizing, but it might well be within the actual operation envisioned for the 2%-ers among us.


I think that just like the 1LE is the Z/28 for people who aren't truly Z/28-level hardcore that the SS is really the Camaro version for people who would upset the 1LE's balance with staggered tire sizes.


Norm

[Cody6.2]

Originally Posted by Norm Peterson

Why not? It's just another tool in the handling tuning toolbox and just as valid as shifting the distribution of lateral load transfer via springs/bars/shocks or compliance steer effects with different bushings. Sometimes, maybe it's the best tool.



Mildly stretching the rear tires past their "measuring width" isn't there to minimize understeer.

Relying too heavily on the rear bar (or rear springs, for that matter) to tune out understeer tends to make it harder to add throttle on corner exit, as those tweaks unload the inside rear tire more. Balancing an understeerish tire effect with an oversteerish amount of rear bar isn't going to provide the same net handling balance all the time. Perhaps this happens above the actual use that you're visualizing, but it might well be within the actual operation envisioned for the 2%-ers among us.


I think that just like the 1LE is the Z/28 for people who aren't truly Z/28-level hardcore that the SS is really the Camaro version for people who would upset the 1LE's balance with staggered tire sizes.


Norm

Which is all fine and dandy until Johhny Cheapass needs to buy tires for his Camaro. I think it's fair to say that 90% of the time tires like the GYSC aren't replaced with the same thing let alone something equal. So all of that tuning by tire type/size just went out the window.

In the end I don't care what someone thinks GM did for them or what GM thinks they did in general. Were talking about the same company that neutered the suspensions on everything from Cavalier Z24's to Camaro SS's in 2000 because of harsh ride complaints.

[Norm Peterson]

Originally Posted by Cody6.2

Which is all fine and dandy until Johhny Cheapass needs to buy tires for his Camaro. I think it's fair to say that 90% of the time tires like the GYSC aren't replaced with the same thing let alone something equal. So all of that tuning by tire type/size just went out the window.

You can't control what Johnny C does, but whatever he does is probably going to be a more frequent occurrence than anybody doing a carefully considered upgrade of everything from what I'll call "mass-market SS" level to the 1LE level from there all on their own. Chances are he won't ever notice the goodness that he threw away, and his choice in new tires' appearance or tread design will be enough to make up for it.

I hope history doesn't once again repeat, else the early 1LE's could end up being the ones we'll wish for later on.


Norm

[2cnd chance]

Originally Posted by Cody6.2

Which is all fine and dandy until Johhny Cheapass needs to buy tires for his Camaro. I think it's fair to say that 90% of the time tires like the GYSC aren't replaced with the same thing let alone something equal. So all of that tuning by tire type/size just went out the window.

In the end I don't care what someone thinks GM did for them or what GM thinks they did in general. Were talking about the same company that neutered the suspensions on everything from Cavalier Z24's to Camaro SS's in 2000 because of harsh ride complaints.

That was 14 model years ago!

[Fraxum]

Whatever you think of Cody6.2, he made this thread interesting. I think he enjoys playing devils advocate.

Cody6.2, your points are thoughtful, but maybe all not well researched.

You could concede at least some points, several good ones were made. That you didn't is why you got the Troll flags. You are not Trolling are you?

I was very tired last night, but I read most of it. My conclusion is the wider ZL1 rear wheels were used at first to save money. But then it worked! It must/could have been serendipity! Those obviously stretched tires go against the advice of all the tire/wheel vendors on this site.

I also thought square tire sizes, if the handling is near neutral, made a car more predictable in the turns. Nice to have that confirmed by those that know.

And as an added benefit the wider wheels allow for wider rear tires for those that like the look, and possibly a little more traction, in exchange for a little more understeer.

Props for the 1LE. Loving mine, even stock.

[Cody6.2]

Originally Posted by 2cnd chance

That was 14 model years ago!

And what has changed since then, nothing.

I'm all for a good handling car but it's stupid that Camaro vs Mustang has turned into a track battle. You can't have a discussion about them without the Camaro owner bringing up lap times. With that being said the intro duction of the ZL1 and updated FE4 seems to be the first time GM has cared about a performance car handling like one since then. But even then they are still trying to polish a turd i'll give them credit on doing well but still.

[Cody6.2]

Originally Posted by Fraxum

Whatever you think of Cody6.2, he made this thread interesting. I think he enjoys playing devils advocate.

Cody6.2, your points are thoughtful, but maybe all not well researched.

You could concede at least some points, several good ones were made. That you didn't is why you got the Troll flags. You are not Trolling are you?

I was very tired last night, but I read most of it. My conclusion is the wider ZL1 rear wheels were used at first to save money. But then it worked! It must/could have been serendipity! Those obviously stretched tires go against the advice of all the tire/wheel vendors on this site.

I also thought square tire sizes, if the handling is near neutral, made a car more predictable in the turns. Nice to have that confirmed by those that know.

And as an added benefit the wider wheels allow for wider rear tires for those that like the look, and possibly a little more traction, in exchange for a little more understeer.

Props for the 1LE. Loving mine, even stock.

I've put complete suspensions on at least three cars now and never once used tires for tuning it. In the end GM built this car to understeer and it will take more than three steps forward to make up for those five steps back. It would've made much more sense to do the same wheel tire combo all around than this set up.