Originally Posted by ghunt
Someone told me about this recently and I had to look it up for myself. In apparently every head-to-head where it's been run, the Camaro SS 1LE is faster around a track than a Boss 302, despite weighing more and being at an 18 hp deficit. WTF?
And it's not even a small difference, it's like 3 seconds! Again I say, WTF? Does the Camaro's IRS make that much of a difference? Does it have better tires? Is it both?
I feel deeply saddened to learn of this...our bad boy track Mustang can't even beat a plain jane SS with some upgraded suspension bits...
When it comes to suspension & handling, the devil truly is in the details. I don't feel saddened by this turn of events at all - if anything it's vindication of a few of my own thoughts plus a fresh look that I might be able to crib some direct benefit from.
Some of the difference is based in the 1LE Camaro option having 285/35 tires all around instead of a staggered arrangement (i.e. 255/xx front, 285/xx rear). It just seems to me that crutching an inherently understeerish big'n' little tire configuration with oversteerish suspension tuning in the hopes of it coming out right under all driving situations is the wrong way to go about it.
The 1LE runs an unusually wide rear wheel - 11", this for 285/35-20's in a regular production US domestic car. Many Camaro enthusiasts criticize the appearance of 285's on 11's, but this is without fully understanding that looks do not equate to lowered lap times (or perhaps in many cases not really caring about that kind of performance). This is another one of those details, where the wider rear wheels - the 1LE front wheels are 10's - help ensure enough understeer to satisfy corporate standards without wastefully throwing away wads of front tire grip (via little front tires) to get there.
I doubt that you'll find very many successful autocrossers running Mustangs with staggered tire sizes. Sam Strano didn't, and I don't think Terry Fair did more than the one time where he found it to be a poor way to go. I know that Terry has used staggered wheel widths to very good success; 4th place against more fully sorted ESP cars at last year's SCCA Solo Nationals with 11" and 12" wheels and what I recall were 315/30-18 tires all around.
Once you get into forced induction and particularly positive displacement supercharging as in the GT500 or ZL1, there is some legitimate basis for tire size staggering. The package is already unbalanced towards brute power and needs a crutch or two for driveability reasons (aka additional cushion against spinning out in case your right foot gets a little sloppy).