Some thoughts on autox and such - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Dr. Evil · 01-17-2014, 02:51 AM

Been thinking about trying autox again this year. I've been out of it for about 7 years now. I used to hit a lot of track days and won a couple of regional solo2 championships back when a C4 corvette was still in SS.
I got a camaro because I have a now 8 year old son and wanted to get something with a back seat that we can all enjoy and take day trips in and such.
All that said...

Tell me if I'm wrong but I ran some figures.
at 3000rpm most LS3 cars stock are about 330rwtrq.
330 x 2.07(2nd gear ratio standard SS) x 3.45 (final gear in standard SS) = 2356

For a 1LE
330 x 1.78 (1LE 2ND gear) x 3.91 = 2296

I use 2nd gear because thats where you should spend most of your time on most courses.

For comparison.

MT82 faound in the Mustang has 2.43 2nd gear ratio.

Assuming they dyno 325rwtrq

325 x 2.43 x 3.31 = 2614

Just something to consider. I know we have IRS and a bit wider tire but we are heavier and with less power at the wheels. I think this also explains some of the disparity at the drag strip too. Just wondering if anyone else had thought of this. I'll post up results from any autox events I make it to this year with observations. I've had this car on a road course once so far on street tires and it did about what I expected (I had pretty high expectations). We'll see if that holds up at autox.

Norm Peterson · 01-17-2014, 10:28 AM

Offhand, I suspect that car weight relative to tire tread width will be at least as important as rear wheel traction to car weight, assuming that everybody is able to keep the tires cambered somewhere near right in the turns.

I prefer to use rear wheel traction rather than rw torque because the tire sizes are a bit different as well (about 27" Mustang, 28.6" SS, 27.9" 1LE).

Norm

Dr. Evil · 01-17-2014, 01:57 PM

Norm, I thought about that too. Theres no 'real' way that I can see other than mixing it up on course to see what really happens though. I'd think that the ability to dial in more camber/toe/castor with the SS IRS may help with that some.

Interesting point about the traction. When you figure tire height the torque gets worse for the SS and 1le and the mustang pulls away even further. However, the mustang is limited by tire size more so than the SS so they may be into wheel spin much sooner.

woodside783 · 01-17-2014, 02:51 PM

Put 305 all around it will handle like it is on rails

Dr. Evil · 01-17-2014, 03:45 PM

I cant fit a 305 on the stock front wheel. I am NOT going to play the "throw cubic dollars at it game" and go to a modified class just yet. In stock class you are allowed to go down in wheel diameter 1" but must keep the same offset and width.
I don't mind running street tires as long as everyone else is too. That's a level playing field and it looks like the SCCA is going to go to a 200 tread wear for stock classes. If that's the case I may give it a try again.

woodside783 · 01-17-2014, 05:46 PM

Then get the same width tire on all four corners and it will handle a lot better

Dr. Evil · 01-17-2014, 10:34 PM

Are you saying to put a 275 on an 8 inch wide front wheel?

Not gonna happen.

anglenasalt · 01-31-2014, 12:29 AM

Interesting point about the traction. When you figure tire height the torque gets worse for the SS and 1le and the mustang pulls away even further. However, the mustang is limited by tire size more so than the SS so they may be into wheel spin much sooner.

Norm Peterson · 01-31-2014, 08:06 AM

Quote:

Originally Posted by Dr. Evil

Interesting point about the traction. When you figure tire height the torque gets worse for the SS and 1le and the mustang pulls away even further. However, the mustang is limited by tire size more so than the SS so they may be into wheel spin much sooner.

Unless/until you can go all the way to WOT it probably doesn't matter, as you will use however much throttle the tires will take. If both cars are still traction limited once straightened out, the Camaro may pick up a slight acceleration advantage based on its more rearward weight distribution (but probably gives some of that advantage back based on IRS rear tire cambers going a little further negative as the car squats.

The current Mustang can end up handicapped on the more open courses by axle ratio options that are too short to allow the driver to stay in the MT82's 2nd gear. Even 3.55's can force 2-3-2 shifting that typically ends up costing time. The downside of overall gearing chosen for street "sparkle" and occasional dragstrip use with a relatively small-displacement engine, I guess.

Norm

01-17-2014, 02:51 AM	#1
Dr. Evil Drives: 2013 SS Join Date: May 2011 Location: Tennessee Posts: 350	Some thoughts on autox and such Been thinking about trying autox again this year. I've been out of it for about 7 years now. I used to hit a lot of track days and won a couple of regional solo2 championships back when a C4 corvette was still in SS. I got a camaro because I have a now 8 year old son and wanted to get something with a back seat that we can all enjoy and take day trips in and such. All that said... Tell me if I'm wrong but I ran some figures. at 3000rpm most LS3 cars stock are about 330rwtrq. 330 x 2.07(2nd gear ratio standard SS) x 3.45 (final gear in standard SS) = 2356 For a 1LE 330 x 1.78 (1LE 2ND gear) x 3.91 = 2296 I use 2nd gear because thats where you should spend most of your time on most courses. For comparison. MT82 faound in the Mustang has 2.43 2nd gear ratio. Assuming they dyno 325rwtrq 325 x 2.43 x 3.31 = 2614 Just something to consider. I know we have IRS and a bit wider tire but we are heavier and with less power at the wheels. I think this also explains some of the disparity at the drag strip too. Just wondering if anyone else had thought of this. I'll post up results from any autox events I make it to this year with observations. I've had this car on a road course once so far on street tires and it did about what I expected (I had pretty high expectations). We'll see if that holds up at autox. __________________ 2013 model 2SS LS3 1969 model wife. Factory stock, no mods. Redhead package. 2005 model son. Special ordered with the hell on wheels package.

01-17-2014, 01:57 PM	#3
Dr. Evil Drives: 2013 SS Join Date: May 2011 Location: Tennessee Posts: 350	Norm, I thought about that too. Theres no 'real' way that I can see other than mixing it up on course to see what really happens though. I'd think that the ability to dial in more camber/toe/castor with the SS IRS may help with that some. Interesting point about the traction. When you figure tire height the torque gets worse for the SS and 1le and the mustang pulls away even further. However, the mustang is limited by tire size more so than the SS so they may be into wheel spin much sooner. __________________ 2013 model 2SS LS3 1969 model wife. Factory stock, no mods. Redhead package. 2005 model son. Special ordered with the hell on wheels package.

01-17-2014, 02:51 PM	#4
woodside783 Casey Woodside Drives: a very fun car Join Date: Jun 2010 Location: Tn Posts: 1,906	Put 305 all around it will handle like it is on rails __________________ Instagram @caseywoodside http://youtu.be/CSc9aPh_X_w

01-17-2014, 03:45 PM	#5
Dr. Evil Drives: 2013 SS Join Date: May 2011 Location: Tennessee Posts: 350	I cant fit a 305 on the stock front wheel. I am NOT going to play the "throw cubic dollars at it game" and go to a modified class just yet. In stock class you are allowed to go down in wheel diameter 1" but must keep the same offset and width. I don't mind running street tires as long as everyone else is too. That's a level playing field and it looks like the SCCA is going to go to a 200 tread wear for stock classes. If that's the case I may give it a try again. __________________ 2013 model 2SS LS3 1969 model wife. Factory stock, no mods. Redhead package. 2005 model son. Special ordered with the hell on wheels package.

01-17-2014, 05:46 PM	#6
woodside783 Casey Woodside Drives: a very fun car Join Date: Jun 2010 Location: Tn Posts: 1,906	Then get the same width tire on all four corners and it will handle a lot better __________________ Instagram @caseywoodside http://youtu.be/CSc9aPh_X_w

01-17-2014, 10:28 AM	#2
Norm Peterson corner barstool sitter Drives: 08 Mustang GT, 19 WRX Join Date: Jul 2012 Location: Eastern Time Zone Posts: 6,990	Offhand, I suspect that car weight relative to tire tread width will be at least as important as rear wheel traction to car weight, assuming that everybody is able to keep the tires cambered somewhere near right in the turns. I prefer to use rear wheel traction rather than rw torque because the tire sizes are a bit different as well (about 27" Mustang, 28.6" SS, 27.9" 1LE). Norm

01-17-2014, 10:34 PM	#7
Dr. Evil Drives: 2013 SS Join Date: May 2011 Location: Tennessee Posts: 350	Are you saying to put a 275 on an 8 inch wide front wheel? Not gonna happen. __________________ 2013 model 2SS LS3 1969 model wife. Factory stock, no mods. Redhead package. 2005 model son. Special ordered with the hell on wheels package.

01-31-2014, 12:29 AM	#8
anglenasalt Drives: Chevrolet Join Date: Jan 2014 Location: London Posts: 1	Interesting point about the traction. When you figure tire height the torque gets worse for the SS and 1le and the mustang pulls away even further. However, the mustang is limited by tire size more so than the SS so they may be into wheel spin much sooner. __________________ littlelioness https://littlelioness.net/2020/10/30...-get-together/ littlelioness.net