Square tire setup - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Sean Summers · 06-29-2015, 06:12 PM

So I have an extra set of front rims for the car from a previous track departure. I have been told that a square setup vs. staggered tire sizes make for more stability on the track. I'm looking at Toyo R888s 285/35R20 to match the fronts with a little extra bite. Running Michelin PSS 285/35R20 on the front. Opinions?

ZO6 Bryan · 06-29-2015, 08:24 PM

It will induce oversteer unless you also change to a softer rear sway bar.

ZO6 Bryan · 06-29-2015, 08:51 PM

Or stiffen the front sway bar.

kidreno_21 · 06-30-2015, 05:09 PM

For road course track days I run a square set up with the Hoosier R7 295/30 R19 on a 19x10.5 wheel. Only difference between front and rear is that I use a spacer up front to avoid rubbing during turns. I also changed to the GM truck lug bolts up front to account for the additional length of the truck lugs. I also changed all my lug nuts to the GM Truck lug nuts - I was having issues with the stock lug nuts rounding off due to the fact that they are not designed to be removed and torqued as often as I go to the track.

I don't know about the over steer comment or changing sway bars, but have fun learning your new set up. Making small changes such as you are doing help us to learn our car.

Enjoy!

Stephen12ZL1 · 06-30-2015, 07:43 PM

285/35-20 square works fine with stock suspension parts. Unless you are Randy Pobst skill level, you will be fine. I ran a square setup with my road course wheels and it felt fine.

Sean Summers · 06-30-2015, 09:09 PM

Thanks very much for the all input!

backeddy · 06-30-2015, 09:50 PM

The ZL1 sway bar setup is made for the staggered setup, the 1LE is made for squared. I tracked the ZL1 staggered setup all 3 days at Laguna Seca last weekend and I could instantly tell the difference (under steers A LOT more). If you want to stay squared and drive at the limits, you need the right sway bars. As far as the 888's go, our cars are too heavy for them.....Same goes for the pilot SS. If you push them, they get greasy and dangerous very quickly.

just my .02

JusticePete · 06-30-2015, 10:18 PM

ALL production cars are built to understeer for liability reasons. The Z/28 is dumbed down so that a novice driver that starts to spin can lift off the throttle, stomp on the brakes and let the ABS and stabilitrac save them from themselves. That is why the 1LE comes with 28mm rear and 27mm front bar. That is why the ZL1 comes with a 28mm rear and 25mm front with the smaller front tires.

Running a square wheel and tire setup on a ZL1 will not induce snap oversteer. It will make the ZL1 understeer less.

For years I have been setting up 1LEs with the front bar from a ZL1 28/25 or retaining the front 27mm bar and installing my 32mm rear bar. There is still no snap oversteer. There is a predicatable and controllable rotation in the corner.

It is a very old racer's adage that says DON'T LIFT!. Ride it!

06-29-2015, 06:12 PM	#1
Sean Summers Drives: 2013 ZL1 Join Date: Sep 2010 Location: Fort Walton Beach, Fl Posts: 106 View My Garage	Square tire setup So I have an extra set of front rims for the car from a previous track departure. I have been told that a square setup vs. staggered tire sizes make for more stability on the track. I'm looking at Toyo R888s 285/35R20 to match the fronts with a little extra bite. Running Michelin PSS 285/35R20 on the front. Opinions?

06-29-2015, 08:24 PM	#2
ZO6 Bryan Drives: 02 Z06, 95 Trans Am, 2012 ZL1 Join Date: Mar 2012 Location: Southeast Posts: 1,838 View My Garage	It will induce oversteer unless you also change to a softer rear sway bar. __________________ Bryan 2018 ZL1 M6

06-29-2015, 08:51 PM	#3
ZO6 Bryan Drives: 02 Z06, 95 Trans Am, 2012 ZL1 Join Date: Mar 2012 Location: Southeast Posts: 1,838 View My Garage	Or stiffen the front sway bar. __________________ Bryan 2018 ZL1 M6

06-30-2015, 07:43 PM	#5
Stephen12ZL1 Drives: '21 ZLE A10 Join Date: May 2012 Location: Mechanicsville, VA Posts: 6,808	285/35-20 square works fine with stock suspension parts. Unless you are Randy Pobst skill level, you will be fine. I ran a square setup with my road course wheels and it felt fine. __________________ '21 ZLE A10 Wild Cherry PDR 2:00.78 VIR Full 10.68@131.69 1.68 60' '17 ZL1 A10 Mosaic Black PDR/Nav 2:03.08 VIR Full 11.003@129.2 1.75 (sold) '15 Z/28 #325 Black a/c & stereo. 2:10.1 VIR Full (sold) '12 ZL1 A6 Black 10.52@131 1.55 60' 2:13 VIR Full (sold)

06-30-2015, 05:09 PM	#4
kidreno_21 Drives: Zr2 Blazer, 2013 ZL1 Black on black Join Date: Aug 2011 Location: Tacoma, WA Posts: 54 View My Garage	For road course track days I run a square set up with the Hoosier R7 295/30 R19 on a 19x10.5 wheel. Only difference between front and rear is that I use a spacer up front to avoid rubbing during turns. I also changed to the GM truck lug bolts up front to account for the additional length of the truck lugs. I also changed all my lug nuts to the GM Truck lug nuts - I was having issues with the stock lug nuts rounding off due to the fact that they are not designed to be removed and torqued as often as I go to the track. I don't know about the over steer comment or changing sway bars, but have fun learning your new set up. Making small changes such as you are doing help us to learn our car. Enjoy!

06-30-2015, 09:09 PM	#6
Sean Summers Drives: 2013 ZL1 Join Date: Sep 2010 Location: Fort Walton Beach, Fl Posts: 106 View My Garage	Thanks very much for the all input!

06-30-2015, 09:50 PM	#7
backeddy Banned Drives: 2011 Boxster Spyder (best car ever) Join Date: Aug 2014 Location: San Jose, Ca Posts: 1,529	The ZL1 sway bar setup is made for the staggered setup, the 1LE is made for squared. I tracked the ZL1 staggered setup all 3 days at Laguna Seca last weekend and I could instantly tell the difference (under steers A LOT more). If you want to stay squared and drive at the limits, you need the right sway bars. As far as the 888's go, our cars are too heavy for them.....Same goes for the pilot SS. If you push them, they get greasy and dangerous very quickly. just my .02

06-30-2015, 10:18 PM	#8
JusticePete Drives: Camaro Justice Join Date: Jun 2007 Location: Virginia Posts: 20,174	ALL production cars are built to understeer for liability reasons. The Z/28 is dumbed down so that a novice driver that starts to spin can lift off the throttle, stomp on the brakes and let the ABS and stabilitrac save them from themselves. That is why the 1LE comes with 28mm rear and 27mm front bar. That is why the ZL1 comes with a 28mm rear and 25mm front with the smaller front tires. Running a square wheel and tire setup on a ZL1 will not induce snap oversteer. It will make the ZL1 understeer less. For years I have been setting up 1LEs with the front bar from a ZL1 28/25 or retaining the front 27mm bar and installing my 32mm rear bar. There is still no snap oversteer. There is a predicatable and controllable rotation in the corner. It is a very old racer's adage that says DON'T LIFT!. Ride it!