[CRBWS6]

On other RWD platforms, I have typically run 0 toe front to retain some streetability. And on the rear a little bit of toe in.

[Msquared]

Originally Posted by CRBWS6

On other RWD platforms, I have typically run 0 toe front to retain some streetability. And on the rear a little bit of toe in.

I agree with this. While a bit of toe out up front might help increase front cornering grip, it tears up the inside should of tires fast when you also have negative camber. The problem with getting rear toe in is that it limits the amount of negative camber you can get. So running anywhere from a teeny bit of toe in to zero is probably what you want, and then all the camber you can get with that toe setting.

[foshjowler]

From the latest event a couple of weeks ago. The local club is just running TNT events this year, so no official results. But I run timing, so I get to see the times being run, and I'm really only being beat by the R-Comp guys.

[AustinTXracer]

I finally got off the stock 20" SC3's and onto 19" MRR's with 295/305 SC3's. Significantly better I have to say. Still not quite where I want to be, but it is definitely capable of being a nats trophy car at this point. The course was a bit non ideal, but I still did better than usual. 4th in PAX. Note the 1st gear pin turn - lots of throttle patience there to not light 'em up! Really felt better about my throttle inputs this time, not as much barking and catching.

https://youtu.be/o7F-15ijY4I

[CRBWS6]

Originally Posted by AustinTXracer

I finally got off the stock 20" SC3's and onto 19" MRR's with 295/305 SC3's. Significantly better I have to say.

Interesting. Do you think it's due to fresh rubber, larger front width, or are the 19's a different compound?

BTW - I just ordered OEM SC3's to replace the MPS4s that came with the car. At least initially, my motivation was to avoid being a tire/wheel swapper....that and the irresistible price. Its nice to spend less on tires than I did on the STU car

[DaveC113]

Last autox of the season was 50 degrees and cloudy, it was fun as always but OEM SC3s never came close to warming up and I was around 2s slower than normal. Normal also isn't that great compared to when it's a really hot day and they actually perform as intended, which maybe happened a few times this year out of a dozen or so events. I did really well when the tires cooperated, and it's more fun.

I have to think other sizes of SC3 are a totally different compound vs OEM sizes.

I've decided OEM SC3 are simply a bad idea for autox use unless it's really hot and sunny out. Even then, if you have to run 1st at 9am it's not long enough for the sun to warm up the surface enough. So, Falken 660 next season, 315/18s...

[AustinTXracer]

I felt like the car was just better everywhere from the worn stock 20's to the fresh 19's. Not terribly better, just a bit better. The OE tires are great and are still just as fast now as they were new. They now have 80 AX runs and @2.5hrs of track time on them and are below 2/32 in the centers. The new tires may not have been most of the improvement, as the much lighter 19" setup saves over 20lbs and shrinks the tire diameter almost 1" which improves accel and gearing significantly over the 20's. The 295 front did bring the balance forward slightly, but not enough to worry about adding a bar.

[UnknownJinX]

Originally Posted by DaveC113

Last autox of the season was 50 degrees and cloudy, it was fun as always but OEM SC3s never came close to warming up and I was around 2s slower than normal. Normal also isn't that great compared to when it's a really hot day and they actually perform as intended, which maybe happened a few times this year out of a dozen or so events. I did really well when the tires cooperated, and it's more fun.

I have to think other sizes of SC3 are a totally different compound vs OEM sizes.

I've decided OEM SC3 are simply a bad idea for autox use unless it's really hot and sunny out. Even then, if you have to run 1st at 9am it's not long enough for the sun to warm up the surface enough. So, Falken 660 next season, 315/18s...

Did the first AutoX run in my Camaroi today, and yes, that is my impression as well.

I loved my SS 1LE on the lapping day where I can get the SC3 all nice and toasty. At the AutoX, not so much, since the temperature isn't that high(15 C/60F tops) and the tire temperature stayed at NORMAL on the tire temp display.

That, and the fact that this is the first time I am doing it in the Camaro and so the bigger size and visibility takes some getting used to. Never had much of an issue in my old RX-8 due to that being a smaller car and I can gauge where the cones better with the better visibility. I only managed 2 clean runs today out of 9 and the best run was with me hitting a cone, LOL. One of the gates is pretty narrow already and some other drivers also said they had trouble with bumping into the cones there.

It's still an AutoX-able car, but yeah, if you are serious I think the tires can definitely be a limiting factor. That, and I am not that great of a driver at AutoX.

Oh BTW the knee pad popped off during my 4th and 5th run. I just decided to run the car without it for the later runs. I used some superglue to secure it just now, but how do you guys secure yours if you have this issue?

[CRBWS6]

Originally Posted by UnknownJinX

so the bigger size and visibility takes some getting used to. Never had much of an issue in my old RX-8 due to that being a smaller car and I can gauge where the cones better with the better visibility.

Coming from a 350z, I can fully relate! Glad I am in AZ where it's rare to run in temps under 50 degrees and/or w/o the sun. Regardless, it sounds like avoiding A group is a good idea.

So the OEM SC3 arrived and the rears are stamped late 2016 and new production is not expected for a while. Fronts are stamped this year.

I'm used to the short life span of 200TW tires (once in service), but since these have been stored in an temp controlled warehouse, will there be a loss of grip for autocross?

[DaveC113]

Originally Posted by CRBWS6

Coming from a 350z, I can fully relate! Glad I am in AZ where it's rare to run in temps under 50 degrees and/or w/o the sun. Regardless, it sounds like avoiding A group is a good idea.

So the OEM SC3 arrived and the rears are stamped late 2016 and new production is not expected for a while. Fronts are stamped this year.

I'm used to the short life span of 200TW tires (once in service), but since these have been stored in an temp controlled warehouse, will there be a loss of grip for autocross?

I had 2017 tires from the Tire Rack sale this summer and noticed no difference vs the previous OEM set.

[94boosted]

One of my local events, first in class, first in PAX.

Originally Posted by AustinTXracer

I finally got off the stock 20" SC3's and onto 19" MRR's with 295/305 SC3's. Significantly better I have to say. Still not quite where I want to be, but it is definitely capable of being a nats trophy car at this point. The course was a bit non ideal, but I still did better than usual. 4th in PAX. Note the 1st gear pin turn - lots of throttle patience there to not light 'em up! Really felt better about my throttle inputs this time, not as much barking and catching.

https://youtu.be/o7F-15ijY4I

Any data on how much faster the 19" Non-OE GYSC3's are compared with the OE 20" GYSC3's? Rumor has it that there may be a slight change to the compound between the 7/32nds OE tires and the 8/32nds non-OE tires. I've been running on 305/30/19 RE71R's for two seasons now and did an event on the 3 year old OE 20" GYSC3's and while they were a bit off the pace I was quite surprised with how well they did. I think I was running the pressures a little too high though (35F/33R). I really want to try the 19" GY SC3's.



Any reason you didn't try the 325 out back?

[AustinTXracer]

I haven't hauled both sets of tires to an event and won't because the OE ones are nearly dead and will be used up at the next track event. 19's for autocross seem to be generally better than 20's is likely the biggest difference. Car feels quicker, brakes better, and is more nimble on the 19's. I didn't go with 325's because I didn't feel like I needed more rear grip and I didn't want the rear of the car to get lazy with oversized tires. Still on 11's.

[94boosted]

Originally Posted by AustinTXracer

I haven't hauled both sets of tires to an event and won't because the OE ones are nearly dead and will be used up at the next track event. 19's for autocross seem to be generally better than 20's is likely the biggest difference. Car feels quicker, brakes better, and is more nimble on the 19's. I didn't go with 325's because I didn't feel like I needed more rear grip and I didn't want the rear of the car to get lazy with oversized tires. Still on 11's.

Thanks John!

[DaveC113]

I have not tested OEM vs other sizes GY SC3 but we do know the OEM size is a tire specifically intended for the SLE and ZL1, so it is definitely different vs other sizes.

I am pretty sure judging by reviews and other's experiences with the non-OEM GYs that they are significantly different, I believe they may be softer and warm up faster, so would be a better AutoX tire vs OEM sizes.