[AJD]

Originally Posted by Mountain

If I were you, I'd run 265/275 or 265/265 in the RT660 on the Turbo 1LE.

I was thinking the same thing. 265/275 might be the move.

Originally Posted by Mountain

Seeing as you are in Detroit, you can take a look once autox starts up.

Counting the days till the season opener. Are you planning on running DRSCCA opener at MIS?

[funked1]

Thanks for the feedback guys. I did the math, and the 295/35/19 / 315/30/19 setup would only change the rake about .28 degrees from stock. I run with everything off for autocross, but I do use PTM for track days so I am wary of screwing that up by changing rolling diameter. I might end up with an autcross set, a trackday set, and a winter set. My wife is going to kill me...

[Mountain]

Originally Posted by funked1

Thanks for the feedback guys. I did the math, and the 295/35/19 / 315/30/19 setup would only change the rake about .28 degrees from stock. I run with everything off for autocross, but I do use PTM for track days so I am wary of screwing that up by changing rolling diameter. I might end up with an autcross set, a trackday set, and a winter set. My wife is going to kill me...

On 19x10 front and 19x11 rear wheels, I would run 275/35 front and 295/35 rear or 275/30 front and 305/30 rear... The 275 really is more in-line with a typical 285 and are as wide as the GY SC3 285's, with the "tread width" actually a bit wider.

[AustinTXracer]

Your PTM will NOT work correctly if you run front tire diameter larger than rear. I've done it and half throttle is about all you'll get - even in 'race' mode.

[funked1]

Originally Posted by Mountain

On 19x10 front and 19x11 rear wheels, I would run 275/35 front and 295/35 rear or 275/30 front and 305/30 rear... The 275 really is more in-line with a typical 285 and are as wide as the GY SC3 285's, with the "tread width" actually a bit wider.

Thanks, I hadn't thought of the 275/295 combo in 35 series. The diameters on those are just about perfect.

[funked1]

Originally Posted by AustinTXracer

Your PTM will NOT work correctly if you run front tire diameter larger than rear. I've done it and half throttle is about all you'll get - even in 'race' mode.

Yeah thanks for that, I definitely like PTM on the track.

[funked1]

I ordered 275/30/19 and 305/30/19. Mr. Hale's youtube videos have me sold.

[Msquared]

I finally got to drive on the Falkens yesterday. First, I chickened out of my 305/315 plan (in B Street, so stickling with 10/11 wheels) and switched over to 275/305. Word on the street has been that "Falkens don't like to be pinched," and that concerned me a bit trying the 305 on the front 10" wheels. I don't know if this was a mistake or not. The upsides to the smaller fitment are: not a pinched fit, and shorter tires lower the CG and roll centers for less weight transfer. Obvious downside is less contact patch compared to the bigger tires. As a comparison, I used the stock Goodyears last year.

Well, to say the RT660s are different then the GYs is understatement! First impression was that they have so much more forward grip that I bogged the car off the line on the first start. Holy crap! These feel better in acceleration than the GYs by a wide margin, and also far better than Rivals. I think they are better than the RE71s that I drove on a friends 6th-gen Camaro, too. Also, they have significantly more lateral grip than the GYs. The rear-end step-out that seems to be caused by the eLSD disappeared. I didn't feel it once, and it wasn't for lack of pushing the car on corner exit. Crazy!

The one negative is that ice mode reared its head, which never happened with the GYs. I'm not sure if that's a product of the increased grip or the slightly bigger difference in front:rear diameter. If the latter, then maybe the 305/315 fitment would avoid this. It was easy enough to avoid with a more gradual brake application.

I tried keeping pressures at 35f/33r, which is a bit higher than I ran the GYs. This seems to be about right based on edge wear. I am running my car at -2.7 camber front and -1.9 rear (basically all I can get), and zero toe front and rear. So far I'm impressed. Temps were about 70F when I ran, with lots of sun and strong breeze, so not very stressful on the rubber compound. The two big questions will be how many runs they are good for, and how greasy will they be when it gets hot? For the latter, I don't mind using a sprayer, and I don't usually have a codriver, so I think it'll be okay.

[AustinTXracer]

YAY! I'm at 48 runs and 1000 miles to/from events across the last 6 weeks, and they still have 5-6/32 left across all tires. I haven't noticed any loss of performance yet, but be aware that they are on galactic backorder in the 305 size. I just placed an order with TR and estimated shipping is 7/2.

[AustinTXracer]

Also, it was 90 degrees here Saturday and I never sprayed. Felt fine and was within .043 of top PAX out of 150 drivers. Great tires! Of course as a tire rises to prominence, it initially goes through big backorders. Hopefully everyone can have the tires they want for nationals.

[DaveC113]

Originally Posted by Msquared

I finally got to drive on the Falkens yesterday. First, I chickened out of my 305/315 plan (in B Street, so stickling with 10/11 wheels) and switched over to 275/305. Word on the street has been that "Falkens don't like to be pinched," and that concerned me a bit trying the 305 on the front 10" wheels. I don't know if this was a mistake or not. The upsides to the smaller fitment are: not a pinched fit, and shorter tires lower the CG and roll centers for less weight transfer. Obvious downside is less contact patch compared to the bigger tires. As a comparison, I used the stock Goodyears last year.

Well, to say the RT660s are different then the GYs is understatement! First impression was that they have so much more forward grip that I bogged the car off the line on the first start. Holy crap! These feel better in acceleration than the GYs by a wide margin, and also far better than Rivals. I think they are better than the RE71s that I drove on a friends 6th-gen Camaro, too. Also, they have significantly more lateral grip than the GYs. The rear-end step-out that seems to be caused by the eLSD disappeared. I didn't feel it once, and it wasn't for lack of pushing the car on corner exit. Crazy!

The one negative is that ice mode reared its head, which never happened with the GYs. I'm not sure if that's a product of the increased grip or the slightly bigger difference in front:rear diameter. If the latter, then maybe the 305/315 fitment would avoid this. It was easy enough to avoid with a more gradual brake application.

I tried keeping pressures at 35f/33r, which is a bit higher than I ran the GYs. This seems to be about right based on edge wear. I am running my car at -2.7 camber front and -1.9 rear (basically all I can get), and zero toe front and rear. So far I'm impressed. Temps were about 70F when I ran, with lots of sun and strong breeze, so not very stressful on the rubber compound. The two big questions will be how many runs they are good for, and how greasy will they be when it gets hot? For the latter, I don't mind using a sprayer, and I don't usually have a codriver, so I think it'll be okay.

Thanks! I'm waffling on the wheel/tire investment due to the Apex group buy... I'm looking at the 18x11 et35 square setup. For about $1550 delivered, including front spacers, it seems like a good deal.

https://www.gangup.com/apex/apex-sm1...o-q1-2021.html

Then I just have to decide between 315/30/18 Falkens or Yoks.

The only issue is the wheels won't get here until the middle to end of May but finding equivalent wheels seems nearly impossible, especially for near the $1500 mark. Gives me time to get more feedback on tires I guess...

[Msquared]

Originally Posted by AustinTXracer

YAY! I'm at 48 runs and 1000 miles to/from events across the last 6 weeks, and they still have 5-6/32 left across all tires...Also, it was 90 degrees here Saturday and I never sprayed. Felt fine and was within .043 of top PAX out of 150 drivers. Great tires!

Those are all things I'm happy to see! Yeah, I know about the backorder problem. That's actually how I was offered the chance to change size combos: someone really needed my 315s and the 275s are still in stock. I will definitely be good to go through Nationals, which I plan to attend for the first time this year (I was going to go last year, but...).

Originally Posted by DaveC113

Thanks! I'm waffling on the wheel/tire investment due to the Apex group buy... I'm looking at the 18x11 et35 square setup. For about $1550 delivered, including front spacers, it seems like a good deal.

https://www.gangup.com/apex/apex-sm1...o-q1-2021.html

Then I just have to decide between 315/30/18 Falkens or Yoks.

I have not personally driven on the Yoks. Every single thing I've heard is that they just don't hold up to heavy cars like ours. They also need lots of camber. I'm assuming you're running CAM C if you're going with 18x11 wheels, so you can run camber plates and rear toe links to get more camber than stock. A friend of mine tried the 315 Yoks on 18x12s on a 2012 (I think) Mustang in CAM, and they just overheated and couldn't be brought back quickly by spraying. On the same car/wheels, the Falkens are holding up much better. OTOH, the guy who bought my 96 Corvette (just under 3000lbs and all the camber you can ask for) put the Yoks on my 18x11s and they are doing very well. But that car was always gentle on tires. So based on what I know so far, for a near-full-weight 5/6th-gen Camaro, I'd go with the Falkens if you can get them.

[DaveC113]

Originally Posted by Msquared

Those are all things I'm happy to see! Yeah, I know about the backorder problem. That's actually how I was offered the chance to change size combos: someone really needed my 315s and the 275s are still in stock. I will definitely be good to go through Nationals, which I plan to attend for the first time this year (I was going to go last year, but...).


I have not personally driven on the Yoks. Every single thing I've heard is that they just don't hold up to heavy cars like ours. They also need lots of camber. I'm assuming you're running CAM C if you're going with 18x11 wheels, so you can run camber plates and rear toe links to get more camber than stock. A friend of mine tried the 315 Yoks on 18x12s on a 2012 (I think) Mustang in CAM, and they just overheated and couldn't be brought back quickly by spraying. On the same car/wheels, the Falkens are holding up much better. OTOH, the guy who bought my 96 Corvette (just under 3000lbs and all the camber you can ask for) put the Yoks on my 18x11s and they are doing very well. But that car was always gentle on tires. So based on what I know so far, for a near-full-weight 5/6th-gen Camaro, I'd go with the Falkens if you can get them.

Thanks! Probably a good idea to order now, should be able to get them by the end of May. Tire Tack says April 16th. Yoks are in-stock, but paying more for tires that don't last as long doesn't sound appealing.

I was talking to the owner of the race shop I plan on buying tires from, he thinks it's better to maintain zero toe and compromise maximum camber for a car driven on the street. He thinks toe out on our cars is not a good idea, and that my current alignment is not sacrificing that much vs ideal... maybe a couple tenths. I like the idea of spending less, that's for sure...

[Msquared]

Originally Posted by DaveC113

I was talking to the owner of the race shop I plan on buying tires from, he thinks it's better to maintain zero toe and compromise maximum camber for a car driven on the street. He thinks toe out on our cars is not a good idea, and that my current alignment is not sacrificing that much vs ideal... maybe a couple tenths.

In stock form, the limiting factor on rear negative camber is the toe link adjustment range. Past a certain amount of negative camber (-1.9 on my car), the toe links run out of adjustment and more negative camber causes toe out. I agree with your guy: we don't want toe out, especially in the rear! That's why if I were running in a class that allowed mods, like CAM C, one of the first mods I'd do would be to install aftermarket toe links with threaded rod ends that allow more range of adjustment. That would allow more rear negative camber. AFAIK, in the front the toe is not a limiting factor in getting negative camber: you just run out of adjustment range at the slotted knuckle attachment. You need camber plates up front to get more negative camber.