mt.nichols' 2019 ZL1 1LE Track Toy - Page 2

mt.nichols · 07-16-2019, 06:17 AM

I had a great day in the TMS infield this weekend. The car performed flawlessly all day, and I suspect I set a new PB but I need to confirm with PDR data.

Harpinc · 07-16-2019, 09:12 AM

FYI...
I am running -3.2 camber in front with Zero toe and have not experienced cording on the inside edge. -2.2 in rear has perfect wear across the tread. This was my 2nd track day on these tires and I will run them one more time before trashing. Ran Cresson 1.7 CCW last weekend and ran 1:19.6 in the heat so they aren't getting babied at all.

mt.nichols · 07-16-2019, 01:06 PM

Quote:

Originally Posted by Harpinc

FYI...
I am running -3.2 camber in front with Zero toe and have not experienced cording on the inside edge. -2.2 in rear has perfect wear across the tread. This was my 2nd track day on these tires and I will run them one more time before trashing. Ran Cresson 1.7 CCW last weekend and ran 1:19.6 in the heat so they aren't getting babied at all.

Ok, good to know. Any street miles?

Harpinc · 07-16-2019, 04:09 PM

Quote:

Originally Posted by mt.nichols

Ok, good to know. Any street miles?

Yes.. Probably 600ish.. Now I have Conti's for my street driving. Those GYs go like mad on the street. Have you run your 18 setup yet?

mt.nichols · 07-17-2019, 07:14 AM

Quote:

Originally Posted by Harpinc

Yes.. Probably 600ish.. Now I have Conti's for my street driving. Those GYs go like mad on the street. Have you run your 18 setup yet?

Yeah they do, I'm convinced that's why I was killing the insides of the tires. I am going to buy some cheap street tires and call it a day, I don't really care about street performance anyways.

I have not tried the 18" setup yet. I might at MSR on August 5th if I can figure out a way to get them to the track.

mt.nichols · 08-06-2019, 07:25 AM

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mt.nichols · 08-09-2019, 10:56 AM

One difference I noted is that TCS was more active with the slicks than it has been with the OEM tires. I usually run the car in PTM Race which has typically allowed for me to be able to steer the car with the throttle to a reasonable degree. It didn't feel that way with the slicks.

The OEM rear tires are 26.7" diameter, rear slicks are 680mm/26.77 inches
The OEM front tires are 26.2" diameter, front slicks are 680mm/26.77 inches

If my thinking is correct, this difference would slow the front wheel speed relative to the rear, and make the computer think there is some rear tire slip when there isn't. I don't know how significant it is, but I am thinking this caused TCS to kick in earlier.

On the straights, Pi toolbox shows a difference in wheel speed of ~2 mph with the slicks vs ~.75 mph with a set of worn GoodYear SuperCar 3Rs. Again, this seems like a really minor difference and might be nit-picking, but I am going to run the car with everything off from now on anyways.

RUQWIKR · 08-09-2019, 01:15 PM

What shows as spec and what is actual rollout / circumference / height may be different. I'd use a flexible tape measure at the same air pressure and measure.

Those Conti slicks are made, as you know by Hoosier. Hoosier's published specs and what the various tire sizes have a lot of variation / difference from what I've seen on R7's (and drag tires in my past life). Maybe Continental holds them to a higher standard...

At the published spec, it's only about 2% delta. That's around the same between my 20" 285&305/30/19 G3's I run with my sons and the 19" G3R's I typically run. I have never felt or seen any anomalies between them as far as TCS other than the G3's will have more TCS intervention if driven the same way as the stickier G3R's.

You are correct that if too much difference in stagger or overall height / circumference, things will start to act up. Not sure what that % is, but, it looks to be beyond 2-3%.

mt.nichols · 08-12-2019, 08:07 AM

Quote:

Originally Posted by RUQWIKR

What shows as spec and what is actual rollout / circumference / height may be different. I'd use a flexible tape measure at the same air pressure and measure.

Those Conti slicks are made, as you know by Hoosier. Hoosier's published specs and what the various tire sizes have a lot of variation / difference from what I've seen on R7's (and drag tires in my past life). Maybe Continental holds them to a higher standard...

At the published spec, it's only about 2% delta. That's around the same between my 20" 285&305/30/19 G3's I run with my sons and the 19" G3R's I typically run. I have never felt or seen any anomalies between them as far as TCS other than the G3's will have more TCS intervention if driven the same way as the stickier G3R's.

You are correct that if too much difference in stagger or overall height / circumference, things will start to act up. Not sure what that % is, but, it looks to be beyond 2-3%.

I will have to take measurements and see what the diameter is actually measuring on the fronts and rears. It could also be increased oversteer because I've gone to a nearly square setup - the fronts, while labeled 305s, have a 12" tread width and a 13" section width. The rears are 315s and have a 12.13" tread width and a 12.75" section width. I did verify those dimensions with a tape measure, but will go check the diameter at some point this week.

mt.nichols · 10-14-2019, 08:20 AM

.

07-16-2019, 06:17 AM	#15
mt.nichols Drives: '19 ZL1 1LE Join Date: Feb 2019 Location: DFW, TX Posts: 127	I had a great day in the TMS infield this weekend. The car performed flawlessly all day, and I suspect I set a new PB but I need to confirm with PDR data. Last edited by mt.nichols; 12-24-2019 at 03:27 AM.

08-06-2019, 07:25 AM	#20
mt.nichols Drives: '19 ZL1 1LE Join Date: Feb 2019 Location: DFW, TX Posts: 127	. Last edited by mt.nichols; 12-24-2019 at 03:29 AM.

08-09-2019, 10:56 AM	#21
mt.nichols Drives: '19 ZL1 1LE Join Date: Feb 2019 Location: DFW, TX Posts: 127	One difference I noted is that TCS was more active with the slicks than it has been with the OEM tires. I usually run the car in PTM Race which has typically allowed for me to be able to steer the car with the throttle to a reasonable degree. It didn't feel that way with the slicks. The OEM rear tires are 26.7" diameter, rear slicks are 680mm/26.77 inches The OEM front tires are 26.2" diameter, front slicks are 680mm/26.77 inches If my thinking is correct, this difference would slow the front wheel speed relative to the rear, and make the computer think there is some rear tire slip when there isn't. I don't know how significant it is, but I am thinking this caused TCS to kick in earlier. On the straights, Pi toolbox shows a difference in wheel speed of ~2 mph with the slicks vs ~.75 mph with a set of worn GoodYear SuperCar 3Rs. Again, this seems like a really minor difference and might be nit-picking, but I am going to run the car with everything off from now on anyways. Attached Images

10-14-2019, 08:20 AM	#24
mt.nichols Drives: '19 ZL1 1LE Join Date: Feb 2019 Location: DFW, TX Posts: 127	. Last edited by mt.nichols; 12-24-2019 at 03:28 AM.

07-16-2019, 09:12 AM	#16
Harpinc Drives: 19' ZL1 1LE Join Date: Nov 2015 Location: Houston,Tx Posts: 128	FYI... I am running -3.2 camber in front with Zero toe and have not experienced cording on the inside edge. -2.2 in rear has perfect wear across the tread. This was my 2nd track day on these tires and I will run them one more time before trashing. Ran Cresson 1.7 CCW last weekend and ran 1:19.6 in the heat so they aren't getting babied at all.

08-09-2019, 01:15 PM	#22
RUQWIKR Drives: 1LEs Join Date: May 2009 Location: DFW - Texas Posts: 1,319	What shows as spec and what is actual rollout / circumference / height may be different. I'd use a flexible tape measure at the same air pressure and measure. Those Conti slicks are made, as you know by Hoosier. Hoosier's published specs and what the various tire sizes have a lot of variation / difference from what I've seen on R7's (and drag tires in my past life). Maybe Continental holds them to a higher standard... At the published spec, it's only about 2% delta. That's around the same between my 20" 285&305/30/19 G3's I run with my sons and the 19" G3R's I typically run. I have never felt or seen any anomalies between them as far as TCS other than the G3's will have more TCS intervention if driven the same way as the stickier G3R's. You are correct that if too much difference in stagger or overall height / circumference, things will start to act up. Not sure what that % is, but, it looks to be beyond 2-3%.

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