[GunMetalGrey]

Originally Posted by seanblurr

I believe the reason ZLE's cord the inner edge of the tires is because of a dynamic toe change during braking and or cornering. I do not believe it is related to camber at all. At least, the cording that track guys are seeing.

R7's were the tires that need more camber and were cording the outer edge.

I simply swap fronts out every few sessions so their wear will mimic that of the rears, thus allowing me to run the "set" at an even wear pattern for 14 odd heat cycles. That way I'm not starting with a fresh set of fronts with rears that already have 7 cycles. It also allows me to complete a full weekend without going to the tire store.

Good insight on the dynamic toe change, thanks for clarifying.

[Mountain]

Originally Posted by seanblurr

I believe the reason ZLE's cord the inner edge of the tires is because of a dynamic toe change during braking and or cornering. I do not believe it is related to camber at all. At least, the cording that track guys are seeing.

R7's were the tires that need more camber and were cording the outer edge.

I simply swap fronts out every few sessions so their wear will mimic that of the rears, thus allowing me to run the "set" at an even wear pattern for 14 odd heat cycles. That way I'm not starting with a fresh set of fronts with rears that already have 7 cycles. It also allows me to complete a full weekend without going to the tire store.

Think this could partially be mitigated by installing the BMR spherical bearings into the large end of the front lateral/radius link (the front-most link)? That link has a very large, rubber bushing and all of the models Camaros have some version of this large busing - I'd have to think that there is some movement during cornering and braking that causes some toe change (toe-out during braking for both wheels and the pull on the inside wheel during cornering causing toe out at that one wheel).

[seanblurr]

Interesting idea, only one way to find out.

[Mountain]

Originally Posted by seanblurr

Interesting idea, only one way to find out.

I would think the only way to truly verify this would be to run a # of events, on the same tires, and see if the inside wear is present or not.

It seems to be that this wear can be seen over about 4-5 events (or 16-20 20-minute session/320-400 minutes of track driving).

The other way would be to monitor the temperature of the tread contact patch over a few track laps, noting temperature of the inside tread on corners and braking. This would require $$ in a nice datalogging IR pyrometer setup to monitor tire tread surface.

[TrackClub]

Originally Posted by GunMetalGrey

Thanks for the further detail.

I thought I recalled reading on this forum that drivers were cording the insides of these tires because they drove the car on the street as well as to and from the track but apparently that’s not the only reason, or the reason. It make me wonder how much of an impact camber level plays and if the reduced handling (with less camber) would be worth the potential increase in tire life span.

I also seem to recall reading that some drivers were cording the outsides of these tires because they didn’t have enough negative camber, but maybe I’m getting that confused with the R7’s...

Also to make sure I’m not missing something; Do you change your 2 sets of front tires every 2 sessions for any reason other than just to make sure they wear evenly at the similar rate?

Or are you accomplishing something over and above the fact that just having 2 sets of front tires will mean you’ll get twice as many sessions compared to having 1 set (such as having more margin/buffer in case 1 set wears faster than the other)?

I’m far from an advanced driver, just started last year, but my local track is very technical and I drive hard, I guess only time will tell how long they will last for me...

No matter how you skin the cat here, G3R are much softer rubber and (as i understand) have less rubber (vs G3). So really there is not much you could possibly do (camber or otherwise) to somehow make them last long.

Also, as with any extra soft tire, inducing understeer on entry and sliding them will finish them off real fast. So you'll have to drive "hard" but also very neat and tidy (aka "smooth"), as on any slick/near slick rubber. That's one of the reasons harder compound "street" tires are much better to learn on, especially of one has a tendency to still overdrive the car.

PS Tread has nothing to do with dry traction (and that's why slicks have no tread at all). Tread is there for water evacuation (and DOT certification) and only this function gets affected (possibly) if you flip a tire. Exception should be noted when a tire has different compound on outside vs inside shoulder. But for an average folks out there like us, it proly doesn't matter much either. Cheers!

[seanblurr]

Originally Posted by Mountain

I would think the only way to truly verify this would be to run a # of events, on the same tires, and see if the inside wear is present or not.

It seems to be that this wear can be seen over about 4-5 events (or 16-20 20-minute session/320-400 minutes of track driving).

The other way would be to monitor the temperature of the tread contact patch over a few track laps, noting temperature of the inside tread on corners and braking. This would require $$ in a nice datalogging IR pyrometer setup to monitor tire tread surface.

If I could get anywhere near 16 sessions out of a front set of G3R's I would be a happy man! I've never gotten more than 8 before cords show.

[GunMetalGrey]

Originally Posted by seanblurr

If I could get anywhere near 16 sessions out of a front set of G3R's I would be a happy man! I've never gotten more than 8 before cords show.

How compromised would you say the traction/grip is once the inner cords start to show? Minor or significant?

For example if you ran your entire 8th session with the tires in this condition.

[GunMetalGrey]

Originally Posted by TrackClub

PS Tread has nothing to do with dry traction (and that's why slicks have no tread at all). Tread is there for water evacuation (and DOT certification) and only this function gets affected (possibly) if you flip a tire. Exception should be noted when a tire has different compound on outside vs inside shoulder. But for an average folks out there like us, it proly doesn't matter much either. Cheers!

Perhaps we just miscommunicated but larger tread blocks are better than smaller tread blocks, especially on the outside shoulder, which is why I asked the question (and obviously no tread blocks (slicks) are superior to having tread blocks.)

I didn’t think Goodyear would put different rubber on the outside shoulder of this tire because I assumed they’d have the softest compound through out given it’s performance and intended use, but I have no idea if it does or not.

I would think that despite my novice driving ability it would make a difference when pushed hard, but that’s just my thoughts.

Definitely agree about Understeer on corners and turning the wheels too sharply too quickly!

Thanks for your input TC

[TrackClub]

Originally Posted by GunMetalGrey

Perhaps we just miscommunicated but larger tread blocks are better than smaller tread blocks, especially on the outside shoulder, which is why I asked the question (and obviously no tread blocks (slicks) are superior to having tread blocks.)

I didn’t think Goodyear would put different rubber on the outside shoulder of this tire because I assumed they’d have the softest compound through out given it’s performance and intended use, but I have no idea if it does or not.

I would think that despite my novice driving ability it would make a difference when pushed hard, but that’s just my thoughts.

Definitely agree about Understeer on corners and turning the wheels too sharply too quickly!

Thanks for your input TC

Agree: larger tread blocks are better. But once the tires wear out some it really doesn't matter much as treads become very shallow anyway. But you're absolutely correct re principle.

Unsure about GYs but some manufacturers put different compound inside vs outside. I dont even bother swapping wheeels never mind paying to have tires flipped with G3s as my wear is pretty much perfect on all corners. And as much as any cording happens on the inside, the outside is pretty much done by then anyway.

Id expect softer tire will give ya more pace, assuming all else being equal and the new rims not affecting the car's balance, or PTM performance, given you still run Sport1?
But sticky tires (even slicks) dont automatically lead to faster laps as a guarantee. For that to happen a driver needs to be able to push the car further towards a new, higher limit (to make use of the extra grip). This also means being able to correct the car while going faster and at higher loads overall. In other words, driving the same as before wont produce faster laps just because of better tires. Ive seen many a beginner driver switching to Hoosiers hoping to gain pace vs working on their driver skill. Usually the outcome is pretty much the same. Usually because they dont yet have a skill of feeling the car, so cant really tell how much grip they got left. So usually they continue to get passed by the same folks as before.

Having said all that, i hope it works out for ya. You may also find that after trying really sticky tires - then going back to a street track tire - you might be faster.
All the best!

[seanblurr]

Originally Posted by GunMetalGrey

How compromised would you say the traction/grip is once the inner cords start to show? Minor or significant?

For example if you ran your entire 8th session with the tires in this condition.

I wouldn't say grip is compromised at all, but your safety is compromised. I check after every session and if I even see a hint of cords about to show through, the tire is in the trash.

[GunMetalGrey]

Originally Posted by seanblurr

I wouldn't say grip is compromised at all, but your safety is compromised. I check after every session and if I even see a hint of cords about to show through, the tire is in the trash.

Oh yeah haha, safety... I guess I should start checking too

[glamcem]

For those who can run 18" wheels Toyo RRs also have great sizes in 295/315/345-30/18" (or in SS 1LE / ZL1 OEM 20" sizes and some more ..sizes are bit awkward for 19" but still doable 295/30/19 SQ setup maybe ...so it can be used as 315 SQ or 295F/315R. I recently ordered some 18" wheels and am planning to use 295/315.

From my own experience (with the Miata) and my local track friends' (on C7 GS and C7 Z07) they're only slightly behind the R7s ( a second maybe in a 2 min lap) without the headaches of R7s.. Of course PBs will still be possible on R7s since they're also lighter while being wider on same sizes.

This setup will be about 44lbs lighter!! than the OEM SS 1LE wheel/tire combo so there's that too.

I will report back hopefully I can attend the club event scheduled next month

[seanblurr]

I'd be all over those if they offered a 345/30/18 to match the 315/30/18. Unfortunately, all they have is a 345/35/18 which is too tall.

[glamcem]

Originally Posted by seanblurr

I'd be all over those if they offered a 345/30/18 to match the 315/30/18. Unfortunately, all they have is a 345/35/18 which is too tall.

I hear you. Ever considered using 18/19" staggered setup? I know the fact they have those sizes for Corvettes.. 315/30/18 and 345/30/19 might be pretty close to overall size for keeping the same rake.

I'm not 100% sure whether or not you can keep the same proportions as stock but worth checking on Tire rack's website

Also have you ever considered 315 Sq setup since wider wheels will be used in the back and you can adjust the ride height on ZLE that might be another option. Afaik RRs typically run wide (well not as much as R7s probably) so with the added grip and already wider tires it may not be a downsizing.. besides the weight savings are tempting