[Evansa22]

http://m.bmrsuspension.com/?page=pro...&maincatid=120
https://www.splparts.com/2016-6th-gen-camaro/
These are the ones I've found, believe the toe rods out back can help with toe change. Also looking at front tension rods to adjust castor

[Zl1+911]

Having gone through a few sets of GY3Rs, and tried a few different things, here are my learnings till date -

1) I don’t think any one thing completely helps
2) BMR toe arm with lockout nut
3) alignment - see below
4) cold GY3Rs and a fast lap don’t go together- this causes premature wear on the inside - I do my first session with slightly higher pressure- start at 31 front and let them go up to 37/38, bleed air after first session to hot 35 fronts
5) if you need to drive to and fro to the track on these - keep them at 35 or higher
6) check insides after EVERY session and Flip as needed - both left to right and inside outside

[5thgear]

Finally tried the GY 3R on track after trying Nitto Nt01 and a set of Pirelli slicks take offs.
Slicks didn’t go well for me. Corded the middle of one of the rear tires on second session.
Nitto didn’t have good grip. Didn’t give me confidence.
Now the GY 3R which I should have tried first. Approximately 3 sec faster than Nitto. Advance level top 5 lap times for that day.
Alignment for the front is Zero Toe, -2.9 camber.
Front GY 3R inner corded bad in approximately 7 sessions. The rear still ok for another day I think.
It would be nice to find the exact source of this wear or know how to minimize it.

[Zl1+911]

what was the starting tire pressure (cold) before you went on track? was this with exclusive track driving?

[mlee]

Originally Posted by 5thgear

Finally tried the GY 3R on track after trying Nitto Nt01 and a set of Pirelli slicks take offs.
Slicks didn’t go well for me. Corded the middle of one of the rear tires on second session.
Nitto didn’t have good grip. Didn’t give me confidence.
Now the GY 3R which I should have tried first. Approximately 3 sec faster than Nitto. Advance level top 5 lap times for that day.
Alignment for the front is Zero Toe, -2.9 camber.
Front GY 3R inner corded bad in approximately 7 sessions. The rear still ok for another day I think.
It would be nice to find the exact source of this wear or know how to minimize it.

That really surprises me with zero toe. My 1st two sets wore perfectly with the stock -2.7 track camber on a good track. With just a little street driving on this setup I corded the insides though.

Fast forward to the set I just completed on a very rough track known for eating tires my insides corded out. Was not expecting that since I hadn't changed anything. Your tires do look pretty rough. Maybe track surface contributed along with a little street driving.

[Zl1+911]

Originally Posted by mlee

That really surprises me with zero toe. My 1st two sets wore perfectly with the stock -2.7 track camber on a good track. With just a little street driving on this setup I corded the insides though.

Fast forward to the set I just completed on a very rough track known for eating tires my insides corded out. Was not expecting that since I hadn't changed anything. Your tires do look pretty rough. Maybe track surface contributed along with a little street driving.

I now go with negative toe for this exact reason. I get no inside wear now. It could be other things too - but negative toe helps for sure. I was tired of destroying new set of tires in few sessions on the inside.

[cdb95z28]

Look at the shoulder on the tire in the first picture. That is not a toe issue. It's abusing the shoulder. Whether it is low pressure combined with aggressive early lap driving and/or inadequate camber dynamic camber control is the question. I've run toe in on my Gen5 and have and the same wear of my 3R.

The graining pattern on that shoulder/sidewall is similar to what we can see on the outer shoulder/sidewall of a tire with inadequate negative camber, where the tire rolls over the shoulder. It rolls so much that the sidewall is getting into the track surface. This is that in reverse. Not enough positive camber (dynamically) or too much negative camber. It's happening to the inner/less loaded tire during a turn. Now when I say not enough positive camber on the unloaded inner tire, it most likely doesn't go into positive camber. Atleast not when the static camber is high like we run on our cars.

In reality, as the car rolls, that inner unloaded tire moves away from negative camber. But on MacStrut cars, the camber curves suck so much that there is still alot of negative camber on that tire, and it ends up dragging that inner shoulder as the car proceeds thru the turn.

ZL1+911 askes a good question. I think guys are going balls out on lap one with the low recommended pressures. I'm guilty. For the ZLE, the recommended cold pressure is 26psi. In my experience, that seems like asking for trouble as far as shoulder wear goes. If a driver has discipline on those first 2 laps, then that goes a long way to helping the tires. It's a double edge sword. I'd like to see the outer shoulders of those same tires.

But I think this also points to an inherent flaw on the fronts of these cars because of the MacStrut. The camber curves suck.

Other variables like track surface/layout, etc. probably matter too.

[cdb95z28]

Originally Posted by Zl1+911

I now go with negative toe for this exact reason. I get no inside wear now. It could be other things too - but negative toe helps for sure. I was tired of destroying new set of tires in few sessions on the inside.

How much toe in do you run? GM recommends toe in for all of the 1LE cars

[5thgear]

Originally Posted by Zl1+911

what was the starting tire pressure (cold) before you went on track? was this with exclusive track driving?

This was a brand-new set with street driving only limited to driving to the track which is 30 miles away. Had pressure at 35 PSI to drive to the track. At the track, I lowered pressure to 27 PSI. I was signed up in two groups with 20 mins in between. First session, ambient was low 50, circulated for 15 mins at an easy pace to put heat in the tires to get them ready for second session. For reference lapping at 2:05 for three laps then worked my way to 1:52.
Second session I was running 1:49 range and third session best 1:47.9.

Hot pressures were around 32 PSI.

Originally Posted by mlee

That really surprises me with zero toe. My 1st two sets wore perfectly with the stock -2.7 track camber on a good track. With just a little street driving on this setup I corded the insides though.

Fast forward to the set I just completed on a very rough track known for eating tires my insides corded out. Was not expecting that since I hadn't changed anything. Your tires do look pretty rough. Maybe track surface contributed along with a little street driving.

Track is Auto Club speedway Roval. 2.3 miles course that connect to the oval. Its a stop and go track. hard on the gas and hard on the brakes so I am sure hard on tires as well. The banking is not easy on tires either. Just wanted to see if anyone have any comments or suggestion that would help the tires not to cord like this.

[Zl1+911]

Originally Posted by cdb95z28

How much toe in do you run? GM recommends toe in for all of the 1LE cars

post #58 has my alignment settings

[Zl1+911]

Originally Posted by 5thgear

This was a brand-new set with street driving only limited to driving to the track which is 30 miles away. Had pressure at 35 PSI to drive to the track. At the track, I lowered pressure to 27 PSI. I was signed up in two groups with 20 mins in between. First session, ambient was low 50, circulated for 15 mins at an easy pace to put heat in the tires to get them ready for second session. For reference lapping at 2:05 for three laps then worked my way to 1:52.
Second session I was running 1:49 range and third session best 1:47.9.

Hot pressures were around 32 PSI.



Track is Auto Club speedway Roval. 2.3 miles course that connect to the oval. Its a stop and go track. hard on the gas and hard on the brakes so I am sure hard on tires as well. The banking is not easy on tires either. Just wanted to see if anyone have any comments or suggestion that would help the tires not to cord like this.

my thinking (based on my learnings) and what i would do -

1) increase front tire pressure. 27 cold might be ok, but already drove to the track and then reduced to 27, so the true cold might be equivalent of 24?
2) I aim for no lower than 34 hot (ok to get to 35 and 36) for fronts. I have observed significant inside wear (roll over wear - like urs) by starting low and not getting to 34+ for a hot lap
3) consider more - toe
4) consider BMR toe arm in rear to protect toe changes

[5thgear]

Originally Posted by Zl1+911

post #58 has my alignment settings

Interesting. I noticed your alignment sheet says Jeff cook which you have referenced that it is someone else alignment. I believe Jeff have couple of records in CA with his ZL1 1LE and extremely fast guy. Never thought of negative toe but I did have mine at zero toe. I will have to try it out and see.

[Zl1+911]

Originally Posted by 5thgear

Interesting. I noticed your alignment sheet says Jeff cook which you have referenced that it is someone else alignment. I believe Jeff have couple of records in CA with his ZL1 1LE and extremely fast guy. Never thought of negative toe but I did have mine at zero toe. I will have to try it out and see.

yes they are indeed Jeff's - i have replicated them shamelessly.

[Zl1+911]

Originally Posted by 5thgear

Interesting. I noticed your alignment sheet says Jeff cook which you have referenced that it is someone else alignment. I believe Jeff have couple of records in CA with his ZL1 1LE and extremely fast guy. Never thought of negative toe but I did have mine at zero toe. I will have to try it out and see.

I should have stated this earlier - the rear toe lockout from factory is notorious for not keeping toe as is on track (which in turn impacts the front -dont ask me how). I would lose my settings every track day. I went to the BMW rear toe arm and that has helped a lot to keep toe intact at track day.