X25

Not sure, but I think the way to do it is to switch to track mode, and then pressing and holding ESC button until it displays "ESC and TC off" on screen .

RafGTS

Originally Posted by RafGTS

Thanks.
My settings on the MCS 2WNR are C=5 R=10.

“Curious, that's quite a bit lower compression than I'd think. I've basically watched through MotoIQ series of videos, and the drive was starting to get bumpy in settings after 8”



Thanks for the link. Lots of good info. No particular reason for my settings other than Ciccio didn’t want to share any recommendations so I used what MCS listed as initial settings and started to move up slowly from there. The only track I really felt the suspension was significantly underperforming compared to my previous cars was the bus stop at WGI where the C8 gets unstable after the first apex and make me significantly slower through the following two turns. I was going to continue to adjust for it at my next event there.



”Also found a review on Paragon rotor rings:
https://www.gtrlife.com/threads/para...tested.321176/”

Does anyone know any other manufacturers also producing spares? Also, any info on Paragon brakes?”

- I bought their replacement rings a few weeks ago as a backup set but the AP rings are still OK so I will report back later.



Re: NPP actuators. I also get error codes that I have to clear every track day. They squeak more now than before. I’m curious if the new actuators will fix the issue for you. Did GM rev the part number?

RafGTS

I've also found a cost-effective splitter option to balance the larger wing. These splitters are the first to go if you put the wheels off so I didn't want to spend $1000s. I've tested the AVL splitter at two events and it's held up very well. The installation takes a few hours but you can't beat the price and apparently, the company has been in business for a while, although focusing on the Mustang platform.

https://liquivinyl.com/collections/f...xoC7N0QAvD_BwE

X25

Rotors: I'd love to hear your thoughts on the rotors and see how they hold up; please make sure you do report : )
NPP actuators: I have added spacers as I showed in pics on both sides, but I only replaced the actuator on the driver side, and left the old one on the passenger side. I did do a track day yesterday. The check engine light came ONCE, and it was for the older actuator I've left on the passenger side. There has been no code from the replaced side. The actuator flaps squeak as usual, but I suppose that's expected, since the squeak is coming from inside the exhaust (you can make the same squeak by moving the flap with your hand). The part number for the new unit is same as the old one as well, so I don't think there's been a change. Anyway, I'm no longer getting the code from the replaced side, and I'll replace the other side as well over the weekend; I'm happy : )


SR21 pads and updated ones
I checked the part numbers, and both the pads on the car and my spare kit have the same part number: BE2167. I've also ordered a new set that I've received, with batch number BA4141. Considering my spare set was old batch number as well, and I've already had quite a bit of wear on the new pad after just one more track day, I will take them out now. I will reach out to EBC and ask if they can replace my spare set as well as the set I used on the car with the new batch. If they can send me the parts in a few days, I can test them out the weekend of May 24th.



This is the state of the pads after just one more track day. The orientation is exactly as how they were installed on the car (i.e. left corner of the car had the pads on the left corner, with inner pad on the inner side). The outer pad of the driver front is the newly replaced one from my spare set, which is why it's a bit bigger than the others. I've also put on brand new pads next to them for reference.


Front pad


Rear pad


The pad I recently bought' it was delivered last week. It has BA4141 batch number, and looks a bit dirtier than other spares.


The one on the left is the new batch, while the one on the right is the old batch (from my spare set). Observe the difference in material color and composition. Clearly, there's something different in its compound with no shiny particles in the new batch.



Inner shoulder wear on tires
After one more track day, the wear is becoming a bit more clear as well. There's more inner shoulder wear than outer shoulder wear, and this is most pronounced at the rears, and especially on the driver side. Makes me think the rear camber is far too much (unless there's another reason causing it). In many many years of going to track with various cars, this has never happened : ) FYI, the camber values are -3.5 Front, -2.8 Rear.



Rear right


Rear left


Front right


Front left


It's clearly a bigger problem at the rear. I wonder if I should pull the numbers back to -3 / -2, or if I should still leave a bit more than -3 up front and/or -2.3 or so at the rear. I will need to decide before Monday since I'll get the alignment then.

Ksteckba

for reference, this was how my rear SC3’s wore with -2.6deg rear camber. 325/30r19 on 19x12 rear. Outer shoulders corded first by a little. On grippy tires I’m guessing the shoulder would’ve corded a lot sooner.

X25

That looks pretty good. On my C7 Z06, outer shoulders would wear so much faster than the inner side.

I should note, I've never seen this wear pattern on any of my cars, before. I did not see this much obvious inner wear on the R7s I've used late last year, either, but definitely see it on CR-S tires (the pics above are CR-S).

I'm thinking about reducing rear camber from -2.8 to either -2.3 or -2, but not yet sure about fronts. They're currently at -3.5, and perhaps a less of a drop to -3.2 or leaving them alone would be fine, too.

Whatever the case, I need to decide by Monday before alignment: )

In other news, EBC USA fast-shipped me a set of rears of SR21 with their updated compound, and now I have an updated set of both fronts and rears. I'll try them out next time and see how they wear. Fingers crossed!

AHP

CR-S v2 and I'm at - 2.5° rear and am wearing the outer shoulders more than the inner but it's not dramatic. If I were to get the car realigned I was planning to add more camber as a result. However, I've also considered it could be the bushings flexing vs not enough camber.


How much Toe are you running front/rear? The GM spec is 0.1 and IIRC we cut that in half. My fronts are wearing fairly even.

X25

I forgot, are you on aftermarket coilovers as well? A friend also suggested bushings, stating he's had similar wear patterns on his C7, which all disappeared after switching to monoballs. I'd like to think this is not the case for me, since the car is very new and I put on the Z06 LCAs on it when I got the car anyway, but not sure. Indeed, my toe is 0 up front, and 0.05 at the rear per side.

To be honest, I'm now even wondering if my toe or camber setting has moved at the rear after alignment...

Could it be wrong suspension settings, like perhaps too much compression? My mind is running wild... It was at 9C/12R.

AHP

Ah.. RE: alignment and tire wear I'm referring my C8. It's all stock except alignment and wheels/tires (and its a heavy 3LT HTC, FWIW). That toe shouldn't be causing the inner wear so I also wonder if something moved. Usually enough movement to cause odd wear would result in the steering wheel no longer being straight, though. At least that's my experience.

I also have a C7Z and have commented in here about AP kit brake pads so I should specify which car I'm referring to.

X25

Below is my update in March with R7 tires which wore very well, and I had the same -3.5 / -2.8 camber; something is not right. The only differences are using CR-S tires and I bumped up compression to 9 from 8. Maybe it skips if it's too high compression? Anyway, I'm starting to think I should leave alignment alone and possibly check on coilover settings, or other possibilities...

Ksteckba

You may start wearing more evenly as your pace with the car increases. Could drop down to a less grippy tire to find the limits a bit more and learn the car. Remember, optimal alignment specs correspond to optimal use of the tires to their max.

oooseun

Highly doubt pace/skill issue is the problem here. These are 3 track day old tires, CR-S as well (maybe common denominator, but i've seen the rt660 do this as well), i pasted a similar picture earlier but this is much clearer. I have -2.9 in the rear (and 3.2F), but you can see my outer shoulder is GONE, and my inside is also worn a lot. These results both tell me to increase and decrease my camber in the rear. Fronts have 3.5 and they're wearing beautifully. There's something up with the rear tires of this car. On top of this, i go through rear tires at 2x the rate of the fronts (again see image).

PRE-Z06

CRS has a softer sidewall relatively speaking and the mass of the C8 works it hard. What’s the camber actually like under a load instead of static? As a stickier than stock tire is going to work the suspension harder as well.

Ksteckba

I wasn’t referring to your case. I was referring to a case where the inner shoulders are only worn, using high grip tires and a not unreasonable amount of camber…

As an extreme example, if a pro driver has x amount of camber and perfectly even wear across the tread, it is almost 100% likely that a first day gumby will have inner shoulder wear which is higher than the outer shoulder.

Uneven wear on both shoulders, greater than the center, can have several combinations of causes that can have you chasing your tail though…an interesting example (unrelated to this chassis): E9X M3’s have a speed sensing LSD from the factory (vs torque sensing) which means that exiting a corner the inside wheel actually has to spin up to some degree before transfer to the outside wheel. Depending on state of modification to the vehicle and wear of the oem lsd, this can lead to significant inside shoulder wear, as a partially unloaded and cambered inner tire is more susceptible to quickly spinning up exiting a corner. Generally the outer shoulders are also getting hammered more than the center on such a heavy and high cg vehicle. I have seen many people confused by this in the E9X community.

That being said, something as simple as pressure being too low can also cause excessive wear on both shoulders. Every case is different.

bc928

Is there a rear suspension geometry that is allowing the outer rear to un-camber with enough force? With ~2-3 degrees camber, ANY toe or toe movement will drag the inner side as we all know. Hence the 0 toe. However if the car movement through a turn has the inner tire scrubbing through the arc, instead of following it, it can also drag the inside. How does the car feel on initial throttle after apex? I can seem to feel (c7) when the rear camber is not enough as you load MORE on the outside to accelerate while still having load from the corner. I would mark the shoulder and sure enough would show it. But not the inside too with no toe.

The car is clearly doing something else unexpected.

X25

Thank you all for chiming in with your take on this wear issue. C8 is an undeniably different platform from other GT cars as well as all other former gen Corvettes. At this point, I am thinking if my increased compression that I was also experimenting with has caused the rear to 'skip' a bit in corners, causing skidding as well. When you look at the wear of the Hoosiers I've used before this one, the wear looked excellent, with a wee bit more wear at the outside shoulders, nicely increasing the life I could get from those tires as well.

Keeping all these in mind, I've decided to revert my compression setting on coilovers back to 8 in case it was the culprit, and will leave the alignment as is at -3.5 / -2.8 camber with zero toe front, and only 0.05 degrees toe in at the rear (and factory spec caster). I'll be driving R7s, and will observe the tire wear. If it wears great again and lasts a long time, then great, I don't need 200 tw tires if track tires last very long time anyway!

I will also be testing the reformulated EBC SR21 brake pads, which I'm also wondering a lot about. If they hold up well, then they might make a great option for many looking to get an affordable, yet durable set of pads. Well, that was the initial promise anyway : ) I will also install temp stickers on calipers (if I don't forget), and will provide that data, too.