[khcoaching]

Originally Posted by eimarshall

Nice Ken!! Way to go!! You look very composed and controlled on all those laps. Not nearly as frantic as the 3R laps.

Get that Supra outta there!! lol!!

I can't even begin to tell you how much easier the car is to drive.

Here's a video of my last session where I lowered the pressure and worked on my driving and for sure my hands were busier, but still very controlled.

https://youtu.be/aNy1M8N-y-0

Ken

[GunMetalGrey]

Originally Posted by khcoaching

And in other news, this happened -

2019 ZL1 1LE -

I was lucky enough to have a local car offered to me at a great price. Has some nice upgrades, but also needs some TLC.

Congrats! Happy for you! A good driver/coach like you deserves a car like that!

[GunMetalGrey]

Originally Posted by khcoaching

And in ZLE news.....

I finally got a chance to start checking out and working the ZLE. Pretty darn nice car! A lot of little things to get it up to scratch, but all pretty easy, just time and $$.

The car has some pretty cool upgrades:

- MCS 2 way
- Custom cage and rear seat delete
- APR Wing

The to do list is pretty long, but is basic maintenance, all new brakes, exhaust rattle, adding adjustable rear arms, update the alignment, along with a bunch of other misc stuff.

So far I have:

- Replaced rear tires
- Bleed the intercooler (Weapon X)
- Brake caliper clean and service
- New rear rotors and pads (Ferodo 1.11)
- New Giro front rotors and pads (Ferodo 3.12)
- ARP extended front studs
- Data logged for the tune
- Lift pads
- Brake ducts

I'll drop the car off at the dealer next week to leave for the alignment and hopefully drive it on track early May - can't wait!

Should I start a separate thread for it?

Ken

Hey just a thought, why not go with Racing Brakes front rotors? They are larger than the Girodisc (same as stock OEM) but also with directional vanes, and apparently only .2lbs heavier than the Girodisc fronts at 28.2lbs. I just ordered a paid and I am selling my lightly used Girodisc fronts (half a track day and twice a month west coast winter driving with stock OEM pads)

[khcoaching]

Originally Posted by GunMetalGrey

I'm very interested to see what you think of the other tires you'll try vs the SC3R's

For my 18s, I used the Z214s and was beyond impressed with them. Mega tire of the money. If I get 2 days at pace with them, totally worth it. For the 19s, I've been impressed with the Kuhmo V730s and want to try them along with the Nankang CRS.

I've driven the RT660s, RE71S and A052 and they are all good and have their own pros/cons, but they are all on the high end of the price points for 305/19 square and the other options seem to be as good, for lower money. I'll report back and do a review after I try them.

re - the front rotors. I've had a few sets of Girodic and while expensive, they seem to be worth every penny.

Ken

[GunMetalGrey]

Originally Posted by khcoaching

#14 Ridge Motorsport Park - April 26, 2023

Without Chicane 1:46.22

Some interesting updates. I signed up for an SCCA "Track Night" since it was cheap and close, I thought it would be a good event to test a few things. I wanted to try a "softer" setup to see if I could get the tires to roll over more as well as address the ice mode issues with different brake pads. I secured a mild sponsorship from Cobalt and have used their pads on client cars, so I was stoked to try a front and rear set.

The changes were:

Sway bars - I went from #2 to #1 (softer) for both the front and rear as the balance of the car is fine, I was just hoping to get the tire to bite a bit more.

Brake pads _ Cobalt contacted me about trying some pads and recommended the XR1 front and XR3 rears for the Camaros. We chatted about my recent ice mode issues and they mentioned it could be due to a too aggressive rear pad. They sent a set of XR1 front and XR3 rears to replace my basically new Ferodo 3.12s and 1.11 rears.

Results -

We did 3x20min sessions and I had maybe 3 clean laps the entire evening. That said, it was enough to figure a few things out and get solid data. Temps were warm! 70+ degrees was a nice change from every other time out this year.

Sway bar adjustments - Bottom line, the car did feel like it dug in better, but I went slower. My official PB is a 45.0, and I went 46.22 feeling like I drove a bit better. (see data) I honestly couldn't tell a lot of difference, other than the car felt a bit freer. Same balance and I did feel like rear grip on exits wasn't quite as good, but data says otherwise. Also note: The temps were over 20 degree warmer and the 3rs worked better in these conditions
For the last session, I dropped to to 31 hot and I feel this was also an improvement.

Data shows where I worked on my driving and found some pretty solid improvement. You can see where I was braking early to not get ice mode, but as the tires got properly hot, no issue there and I need to build some confidence with this.


Brake Pads - The ice mode issues have only showed up recently. I never have had an issue until I got the last alignment and part of me think the extra camber in the front is the issue, though I think that is an emotional response. I think the actual issue is I am pushing my braking later and later and the 3rs, just aren't that good. My contact at Cobalt thought maybe my current pad election may be the cause.

The Cobalts were a bolt on and go. My Girodisc rotors came new at 36mm and during this change I was qt 35.8mm and the MIN is 34mm, so no issue there. They required basically zero bed-in other than an easy out lap. I'm a pretty big Ferodo 3.12 fan and while they work great and are pretty easy on rotors, they are not easy on your wallet. The Cobalts have slightly less initial bite, but better power in the middle of the pedal stroke. I'm a fan of these and the data shows less brake pressure is needed. (Though I was braking early) They do seem to be harder on the rotors and I'll my eye on that.

What about Ice Mode? Yeah, I got it twice in earlier sessions. I really think this comes down to the 3rs and not anything do with the brakes. The last session where I lowered the psi, I didn't have a single issue and was working my way up to my normal brake points.

Here is the data: Note - you can see where I was bit better in some spots, but braking early in others. If you look closely, I also was getting slightly better drives.

So...this has turned into a bit of a disappointment. When I did the first run, the car felt slow and MPH was way off....like way off. The top speed was down 4mph. For the 2nd run, I loaded the stock tune and the speed came back. When these things are stock, I think they are tuned pretty well and are very finicky to conditions. For proper results, I think the car need to be tuned in person and not remote tuned.

I'm doing a time attack Sunday and this is where I'll running the Hankook Z214s. They are 315/30/18 and I'm looking forward to what is hopefully a lot more grip. Finger crossed. I also went back to my baseline swaybar settings.

Here are a few pics, including what I think I an optimistic 0-60. The 3R tire wear is pretty good for over a day of hard laps!

Ice Mode!

Ken I have had 3 episodes of this in only 3 half track days last summer (so it seems to be getting worse) and it almost wrecked my car each time (almost crashed into dirt banks). I really need to know more about this, can you explain why the SC3R tires would have anything to do with this.

I had this issue with the Trofeo R tires as well. I have Hawk DCT 70 pads as well.

[GunMetalGrey]

Originally Posted by khcoaching

The tires were impressive. I'll take some pics of the wear, but they seemed to wear well, have instant grip and feel like an R7 Hoosier. Their consistency is out of this world. EVERY hot lap I did was in the 44s, crazy. And.....no ice mode. The Cobalt pads worked great although I did experience some ABS when I lost my mind a bit on the brakes.

Did you change your braking style at all? Do you think it was the tires or the pads that helped you avoid ice mode? I've heard/read that applying the brakes gradually helps as does not transitioning from throttle to brakes so quickly with two foot auto driving however considering your car is a manual I'm assuming you had a reasonable time delay between throttle release and brake application?

Also something to note, my car's engine often does not slow down the car like it should after taking my foot off the throttle, it often takes a few seconds for it to start acting like there is absolutely no throttle, (it almost acts like there is a maintenance throttle when there is none) and then after a few seconds when the engine is at a lower rpm than it previously was, it will start slowing the car down more than it was just a few seconds before in the same gear.

I am particularly concerned because I think that could make "ice mode" happen more often, which it has been for me.

I talked to my tuner, Dyno Steve and he said "Sounds like the bypass valve spring needs to be tighter to bypass the boost"

[khcoaching]

^^I think tires are the main culprit vs the more aggressive brake pads. I had zero issues with the Z214s (and Toyo RRs) finally going back to the brake markers I wanted. I think the reason I didn’t have issues before was all my previous times with this brake combo was in warmer weather and the tires didn’t get hot enough.

For sure building pressure the first 5-10% of braking helps, but at pace, my 5% needs to be very short. I did change my braking with the 3Rs in cooler temps, going to them earlier and lighter initially.

Ken

[GunMetalGrey]

Originally Posted by khcoaching

^^I think tires are the main culprit vs the more aggressive brake pads. I had zero issues with the Z214s (and Toyo RRs) finally going back to the brake markers I wanted. I think the reason I didn’t have issues before was all my previous times with this brake combo was in warmer weather and the tires didn’t get hot enough.

For sure building pressure the first 5-10% of braking helps, but at pace, my 5% needs to be very short. I did change my braking with the 3Rs in cooler temps, going to them earlier and lighter initially.

Ken

Hmmm but why would the Toyo RR's be better than the SC3R tires since they have less grip? Warmer weather I guess

I would think pads and tires and temps should all be key factors considering higher friction brake pads would lock up less sticky tires more easily though, right?

My experience with ice mode has happened at the start and middle and end of sessions. I've only ever gone on 20 plus degree Celsius days (so never cool out). It didn't happen to me at all the first year I went when I had just the stock OEM SC3 tires and stock/OEM pads. Then I upgraded to SC3Rs and Hawk DCT70's and started driving harder and braking later...

It still happened to me after I had the smaller Girodisc front rotors and slightly less grippy Hawk DTC 60 pads on the rear (fronts still had Hawk DCT 70s) but those are probably relatively minor changes.

Maybe I'll try slicks and Cobalt XR1's on the front and XR2's on the rear since the Trofeo R had the same issue

Lastly, have you tried substituting your EBCM braking module for one from a ZL1 1LE that I believe has been calibrated for stickier tires? I have switched mine without testing the results but I got a "Service brake assist" message when bedding the brakes and engaging ABS

[khcoaching]

I have not tried that EBCM, but would try it for sure. The Cobalt rep mentioned that the ice mode can happen with too aggressive rear pads and I’m using XR3 rears at the moment.

[carguy55]

Glad you like the Z214s

[GunMetalGrey]

Originally Posted by khcoaching

I have not tried that EBCM, but would try it for sure. The Cobalt rep mentioned that the ice mode can happen with too aggressive rear pads and I’m using XR3 rears at the moment.

The only thing I don't understand about the aggressive rear pads is as long as the bias with the front is kept the same as stock/OEM wouldn't that not create an issue? I think a read/heard that even guys with stock set up were experiencing ice mode though too... I don't know... Please keep us posted on your experience with ice mode at the track

Re EBCM; Just make sure it comes from a manual not an auto (I believe it also has to have all other options the same like NPP exhaust)
Used they are only $70 on eBay but brand new they are expensive! But brand new won't work anyways since they would need to be programmed with a VIN

I changed the traction control module as well to one from a ZLE, it did not work when it was from a manual but seems to have worked fine from the next one I got from an auto.

[khcoaching]

Originally Posted by GunMetalGrey

The only thing I don't understand about the aggressive rear pads is as long as the bias with the front is kept the same as stock/OEM wouldn't that not create an issue? I think a read/heard that even guys with stock set up were experiencing ice mode though too... I don't know... Please keep us posted on your experience with ice mode at the track

Re EBCM; Just make sure it comes from a manual not an auto (I believe it also has to have all other options the same like NPP exhaust)
Used they are only $70 on eBay but brand new they are expensive! But brand new won't work anyways since they would need to be programmed with a VIN

I changed the traction control module as well to one from a ZLE, it did not work when it was from a manual but seems to have worked fine from the next one I got from an auto.

At some point I'll try the EBCM if I can find.

Still trying to figure out next steps with the SLE, I'm super happy with it and the only want would be more power, but I'm not investing in engine work.

Ken

[GunMetalGrey]

Originally Posted by khcoaching

At some point I'll try the EBCM if I can find.

Still trying to figure out next steps with the SLE, I'm super happy with it and the only want would be more power, but I'm not investing in engine work.

Ken

Cool, yeah there are lots of used EBCM's out there for $70 or less

I have the stock OEM supercharger off my ZL1 if you want it for $1000, but not sure if supercharging that engine is the best idea for longevity when tracking the car as much as you do

[khcoaching]

Another update looking at data -

The SLE really suffers on the 4-5th shift, essentially lagging in acceleration just after the shift is made. At The Ridge, the top speed is great enough you can't hold 4th gear and even when I experimented with bumping the rev limiter, it still hit it. (I'm back to stock now) This last weekend, The 315/30/18s were about .5 inch shorter than the 305/30/19s I've been using and my top speed were right at the best I have run.

So what does the data look like?

Graph #1 is a solid run, matching the speed up until the 4-5th shift where you can see with the 26.3" tire (305/19) falls off and the 25.8" tire (315/18) keeps going.



Graph #2 is with the bumped rev limiter, which shows how the speed stays close to even, but hits the rev limiter early



The car clearly likes the shorter gearing and given the stock motor and stock tune, when it come to a time attack, the shorter tire will be the way to go.