sothpaw2

Hi,

I am just curious how the new C8 holds up on the Road course. I have my eye on possibly buying one in a few years but I would want it to be reliable on track without nearly as many mods as my C5Z needed.

Any experiences yet? Heresay?? If it needs something just to get through a track day in Black or Instructor group, what does it need?? I am especially interested in if it needs aftermarket diff or trans cooler installed just to keep the orings sealed. The C5Z needs that treatment.

Thanks

Andrew

smitty2919

Talk to LG Motorsports, Louis at GSpeed and Pietz Performance Tunes. They have been around C8's and setting them up for the track. They should have some good intel on them.

Each of those shops have been developing products for the C8, and I'm not talking about useless engine bay beauty covers LOL.

sothpaw2

Thanks. I will ask. I guess nobody has seen the C8 at a track event in 2020?? Just seeing it in action (or lack of it) might tell a lot. I remember losing a track session at VIR because a c6Z on R comps blew his engine and oiled down the track. The c6z engine issues became very real to me with this observation.

smitty2919

Well since the C8 recently launched AND Covid killed a lot of racing last year it's no surprise you don't see much about them. Give it time.

TrackAire

Check out this kids youtube channel where he tracks his C8 quite a bit. I think he even did a day at Laguna Seca with temps near 100 degrees. He goes into a lot of detail about his experience with the C8, tires, etc.

64drvr

Hopefully Foosh chimes in as he has been tracking his alongside his beastmode C7GS.

nakkinator

There was a C8 lapping in advanced at NCM this last weekend. Seemed to do fine, no issues - at least none that caused the car to come off track early.

sothpaw2

I read that the c7Z06 has severe engine cooling issues from factory...at least the early model years. I think the issues were more than can be solved by simply swapping to a larger DeWitt Radiator. I am hoping that the design team put more thought into power training cooling for track use during C8 development. Maybe the c7GS has less issues than Z06 because of less heat generation?
I would not even be looking to track on Hoosier R. I used Nitto Nt01.

J5isalive

Over 2000 track miles on mine so far.... Cicio Performance has developed proper coilovers for the car in partnership with MCS, LG helped us out with the aero.... the car is phenomenal. Car handles 30 minute sessions with no issue. I'll have to do a post with our experiences so far.

sothpaw2

Thanks! I am would love to read about your experiences. I am sure that many in this forum would be interested. I personally am excited about the C8 but I would want to use it on the track.

C6psi

I have tracked my C8 once since I have owned it and also have a built C6 that I have been running for around 10 years. I also have several track rat buddies that have had their C8's since early 2020. My experiences on 100% stock car aside from 20x10 upfront with MPSS and 20x12 MPSS rear. Later I found out the MP4S is a better tire than the MPSS.

- Protect the front radiator openings with screen. They will look like they have been treated to 1000 miles behind a dump truck hauling pee gravel after a few track days. I followed advice from others and had no damage with zip tied window screen protecting them.
- Stock brake pads are good for a day, well at least me at COTA with my car.
- Have a slight vibration in front rotors after tracking, my buddies all had this and swapped to Giro disc rotors with no issues afterwards.
- Never had any heating issues but the warmest I saw was 60 degrees ambient.
- Car balance is great, easy to move the tail with the brakes or the throttle.
- Understeer....I am not sure where this BS started, I saw none and I know what it feels like because my C6 will plow like a tractor.

blueray16

Also check out HiPo Driver on you tube. He has a PDR video of a 2:02:xx lap at VIR,
I'm pretty sure its still stock other than brakes and tires

Poor-sha

I have about a half dozen events with my C8. Flush the brake fluid as I boiled it doing lead/follow in intermediate group and add the required 2 quarts extra of trans fluid. As others noted the stock pads work but don't last long. I ended up putting the AP Racing kit on mine because I love their stuff and it uses the same pads front and rear as my C7 with their kit runs in front. Also, changing pads on the stock setup is a bit of a pain so this was just easy.

I do consider the car very setup sensitive and I felt the GM track alignment was too loose on turn-in but some of that could just the feel of that weight moving behind you. If you get the setup right the car is magic and you can steer it with the pedals doing left-foot braking. Temps have been fine and the other reliability concern is if you get one with the batch of bad valve springs and they let go on track you will end up with a new motor.

There are a few little annoying things. I find the square wheel and the way the cockpit tapers in towards the driver limits elbow room for fast wheel movement without hitting your elbow. If the engine dies know that you can't get it out of park so you need dolleys to tow the car. Trying to winch it on to the trailer is a pain because the car goes in park as soon as you open the door.

I didn't care for the PS4S tire on track and feel they are a step backward from the MPSS on track. On the street they are a huge improvement. I'm running the Goodyear 3R on track in stock sizes and like them much better but they are treacherous when cold.

Here's a vid from a couple of weeks ago at VIR. There's still a lot of lap time left in the car. It's consistently 3-5 MPG faster than my GS on the big straights which I attributed to the transmission. If I can get used to the way it moves I expect it will at least be in the 2:00.xx range at VIR.

J5isalive

What pads are you running on your AP Kit. i just ordered mine, originally went with DS3.12's then switched the order to DS1.11's.... heard the 3.12's will overhwelm a street tire, so i figure i'll start with the 1.11's and see how they feel and then move up to a pad with more mu. So few people have the kit on the C8 so far.

Poor-sha

I'm running the 3.12 on track and I have to agree that I can't left foot brake with them as well. We'll see if I get used to them and if not l I'll try the 1.11.

c5racr1

joined that club, 9668/9661 going to us cobalt xr1 pads. Have tracked it with GS3 and the stock PS4, GS3 is the winner there. Going to cota in April going to use GS3 and R7. I have noticed a bit more noise on the street with hawk 50 pads. I have the anti rattle clips on all 4 corners and still get a “clunk” when I apply the brakes. Anyone else get this?

c5racr1

Anyone willing to talk about set up?....I tried the factory recommended -3.0 -2.0 but went 0 toe front and -1.0 mm in the rear. Turn in was a bit slow, probably because of the 0 in the front, but was able to get on the power very early. Tire temps were within 10 degrees across the tread at 32 psi hot. No issues with overheating. When I ran that setup, i had xp12 carbotech F/R worked fine, however the next track day same pads stock rotors i had a horrible vibration under braking. Seem others had the same issue with the stock rotors. I then changed to some girodisc and used stock pads and it worked fine. Pulled the trigger on the AP kit right after that but I agree the stock rotors were crap.

JRitt@essex

Thanks for the purchase c5racr1! You will not be disappointed with our brake system. Do you have any side profile pictures in which we can see the whole car with the brakes on it? I'd love to see it.

Aftermarket racing calipers like the AP Racing Pro5000R are designed to accommodate a wide range of pads from the full array of pad manufacturers. Every manufacturer has a different specification for their version of the pads that fit a given caliper. For example, Ferodo specs their pad for our AP Racing CP9668 Radi-CAL calipers to be 152.1mm long from end-to-end. Hawk specs their equivalent pad to 150.0mm long. CL Brakes specs their version of this pad at 150.7mm in length. They establish those specs based on the characteristics of their pads. Since CL Brakes pads are sintered, they tend to expand more when heated to track temperatures. That means CL needs to leave a little more 'breathing room' for the pad to expand and still fit properly in the caliper and slide in towards the disc without binding, so their pads tend to be on the smaller side. Each manufacturer also has an acceptable manufacturing tolerance range for their pads. If you pull two Hawk pads in a given shape off the shelf and measure them, they aren't going to be precisely the same size down to the tenth of a mm. There will be some slight variance in length (and all other dimensions).
When AP Racing designs a racing caliper, they have to take the variance of pad sizes into account. They must provide enough space in the caliper for the owner to fit each manufacturer's version of the pad in the caliper. Unlike an OEM road caliper, the assumption is also that the pads are going to be super-heated to 1600 degrees F on a racetrack, which as noted above, will make the steel backing plate grow in size. Enough room must be left in the caliper to accommodate that growth.

So what does that mean for owner? It means that every set of pads, from every manufacturer is going to fit slightly differently in the caliper. If a particular pad is on the low end of the size scale across all manufacturers, and it also happened to be produced on the lowest end of that manufacturer's acceptable tolerance range, it's going to be a bit loose in the caliper when inserted cold. It may have some lateral (end-to-end) movement, which usually occurs when switching from forward to reverse, and back again. As the disc rotates it pulls the pad along with it when the car changes direction, and the result is a 'clunk' sound as the pad backing plate makes contact with the caliper body or abutment plate at the end of the caliper opening.

The pad tension kit is designed more to control the vertical movement of the pads. As with length, pad height varies by manufacturer. How tall the pad is determines how much of gap there is between the top of the pad backing plate and the caliper bridge. The pad tension kit is designed to exert a gentle downward pressure on the top of the pad via a spring, in order to mitigate some of the vertical pad movement and the resulting rattling noises.

Hopefully the above makes sense.

J5isalive

I'm installing my kit this weekend with DS1.11's, i'll take lots of pics. Very excited to get the brakes on and see how they do at the next DCRA track day. You should come down so if i have complaints or concerns or am jumping for joy you can be there to observe

Thanks for you guys getting the kit out the door so quickly to arrive by the weekend.

JRitt@essex

Excellent! Thank you very much for your support! Definitely take lots of pics. When is the next DCRA day? We're finally now getting some staff out to events, which we have unfortunately not been doing for the past year due to Covid. I need to come down so I can, ahem, test the brakes from the drivers seat. Seriously though, I'll see if I can make it out. The DCRA guys are great, and typically attend at least two days per year. We are insanely busy right now with the spring thaw however. Getting out of the office on a weekday can be extremely tough at this time of year. Thanks so much again for your purchase, and definitely let us know if you have any questions, concerns, etc.

Oh...almost forgot. Have you watched this video yet? We just shot this the other week..it is for new owners who just installed their kit. It addresses how to avoid common mistakes and get the most of out the kit. If you look at the video timeline, it's broken up by segment so you can skip ahead if the topic is irrelevant to you.


0:00 Thank you for your purchase!
0:59 Unboxing your AP Racing by Essex Brake Kit
2:41 What do I do before my first use?
4:48 Why are my brakes spongy?
5:44 What is a pad tension kit?
6:11 How do I stop pad squeal
7:01 Do I need brake ducts
8:05 Should I keep my disc splash guards
9:38 Are my brakes dragging?
11:21 Thanks and FAQ/Blog Information