I'm starting to see more and more of these for sale at semi-reasonable prices. They've been out for a few years... I'm assuming by now they've been de-bugged and any critical flaws are known? Anyone of our GRM people putting one through heavy track use with an advanced driver? Does the stock suspension let you get reasonable camber or does it take a bunch of aftermarket hardware? I know they're fast, just curious to see what problems people are having.
The cars are phenomenal. If you run a lot of track days and are fast, the clutch is a major weak point. Good chance you'll burn it and or the trans itself. Damn shame too because they are outstanding on the track.
Hmm. Don't thwy have a dual clutch automatic setup? How do they end up failing, heat? I assume it's an expensive job to replace the clutch in these things?
Yes, yes and yes. They can't handle the heat of extended track time and it kills them. If you watch trans temp and keep it cool you will probably be ok.
The front brakes are undersized. I used Girodisc two piece rotors and Cobalt Racing pads and ran into brake pulsing issues about halfway through my first track day. It seems to be a common problem. I'm looking at installing an AP racing BBK soon.
In reply to CAinCA :
Is that with the base brakes or the Z51 package? Those AP racing brake kits are not cheap, that's a pretty expensive upgrade.
With the Z51. I haven't found it to be too bad, just show them a little sympathy from time to time.
A friend has one. He is a local instructor and has done 20-30 track days with his.
The only issue he has mentioned so far is a cracked wheel (happened on track). It was replaced under warranty.
Very excited for 10 years from now when these dip into the 35k-40k range.......
SKJSS (formerly Klayfish) said:With the Z51. I haven't found it to be too bad, just show them a little sympathy from time to time.
I did some reading on the forums about this. There's a theory that the issue is that the car automatically puts the rear parking brake on when shifted into park after a session, which is leaving deposits on the rotors. There is some anecdotal success leaving the car in neutral after coming in hot from a session. Does that track with your experience?
pushrod36 said:A friend has one. He is a local instructor and has done 20-30 track days with his.
The only issue he has mentioned so far is a cracked wheel (happened on track). It was replaced under warranty.
This is encouraging.
ShinnyGroove (Forum Supporter) said:SKJSS (formerly Klayfish) said:With the Z51. I haven't found it to be too bad, just show them a little sympathy from time to time.
I did some reading on the forums about this. There's a theory that the issue is that the car automatically puts the rear parking brake on when shifted into park after a session, which is leaving deposits on the rotors. There is some anecdotal success leaving the car in neutral after coming in hot from a session. Does that track with your experience?
It's possible, but that's not my experience. I don't think the rear brakes are the issue. The front s are the ones that usually get hot.
My car has the Z51 package. I don't think my problem was from the parking brake. I could go 4-5 hard laps and then start feeling pulsing through the pedal. I took a cool down lap or two and the brakes would be good for another couple laps. Next session it would do the same thing. I drove home and the brakes were fine. I also left the rotors on when I swapped back to my street pads and there haven't been any issues.
I'm sure it's track dependent to some extent. Laguna Seca has a 3000ft front straight. I'm hitting 132mph at the end. That's quickly followed by two ~75-85mph braking points (3,4), and then three in the 110+ mph range (5,6,7).
I'm also running Nankang CR-S which are pretty sticky tires, at least compared to the stock PS4S.
Ken from KNS Brakes said that they've seen the same issues with the Z51 brakes. They can only handle so much. They've swapped to the front AP kit and the problem has gone away. Personally, I'd like to run 20+ minute sessions without any issues. I want consistency and confidence when I step on the pedal. I don't want to have to think about which lap I'm on or how hard the last couple laps have been. I think the AP kit is the only way to get there.
Once in a while I think "I should just get another Porsche". Then I spin in circles over the ridiculous price escalation, and go down every other rabbit hole, and hear things like this, and think "I should just get another Porsche".
ShinnyGroove (Forum Supporter) said:Once in a while I think "I should just get another Porsche". Then I spin in circles over the ridiculous price escalation, and go down every other rabbit hole, and hear things like this, and think "I should just get another Porsche".
Let's compare apples to apples. Are you talking a new C8 or used? For your dollar the C8 is an incredible buy. I have tons of track experience in P cars. There's nothing like them, period. However you're going to pay for it, now and ongoing. I am a huge fan of the C8, it's spectacular.
SKJSS (formerly Klayfish) said:ShinnyGroove (Forum Supporter) said:Once in a while I think "I should just get another Porsche". Then I spin in circles over the ridiculous price escalation, and go down every other rabbit hole, and hear things like this, and think "I should just get another Porsche".
Let's compare apples to apples. Are you talking a new C8 or used? For your dollar the C8 is an incredible buy. I have tons of track experience in P cars. There's nothing like them, period. However you're going to pay for it, now and ongoing. I am a huge fan of the C8, it's spectacular.
I guess apples to apples, a 3LT C8 with a big brake kit would put you somewhere close to a 4.0 Cayman GTS with a set of LCA's for camber. I suspect the C8 would be faster. Not sure which would be better for fun, trouble-free laps at pace.
A Cayman GTS is probably going to cost you a good bit more than a C8. As awesome as the C8 is, the Cayman is going to be a better track car, especially with the PDK. The C8 is slightly quicker in a straight line, but not a lot. Steering, braking and balance are better in the Cayman. Cayman will also heat the front brakes if you go balls out too long.
SKJSS (formerly Klayfish) said:ShinnyGroove (Forum Supporter) said:SKJSS (formerly Klayfish) said:With the Z51. I haven't found it to be too bad, just show them a little sympathy from time to time.
I did some reading on the forums about this. There's a theory that the issue is that the car automatically puts the rear parking brake on when shifted into park after a session, which is leaving deposits on the rotors. There is some anecdotal success leaving the car in neutral after coming in hot from a session. Does that track with your experience?
It's possible, but that's not my experience. I don't think the rear brakes are the issue. The front s are the ones that usually get hot.
It's a common problem on Silverados that tow. Hot brakes, e-brake engages, trashed rotors ensue.
Randy Pobst posted a 1:37.83 in a 2020 C8 at Laguna Seca for MotorTrend's 2020 Best Driver's Car.
He posted a 1:38.79 in the 2018 Cayman GTS 2.5T for Tire Rack's 2018 Hot Lap. The GTS 4.0 has 50 more HP but the 2.5T has more low end torque. They have similar 0-60 times. I'm sure the 4.0 would be a smidge faster than the 2.5, but not by much.
When I was cross shopping, used Cayman GTS 2.5s were priced pretty close to the 2LT Z51 C8s, roughly, $75k. At the bare minimum the Cayman would need adjustable LCAs F/R and possibly rear toe links to achieve a similar track alignment to the C8 recommended track alignment. That's about $2200 or so. The GTS 4.0 are a least $20k more for an equivalent car.
I've driven both Caymans and the C8. I think the C8 is more fun and playful. It has enough torque to spin the tires in second gear. The Caymans I've driven don't have that kind of torque. IMHO the Caymans do handle a little sharper.
ShinnyGroove (Forum Supporter) said:Once in a while I think "I should just get another Porsche". Then I spin in circles over the ridiculous price escalation, and go down every other rabbit hole, and hear things like this, and think "I should just get another Porsche".
The problem you will have now is there is no going back from the Radical.
My cousin reset the P2 lap record at Laguna Seca and I think it's sub 1:30, which would be 10 seconds faster than a C8 or Cayman
In reply to CAinCA :
I would not disagree simply because some of it is subjective. To me, the 718 is the world's best go kart. Agile, nimble and playful. I'm not a fan of the 2.5 but any 718 is fun. The C8 is a great track car, it just drives "big" and doesn't have the razor sharp reflexes of the Porsche.
CAinCA said:My car has the Z51 package. I don't think my problem was from the parking brake. I could go 4-5 hard laps and then start feeling pulsing through the pedal. I took a cool down lap or two and the brakes would be good for another couple laps. Next session it would do the same thing. I drove home and the brakes were fine. I also left the rotors on when I swapped back to my street pads and there haven't been any issues.
I'm sure it's track dependent to some extent. Laguna Seca has a 3000ft front straight. I'm hitting 132mph at the end. That's quickly followed by two ~75-85mph braking points (3,4), and then three in the 110+ mph range (5,6,7).
I'm also running Nankang CR-S which are pretty sticky tires, at least compared to the stock PS4S.
Ken from KNS Brakes said that they've seen the same issues with the Z51 brakes. They can only handle so much. They've swapped to the front AP kit and the problem has gone away. Personally, I'd like to run 20+ minute sessions without any issues. I want consistency and confidence when I step on the pedal. I don't want to have to think about which lap I'm on or how hard the last couple laps have been. I think the AP kit is the only way to get there.
Are you swapping pad compound on the same rotors? My dart throw is you would eliminate the problem if you ran a dedicated set of rotors, then matched your pad compound to rotors.....
Of course a 9k brake setup would be a vendor's recommended solution, but brake rotor pulsing is 95% of the time uncompatable pad deposits. No way are you over working the brakes in an HPDE to somehow warp a rotor surface. Which pad compound are you using?
ZL1 (3800lbs) with 650hp and AR1 tires running stock rotors/calipers and DTC60s without issues on back to back sessions....
ShinnyGroove (Forum Supporter) said:SKJSS (formerly Klayfish) said:ShinnyGroove (Forum Supporter) said:Once in a while I think "I should just get another Porsche". Then I spin in circles over the ridiculous price escalation, and go down every other rabbit hole, and hear things like this, and think "I should just get another Porsche".
Let's compare apples to apples. Are you talking a new C8 or used? For your dollar the C8 is an incredible buy. I have tons of track experience in P cars. There's nothing like them, period. However you're going to pay for it, now and ongoing. I am a huge fan of the C8, it's spectacular.
I guess apples to apples, a 3LT C8 with a big brake kit would put you somewhere close to a 4.0 Cayman GTS with a set of LCA's for camber. I suspect the C8 would be faster. Not sure which would be better for fun, trouble-free laps at pace.
I do know which one you can cheaply purchase a 7-8 year warranty to cover all maintenance. Also, a 4.0 GTS is 100k car used.
Now I also know I would rather DRIVE a 4.0GTS on track. The brakes and manual tranny alone are slick, add in the weight penalty of the C8 and if money were no object, I would trade the 3 seconds a lap for those things alone.
In reply to Olemiss540 :
Totally agree on the brake pulsing. As much of a manual transmission guy as I am, personally for a track car I would take the PDK all day every day. It's waaaay faster and smarter than me, and I've got a lot of seat time.
SKJSS (formerly Klayfish) said:In reply to Olemiss540 :
Totally agree on the brake pulsing. As much of a manual transmission guy as I am, personally for a track car I would take the PDK all day every day. It's waaaay faster and smarter than me, and I've got a lot of seat time.
100% faster and smarter, but the revmatch on the manual tranny pcars, combined with the clutch/tranny feel and pedal spacing, gives me goose bumps.
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