Well you'll need a stick and an NA engine to be safe. I've over heated a zo6 and my z51 auto. It really pisses me off that I can't run a 20 min session with out going into protect mode on the transmission.

 

If you have the money, buy a Viper. TA to be exact. If not, make sure you get at least a 2017 M7 and don't track June to August.

 

Weight is the weakest link. These cars are so much heavier than the C5/6 Zs and you pay for it in all aspects from tires to brakes. They can be really fast, and can be modified to deal with the heat, but you can only do so much about the weight without just gutting it.

 

Why at least a 2017?

 

They added the secondary heat exchanger for all M7 cars from the factory. Its a few hundred dollars and couple hours of your time to buy the parts and upgrade a 15/16. Automatics get no benefit as they already use the area for the automatic trans cooler.

 

Is that for Z06 only?

 

no, my 2017 GS has it.

 

My 16 Z51 A8 has been upgraded with a Dewitts radiator and has no problems with heat.
I also changed the grill to Z06 for more airflow and added the extra brake cooling along with Ap racing discs

 

Of all of the recent versions of the Corvette the C7 is the most track capable. The Z51, GS, Z06 and ZR1 are all great track machines if configured correctly.
Each of the manual models come with an differential oil cooler and transmission oil cooler. The secondary radiator is either stock or can be added in the Z51, GS or Z06. As far as I know the ZR1 has all the cooling required right out of the box. The A8 models come with the diff cooler and two transmission coolers, one in the rear where the M7 cooler is located and one in the front where the Z51, GS and Z06 M7 cars have the secondary radiator. All of the cars have much better brakes than any of the C5s, the C6, Z51, and Z06 (non Z07 version) came with. The C7 GS Z07, C7 Z06 Z07 and ZR1 come with carbon ceramic brakes which are great but have very high consumable costs. I swapped my ceramic brake system to the Essex AP Racing BBKs front and rear and actually broke even on cost when I had to replace the front rotor rings the next time. With the rears I broke even on cost the day I replaced the rear ceramics.

2015 and 2016 M7 Z06s make great track cars as long as you add the GMPP Secondary Radiator that GM made standard on the 2017 models. They run long and hard at lots of tracks around the country. The 2017 Z06s also had a slight supercharger modification that improved the charge air cooling for the rear two cylinders of the engine which typically have higher combustion temperatures. The cooling bricks inside the S/C were tilted which required adding a taller lid to the S/C and changing the under hood insulator. That is why people recommend the 2017 models over the two earlier models.

The Z06 A8 cars tend to cause engine over heating due to running the engine in lower gears to maximize performance. People either over heat the oil or over heat the coolant. GM says to manually shift the car and to limit rpms. Some people interpret that as short shifting but I interpret that as running the car like I would an M7. Don't use the lower gears at all. The M7s can operate on most tracks using 3rd and 4th gears with some usage of 5th on long straights and occasional usage of 2nd on low speed corners but in most cases they are 3rd and 4th gear cars. The A8 has two similar gear selections which I believe are 4th and 5th but could be 5th and 6th. Like all Corvettes the Z06 has a large low end torque value. However, what most people don't realize is the torque value is stupendous compared to others beside the ZR1 which is insane. Torque doesn't make you go faster but it does generate the HP that does make you go faster so lots of low rpm torque generates more low rpm horsepower.

The iron brake systems that come on the cars seem to do fairly well under track duty but if running a lot of events I would upgrade the Z51 brakes to the GS/Z06 iron version for track duty at a minimum.

Tires you have a huge selection depending on which model you choose and what wheel size you choose. The GS Z07, Z06 Z07 and ZR1 track package all come with Michelin Sport Cup2 Run Flats which seem to be a damned good track tire but expensive compared to what is available in the used race tire market.

As Fleming explained these cars are heavier than previous models and that shows up in consumable costs as well. A Z06 run hard at VIR can get through maybe 30 minutes of track time before requiring 18 gallons of gas.

Bill

 

Anyone who has driven both has said they prefer the Grand Sport. Z06s have a documented problem and two class action law suits pending due to inadequate cooling. I've watched 2018 Z06s with the extra cooling pull timing and/or go into limp mode personally and they weren't being driven super hard (for reference, I was keeping up with them in a Z51, so it wasn't running all out. Honestly, I'm not sure why you'd want a Z06 if you're 75% track duty.

Weakest link is definitely cooling on the track, which is pretty typical for Corvettes. It's not really an issue on Grand Sports or Z51, but the GS is vastly superior to the Z51 on the track in terms of performance and reliability. Other than cooling, I'm not sure they really have a weak link. I haven't found it, if it exists

Consumables are the same as any other car. Tires, tires, tires, and brakes. Carbon Ceramic brakes are expensive. Steel rotors (GS/Z06) aren't that bad, but not great. $350/rotor ring is about right. They take some abuse though. I probably got 20 hours on mine and they're still good on tracks that are HARD on brakes and I'm running very aggressive pads. I'd definitely say you should add the OEMZ07 cooling ducts. They're only $80 or so.

Unless you're in a class that limits your wheel options, most opt for 18's and run R888R, NT01 or Hoosiers. They're all available in 315F and 335(or 345) rear.

The Competition seat isn't much better than the touring seat so don't bother. Just get a true race seat. Head room with a helmet can be an issue for people above 6'-2" ish with factory seats.


edit: Alignment seems to be the biggest hassle. Finding someone to adjust rear caster can be a pain.

 

Great info, thanks guys.

 

One other note: I have been running my Z06 hard for 2.5 seasons without an engine overheat issue. I did have an engine misfire issue which seems to be corrected since the intercooler was bled to get almost all of the air out if the intercooler circuit. If you are a good driver then you will go faster in a Z06 than you will in a Z51 and you can do it consistently lap after lap without issues in ambient temps in the low 90s. The car is fast and reliable. However, it can cost a fair amount to track it due to consumable costs. One time I was running at VIR coming through a series of turns with a Z51 behind me. He had modified his car for more power but when we got to short straight I was in third gear at about 80 mph and went wide open. That was when I lost him. His car didn't have the response to come out of that series of turns and accelerate like that in the mid rpm ranges. I was a few feet in front of him and then I was 150 ft in front of him. That is what the LT4 gives you over the LT1. We have one forum member who was lapping his 15 and 17 Z06s on the full course in the 1:59s pretty regularly depending on traffic. That is damned fast considering I have been at a Ferrari Challenge race at VIR during the same period and the fastest laps being turned in with fully prepped race cars were in the 1:57s.

Bill

 

Not to take anything away from a 1:59 or an F430 is pretty awesome, but keep in mind the Z07 has 200hp and nearly 2" of tire on it. That's not exactly a small difference. At my track I think I'm 3 seconds off the pace in my GS (1:54 vs 1:57) and I know the GS has at least a 1:56, if not 1:55 in it.

2017 updates or not, you're going to be staring down cooling problems in a Z06 on a hot day. A lot of it probably has to do with the track you're running on, but on hot days, it will get very hot.

 

I'm in SoCal so it's pretty hot, part of why I ask for input, as I see the C7's having issues at the track frequently.
Any thoughts on tire wear for r comp or R7's? I only get 5-6 sessions with my current car and looking at alternatives that are easier on tires, but doesn't sound promising.

 

Did you guys have to change out your DOT3 brake fluid to DOT4?

 

I can get several track days out of a set of used DOT R Hoosiers, the same for used Pirelli Slicks. I did 5 sessions at VIR at the end of June and I plan on using the same set of Pirelli Slicks for two days at the Glen.

Bill

 

DOT4 doesn't really guarantee you anything except a specific wet boiling point that is higher than the specific wet boiling point for DOT3 fluids. What you get in an auto parts store may have better dry boiling points than some DOT3s and sometimes not. Ford DOT3 is specified with a dry boiling point of 500 degrees which is higher than a lot of general run of the mill DOT4s on the shelves of auto parts stores. I use Ferodo Super Formula Racing Brake Fluid which has a dry boiling point of about 620 degrees compared to the Castrol SRF which only has a 590 degree dry boiling point. However, SRF has a 518 degree wet boiling point while the Ferodo drops off to 392 degrees after a while. If you can get by with that wet boiling point you can use it and not have to change fluid for the next track event.

Bill

 

C7s are powerful, have huge tires, heavy, have lots of down force and massive brakes. It's VERY easy to cook brake fluid. You should be running, at the least Motul 600. At the least. It's your brakes for crying out loud. Save $5 on your coffee, not your brake fluid.