fleadh

Took my Z06 out to the track for the first time yesterday since I bought it a few months ago (it's first time, not mine). It was about 90 degrees with a solid breeze @ Thunderhill in nor cal. The water temp would slowly creep up to ~250 (rite before the red on the dash gauge) over about 4-5 laps. When it got to ~250 I'd normally do a cooldown lap then come into the hot pits (no pun intended :P), then go back out.

The car had RA1's, headers, mufflers, coilovers, and swaybars. I was running decent lap-times (nothing record breaking, but was not a moving apex. was running ~2:03 with only 2 or 3 clear laps all day).

I noticed the Vararam intake blocks the upper portion of the radiator and was worried this might cause some cooling problems. Has anyone else noticed this? Was just curious before I swap that intake out for a different one before my next track day.

If it is the intake causing my heating problems, does anyone recommend a more track friendly CAI?

-mike

davidfarmer

any intake that takes air from the radiator, or reduces airflow and possibly even causes leaks around the shroud/radiator, is bad for track duty. What's extra power if you can't use it right???

I had a K&N intake, car ran like crap at WOT. I'm running the stock box now

froggy47

250 deg f is WAY too hot for coolant.

J.R.

Mike,

C6 ZO6's tend to run hot on the track with the stock radiator, especially with the respectable times you are running at Thunderhill. The Vararam may or may not have exacerbated that condition. Most of the ZO6's I have have seen that do not have issues are running aftermarket radiator and or oil cooler systems ( DeWitts/Ron Davis ).

There are quite a few forum members with track ZO6's so you should get some good feedback on their solutions.

fleadh

Thanks for the info guys.

J.R.: I just wanted to make sure I had the optimal stock cooling capacity before upgrading the radiator (been eyeing the LG one with the built in oil cooler).

Wonder if I can just remove the air scoop on the Vararam or cut it so it's not blocking so much of the radiator....


I was having brake problems as well, but I think it was a result of not bleeding/flushing the fluid since I got the car. If there's enough life left in the rotors, I'm going to get a set of track pads for the stock calipers, bleed and flush the system. Then the next track day I'll run the stock pads for a session and see if the pedal goes soft. Either way I'll throw the track pads on, and leave those until the rotors are finished (which should be soon after.. they were at 70% before my track day).

When it's time to swap the rotors I'll put on the stoptech's that're on the way..... at which time it'll probably wreck my braking balance and i'll start over form square one. It never ends... lol!

-mike

J.R.

Mike,

I will PM you re: radiator and brakes. I have a lot of info on the C6 ZO6 stock brakes and their issues - potential solutions.

J.R.

CorvetteZ51Racer

I would not recommend running the stock pads at HPDE if you're going to run the car hard. They are not designed for the rotor temps you'll see in a climate like yours.

I'm running Motul 600 fluid in mine, flushed every 3 events or 3 months, whichever is less. I'm also running the Cobalt GTS 1 piece pads. With that setup, I have yet to experience any fade or soft pedal issues, and my last DE had a 170+ mph to 30 mph braking zone on a circuit with 1:20 lap times, so I was hammering on the brakes.

JR, I would be interested in hearing your Z06 brake comments as well.

Bill Dearborn

I have run my Z06 with ambient temps in the low 90s and haven't had any coolant or oil temp problems. Running 20 to 40 minute sessions I haven't seen an oil temp over 252. Coolant temp is always much less. The C6Z has been a pleasant surprise since I did have to have a Ron Davis radiator with EOC built into it to keep my 97 and 03Z cool.

Bill

davidfarmer

I see 275º oil temps all year long in the stock C6Z. Seems to be the steady-state regardless of ambient temp when running hard. Still better than the 320º I've seen in C5Z06's at the track!

LEAVINU

Try removing the black rubber piece that's right under the oil cooler. It sortof bows upward. It's there to help channel the air into the radiator but with a vararam most of that channeled air is now blocked. Six screws hold it into place and it takes 5mins to remove or install. Won't cost you anything to try this first.

I removed this piece on my car and noticed a 12-14deg coolant drop cruising in this summer heat.

johnnywoz

J.R., please post your comments instead of PMng them as I am sure we are all interested in hearing your opinions.

AU N EGL

Has anyone turned a C6Z06 from a bottom breather to a full front breather? and what was the difference ?

froggy47

I don't run vararam, but that sure seems to make sense. Wouldn't the install instructions for vararam tell you to do that or no?

Pumba

Your high water temperatures are not caused by your VaraRam!

Your problem is because the stock C6 Z06 radiator is too small for track events.

You should spend the money and purchase either a DeWitts or a Ron Davis Racing radiator. In my opinion you should not use an in radiator oil cooler. Those in radiator coolers severely restrict oil flow and cause a significant pressure drop - 4 psi @ 2 gpm flow rate.

You would be better served by a separate oil cooler, if your Z06 is not already so equipped:




Mine is a SETRAB model 172. You can install a cooler like this, or you can install the oil cooler that came on the 2008+ Z06s.

I also have a VaraRam. You can see it behind my grille:



-

0Anthony @ LGMotorsports

Well I'm going to agree with some of them and not with others.


1. VaraRam's work very well at forcing air into the engine, but it does create a big block right dead center in front of the radiator. I typically do not use them for track cars. Same thing happens if you have a front mounted license plate that cover the grill opening. Had a couple customers run hot on track because the plate was blocking the air coming in as well.

2. The factory radiator isn't bad. It should handle a stock car, but it is going to run on the hotter side of things, probably 220-240 on track depending on air coming into it. To me that is a bit hot. If you are going to be serious about track performance, and run the car in the hotter southern states then yes a larger aftermarket radiator and lower thermostat are going to be things you should think about doing with the car.

I would go back to a sealed radiator air box and pick another area to feed the engine for air. Not only for cooling but also for aero as well.

Katech_Zach

Exactly.

The C6 Z06 is a full front breather.

fleadh

Thanks for the info guys!

Anthony/Jason, are there any off the shelf intake systems you guys would recommend for a track car? Or just go back to the stock setup?

While I only use the car for track days, I'm not really interested in fabricating parts for it...

-mike

Katech_Zach

Halltech

J.R.

Sorry for not elaborating on forum but my PM dealt with contacting Anthony at LG and relating to a previous post by RAAM audio on C6Z brakes. It was rather lengthy.

Buckeyefaninks

This is an interesting thread...

I currently own a supercharged C5 Z06 which I participate in HPDE's with. It has numerous heat issues which I've fought, and learned a lot about. Have you tried running straight distilled water and Water Wetter in your radiator? Ensure your radiator / AC Condensor (sp) are blown out / clean? Done any minor mods to ensure the air goes through, and not around it? Considered a louvered hood? And certainly, a DeWitts radiator (the non-oil type) would be benificial as already noted. PM me if you have any questions...

Now... since I'm going to be getting rid of the C5 for a C6 Z06, I'm interested in the conversation about what is the best intake for a C6 Z (for road racing use).

Jason and Anthony, do you have any recommendations? Make and model?

Thanks!

Steve