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250* is not unusual and is not excessive for track day use but there are too many variables to give an educated answer to your questions. As Froggy said you can change to a better/bigger radiator, go to a 0-40 oil, and keep revs below 6700--6500 would be better.
I am running 0-40, my limiter is set to 6700 I think.
Thanks Steve, now I see how this can be possible. The hose from the valve cover to the throttle body. Valve cover fills up, throttle body sucks it in.
NOLA motorsports park turn 2 is what did it I bet, big sweeping high rpm 3rd gear corner, you are on the rev limiter for turn 3 right before braking then another big left hander.
On the 04, did you leave the PCV hose form the valley to the intake neck intact?
NOLA track map, turn one turn in is about 60 mph in 3rd, then back on the gas.
There you go. High rpm left hand turns will do it every time. Don't even think about buying one of those oil cap breathers. My 04 PVC is left stock. Only change is the valve cover with catch can. It wouldn't hurt to put one on. I just felt it wasn't necessary, because of my experience on my 99.
There you go. High rpm left hand turns will do it every time. Don't even think about buying one of those oil cap breathers. My 04 PVC is left stock. Only change is the valve cover with catch can. It wouldn't hurt to put one on. I just felt it wasn't necessary, because of my experience on my 99.
I already have a single catch can, just install a single like you have on your 04 Z06 ya think?
I have to do something, I cannot track the car at all like it is.
These are common issues and there's probably nothing wrong with your car. With my old T1 C5Z which was basically stock, this would happen especially if I overfilled the oil at all. Vararam won't hurt anything but I personally didn't like it. Steve's PCV setup looks like a winner. I did basically the same thing on my car.
Your water temps were quite high. Do you still have the AC condenser? It's hard to get a good air flow through the radiator with the stock C5 setup IMO. Aftermarket radiator and Trackspec hood louver would help cool things down. Ditching the AC condenser would help also. I bet your oil temps were in the 300 range so you might want to change it. If you keep things cool on a C5Z it's a great track car that can go all day long. But the stock cooling just isn't sufficient for a skilled driver pushing the car.
Radiator, oil cooler, trans cooler, brake cooling, Turn 1 ps pump with cooler. All things that I found necessary to track my C5Z.
These are common issues and there's probably nothing wrong with your car. With my old T1 C5Z which was basically stock, this would happen especially if I overfilled the oil at all. Vararam won't hurt anything but I personally didn't like it. Steve's PCV setup looks like a winner. I did basically the same thing on my car.
Your water temps were quite high. Do you still have the AC condenser? It's hard to get a good air flow through the radiator with the stock C5 setup IMO. Aftermarket radiator and Trackspec hood louver would help cool things down. Ditching the AC condenser would help also. I bet your oil temps were in the 300 range so you might want to change it. If you keep things cool on a C5Z it's a great track car that can go all day long. But the stock cooling just isn't sufficient for a skilled driver pushing the car.
Radiator, oil cooler, trans cooler, brake cooling, Turn 1 ps pump with cooler. All things that I found necessary to track my C5Z.
Yes I have AC, it's a street car that sees DE duty. I only run in the winter months but will put an oil cooler on it this summer.
NOLA motorsports park turn 2 is what did it I bet, big sweeping high rpm 3rd gear corner, you are on the rev limiter for turn 3 right before braking then another big left hander.
I bet you're right. I was driving the yellow C6 behind you through this section, and it was just after turns 3 and 4 that it looked like you were burning some oil.
I bet you're right. I was driving the yellow C6 behind you through this section, and it was just after turns 3 and 4 that it looked like you were burning some oil.
Was frustrating that I could not run the car like I wanted. But I did learn what the car needed.
Does anyone think the Vararam is doing anything adverse to the car? It has this version:
Yes it blocks air flow to the radiator
not good on road course driving, works fine on the street or drag strip
well maybe not didn't look close if it hooks up behind the screens, the one for a C6 definatly does block air
I run the VR with no issues. It goes over the shroud so it is in no way of the radiator. First time I had overheating issues at track, was like my 12th track day. I ran right out and bought a DeWitts. When I took my stock rad out, it was full of dirt and grime. That was the issue more than the rad. When I went to built LS2 though, the rad was definitely needed. I would take it out and clean it really good before upgrading. But then again, eventually as you get better, you will need to, so it is a matter of when it fits your budget.
When I upgraded to a DeWitts, I used 100 psi from the compressor to blow jump out of the condenser, and there was definitely a good amount of debris, especially up at the top. I mostly upgraded to get the oil temps down and be able to hook up the integrated EOC, I was seeing oil temps up around 290 on hot days in the 20 minute sessions. Even before getting the EOC hooked up, just the radiator helped bring the oil temps down a bit.
I've been fortunate with minimal oil coming into my catch can, but the tracks I have run are clockwise and really don't have any long left handed sweepers.
The other thing could be tires, I'm still running on street tires, so I can't pulling as many G's as the guys with slicks.
Yes it blocks air flow to the radiator
not good on road course driving, works fine on the street or drag strip
well maybe not didn't look close if it hooks up behind the screens, the one for a C6 definatly does block air
Please explain
See how the seal is off the right side up at the top? Mine is the same way.
See how the seal is off the right side up at the top? Mine is the same way.
Your good on a c5 the variant on a c6 goes through the radiator shroud and partialy blocks the radiator not so on a c5 as it connects to the bumper cover directly ( fog lights)
See how the seal is off the right side up at the top? Mine is the same way.
From the picture you are missing the plastic air dam. Without that you will not push air through the radiator. I damaged mine and my car overheated quickly on track, I fixed it with zip ties and back to normal. Definitely a problem 250 water is too hot.
From the picture you are missing the plastic air dam. Without that you will not push air through the radiator. I damaged mine and my car overheated quickly on track, I fixed it with zip ties and back to normal. Definitely a problem 250 water is too hot.
Not my car^^^
250 on a pressurized system is not real hot, as mentioned a few times in this post.
I was out at NOLA a few months ago, 70 ish temps. I'm not a pro by any means but oil tems got up to around ~265 but water temp stayed below 200 (I didn't pay attention much to water temp since it was well within acceptable range). Stock radiator, heads/cam and bolts on 2003 Z06. I have a single catch can between the crankcase/valley cover and the pcv valve/intake. Haven't noticed any sort of oil burning issue and that can does not collect too much oil, but then again I don't drive the car all that often.
As already suggested, #1 I would remove the top radiator cover or the entire shroud and clean out the AC condenser/radiator...and then go from there. Mine had a disturbing amount of of crap, dirt, sand in there and in between the AC condenser/radiator. I found a dryer lint brush to be very useful for this...and just went back and forth between that and compressed air.
As for the Vararam I am really not a fan of it. It does block some air that would otherwise enter the engine bay, but I doubt that is a big factor in your 250+ water temps. My biggest gripe with it was even after a tune and trying to fix the issue, my car had a slight surge at low rpm/load with it. I bought a new intake (airaid) and did a before/after datalogs and you can clearly see how 'noisy' the MAF signal is with the Vararam....poor overall design IMO that causes air flow turbulence across the MAF. Switched intakes and have been happy since. Just my 2 cents.
I am planning on heading back there in the fall... I don't really think I will have much fun out in the sun all day in the summers down here.
250 on a pressurized system is not real hot, as mentioned a few times in this post.
I guess it depends on your perspective, I think it's pretty hot. In my C5 race car my water stays around 220 in a 30 min race. Oil is around 230 with the cooler. In my first c5z, a stock 2001 I would see oil temps over 300 but water was never over 230.
My second opinion is that if you are puking oil all over the place you have a problem with the engine, I have never seen this with thousands of track miles on c5's.
The C5s cooling problems are well known. It doesn't have sufficient cooling capacity to run at high throttle openings for really long periods of time. If the air flow through the cooling system is compromised in any way due to poor seals, blockages in the condenser/radiators or not enough air getting to them it will be worse.
Have you cleaned out the AC Condenser and Radiator? All sorts of crap gets blown to the top of the AC Condenser and can block air flow through the Condenser for the top 5 or 6 inches. The seals between the radiator and the condenser have to be in place otherwise air blows by both of them without providing any cooling affect. I made some of my own and then used duct tape between the radiator and condenser to reduce the air pressure against them.
Take the radiator out of the car and use a hose to backflow through the fins to get dirt loose then drop it flat from about 10 ionches onto some smooth concrete or asphalt to dislodge dirt in the fins. This can produce a nice size pile of small dirt particles. Then use a hose to back flow water through the condenser and then take a pick to clean the fins of the AC Condenser.
To get more air flow through the radiator at speed take some duct tape and wrap it around the horizontal bar of the radiator support with the other end taped to the center air dam. Do that on both sides and the center. The center air dam is spring loaded to deflect backwards when it hits something but it will also push backwards at Triple Digit speeds. The tape keeps that from happening.
A bigger radiator like an RD with built in EOC will provide a huge improvement and get your oil temps down in the mid 200s even when running a stock thermostat.
Oil coming out the intake isn't normal. A catch can might catch the oil but that is like putting on a band aid to stop melanoma. I have never run a catch can on any C5 or C6 and have never had oil issues like that. That is 18 years of running 4 different LS engines at high revs without any oil issues.
The C5s cooling problems are well known. It doesn't have sufficient cooling capacity to run at high throttle openings for really long periods of time. If the air flow through the cooling system is compromised in any way due to poor seals, blockages in the condenser/radiators or not enough air getting to them it will be worse.
Have you cleaned out the AC Condenser and Radiator? All sorts of crap gets blown to the top of the AC Condenser and can block air flow through the Condenser for the top 5 or 6 inches. The seals between the radiator and the condenser have to be in place otherwise air blows by both of them without providing any cooling affect. I made some of my own and then used duct tape between the radiator and condenser to reduce the air pressure against them.
Take the radiator out of the car and use a hose to backflow through the fins to get dirt loose then drop it flat from about 10 ionches onto some smooth concrete or asphalt to dislodge dirt in the fins. This can produce a nice size pile of small dirt particles. Then use a hose to back flow water through the condenser and then take a pick to clean the fins of the AC Condenser.
To get more air flow through the radiator at speed take some duct tape and wrap it around the horizontal bar of the radiator support with the other end taped to the center air dam. Do that on both sides and the center. The center air dam is spring loaded to deflect backwards when it hits something but it will also push backwards at Triple Digit speeds. The tape keeps that from happening.
A bigger radiator like an RD with built in EOC will provide a huge improvement and get your oil temps down in the mid 200s even when running a stock thermostat.
Oil coming out the intake isn't normal. A catch can might catch the oil but that is like putting on a band aid to stop melanoma. I have never run a catch can on any C5 or C6 and have never had oil issues like that. That is 18 years of running 4 different LS engines at high revs without any oil issues.
Bill
I will pull the radiator and clean it and back flow the condenser as well.
I will also take the aluminum wheel tape we use to hold on balance weights and seal up the duct work.
I will also make the air damn where it won't bend back(thanks for the tip)
The oil issues seem pretty well known, a few in this post have encountered it as well as a few phone calls I made to shops that mod these cars for track days.
I guess it depends on your perspective, I think it's pretty hot. In my C5 race car my water stays around 220 in a 30 min race. Oil is around 230 with the cooler. In my first c5z, a stock 2001 I would see oil temps over 300 but water was never over 230.
My second opinion is that if you are puking oil all over the place you have a problem with the engine, I have never seen this with thousands of track miles on c5's.
Tim
Same conditions on my 04 Z06 in autocrossing and lite track runs. No oil blown out of engine - temps at 220, two driver car in all day events.
I think I found the reason it runs hot on track. Truly amazed at what has come out of this radiator, still not 100% but at least I can see through it now.
A bunch came of the condenser also by blowing it out with an air hose.
05-07-2015, 08:41 PM
High rpm left hand turns will do it every time. Don't even think about buying one of those oil cap breathers. My 04 PVC is left stock. Only change is the valve cover with catch can. It wouldn't hurt to put one on. I just felt it wasn't necessary, because of my experience on my 99.
