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Also, a random question I can't find the answer to. Does the radiator fan turn off past 35 mph if the car is above X degrees? I know it turns off under normal temps but does it come back on even while driving fast? If it doesn't come back on, then I am building up the courage to trim the excess plastic on the radiator fan shroud to help with flow at the track.
No it doesn't turn back on above 35 mph as it would reduce cooling air flow. Better to let it freewheel in a 150 mph air stream rather than try to spin at a 35 mph powered fan speed. Best thing would be if it had a variable pitch and could be feathered like an airplane propeller.
Eh sort of... Remember that while exhausting out the radiator is a good thing, manufacturers have to engineer for worst case scenario too. What if the customer drives in heavy snowfall, what about heavy rainfall, can I shoot a hose at the vents and hit something I shouldn't if I didn't have the duct, does it affect paint quality, on and on. The duct actually blocks quite a bit of air from the radiator.
I am going to test this with actual data on track in 3 weeks. 1 session with both parts of the duct and 1 session without.
Also, a random question I can't find the answer to. Does the radiator fan turn off past 35 mph if the car is above X degrees? I know it turns off under normal temps but does it come back on even while driving fast? If it doesn't come back on, then I am building up the courage to trim the excess plastic on the radiator fan shroud to help with flow at the track.
We get rid of the oem shrouded fan and radiator duct but it's always been in conjunction with our radiator and other mods so I'm interested to see what kind of results you get with these changes alone.
Last edited by Dane@LGmotorsports; 08-23-2018 at 09:54 AM.
What the shroud does is keep rain water off the front of the engine in wet conditions but blocks air from completely venting out the hood louvers . With it removed I ran 10 degrees cooler both oil and water. Gm engineering isnt always correct . How about the coolant to oil heat exchanger an inch and a half from the cat . DUH . dk Corvettes forever .
What the shroud does is keep rain water off the front of the engine in wet conditions but blocks air from completely venting out the hood louvers . With it removed I ran 10 degrees cooler both oil and water. Gm engineering isnt always correct . How about the coolant to oil heat exchanger an inch and a half from the cat . DUH . dk Corvettes forever .
Speaking of... we delete that and run a cooler up here.
Last edited by Dane@LGmotorsports; 08-23-2018 at 12:40 PM.
No it doesn't turn back on above 35 mph as it would reduce cooling air flow. Better to let it freewheel in a 150 mph air stream rather than try to spin at a 35 mph powered fan speed. Best thing would be if it had a variable pitch and could be feathered like an airplane propeller.
Bill
Great! Time to get creative with the Dremel. Not sure if id remove entire shroud cleanly so I can put it back on if it overheats on street or something else... Deciding...
Originally Posted by Dane@LGmotorsports
Speaking of... we delete that and run a cooler up here.
That's a phenomenal idea if I'm able to fit it with supercharger intake piping in the way. This way, you don't have to run a thermostat for that cooler since air is always warm going through there as long as coolant is warm and flowing through the radiator. May take a bit longer to warm up oil but should work for a street car too. Also centrifugal supercharger intercooler blocks the aux cooler original location. For others researching this, in my testing the temperature exiting the vents is almost exactly the average of ambient and coolant temps. So for about 80 ambient, coolant at 200, air coming out of vents was about 140. See below. Driving at 75 mph. T1=vent, T2=fender well, T3=infront of open Procharger filter, T4= behind filter, infront of alternator.
At the end of 50-110 pull, hard to see but 127, 81, 82, 112. So you can tell that the intake is now pulling fresh air INTO the hood vent #1 and more from inside the engine bay #4 also.
FYI, Sitting still, the air in the engine bay is 180 degrees at normal operating temps.
Last edited by BrunoTheMellow; 08-23-2018 at 06:46 PM.
That's a phenomenal idea if I'm able to fit it with supercharger intake piping in the way. my intercooler blocks the aux cooler location. For others researching this, in my testing the temperature exiting the vents is almost exactly the average of ambient and coolant temps. So for about 80 ambient, coolant at 200, air coming out of vents was about 140. See below. Driving at 75 mph. T1=vent, T2=fender well, T3=infront of open Procharger filter, T4= behind filter, infront of alternator.
At the end of 50-110 pull, hard to see but 127, 81, 82, 112. So you can tell that the intake is now pulling fresh air INTO the hood vent #1 and more from inside the engine bay #4 also.
FYI, Sitting still, the air in the engine bay is 180 degrees at normal operating temps.
PM or email dane@lgmotorsports.com if you need help with a cooling set up, we have our normal website products but we also do a lot of custom/one-off products based on customers application.
Last edited by Dane@LGmotorsports; 08-23-2018 at 01:41 PM.
I've never done Ron Fellows events, but I've done a few drive and follow events in very similar format with BMW ///M school. The amount of "pushing" and heat generated at a solo'ed HPDE vs how lead follow events generate heat is entirely DIFFERENT.
You will see in my profile picture my c5 z, exclusively used for HPDE events. I had to add an oil cooler because in FL during the summer my oil temps were extremely high. I know how to push a car but went to RF for a couple of reasons. One my GS is A8 which I wanted to get a handle on in a HPDE event, in . a car I did not own. Plus it was an excuse to go to LV for a few days. But anyway the lead instructor ran as fast as the class pushing him would go. Maybe at a BMW school they run at 5/10 max but we ran a lot harder. We did alternate the lead student so in some cases we ran slower, but once, when we changed leads and I went to the back after a lead I had to "beat feet"to hang in there.
So yes there was heat, and it was Nevada in August
And this is all while they're driving one handed, talking to you on the radio, looking out the back window, and still ready to pull on you at anytime lol.
Sorry to disappoint but there is no license plate on the car. It is trailered to the track, And secondly also in my profile you will see I live in Florida and we don't have front licences plates.
Sorry I commented to start, just trying to help a forum member out.
Sorry to disappoint but there is no license plate on the car. It is trailered to the track, And secondly also in my profile you will see I live in Florida and we don't have front licences plates.
Sorry I commented to start, just trying to help a forum member out.
Bruno and I were responding to the original poster with the heating problem who lives in Virginia, a state that requires front plates. By the way, my A8 does not over heat at the track using manual mode with paddles all the time.
RF School is in Los Vegas. I was there last August don't think anyplace could be any hotter. And none of the cars in my class including z06 had any overheating problems.
I was at the RF COS in Pahrump this summer too--and the auto Z06 cars had cooling issues... .
I have a C7 Grand Sport (automatic transmission) that has had overheating issues on hotter track days (probably high 80's-90's) at Dominion Raceway (VA) and Summit Point (WV).
Has anyone made progress getting their Chevy dealership/GM to fix/address this overheating issue (which I think is ridiculous as the Grand Sport is marketed as a track car)? If not, any suggested solutions?
I've done multiple track days at Summit Point and VIR in a 2017 Grand Sport A8 with no overheating issues. I paddle shift now, but didn't have an issue in full auto either. I don't believe this is a "known issue". Just finished two days at VIR in low 80s with no issues running in the 2:09s. I shift at red line pretty much every time.
Which dealership are you working with? I've had great service at Criswell Chevrolet in Gaithersburg. Some dry sump cars are incorrectly delivered with the front center air dam which can reduce air flow across the bottom of the engine. Do you have PDR data you can post? Bottom line: find a dealer who will find the source of the problem.
Last edited by grandsport2017; 08-27-2018 at 09:46 AM.
I've done multiple track days at Summit Point and VIR in a 2017 Grand Sport A8 with no overheating issues. I paddle shift now, but didn't have an issue in full auto either. I don't believe this is a "known issue". Just finished two days at VIR in low 80s with no issues running in the 2:09s. I shift at red line pretty much every time. VIR
Which dealership are you working with? I've had great service at Criswell Chevrolet in Gaithersburg. Some dry sump cars are incorrectly delivered with the front center air dam which can reduce air flow across the bottom of the engine. Do you have PDR data you can post? Bottom line: find a dealer who will find the source of the problem.
That max oil temp is troublesome, if you ask me. Here in California, Nevada and Arizona desert temps can reach 110-115 on any average summer day. That's 30+ degrees on ambient, and probably another 20-30 degrees ON TRACK where the tarmac soaks, absorbs, and radiates heat (a friend read a 165ºF with an infrared thermometer pointed at the track surface). If you're running 286º in 80º days, it could go into 300º+ in 110º desert summer days at tracks near me. That's too close to flashing point for most oil and frankly, isn't good for sustained operation of ANY KIND.
For a point of reference, my BMW ran a high of 265º F oil temp on the aforementioned 115º F day and that's as high as I've ever seen on the 10W-60 oil. This is my GS on a 105º day at the same track (Buttonwillow) in July.
Apples and oranges, I know...I wasn't pushing it full tilt as it was the first track event ever with the GS and I had to burnish the CCM brakes before I was comfortable "punishing" it. I noticed your oil pressure was consistently lower than mine, were you running the 5W-30 or 0W-40, or were you using the 15W-50? I've found the heavier oil tend to lower the operating temperature of the engine when push came to shove.
That max oil temp is troublesome, if you ask me. Here in California, Nevada and Arizona desert temps can reach 110-115 on any average summer day. That's 30+ degrees on ambient, and probably another 20-30 degrees ON TRACK where the tarmac soaks, absorbs, and radiates heat (a friend read a 165ºF with an infrared thermometer pointed at the track surface). If you're running 286º in 80º days, it could go into 300º+ in 110º desert summer days at tracks near me. That's too close to flashing point for most oil and frankly, isn't good for sustained operation of ANY KIND.
Apples and oranges, I know...I wasn't pushing it full tilt as it was the first track event ever with the GS and I had to burnish the CCM brakes before I was comfortable "punishing" it. I noticed your oil pressure was consistently lower than mine, were you running the 5W-30 or 0W-40, or were you using the 15W-50? I've found the heavier oil tend to lower the operating temperature of the engine when push came to shove.
I am running 0W-40. Looks like the flash point for Mobil1 0W-40 is 449ºF. Seems like 286F is safely below the flash point.
Interesting difference in oil pressure. No idea why it would be so different.
This is from the GS I used at the Corvette Owner's School on a 110+ degree day. Ran the AC the whole time. The Spring Mountain track is a much lower speed track than VIR.
Last edited by grandsport2017; 08-27-2018 at 01:28 PM.
I am running 0W-40. Looks like the flash point for Mobil1 0W-40 is 449ºF. Seems like 286F is safely below the flash point.
That's interesting. Looks like the newer batch of motor oil introduced in the last 5-8 years has been in response to the newer engines requiring a much hotter running temp to get the cats up to temp quicker in order to prevent NOx emissions while operating cold. Typical synthetics of last generation would flash at 340º F.
There used to be a chart about BMW's new twin turbo engines, that at 290º+ oil temp the engine will start to pull timing to try and keep it cooler, and at 305º will go into reduced power mode. I wonder if the LT1/LT4 has reduced power mode like BMW engines for heat?
I would also have to assume that the 15W-50 runs much cooler for track use, as typical heavier oil tend to be. I don't have empirical data, but my M with 10W-60 runs "cool", and the 15W-50 I put in the GS runs cool. I've also read suggestions for people with engines that tend to run "hotter" to run heavier oil for motorsport applications too.
I wonder if the OP ran 5W-30, 0W-40, or the 15W-50?
That's interesting. Looks like the newer batch of motor oil introduced in the last 5-8 years has been in response to the newer engines requiring a much hotter running temp to get the cats up to temp quicker in order to prevent NOx emissions while operating cold. Typical synthetics of last generation would flash at 340º F.
There used to be a chart about BMW's new twin turbo engines, that at 290º+ oil temp the engine will start to pull timing to try and keep it cooler, and at 305º will go into reduced power mode. I wonder if the LT1/LT4 has reduced power mode like BMW engines for heat?
I would also have to assume that the 15W-50 runs much cooler for track use, as typical heavier oil tend to be. I don't have empirical data, but my M with 10W-60 runs "cool", and the 15W-50 I put in the GS runs cool. I've also read suggestions for people with engines that tend to run "hotter" to run heavier oil for motorsport applications too.
I wonder if the OP ran 5W-30, 0W-40, or the 15W-50?
Coolant temps pull timing in our car. Point being. By the time oil is hot, so is coolant, so itll pull timing. Pretty severely too.
Last edited by BrunoTheMellow; 08-27-2018 at 07:48 PM.
08-23-2018, 08:52 AM
