Motor Trend vid: GT-R NISMO vs Z06

[hotrodalex]

I was reading the road and track Camaro z28 vs the world track comparo and after three laps of a ~1.5 mile course the oil temps went over 300. The only car in the test to do it with a gtr, viper, andPorsche something or other.

I'd like gm to say something at least

I can't find any other Z28 oil temp problems, that seems to be an anomaly.

[GoCougs]

So, I reread it.

As to this retest, first, the M/T test driver says the car loses a lot of power but then the M/T writer immediately counters that the data says the "loss" was only a few tenths and a few mph per lap.

Second, nowhere is it stated that the car "overheated" or when into "limp mode." The test driver simply notes the temperature read high. When cars overheat they hit a falloff point and they they are done.

All this is pointing to typical F/I heat soak, which will be present for any S/C motor.

[r0tor]

Heat soak on a 70deg day doing one lap on a 1.5 mile track?  You have to be a fairly bad apologist to consider that an acceptable defense.

[r0tor]

I was reading the road and track Camaro z28 vs the world track comparo and after three laps of a ~1.5 mile course the oil temps went over 300. The only car in the test to do it with a gtr, viper, andPorsche something or other.

I'd like gm to say something at least

They undersized the Z28 cooling so badly they had to come up with the "flowtie"...

[MX793]

They undersized the Z28 cooling so badly they had to come up with the "flowtie"...

The Camaro wasn't really originally designed to play in the performance field that the Z/28 plays in.  They had to find cooling wherever they could.  Just as the Aston Martin Vantage wasn't originally designed to accommodate the V12 motor and the guys at Aston had to put a bunch of louvers and vents all over the front bodywork to keep that motor cool.

And as this is the first instance I've heard of the Z/28 getting hot in such a short running time, I also think it may have been an isolated issue.

[GoCougs]

Heat soak on a 70deg day doing one lap on a 1.5 mile track?  You have to be a fairly bad apologist to consider that an acceptable defense.

I only consider facts, logic, knowledge and experience, which says that cars don't incrementally overheat and then incrementally lose performance.

[MX793]

So, I reread it.

As to this retest, first, the M/T test driver says the car loses a lot of power but then the M/T writer immediately counters that the data says the "loss" was only a few tenths and a few mph per lap.

Second, nowhere is it stated that the car "overheated" or when into "limp mode." The test driver simply notes the temperature read high. When cars overheat they hit a falloff point and they they are done.

All this is pointing to typical F/I heat soak, which will be present for any S/C motor.

The oil temp gauge was reporting 320 degrees, which is as high as the gauge reads in the Corvette (and beyond the "redline" on the gauge).  It's possible that there's some gauge error and that's why the car didn't go into complete limp-mode, but that's still not a good sign after only a couple laps on a relatively cool day.

Does beg the question if a lot of the reported heat incidents aren't related to an incorrectly calibrated gauge.

[hotrodalex]

A simple trans cooler + oil cooler + ceramic coated headers would be easy mods if you live in a hot climate.

[hotrodalex]

The oil temp gauge was reporting 320 degrees, which is as high as the gauge reads in the Corvette (and beyond the "redline" on the gauge).  It's possible that there's some gauge error and that's why the car didn't go into complete limp-mode, but that's still not a good sign after only a couple laps on a relatively cool day.

Does beg the question if a lot of the reported heat incidents aren't related to an incorrectly calibrated gauge.

Could be too close to the exhaust, maybe? I know that can be a problem with aftermarket gauges.

[FlatBlackCaddy]

A simple trans cooler + oil cooler + ceramic coated headers would be easy mods if you live in a hot climate.

But then you would be removing the much better designed and optimally efficient oem units in favor of poorer designed and performing aftermarket units.

[hotrodalex]

But then you would be removing the much better designed and optimally efficient oem units in favor of poorer designed and performing aftermarket units.

Good thing I'm not Cougs.

[MX793]

Could be too close to the exhaust, maybe? I know that can be a problem with aftermarket gauges.

A simple trans cooler + oil cooler + ceramic coated headers would be easy mods if you live in a hot climate.

The Corvette's transmission isn't anywhere near the headers.  Transmission is at the back of the car, bolted straight to the differential, for better weight distribution.  Transmission cooler is also at the back of the car; behind the driver's side rear wheel.  Could be that they just aren't getting enough airflow.  On most cars, with more traditional transmission mounting, the trans cooler is integrated into the radiator at the front of the car where it gets lots of fresh air.

[FlatBlackCaddy]

Either way,  I'm sure if there is a problem with the z28 Gm will address and repair it asap.

[hotrodalex]

The Corvette's transmission isn't anywhere near the headers.  Transmission is at the back of the car, bolted straight to the differential, for better weight distribution.  Transmission cooler is also at the back of the car; behind the driver's side rear wheel.  Could be that they just aren't getting enough airflow.  On most cars, with more traditional transmission mounting, the trans cooler is integrated into the radiator at the front of the car where it gets lots of fresh air.

The headers comment was just for engine bay temps. I'd move the trans cooler to the radiator.

[GoCougs]

A simple trans cooler + oil cooler + ceramic coated headers would be easy mods if you live in a hot climate.

No.

[FlatBlackCaddy]

No.

So...........Much..........Information................

[Gotta-Qik-C7]

 

[hotrodalex]

No.

You can ceramic coat the stock exhaust manifold if headers scare you.

[MX793]

The headers comment was just for engine bay temps. I'd move the trans cooler to the radiator.

Which means running long fluid lines from the back of the car to the front, drastically increasing system pressure drop.  You'd also be running said lines along the center tunnel, right next to the hot exhaust.  By the time it got back from the front heat exchanger, may well be nearly as hot as when it left the transmission.

[hotrodalex]

Which means running long fluid lines from the back of the car to the front, drastically increasing system pressure drop.  You'd also be running said lines along the center tunnel, right next to the hot exhaust.  By the time it got back from the front heat exchanger, may well be nearly as hot as when it left the transmission.

Side pipe exhaust.

Problem solved.

[GoCougs]

How about not taking a slushie AT to the track?

No matter what size/location of (traditional) cooler it's gonna overheat fairly quick. You'd have to have some sort of Rube Goldberg-esque active chiller (i.e., with refrigerant) and goofy fluid routing to keep the fluid cool.

[12,000 RPM]

FWIW EVO ran the Z07 against a 991 GT3.... couldn't get the track at Willow Springs but they loved it. Then again EVO has never sought to satiate spec hungry bench racing dorks....