R34 Gtr Overheating On Race Track

[geoffw]

Hi,

I have a reasonably stock R43 GTR that is getting unusually hot on the race track. Other R34 GTR's I've driven on the track don't have the same issue, so I suspect there's something wrong with mine.

The only modifications are Pod Air Filters, Cat Back Exhaust, FMIC. And it now reports ~1.0 bar boost, spiking at around 1.1 bar.

After 2-3 hot laps (or less) the Oil temp starts to climb over 100 degrees. Then the Water temp quickly climbs to over 100 degrees. Oil and Water temp both keep climbing rapidly until I back off (I've seen Oil go to 115 and Water about the same). Temps will slowly reduce when I do slow laps.

Temps on the street are OK, but sometimes get a little high on hot days (Water temps close to 100 degrees). I don't drive hard enough on the street to get the really high temps.

I've had the following done, but the problem still persists (though temps have improved slightly).

- Koyo 50mm Radiator (fitted new)

- Nismo Thermostat (fitted new)

- Coolant changed

- Royal Purple ICE added to coolant

I expect I could fit an Oil Cooler to reduce the Oil temps, however I don't want to mask another issue.

Any suggestions on what I should check or change next?

Thanks for your input.

Geoff.

[Scooby]

maybe:

head gasket issues

cracked head or block

based on the list of mods i take it you haven't got a pfc so it can't be a tuning issue.

[geoffw]

maybe:

head gasket issues

cracked head or block

Is there any way to test for these things to confirm if they are an issue or not?

[Beer Baron]

why does it have an aftermarket IC? and what type and how thick is it? the problem is everything is very well balanced from the factory. when you put in a big FMIC you ballsed that balance up. with your modifications you don't need anything other than a stock one. but ok, you've got it now so you may as well stick with it. oil temp of 115 degrees is not uncommon on track and is nothing to much to worry about. 100 is about normal. water temp ideally you want to keep under about 105. a decent oil cooler will most likely solve these problems, and is pretty much a must for any track driven GTR. I would have gone oil cooler first as you may well have found you didn't need that big radiator, but you've got it now I guess.

[Scooby]

Is there any way to test for these things to confirm if they are an issue or not?

absolutely - any good workshop should be able to do so but head gaskets and cracked blocks / heads can be hard to diagnose unless they're like the grand canyon, and in this case it appears they're not.

if it's a head gasket you might see coolant weeping on the side of the block. comp test might also show this up. pressure testing the cooling system will show leaks from places there shouldn't be, and also check for tiny ie not cavitation type bubbles in the coolant when warm.

the fan might not be operating correctly but that shouldn't affect it at the track so it's likely to be another gremlin. make sure the system is bled correctly, not sure exactly how much difference it makes but air in the cooling system is not your friend.

as beer baron said temps will get high on track but i take from what you're saying that there appears to be an issue in comparison to other cars.

Edited December 31, 2007 by Scooby

[rb26s13]

Purple Ice is a high performance, synthetic, radiator coolant additive. It reduces engine heat by reducing the surface tension of the radiator fluids for improved heat transfer.

Purple Ice also helps to prevent the formation of scale deposits in the radiator for optimum coolant flow, and it lubricates the water pump seals.

Purple Ice should always be used in conjunction with antifreeze in regions where freezing temperatures occur. Purple Ice is compatible with traditional ethylene glycol antifreeze (green) and GM Dex-Cool® antifreeze.

to me this sounds like it wouldnt do anything to aid cooling in hotter climates.. some one care to explain this to me?

Edited December 31, 2007 by rb26s13

[Simon-S14]

its the same as redline water wetter really.

[rb26s13]

never mind now.. did a little bit more searching.. and understand how it aids in cooling now

[Dahtone Racing]

and from my experience it DOES work

i tested it in an evo 6 dropped temps by about 5-10 degrees

[Abo Bob]

I don't think adding an oil cooler will help as you already have an aftermarket radiator. There is something wrong. As suggested, make sure the system is bled of air properly, look for things like oil in the coolant, is it losing fluid at all? Did you do those things, rad etc, to fix this problem or did it happen before then.

[ferni]

What the hell are you talking about Abo!?!? Of course an Oil cooler will help.

Anyone who takes a GTR out on the track without an oil cooler is asking for trouble. Make sure it's ducted as well.

Try to keep oil temps below 120-130.

Try to keep water temps below 100.

Hitting water temps of 115 - that's pretty hot, you could have done damage to the head gasket, which in turn will make your heating issues worse.

[GTR-32U]

I would highly recommend that oil cooler...! I wouldnt even do a track day without one.Nice big one well ducted in good airflow. What many people fail to realise is that radiator coolant isnt the ONLY substance that cools the engine.A percentage of that heat gets passed on to oil and even some to transmission.You drop the oil temp and it has the effect of passing on the saving to the water.I would still have everything checked, like combustion leak into cooling system...- a dud headgasket or even hairline crack in block or head can cause this.I had one ( Crap heap ) VK commodore plague me with this.Had 4 core radiator fitted-still o/heating, Thermo fans permanently on-still o/heating, Had to switch heater on full bore several times to make it home.Ripped motor out had block and heads crack tested...Nothing.Rebuilt motor and guess what ? Even worse...!swapped motors sold car-good riddance!

[geoffw]

The core problem is not only limited to the track - today I was driving (not hard) around in the ~30 degree heat and the Oil temp kept climbing up and hovered around the mid to high 90's. Water temp climbed up to low to mid 90's when moving, and when waiting in traffic went to high 90's.

I then drove a little harder (not super hard) for around 3-5 minutes and Oil Temp went to 103 before I backed off. Water temp then started to rise and went to around 100.

I've owned a GTR before and it didn't have these cooling issues, and I've also driven many other GTRs on the track and normally they cool reasonably well. So I suspect there's an issue with this car, so I would welcome any further suggestions on how to diagnose/fix it.

Thanks.

[GTR-80Y]

Oil temps in the low hundreds is normal but the water temp is not. Even on the hottest days i don't see over 85 and thats with a standardish type radiator.

I would definetly check the radiator and thermostat u had put in, the last time i had a semi blocked radiator it ran temps of 90-100+ and resulted in a head gasket.

[Gav]

Is there any way to test for these things to confirm if they are an issue or not?

Head gasket leaks can be diagnosed by using a hydrocarbon test kit connected to the radiator. Basically this shows if there is any gas leaking into the cooling system. This may only occur under high load, so ideally if they have access to a dyno it makes the test easier.

[infamous_t]

Had a good & proper radiator flush lately? If its partially blocked that'll kill ya.

Sometimes its the simple things....

Edited December 31, 2007 by infamous_t

[rockabilly]

I expect I could fit an Oil Cooler to reduce the Oil temps, however I don't want to mask another issue.

hi mate. i run a 33gtr on track alot..

i have a 25 row oil cooler

50 mm koyo radiator

2 x10 cooler under boot floor,one for gearbox,one for transfer box

1 x 10 row fuel cooler.

on a hot day here in the uk 30deg @ silverstone.

water is 90 and oil is 90.

i also have a vented bonnet.

if you want to track agtr you will need all this cooling capacity.

gtr,s are not like gts-t they create masses of heat from the turbo,s gearbox etc.

you have to remove that heat somehow..bernie uk

below are the gearbox/transfer box cooler, they are operated by 100 deg surface mounted switches and are on alot on track.

also the fuel cooler picture.

Edited December 31, 2007 by rockabilly

[Duncan]

well it sounds like you have a problem with the cooling system as well, but I wouldn't do too many laps at a time without a good oil cooler on board.

water temps >110 are bad news you are about to blow something so get it looked into.

Is the radiator flowing properly? thermostat opening? plenty of coolant? water pump in good condition? coolant bled properly? (there is a bolt on top of the manifold).

[Snowman]

Geoff - I think you will find this problem in inherint in R34's. Everyone of the R34's I know that gets punted on the track has the same issue (including mine).

Oil I think you are a little over worried about. You will need an oil coiler but anything upto 120 is ok. Above that and you'd begin to worry. But with an oil cooler you shouldn't have that issue.

Water however is a different problem and one we all seem to suffer from. I have a good radiator, all the ducting in the world and I'm still cracking 100+ before the end of the 2nd lap. I'm begining to think the problem is air flow through the radiator and I believe the issue has to do with the underbody diffusers.

It's interesting to note that the Z-Tune has not only the big vented bonnet - but it also has those vented side skirts and also doesn't have the front underbody diffuser (it only has a small front lip about 5cm's in size). It also doesn't suffer from these water temps issues. I'm just in the process of ordering a Z Tune style bonnet and I'll be running some tests including taking the under body stuff off and seeing if I can't get the water temps under control. But there is no doubt I have also damaged my head gasket as well as it has got too hot already so thats not helping but I'm sure for the water, air flow through the radiator is a big problem in the R34's.

[Sydneykid]

My 20 cents;

Personally I would flick the aftermarket intercooler and put the standard one back on. You don't need it for your mods level, it is costing response and most likely is the biggest problem causing the water temp climb.

With a 50 mm radiator it should have heaps of cooling capacity.

I would never do any track work without an oil cooler.

Cheers

Gary