LoveFab NSX overheating on track

[CB72]

Following my latest Le Mans outing, I had the cooling system drained and refilled following the Honda service manual.
I'm sad to report that once again the temperature went out of control during a local track day meeting.
This time it did not reach the boiling point as I nursed the car around until the temperature dropped.
To get back home I had to add about 2 liters of water.
The level remained the same when I got home after 120 km.
When we initially refilled the cooling system we saw no trace of any leakage?
Could it be one of the cylinder head gaskets?
I was planning to look at the spark plugs to detect any issue?
Any other suggestion?

 

[sca037]

By all means check the plugs, but my experience has been that it's fairly easy to trap air in the cooling system when refilling it.....so this might have just been a pocket that worked its way out and now it's truly full.

I sure hope that's the case, anyway :biggrin:

 

[CB72]

By all means check the plugs, but my experience has been that it's fairly easy to trap air in the cooling system when refilling it.....so this might have just been a pocket that worked its way out and now it's truly full.

I sure hope that's the case, anyway :biggrin:

Thanks sca037 but I doubt this is the issue...
In fact I believe it could be related to a design issue!
Last night I watched the many videos I took during my track day meetings and clearly the problem only occurs on hot days ( above 28°C)
So apparently the cooling system is not sufficient?
My setup includes a Driving Ambition racing radiator to offset the negative effect of the intercooler radiator that sits right in front of it.
Honda in it's wisdom designed the cooling system with an integral oil cooler that exchanges heat with the engine's liquid cooling.
While this is a great idea for a street car, it must create a hot spot when the car is raced?
When the engine oil gets very hot, the cooling liquid gets hot enough to start boiling and the engine cooling goes kaput!
I'm sure the racing community must have solved this issue by disconnecting the OEM oil cooler and replacing it with a standard item.
Searching through the posts, I found the oil cooler kit built by [MENTION=22066]Operator[/MENTION] http://www.nsxprime.com/forum/showthread.php/158232-Amw-oil-cooler-kit?highlight=oil+cooler+kit
I'll see if he can still build one for me?

 

[goldNSX]

If you have double the power than stock you have double the energy that dissipates as heat. Simply spoken, you're cooling system is not designed for double of the power at a track event.

 

[CB72]

If you have double the power than stock you have double the energy that dissipates as heat. Simply spoken, you're cooling system is not designed for double of the power at a track event.

Right you are but it doesn't solve the problem lol
In the meantime, I got an answer from [MENTION=22066]Operator[/MENTION]: he doesn't build the oil cooler anymore.
Maybe [MENTION=20915]RYU[/MENTION] can provide some guidance?

 

[docjohn]

http://www.nsxprime.com/forum/showt...ted-hood-or-not?highlight=cooling+ducted+hood

 

[Ponyboy]

Ron Davis Radiators will build their NSX radiator with an oil cooler. That may be an option for your water temps and oil concern in a simple and clean package.

I don't think I've ever gotten over 230 F on track in the heat and humidity of Oklahoma summers with my Ron Davis rad (water only) and SOS oil cooler.

 

[CB72]

http://www.nsxprime.com/forum/showt...ted-hood-or-not?highlight=cooling+ducted+hood

I have a VIS ducted hood on my car but I don't have the ducted scoop that should go with it...

 

[CB72]

Ron Davis Radiators will build their NSX radiator with an oil cooler. That may be an option for your water temps and oil concern in a simple and clean package.

I don't think I've ever gotten over 230 F on track in the heat and humidity of Oklahoma summers with my Ron Davis rad (water only) and SOS oil cooler.

It would not be possible to mount a combined oil and water radiator on a turbocharged NSX given that the intercooler lines take up the little space left under the car body.
My only option is a separate oil cooler in the rear wing.

 

[Ponyboy]

It would not be possible to mount a combined oil and water radiator on a turbocharged NSX given that the intercooler lines take up the little space left under the car body.
My only option is a separate oil cooler in the rear wing.

It's been done before but I understand what you're saying, there's not a lot of room in that central tunnel.

Either way, good luck with whatever solution you choose!

 

[sca037]

Another simple solution to check, is to see if your radiator cap is still holding its rated pressure......as they do sometimes go bad.

 

[CB72]

Good news, Christian from ATR racing in Austria (@austrian type-R) has taken over the plans from AMW ( Operator) to build the NSX oil cooler.
I've ordered one and should get it next week!
I suppose my NSX will now have all the goodies now produced for this car...

 

[CB72]

Another simple solution to check, is to see if your radiator cap is still holding its rated pressure......as they do sometimes go bad.

Yes, I saw the note from SoS on the subject but I still have my original cap...
BTW, I looked up a table that shows the water boiling point versus pressure and you need 1.42 bars to contain the water up to 110 °C and 2 bars to reach 120°C.
So the effect is almost negligeable at 1.1 bar...