R33 GTR engine overheating issue - low boost

[Tomak]

R33 GTR engine overheating issue - low boost

Hello,

Just come back from a track and tested my car in high temp weather, around 25-28 Celcius

My actual set up is 1.4 bar and around 500hp.

Upgrades:

- Mishimoto 50mm radiator

- Mocal oil cooler

My car actually lasted one full lap on full boost, around 4 km of the track. I am experiencing big overheating issues, then my boost drops down rapidly to around 0.8-1.0 bar. The water temperature hits the H mark.

I still have AC radiator and thinking to remove it if necessary and also move the oil cooler to the side of the front bumper so the water radiator can have better air flow. 

Maybe there are any smaller AC radiators on the market so can be used instead of OEM ones?  

What else i can do to reduce the overheating issue?

You guys in Australia experiencing hot weather, how do you race your cars in such a high temperatures?

I need my car last around 10-15 minutes one session on full boost so i can use my 500hp not one lap....;/

 

 

 

 

 

[KiwiRS4T]

Do you have the OEM fan and shroud? Cooling system properly bled? Could be tune related.

[Tomak]

Aftermarket Spal fans. Maybe i should get better fans first. That is a good idea. 

How to bleed properly cooling system in aftermarket Radiator MIshimoto? I thought it bleeds itself...no? I had to take out the cooling radiator some time ago so maybe i done something wrong i dont know. My car also has a new map so it can be everything now 

 

[Dobz]

Definitely needs bleeding. Bleed screw is on the throttle body assembly above injector 1. What is the condition of your cooling system, any dirty stuff in your radiator?

[Jordy32]

You have all the right parts for the car to keep itself well and truly cool.

Sounds like it needs a good bleed so start with that.

[Dale FZ1]

"Splash guard" under the engine is an essential part of managing cooling airflow through the radiator.

Ambient 25-28 isn't hot...

[KiwiRS4T]

If you still have them put the stock fan and shroud back on. Make sure you bleed the cooling system - heater on full etc - Google to find best ways.

[Tomak]

One of my spal fan stoped working, i did not expect that.... . Some shitty spal fans. 

What fans are you guys using? 

Are the mishimoto fans with the shroud way to go?

I am actually using spal va10-ap10/c-61a 12v x 2

By the way the cooling bleeding was ok, i did not noticed any air inside the cooling system after 20 minutes of driving. But thanks anyway for letting me know.

[KiwiRS4T]

How would you notice air in the system after 20 minutes driving? You need to bleed from cold..

[Tomak]

How much air needs to come out and how would i know there is no more air in the system? 

So i start my car and open a bleed screw and what else? Wait 10-15 minutes? How much coolant needs to come out over this bleeding screw?

Also do i have to keep the main valve of the water radiator close or open during this bleeding process?

I have read somewhere that i need to drive first and worm up car good then open bleed screw and ll the air goes up... no?

 

 

[burn4005]

I'd recommend installing a coolant breather tank. You can get knock off greddy ones from ebay for cheap and since I've done mine I've never had coolant issues, and it's constantly bleeding itself from the head and radiator when running. Most overheating rb26s are due to not being bled properly and one of these takes the guess work out of it.

If you've overheating on the track at speed it's not your fans.

[Dobz]

After you had been on the track was there a lot of coolant pushed into the overflow tank?
My method of bleeding coolant that has always worked: Cold engine, open radiator and take out bleed screw. Slowly top up coolant until a small stream comes from bleed, you will see little bubbles coming out. Once the stream looks like no more air is coming out put the bleed screw back in a few threads. Start the engine with the heater and fan on full. Keep the radiator topped up as the engine warms, give some small revs at times to help it flow through. When hot air comes from heater in car undo the bleed screw and allow any built up air out until some steady coolant is rushing out. Put the screw back in and do it up, top up radiator and overflow tank then take it for a drive with heater still in full. You'll notice once it cools down it will suck some coolant in, that's normal, just top up overflow to max mark and that is it.

[Dose Pipe Sutututu]

Throw your American Spal shit into the bin.

Install the OEM shroud, OEM fan blade and a good condition fan viscous hub.

Raced my car last summer is 38+ Celsius degree water, water temperature never exceeded 110 degrees. And I'm sure my car made heaps more power than yours.

[GTSBoy]

55 minutes ago, Dose Pipe Sutututu said:

Throw your American Spal shit into the bin.

Install the OEM shroud, OEM fan blade and a good condition fan viscous hub.

Raced my car last summer is 38+ Celsius degree water, water temperature never exceeded 110 degrees. And I'm sure my car made heaps more power than yours.

This.  So much this.

And when it comes to bleeding.....several times we have had to jack the front of my car up whilst bleeding the cooling system to convince it to burp the last air out of it.  Even a fancy bleeding funnel into the radiator was not as good as jacking it up.  It is also worth having several goes at bleeding it up with short drives in between, just to try to shake lose the problem spot.

[iruvyouskyrine]

Throw your American Spal shit into the bin.
Install the OEM shroud, OEM fan blade and a good condition fan viscous hub.
Raced my car last summer is 38+ Celsius degree water, water temperature never exceeded 110 degrees. And I'm sure my car made heaps more power than yours.

While I completely agree that an engine fan and shroud is miles better, I though spal fans were supposed to be the tits if you were so inclined to run an electric fan?

[KiwiRS4T]

Unless they are running backwards fans should not make any difference on the track at speed. If OP is not familiar with bleeding procedure it is very likely the problem.

[Tomak]

On 6.06.2017 at 11:35 PM, Dobz said:

After you had been on the track was there a lot of coolant pushed into the overflow tank?
My method of bleeding coolant that has always worked: Cold engine, open radiator and take out bleed screw. Slowly top up coolant until a small stream comes from bleed, you will see little bubbles coming out. Once the stream looks like no more air is coming out put the bleed screw back in a few threads. Start the engine with the heater and fan on full. Keep the radiator topped up as the engine warms, give some small revs at times to help it flow through. When hot air comes from heater in car undo the bleed screw and allow any built up air out until some steady coolant is rushing out. Put the screw back in and do it up, top up radiator and overflow tank then take it for a drive with heater still in full. You'll notice once it cools down it will suck some coolant in, that's normal, just top up overflow to max mark and that is it.

I didnt check it so i dont know.

I just got my second fan back working, so i am done with one thing. I try to bleed it the way you said.

I also notice that my spal fans were the weekest on the market from the series. I just bought a new one with bigger engine and the air sucking is much stronger.

Anyway, i had a lot ot things to improve about the cooling.... everything i guess...

Cooling breather tank is also good advice i think, thanks!

I am going back on track next week so will see how my car performs.