Overheating?

[davekmoore]

I have one rad cap that say "1.1" on it and one that says "108 kPa 16psi ".

Is either of these a high pressure one as mentioned earlier or do I need another one?

[timk]

Those are both the same.

[davekmoore]

Those are both the same.

Thanks saboteur.

Are they any good for what I want to do - in the context of the thread?

[93_Clubman]

Those are both the same.

Thanks saboteur.

Are they any good for what I want to do - in the context of the thread?

Dave, standard NB8 runs a 1.1 bar rad cap, so I'd suggest 1.3 bar would be worth trying, especially as a few of the other turbo guys run these.

[davekmoore]

Once again, thanks to everyone for your thoughts. Will report back next week after some mods and Phillip Island on Sunday.

[dbr]

It would appear that I am going to need a bigger radiator for track use of my NB turbo.
So far I have found that;
SE radiators are twice as thick as standard (16mm).
SP radiators are twin row, survive track days on sp's and cost $370 from Mazda dealers.
Cooling-pro make an all Aloy radiator 52mm thick wich costs $399 at mx5 Mania.
PWR makes a 40mm all Aloy radiator that Mx5 mania sells for $770.

Does anybody have any experience using these radiators in sprint races (track days)?
Radiators that are to thick or dence (number of fins per inch) will adversly affect intercooler and air conditioning performance by restricting the air flow the cores. So the cooling-pro may not be the obvious choice.

[davekmoore]

So the oil cooler and filter relocation kit are in along with Redline Water Wetter and a 1.3 rad cap.

Warmish day at Phillip Island yesterday for the sprints. Car wasn't always flat out because it was my first time at PI and I'm not very brave - especially, it would seem, at a faster track like PI.

Still, I pushed it harder as the day went on and the motor was then working pretty hard.

And HOORAY the temp "gauge" stayed rock solid in the middle, just where it stays on the road.

Some fellow MX5ers at PI reckoned I may need to blank off the oil cooler on the road during cooler times of the year to avoid over cooling the oil. But would this only apply to normally aspirated cars?

[93_Clubman]

Good stuff Dave - take it that was also without adjusting timing via the Haltech map?

[greenMachine]

Some fellow MX5ers at PI reckoned I may need to blank off the oil cooler on the road during cooler times of the year to avoid over cooling the oil. But would this only apply to normally aspirated cars?

Agree.

Do you have an oil temp guage (not sure if you are referring oil or water temps above)? On my racecar, minimum oil temp is around 80c, max 120c (Castrol Edge).

I would install an oil thermostat to bypass the cooler until/unless the oil temp exceeds 80, or even higher. 80 might be the minimum, what is the optimum operating temperature for your oil? Or replace the cooler with an oil/water heat exchanger ...

[davekmoore]

Good stuff Dave - take it that was also without adjusting timing via the Haltech map?

Yup, no Haltech changes.

It's also got rid of the mild pinging off boost on very hot days.

[davekmoore]

Some fellow MX5ers at PI reckoned I may need to blank off the oil cooler on the road during cooler times of the year to avoid over cooling the oil. But would this only apply to normally aspirated cars?

Agree.

Do you have an oil temp guage (not sure if you are referring oil or water temps above)? On my racecar, minimum oil temp is around 80c, max 120c (Castrol Edge).

I would install an oil thermostat to bypass the cooler until/unless the oil temp exceeds 80, or even higher. 80 might be the minimum, what is the optimum operating temperature for your oil? Or replace the cooler with an oil/water heat exchanger ...

No oil temp gauge, just the factory water temp "gauge".

Aware that ideally there'd be proper water temp, oil temp and oil pressure gauges but they'll have to wait for a future pay day - and somewhere to house them bearing mind the boost guage already takes up one of the three spaces below the single DIN radio.

Any suggestions for sources for the oil thermostat? And will this wait until the end of summer bearing in mind my pattern of usage is generally to drive 60-400kms between customers?

Also, given that I don't plan to spend a lot of time on the track, will having the oil cooler mean I could safety extend oil changes from 5,000 kms or use something less than fully synthetic?

[bigdog]

SP radiators have special dimpled tube cores to increase the surface area of the tubes for extra cooling, whilst fitting the std top and bottom tanks. The rad Mazda list as a spare is most likely a stock NB rad, as PWR made the last 60 SP radiators, and I doubt they cost less than $400 supplied to Mazda. The first 40 SP rads were hand assembled by a Sydney radiator specialist until they had perfected the design, then the job was contracted to PWR. An SE radiator sounds like the cheapest OEM fix for overheating, followed by aftermarket suppliers, like PWR and Koyo, then Cooling Pro etc Chinese jobbies.

[dbr]

Thankyou for the SP info. The parts clerk had trouble finding the SP Turbo radiator in his list. He may have quoted the SE unit.
I have seen adds in this forum from people selling SE radiators. Does that indicate that prople are overheating with these radiators during track work?

[davekmoore]

Thankyou for the SP info. The parts clerk had trouble finding the SP Turbo radiator in his list. He may have quoted the SE unit.
I have seen adds in this forum from people selling SE radiators. Does that indicate that prople are overheating with these radiators during track work?

Probably worth having a good look through the thread. To save you a bit of time though, my quite highly modified SE has had a slight tendency to overheat on the track apparently completely cured by the addition of an oil cooler, suggesting that the issue on the track is that the turbo runs hard nearly all the time instead of hardly any of the time on the road, and that the oil cooler reduces the temp of the oil to the turbo, thus reducing overall engine temps.

[dbr]

Thankyou again for your reply.
I had read throught this thread but the specifics of which radiators work is not covered other than "over 40mm thick".
The performance of radiator varies even if the tube thickness and fin density are the same, depending on details such as the sharpness of the fin forming tool.
Without the oppertunity to test the radiators, the best indicator is the experience of other people with similiar cars.

The change due to the oil-air cooler is probably primarily due to the removal of the standard oil-water cooler that rejects its heat through the radiator. The oil-water cooler have the advantage of warming up the oil during cold start opperation, improving lubrication and fuel consumption (less pump drag). An alternative to improve the cooling for track days maybe to temporilly remove the cooling fans and shrouds. The fans provide air flow during low speed opperation but the shrouds restrict the amount of air that can flow through at high speeds. Use the cooldown lap to cool the turbo so that you don't need to idle to long in the pits.