DRE350

I'm using Motul 300V (forgot what weight) and in the middle of winter here in OZ have been getting 120-125 degrees Celcius after 4 laps. After asking a few guys, I have received differing views.

Some guys come into the pit if temps go over 120 and some guys who race semi-professionally say they frequently see 140 with their race cars without any issues.

What are your views?

MoodDude

Ideally your oil temp should be around 85 C. You can run your oil without any problems up to 120 C, after that I would cool the car down unless you are in a race and winning. Your water temp will be within 10 C of your oil temp and if you are getting that hot in winter and want to run in Summer, you may need to look at doing some work on your cooling system.

betamotorsports

iTrader: (1)

Answer: It depends.

If your leading 2 laps from the end of the deciding race in the championship the only things that are going to bring you into the pits are the checquered flag, a tow truck, or an ambulance. If its an open track day and you're tired after 2 hours of track time; many, many minor things are an excuse to come into the pits.

A lot also depends on where you're measuring the oil temps. A stable 140C going into the oil cooler isn't much to worry about. 140C coming out of the cooler is not good. Also, a lot depends on what you're comfortable with. If you're constantly worried about oil temps at 140C you're not driving as well as you should. Do something to cool it down so you can focus on your driving.

scotts300

iTrader: (46)

Conventional oil is limited to about 110C, as its viscous properties begin to diminish from the high temperatures. Synthetic oil, in general, can run a bit hotter than conventional, but I'd still back out of the throttle over 115C and certainly stop at 120C. The issue with the higher oil temps is also one of tracking water temps. What are your coolant temps when the oil is this hot?

I'd invest your energy, time, and resources, in supplemental cooling for both systems. Is your car F/I? Overheating on F/I cars is quite common, and if that's the case, you could/should turn the boost down. I've NEVER had a problem with overheating in the N/A 350, even in 30-minute sessions where the outside temp is 45C.

DRE350

Thanks guys.

I am FI and have an oil cooler and an upgraded Koyo radiator, albeit the slim one. I've cut holes in my bumper so airflow to these coolers aren't a problem, What else can I do in terms of cooling (larger radiator, water spray onto coolers)? Or maybe I'll have to resort to putting the boost down.

I'll have to check where I'm getting the oil temps (after or before the oil cooler).

MoodDude

For an effective and relatively inexpensive fix, ensure that all the air for the radiator is going there and same with the oil cooler. This means building a shroud between the bumper cover and the radiator. Also, make sure the oil cooler is in front of or behind the radiator, it needs its own cool air to be effective.
A header tank will also help to ensure that all the air is out of the system and that you have a good head at the inlet of the pump.
A double pass radiator is what most pro-teams use to ensure cool temps along with the above, yet these usually have to be custom build and are expensive.
You can also create more effective cooling by creating a negative pressure inside the engine bay.

MoodDude

For an effective and relatively inexpensive fix, ensure that all the air for the radiator is going there and same with the oil cooler. This means building a shroud between the bumper cover and the radiator. Also, make sure the oil cooler is in front of or behind the radiator, it needs its own cool air to be effective.
A header tank will also help to ensure that all the air is out of the system and that you have a good head at the inlet of the pump.
A double pass radiator is what most pro-teams use to ensure cool temps along with the above, yet these usually have to be custom build and are expensive.
You can also create more effective cooling by creating a negative pressure inside the engine bay.
Another way is to tune your car, changing the A/F ratio and timing can help keep the engine from producing that much heat.

Kolia

iTrader: (2)

Simple, albeit a bit "getto" solution: cut the hood to create vents directly behind the radiator. You want to get the warm air out of the engine bay.

Look at WRC cars for inspiration.