Thom

Curious to see what kind of results you get with this.

Liquid-to-air intercoolers seem to be popular among the drag crowd, but on an engine undergoing prolonged full load runs, I'm curious if thermal inertia may be detrimental to cooling, especially when it's about oil. In fact I do not think I have heard before about air-to-oil intercoolers.

BMW are using liquid-to-air IC on their current M5 and M3/M4, and I guess they work well enough considerng how small they look, but oil gets of course a lot warmer than compressed air.

What kind of oil temp do you currently see with the 964/993 oil cooler? Isn't it actually a bit too big when used with a dry sump?

333pg333

We moved from the big 993 oil cooler when this particular version of this car was 'unwrapped' last October. However it was too small and we were seeing temps over 110c. So put in something that was as big or bigger than the 993 and the temps dropped to about 90c peak. With the car primarily used for short bursts we think we'll be ok and have been recommended this path by someone with a lot more experience than me. Looking to use one of these Thom. http://www.laminova.se/
The benefits will be mulitple (provided it works!) but mainly drag reduction by removing it from the airstream and also allowing a diffuser to rise up where the oil cooler currently sits.

Thom

Interesting... Now that the restrictions on my engine are properly-balanced again (short of going wild on an expensive CAD head work) perhaps I should focus on some of these proper modern neat parts.

So do you plan to move back the main rad in order to make some room for the coolant rad for this new liquid-to-oil IC?

Duke

The Laminvo cooler taps into the engine's coolant system so no extra radiator is added. Also have the benefit of getting the oil temp up to speed quicker and eliminates the need for an oil thermostat.
When Patrick mentioned this idea some time ago I did some research and it's a route I want to go too. My coolant temp never exceds 82 deg C so I'm sure it has enough capacity left to cool the coil too.

Thom

In that case I don't see how it's going to perform better than an external oil cooler. This is going to keep coolant at a higher average temp, and this is pretty much the reason why people running cars that come with coolant-to-oil engines usually add an external oil cooler. Perhaps installing a massively larger main rad may help?

Duke

You right it won't perform better but it doesn't require air so you can reduce the openings in the front bumper and in turn get better aerodynamics.
These Laminova coolers are very efficient and the bigger version should be able to keep oil temps just a little higher than coolant.
Not a bad idea as I almost have the opposite issue. Even with an oil thermostat it takes forever to get my 13 liters of oil up to temp. (Part because oil thermostats always leak through to the cooler)

Thom

I see... so basically reducing the area of air penetrating the front of the body may also increase the pressure through the inlet(s) left, thus improving main rad efficiency? I suppose that would depend on the variation of section in the ducting between the inlet itself and the surface of the rad.

968turbos2

The V8 twin scrolls BMW is using used the air-water intercooler just because of space. The F10 M5 has overheating problems on the track.

Duke

Just to clarify, what Patrick is talking about is only about cooling the oil, not the charge air from the turbo.

Duke

The less air you take in through the bumper, the less the frontal lift will be.

Thom

Balancing drag with cooling system performance... this will be very interesting!

Duke

As long as the radiator have the capacity to remove the heat added from the oil heat exchanger it's a win/win. I would expect me and Patrick having about the same cooling capacity and I can see that I have headroom in my water cooling system given the temp is hovering around the thermostat values. My coolant temp could even go up 15 deg C from where it sits today before having to do cooling laps so this setup should work well.

333pg333

Pretty much spot on what Gustaf is saying. Something that doesn't get taken into account very much at all in this forum is the formula which is essentially;

Downforce vs drag vs cooling. To that I add the 4th constant which the engineers overlook....budget.
So essentially the formula is purpose driven. For a T.A. car drag and downforce are paramount. Cooling isn't quite as essential as normal racecars. Of course it's a balance. Yes, only the oil is going to be cooled by water. The Rad and I/c are still air cooled. We are raising the Rad a little purely to make way for the diffusers in the splitter (which haven't been built yet). Step by step. Today's bill was enough for me at the moment!

333pg333

Just had to post this pic. After a lot of work over the last few weeks it's always a bit of a thrill to see the car loaded up on the trailer ready to go to the track.
Note that the new wider splitter only just allows us to fit. Considering that the trailer was pretty much made for this car by my builder, we didn't take into account that we'd be wider than we were in October last year.

333pg333

Actually I asked Paul about this and he said that we'd be unlucky if the current sway setup weighed more than 1kg extra (over the previous Tarret) as most of the parts were made from chromoly.