Heat problems on track: TECH. Read before adding an oil cooler!

[jay745]

This thread has earned a sticky. Well done

 

[gboticus]

This has me very curious about your note that the oil cooler on the hot side of the intercooler may have less of an impact on IAT. It's still not ideal, but with the VR swap, the intercooler air flow direction is inverted: the hot side of the intercooler is the passenger side.

I'll add some downward ducting to move its hot air to the list of items to fab/tackle, great work! Now I'm just stuck with my own Seibon hood now

Now if only I can get on track to capture some data...

 

[Redslaya]

I'm now working with some friends to CAD up a exit duct for the oil cooler. current plan is to just dump the air out of the bottom of the bumper by cutting a hole in the under tray. ill probably add some sort of deflector in front of it to give the air a place to exit without turbulence. will prototype in PLA but the final product will probably be 3D printed in polycarbonate for proper heat resistance. If this is successful, and i get the designers permission, i would likely open source the CAD file for others to use.

 

[DerHase]

This has me very curious about your note that the oil cooler on the hot side of the intercooler may have less of an impact on IAT. It's still not ideal, but with the VR swap, the intercooler air flow direction is inverted: the hot side of the intercooler is the passenger side.

I'll add some downward ducting to move its hot air to the list of items to fab/tackle, great work! Now I'm just stuck with my own Seibon hood now

Now if only I can get on track to capture some data...

It's just a bit of a hunch of mine. Would keep the highest delta-T portion of the IC on the LAST half rather than on the first half in the case of this car with the oil cooler in the way, BUT at the same time it's still putting heat into ~1/4 of the entire IC/radiator.

I'd still expect a negative effect overall, but just maybe slightly lessened?

Something else I thought about is mounting the oil cooler up higher. The IC inlet/outlet are both at the bottom, so it stands to reason that more air is flowing inside the bottom half of the core and perhaps mounting an oil cooler higher up might not be as detrimental to IATs.

As far as coolant temp goes, as long as you can keep it below 235F regardless of how hard you're running it, IMO it doesn't matter.

I suspect the best move is to put it in place of the aux radiator IMO. If you're shedding heat from the oil directly, then it stands to reason that there won't be as much heat energy being put into the coolant.

There is absolutely a trend in adding IC = increased coolant temp. Some is likely because the car is able to make more power with the IC, some may be because of airflow through the IC and/or more volume of warmed up air coming off the IC and causing a lower delta-T across the radiator. Finding the right balance between all these temps is probably the safest thing to do.

This chart is IS38 only, TUNED only, and EXCLUDING @Redslaya since it is the outlier with these oil cooler problems:

If I could beat on the car all day on a 90F day without ever exceeding:
235F coolant
265F oil
25F (average) IAT over ambient

... I'd be pretty happy. It seems striking a balance is what needs to be done since airflow/cooling real estate is at a premium on these cars.

 

[Redslaya]

working on designing the ducting now. decided to move away from 3d printing and go to aluminum. should be easier/quicker to make and iterate and the material will hold up better. End goal is to have a 2D CAD template that is able to be printed out and overlayed on a sheet of metal and then cut/bent into the correct shape.

considerations are being made for airflow through the cooler as well as air flow direction and velocity out of the duct. thankfully i have a second 19 row setrab laying around to measure and mock stuff up on.

 

[Redslaya]

V1 design. made to be easily bent and riveted out of aluminum. Would seal the edges with metal tape and use rubber/foam to isolate from the cooler itself.

 

[DerHase]

Only recommendation I'd make @Redslaya is radius that upper edge a bit more. I suspect it'll work pretty well.

Any plans to implement a gurney flap on the underside to promote more airflow through the oil cooler? It could be integrated as a flap part of the oil cooler mount (and just have a simple hole cut in the bottom of the undertray/bumper), or could also be done at the bumper itself. I think integrating with the cooler would be easier and also not have as much a need to seal. The back edge of your deflector could also be extended downwards but curve to become flat with the underside.

 

[Redslaya]

Only recommendation I'd make @Redslaya is radius that upper edge a bit more. I suspect it'll work pretty well.

Any plans to implement a gurney flap on the underside to promote more airflow through the oil cooler? It could be integrated as a flap part of the oil cooler mount (and just have a simple hole cut in the bottom of the undertray/bumper), or could also be done at the bumper itself. I think integrating with the cooler would be easier and also not have as much a need to seal. The back edge of your deflector could also be extended downwards but curve to become flat with the underside.

There is about 2" of space from the bottom of the cooler to the bottom of the car that's not shown. It will have a chute downwards to dump the air under the car. I'm thinking using garden edging as a forward deflector to clean up the air around the exit is the way to go. That way if the car bottoms on something it's flexible.

 

[Redslaya]

Starting with Cardboard to test fitment before sending the files out to be cut out of aluminum.

 

[Redslaya]

Through the magic of buying two of them I was able test fit the prototype duct against the cooler and fitment was near perfect. Going to now check fitment against the car. I believe I will need to trim one of the side deflectors to make room. If everything looks good I'll get some data with it on the car to ensure functionality before sending out the file to be cut

 

[Redslaya]

Went to test fitment today and the duct didn't clear where I had the cooler off to the passenger side. So, I moved the cooler to the middle rather than redesigning the duct. Will get some data for @DerHase before I trial the duct to see if cooler placement has a noticable effect on IATs

 

[DerHase]

Went to test fitment today and the duct didn't clear where I had the cooler off to the passenger side. So, I moved the cooler to the middle rather than redesigning the duct. Will get some data for @DerHase before I trial the duct to see if cooler placement has a noticable effect on IATs

View attachment 286327

I see you removed all the foil tape around the edges

 

[Redslaya]

I see you removed all the foil tape around the edges

it was ugly. I've got black aluminum tape on its way. Looking good is half of going fast

 

[tigeo]

it was ugly. I've got black aluminum tape on its way. Looking good is half of going fast

Where/what brand?

 

[Redslaya]

Where/what brand?

There are plenty of options on Amazon. I just searched black aluminum tape.