QUOTE(Rleog @ Oct 29 2010, 02:03 PM)
Beautifully done, Pcar916!
Thanks! It was an adventure since I'm not a sheet metal guy. But my first attempt with the same cooler vented under the car and weakly-ventilated (even with two big fans) was not enough. The 993 motor doesn't have an on-board cooler behind cylinder number 6, so external is all there is unless you dump the second filter console and put back a cooler in that location.
There are more elegant sheet-metal craftsmen out there but this has worked for 10 years (with a small additional cooler in the high pressure circuit during the summer months) so I'm happy with it... zero-maintenance.
There are great examples in this thread. Hopefully they'll give enough ideas to build something functional.
Hood exit rules: Functional 1st
- The closer to the front of the car the better. It's a low pressure zone. Pressure gets higher farther back on the hood peaking at the bottom of the windshield, which is why cars have a vent there that forces air into the interior.
- The cooler intake must be sealed. Intake air WILL escape if not forced to go through the cooler fins.
- Don't make you exit the same shape as mine. I included those little tabs because of the 917 cooler-exit I modeled it after (my all-time favorite Porsche race car). But they're always in the way when I have to use a gas jug and are all bent up because of it. Simple is gooder.
- I should've used -16AN rather than -12AN. The cooler IS -16. I suspect with -16 I wouldn't have had to add another auxilliary cooler.
Class rules: Check 'em. The SCCA regards hood exits as an aero-improvement. If the car didn't come with one it's usually illegal in road racing. I don't think it matters in AX.
It's fun to build stuff.