RoadRacer78 New Reader
9/22/12 9:39 a.m.

I hope I posted this in the right section.

Howdy all. Been a member here for a while but I don’t post much, I tend to just lurk. I read GRM from cover to cover every month though.

Seems to me there is a lot of experience and ingenuity on this board so I would post my dilemma up here.

The car in question is a 2007 Mustang. This winters project is aero and a little more power. The "little more power" has run smack dab into the "aero" part of the project.

Keeping the supercharger (air to water) cool is a task and the engine temps aren't far behind. We already have as much cooler as you can possibly stuff in the front of the car and it has a hood with MASSIVE (Tiger Racing) vents to get as much air moving through them as possible. Were maxed out at the front of the car. So I'm going to move to the back. There is a ton of unused space back there and the car is so nose heavy you couldn't possibly unbalance the car.

The off season plan is to completely belly pan the car from splitter to diffuser. Or as much as we can and it still remain a "street car" (If there were bigger quotes I would use them there).

I only have a rough idea of what I can accomplish and an even rougher idea of how best to do it. Right now the plan is to run either NACA ducts or "scoops" in the rear quarter windows that feed the trunk through hoses (trunk is sealed). I don't think they will move as much air as I would like them to but short of cutting into the body that's probably the limit. The big question is how to mount and exhaust the heat exchanger (HE) that will be in the trunk.

Idea number one is to mount it vertically in the trunk and duct it (it would only be a couple of inches) to the trunk door/lid between the tail lights and replace that panel with grill/screen. I could get a HE that is about 26x13 in there and run two 10" puller fans. My thinking behind this HE position is that the air behind the trunk is either "dead" or fingers crossed, a low pressure zone that will allow as much air movement as the inlets will limit it to. Is the area behind the trunk between the tail lights a dead zone? A low pressure zone? Turbulent air?

Idea number two is to cut the floor out of the trunk and mount the HE parallel to the diffuser (which is not built yet). The main plane of the diffuser where it has HE above it would be grill/louvers/open to the HE (haven't solved that either) so as the air runs under/past the diffuser it will exhaust the HE out of the bottom of the car. One nice thing about this approach is I could run a LOT bigger HE and fan(s) than if I exhausted it out between the tail lights.

A third idea, and one I am not thrilled to death with because it would require paint (I could do the trunk lid without painting it), fab work on the bumper cover and two coolers would be to run a HE behind each wheel and exhaust them ala' Porsche 996TT. I couldn't run very big coolers, there would be hoses all over the place and if I tagged something with one of the rear corners it would require custom everything to fix.

I realize that having an additional HE at the back of the car is not ideal, but it is the only space I have left. And I know these ideas are very rough. I'm pretty much stuck where I'm at, I can think of pluses an minuses for the three configurations. Which one is the lesser of three evils? Is there another solution I'm not seeing?

I can fab just about anything. But the car has to remain streetable (I use that loosely) and "crashable". By crashable I mean that the core of the car is not custom, or the parts that are custom are easily made again. I don't want to have a simple spin turn into a huge fab project.

I'm open to any help that you guys (or girls) can throw my way.

Thanks a lot! Jason

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