Quote Originally Posted by Jim Schenck View Post
My current thinking based on what we have seen testing intercoolers seems to be pointing to different solutions based on the intended use of the car. Testing the air to water systems on the track has shown that with no recovery time they tend to gradually increase in temps over the course of the longer runs, whereas on the street the recovery time at either cruising speeds or idle allows them to stay cooler than either the top mounts or relocated air-to air units still in the engine bay. The two W2W systems we tried were different in that one used a large reservoir and a medium sized cooler and exchanger and the later system used a bigger cooler and a full sized radiator as the heat exchanger with no reservoir. The second system worked better and was overall lighter than the one using the extra tank.

For air to air I still think the top mount is viable for stock and mild builds, on both street and race cars, and that is where we concentrated our street car efforts in the tunnel trying to find the best spots to pull and from and exit air to. The plan going forward for ducting to the top mounts is to use four inlets to feed the intercooler. The two side inlets are effective if they are cut out correctly (the cutout shape made a HUGE difference which was something we missed in our first trip to the tunnel) and either the decklid vents or the roof scoop ducts for the other two depending on which model it is.

During our track testing we also tried several different very large scoops feeding the intercooler from in between the humps and this was not as successful. Even with a large top mount (Turbo XS) the temps were not as low as we would like them to be and the drag/reduced downforce was not good at all. Airflow in that area is just very turbulent and the cockpit itself is a low pressure so air will actually flow backwards into it.

As far as air exit goes the best place is the lower section of the car, the upper vents still allow air to exit but the flow is much slower and more chaotic. The rear trunklid vent is somewhat variable, with the spoiler in place you get air flowing in, but with the wing in place there is not much flow through that vent at all. I still think the vent is useful, particularly for escaping heat when the car is sitting still, but it isn't a good place to get reliable air entry or exit from. Cutting additional vents on either side of the low vent seems to make the most sense for someone needing to get additional air out of the engine bay.

The front mount in the race car is really just going to come down to testing turbo lag. This setup will only be a real possibility for R models as the tubes run through the top of the doors, but the plumbing was actually pretty straightforward and the amount of tube relative to a WRX with a front mount is not that different (maybe 50% more but not 2 or 3 times as much). We stayed with a fairly small inlet tube to try and keep the overall volume down but we still have testing to do to see if this really is the best solution for big power track only cars.

Also on the R, the windscreen makes a big difference, improves drag, downforce, and cooling and running without it does not improve flow into the rear decklid area.
Good afternoon, have you folks done any testing on sidemount configurations?