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Not exactly a locost (or low-cost, for that matter), but I figured you guys could help me.

Recently, I've been making some progress on my turbo rotary engined Bugeye Sprite. One the latest things checked off the to-do list was the intercooler mounting. I've top-mounted the IC, and now I'm trying to figure out the best way to feed it air.

So, my question is this: cowl induction or traditional hood scoop? I want something very clean looking and unobtrusive. For those of you that know Bugeyes, the exterior shape is very distinctive, especially the bonnet (hood) and the protruding headlights. Whatever solution I come up with, I don't want to screw up this look too bad. On the other hand, I plan on running 12-15 psi of boost, so I'm going to need pretty good air flow.

Any body have any experience with cowl induction scoops? How well do the really work?

Any other ideas or opinions?

Here's an engine bay shot of how the IC currently sits:

Thanks guys,
Bug

Well if you have a top mount intercooler that pretty well ensures you'll have some sort of louvers in the hood.

Cowl induction should work well if you're going to be running a windshield that will create a high pressure area to feed the cooler. But, (there's always a "but", isn't there) you'll also need to duct the cooler's exhaust to a low pressure area to get the airflow that you will need. I did this on a Street/Stock Camaro that I helped build for the dirt track. Rules said we had to run an auto trans and most competitors just hung their trans cooler somewhere in the passenger compartment rather than out front to keep the mud out of the cooling fins. I placed the cooler in the cowl plenum chamber and let it exhaust into the passenger side foot well. Never had any tranny problems due to heat.

Hmmm. Louvers are usually used to draw air out of a confined space. I'm trying to draw air in to the engine bay, through the intercooler. I think this means either a traditional forward-facing hood scoop, or a rear-facing cowl-induction scoop. I.e., I don't think louvers are a solution.

Good point. My assumed path for air down and out of the intercooler is through the tunnel, down and around the transmission. I've got room to mount a puller fan on the bottom of the IC, but kind of want to avoid that if I can. A "passive," non-active/forced air solution would be what I'm shooting for.

period correct ?
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Water to air is the best option for that space.

All that matters is having decent pressure differential across the core. As was said, assuming a normally-slanted windscreen, there's high pressure at the base of it. Usually the air pressure in or behind the wheelwells is fairly low, so that's a good exit location (or even the passenger compartment since the air won't be that warm.)

An air-to-water heat exchanger work but isn't a guaranteed solution since its efficiency drops each time there's an exchange. The hot charge air in the intercooler warms the water, which is then pumped to another heat exchanger in an *assumed* better location (arguments for air-to-water exchangers always assums it's better, even if it's not.) At each exchange there's a loss of efficiency, so unless some sort of testing is performed between the two setups, there's no guarantee that the air-to-water type is better. There's also the issue of more weight, leak-prone connections, and an electric pump that can fail with or without notice.

If it were my car it would get ducted into the passenger compartment since it's right there and is a good low-pressure area. The air will only be a few degrees warmer than ambient.

Any properly designed water to air system never gets above ambient. The car will never be able to be in boost for long enough to heat the mass of the water. Every time you take your foot off the throttle the intake temp drops and any heat above ambient moves the other direction and out the exhaust. Even on a road course you cannot overcome the mass of the intercooler cooling system.

If we are going water to air, why not go refrigerant to air? Would that work, or would the AC pumping losses more than offset the power increase from the increased charge density? Would the refrigerant charge & AC pump weight less or more than the water and its pump? Can you get electric AC pumps? An electric AC could reduce the pumping losses during WOT as the battery will act as a buffer.

Tom...

Its been done like that. You would want to only run the pump at less than full throttle.