I have to agree, it's generally easier to install a low profile blower (or cut a hole in the hood) than a turbo because of all the plumbing and the room it takes up beside and in front of the engine. You can cut a hole in the inner fender well, but there's other things under that fender! It's not like going up where there's nothing but the hood (well, lack of vision around the blower counts).
It's not as efficient, but what about the remote turbos like Squires (
www.ststurbo.com)? I already know some efficiency is lost, but it still takes lost power and adds boost. If you're looking for a bit more power but not something like 20 psi, this sounds to me like a really good option. Since it takes the place of the muffler it's not creating any more back pressure. Typical output seems to be around 5-8 psi, but Squires mentions getting "near 20 psi" (which I read more like 15 psi) out of a remote unit. Still takes a ton of work and some tubing welding, but for relatively low boost seems like a good idea. I plan on eventually using a Chrysler 2.2L turbo remote mounted on my 4.6L in-line six (bored/stroked Jeep 4.0L). Instead of routing engine oil to the turbo I'm going to make a remote reservoir with electric circulation pump. I'm only concerned a bit about oil pressure -- finding an electric pump that will circulate is easy, that will do it at 10-15 psi might be a bit tough. Since turbo bearings typically "float" in oil, pressure is needed. Might have to run a line from the engine. Squires does that but uses a pump to take it back to the engine. I really question using a return pump though -- shouldn't be necessary should it?
And before anyone cries "it won't work", look at Squires site for one thing, then go visit your nearest museum with WWII vintage aircraft. A B-17 bomber uses a huge remote turbo on the back of each 1820 cubic inch radial piston engine. An approx. 6" ID pipe runs 10' back on the outboard engines, near 20' on the inboards (where the landing gear is -- turbo is behind gear well). The center section of pipe has cooling fins! The P-47 Thunderbolt also had a turbo mounted in the rear part of the fuselage, 15-20' from the engine. So this isn't a new idea.
I already stated I know it's not as efficient as a turbo mounted close to the engine. But please, don't anyone come up with "if it works so well manufacturers would have used it"!! It's more cost effective to put all the engine parts in one unit and drop the hole shebang in. It's not that hard when you can start from a drawing board and have a hefty R&D budget to work with, and since it's a bit more efficient, that's the best way to go. Adding it to an existing vehicle NOT designed with space for a turbo, or where everything has to be custom made, is a different story.
On a drag car cut the rear floors out and run the turbo just a foot or two behind a standard aftermarket header. I don't mean leave the floor out, but make a raised floor and stick the turbo in the well. Then you can dump the exhaust almost straight out the side, angled to exit in front of the rear wheel. Pipe the compressed air through the car and out the center of the dash.
Will be a lot less cost and work than a trasitional under hood mount. I can afford to lose a little efficiency as long as there is adequate boost.