Hey @batguy . You're a car guy. I had a question about the Interceptor, specifically about the blower. It was of course non-functional on the prop car (well, it was functional in the sense that the belt and wheel spun). I was checking out some custom built MM cars and wondering if it was possible to integrate the blower as we see it in the movie with an on/off switch. I assume it's not practical at all because the blower is the only intake into the engine so basically it's always 'on' persay and... why would you even want it 'off'?. I realize the MM movies take cinematic liberties in that regard to have exciting boost moments. Nevertheless, can it be done somehow?
Hi. Yes, I'm a car guy, to put it mildly!
Short answer: A switchable blower might be do-able on paper but it's not worth the compromises. The final product would have more drawbacks than the movie version.
- Mechanical:
You would need some kind of electric clutch on that front blower belt like an overgrown AC compressor clutch. But it would need to be REALLY strong for that job. Enough to hold at least 150-200 horsepower. (An A/C compressor clutch deals with maybe 10% of that.) This is why the rubber belt on the front pulley of a blower is so much wider than the other rubber belts on the rest of the engine.
- Another issue would be the engine compression. Engines making big horsepower with blowers are rebuilt for the job with low compression pistons. (It offsets the extreme cylinder pressure squeeze.) So this switchable-blower engine would be a total dog when the blower is not running. It would be much slower than stock (and it wouldn't even have a big fuel-efficiency gain to show for it).
There is also the intake situation. The engine would have to pull the air/fuel mixture through the blower (in place of an intake manifold) when the blower is not turning. Not efficient, to put it mildly. More power & mileage losses. More reason why this hypothetical engine would run like crap when it's in blower-off-mode.
- Appearance:
The Mad Max prop cars had the fake blowers mounted a few inches too far back on the engine. It's enough to be clearly visible if you had a real & fake setup next to each other. (I suppose you could cope with that problem by building a recessed firewall and moving the whole engine back a few inches, if you were so inclined . . . )
A
fake prop version of a switch-able blower? Sure. That's no problem.
The 'Fast & Furious' 1970 Chargers have been done that way for years. Since the 4th movie they have been running a stock GM LS3 Corvette engine in those cars + a fake blower housing bolted onto the top of it. An electric motor inside the blower case is what spins the pulley on the front of the blower.