Question about the Landau in the opening scene

[flightsuit]

What are the structures poking out of the car's hood? I've seen plenty of hot rods with various types of aftermarket intakes and superchargers sticking out of holes in their hoods, but never anything quite like the two bizarre things on the hood of the Landau.

[flightsuit]

Opening scene of MM2, that is.

[waynegt351]

its like a pair of turbos with some carbs on the front

[HUMVEE Driver]

There was a big discussion about this a few years back. Maybe a search of old posts might locate it? If I remember correctly, they are turbos, and that kind of setup would function. However, it would be dangerous and I'm not sure what the consensus was about how much extra speed you'd get out of them.

HUMVEE Driver

[flightsuit]

Hmmm...

That would certainly be an odd place for turbochargers to be located. I suppose it might aid in the cooling process to have them exposed to all that fresh air, as opposed to being inside a hot engine compartment.

[Peter Barton]

Mounting the turbos there also means you can't open the bonnet (hood) without disassembling the whole arrangement, so not exactly practical in reality.

Try these older threads, there may have been others...
http://www.madmaxmovies.com/forum/viewt ... f=4&t=6313
http://www.madmaxmovies.com/forum/viewt ... f=4&t=4963

[flightsuit]

Fascinating stuff! I hadn't realized the Landau had three rear wheels. I wonder how that affected performance?

[Foxtrot X-Ray]

I don't really see how they'd be dangerous.

My question would be how do you open the bonnet?
Setup like that would need to be fixed to the engine and the hole in the hood was only large enough to plumb the intake & exhaust tubes through.

As for how much Speed it would add, think of the V-8 engine as two Four cylinder engines.
the 351 is approximately 5.8 liters, so it'd be 2.9 liters twice. No problem feeding that ("Those") with Turbos that size.
Pretty sure 1 PSI of boost would be noticeable.. Might get 5-6 out of those Turbos.. JUST GUESSING! Turbocharging is not my field of quote/unquote expertise.
I've always found belt driven superchargers to be more interesting.

Not so sure the Carbs would fuel a boosted V-8 though.. Anyone know what kind of CFMs Side-draft carburetors like that typically run?

[flightsuit]

So these carbs and turbos were basically technical-looking stuff tacked on to the hood of the car to make it look hot roddish and, perhaps, vaguely futuristic. I think the look works perfectly well in the film, because everything's happening so fast, and the viewer doesn't have a spare moment to contemplate the underlying mechanical principles. What's really funny is the way so many MM2 rip-off films grabbed this concept and ran with it, offering up all manner of wasteland hot rod festooned with the most absurd add-ons they could possibly think of.

[HUMVEE Driver]

Here's part of one of my responses that Peter posted a link to. The 'dangerous' part is explained there. Keep in mind that I don't know much about this stuff; I had asked a friend about his opinion.



As you can see, the Landau has a very unusual air intake system on its hood. March Hare has stated the parts are two WEBER 48IDA's or 44IDA's turned sideways to appear side-drafted. Some people have said this set up is called a 'Draw through Turbo System' or possibly a 'Blow Through System'. I asked a mechanically inclined friend about it, and here is what he had to say:

It looks like two modified carburetors attached to two turbos attached to a custom manifold which runs down to the intake. If that is what they were going for, my question is this.....why?????

I'm sure you are aware of how a standard turbo'ed carb car works in that it uses the exhaust flow to spin the internal turbines of the turbo which in turn compresses the air to be used before being routed to the carb and into the engine. It looks like they took two turbos and tried to work them like a super charger instead. This being that in a supercharged engine, the air is drawn through the carb before running through the blower and being compressed and forced into the intake manifold. Like you mentioned, there would be some major issues with this setup......First off, we really have to assume that this isn't a fire hazard (which it would be). But, just to go through that aspect, having the air come through the carb and then through the turbo charger (which runs off of hot, hot, hot, exhaust gases, right?) would be a huge mistake because after the air passes through the carb, it picks up the atomized gas and comes out as a (roughly) 14:1 fuel mixture which is highly combustible. Now since we already know that gas isn't explosive, but its fumes are and we further know that pouring raw gasoline onto a hot set of exhaust headers can cause a flash fire (trust me on that one), it's pretty safe to assume that passing an explosive fuel mixture through a mechanism which is directly attached to a pipe with 500+ degree exhaust gasses running through it (not to mention the mechanical heat caused by compressing the air, it would probably ignite well before it even reached the combustion chambers. Now, for the sake of argument, let's say that the turbos are attached to some sort of intercooler system (which it doesn't look like) and they are kept cool enough so that the fuel doesn't ignite prematurely, lets get to the mechanical reason why I don't think this would work.

We know that turbo'ed engines work better at higher revs and not as much at lower revs because you haven't built up any boost at low revs. That's because a turbo's internal turbines are spun with exhaust gases, and if your engine revs are low, there isn't much gas to spin the turbo so the engine has to speed up in order for the exhaust gasses to speed up to get the turbo really moving. So there is usually a slight lag in the boost from a turbo from the time you hit the gas until it actually starts punching your power up. That's my main problem with having the turbo downstream of the carb like it is in the Mad Max movie. Normally when you start a car up, you have the starter turning the engine over which allows the pistons (and gravity) to suck in the fuel mixture into the engine and get her running. With this weird turbo set up, I don't see how you would even start the car. You'd be cranking the engine, and there would be no exhaust gases to turn the turbines in the turbo over to suck in the air through the carbs. In a supercharged engine, the blower is mechanically connected to the crank pulley with that huge belt, so it is turning when the starter is turning, so that is why that works. And in a normal turbo, the turbo is upstream of the carb and the carb is right on top of the engine and the turbo doesn't have to turn to get air through the carb (I think there is a bypass valve). But even if there is some sort of weird mechanical bypass just for starting purposes on this thing, when cranking the engine, the air/fuel mixture would have to pass horizontally backwards for about 8 to 12 inches, make a 90 degree turn and travel a foot or so toward the intake stack, make another 90 degree turn before traveling a good 14 inches or so into the combustion chamber. And this is if they were able to somehow bypass the non-rotating turbine blades in the turbo. You don't need a deep understanding of air flow and fuel mixtures to know that this is a shot in the dark just to start the damn thing. It definitely looks like someone said "Hey, turbo's are cool too, but you can't see them because they're always under the hood. Let's make a car with turbo's on the outside for the sake of a very cool, eye pleasing monstrosity!" And then they came up with this arrangement and attached it to the hood of a normal carbureted car like they did with the Interceptor's blower and called it good.