Weird Landau engine setup

[HUMVEE Driver]

Hey, all, I asked a friend who has the knowin' of a lot of things about the weird air intake system on the Landau from The Road Warrior. I don't claim to understand all of it, but it sounds as if the system on the Landau probably couldn't work. Here is what he had to say; let me know what you think:

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.

HUMVEE Driver

[Bozz]

I stongly suspect that He's got the right of it.

The intake setup was for show, not go.

Think of it this way...

You've been contracted to build some whacked out looking cars for a movie, and they HAVE to run and perform their own race stunts.

Are you really going to go to the trouble of engineering an entirely new engine for the thing?

Nope, you're not.

After all, you get paid in a lump sum, not per hour, so you've got to be quick to make your cash.

So, you stick on some cool looking salvage to an old beater of a car and give the stock engine a quick tune up.


That being said though, it can't hurt to dream, can it?

[Foxtrot X-Ray]

Interesting..

My thoughts on the matter.

The "Actor" car: No, the turbos don't work and wouldn't need to anyway.

The "Character Car: A pair of Side-Draft carbs (Mikunis, perhaps?) in a Draw Through turbo setup..

No, I don't think this would work.


HOWEVER, Perhaps what we see as a Draw through Turbo system is really a Blow through?
I.E. these Draw through carbs are there ONLY as Mounting for the Air Filters, and the Carb that actually works is in the normal position?

I have actually seen a Ski-Boat engine with a very similar intake setup to what I describe (Without the Side-draft carbs, though)

This engine simply had a pair of custom headers with Center dumps turned upwards with the turbo exhaust inlets bolted directly to the dumps, and the Air inlets dumping into a box around the Carb.

[z boy]

I've had few turbo cars both suck through and blow through and not had a worry with starting either.


one was a straight six 202 cube holden with a suck through T04 fed by a 600 square bore holley via a 90degree intake so the carb was upright and it ran like a charm, so it is possible to run the set up shown.


i have also had a big single turbo setup on a 308 v8 that was a suck through using a rochester quadrajet carb, with no hassles either.

[Nightwalker]

I also have my doubts about taking combustible fumes through the turbo. I have little experience with turbo engines and the turbo can really get that hot that he wil glow. And thats hot.





But I disagree that you can't get a car started with the turbo after the carb. It doesn't matter were the turbo is in the system. After the airfilter the whole system is closed from the oudside. A turbo will cick in at about 3000rpm. Befor that the turbines stands stil or turns slowly. The air is able to go through the turbines at any time.

[mfpmax]

The turbine side gets hot, but if the side with the fuel is getting glowing red hot...you've got other problems to worry about





My friend has no problem with his blow thru carb setup on his RX7. Nor do plenty of people running blow thru carb supercharger setups.

[Nightwalker]

The comlete turbo will get hot. Not only the exhaust part. And a turbo has 2 turbines. 1 propelled bij the exhaustgasses and which is connected bij a little axle with the turbine that will compress the air into the engine. Some guys at the Dutch Fiat Uno turbo club tested there turbo's by driving at high speed for a while and then stop and look under the hood. The turbo was glowing red. As long as you keep the engine running so the turbo wil get fresh oil to cool down there is no problem. When the tubo has cooled down enough you may shut down the engine. That's why it is the best to drive the last few kilometers under the 3000rpm so the turbo won't work and wil be able to cool down.

[mfpmax]

The compressor side gets hot, but not 1300 degrees hot. Thats where the cherry red comes from. Highest compressor side temperature is around 300 degrees...and thats the air charge temperature.





And yeah, the turbo cool down is to make sure the oil in the center section of the turbocharger doesn't get baked and clog up the bearings of the center section.





As stated, if the side with the air and fuel gets to 1300 degrees. You've got problems.





BTW. My car is turbocharged.

[rockatansky4073]

I'm not a 'car guy' i barely know sh*t, but i've read on a number of occasions that the LANDAU's set up is valid and did work, i can't prove this, but i have read it around the place.

[Biker]

My take on this is as Bozz says above. I think the costume dept and the car dept that made MM2 got together over a few dozen beers and a roo burger or two, one evening and thrashed out the general look of the cars as well as the costumes. Bolting bits of engines parts to the outside of the cars would make their appearence radically different when compared to most road going cars, what did it matter that it didn't actually work? As most of the audience at the time were just being entertained by the action going on in the film not whether such and such a carb set up would work or not.


The same with the costumes, there is no way on gods little earth I'd even consider riding my bike with my arse hanging out like Wez's. If you've ever had to "abandon ship" due to a Volvo driver pulling out in front of you, the first thing you slide down the road on are your 'hams' closely followed by your elbows, knees, head and back then hams, elbows, knees all over again.... depending on your speed of course. lol!


Nope, artistic license was used liberally on those cars for the film, that's why they looked so weird and good however when you analyse it too deeply the paradoxes begin to show. It's a fruitless excercise to try and wonder whether such a setup would actually work or not, since it's "for show not go" as Bozz so rightly put it.... like 90% of the boy racer cars I see on the roads nowadays it seems. Those big bore exhausts and neon lights under the sills really make those car zip along don't they? Not to mention those huge base speakers.. gasp! Hehheheheheheeeee


The Fast and Furious films have triggered a whole new generation of boy racers into believing that fancy paint jobs and loud speakers in the boot would get thier shagged out Ford Fietsas going faster than 90mph and a girlfriend with legs up to her neck wearing micro skirts and no knickers. Sadly all they get are other deluded fools, like themselves, drooling over each others idea of a gorgeous car. It's simply collective masturbation for boy racers.


Biker