Lister Storm

[v10_viper]

While playing Gran Turismo 2, yes I still play it, I'm waiting for Gran Turismo 4 to come out before I get a PS2, but I was looking at the details or w/e of the car, it says it uses a twin supercharged Jaguar V-12 engine, that's the first I think I've heard of twin superchargers, is this true, and are there other cars out there like this??

[Hudson]

The Aston Martin Virage Vantage had two superchargers.

[v10_viper]

What is the point of it, more boost, I think running two superchargers would be worse strain on it when you could go with one supercharger that is better, thanks Hudson, I think I'll look into the two of these cars a bit, too widen my knowledge of course, haha

[LancasterWannaBe]

I don't know why people run two blowers.
Iv'e seen people do it though, and they said they liked it better????

I'de just use one from procharger or something since they're strong enough to run high boost.
It's not like a turbo though, where you have to connect it to the exhaust so that it's actually easier to run two turbos on v-engines.
But two superchargers?

Truely one must ask, "Why?"

[supadupasupraman]

The Bugatti concept is a Quad- charged engin. Sort of ridiculess huh! I also think RX-7's are twin turbos. And of coarse nissan 300x twin turbo's.

[LancasterWannaBe]

My dad knew a guy he used to race with that used a quad turbo setup for his BBC V8 (couldn't tell you how large exactly). This was about 30 years ago I believe.

He used the quad as apposed to twins so there would be less rotational mass. Damn did that thing spool quickly [dad said]!

Also becuase there was less rotational mass, the turbos could spin faster without flying apart - which might be one reason for twin superchargers.

[Sluttypatton]

The simple answer is volume. Two superchargers can move higher volumes of air than one, which is what is important in the long run. After all, it is the quantity of air being induced rather than the pressure at which it is done that allows for additional fuel to be introduced and additional power to be created. So unless you want a motor to be a power monster, chances are you wont need it to breath the quantities of air that a dual setup can output.

To get the setup right, he used four smaller turbos in place of two larger ones? There must have been some major plumbing in that engine compartment. I personally find anything over two to be sort of pointless, with two you can stagger the sizes so a smaller turbo can run in peak efficiency at lower RPM and spools quickly, and the larger one takes over when the smaller one becomes inefficient at higher RPM's, that way the combined effect is a larger efficiency island to stay in.
Your right when you say that there would have been less rotational mass per turbo but the net mass would probably have been larger, and each turbo would have less exhaust energy to run them. Of course I dont know anything about that particular engine so I can't really critisize, maybe it worked really well. , Bugatti's setup however is not ridiculous as feeding 16 cylinders takes some serious equipment, also with 16 cylinders each turbo has 4 exhaust ports feeding them, not too shabby, same as a twin turbo V8 (of course each cylinder in the W16 is smaller).

[LancasterWannaBe]

yeah like I said it was my dad's friend so I never saw the engine layout

I think he took his set of headers and cut them before they got to the the main pipe and did some welding so it was 2 cyl/turbo. He might have engineered it so the boost would be suplied to the cyls that could use it best from each turbo. I really don't know though. I wish I had seen it. I should try and get his phone number and see if he still has it or if he could tell me something about it.

Personally I would also stick with just twin turbos myself. It would also be way less money!

This guy went kinda extreem with his car though. Every time he needed to get a smog check or take care of a "fix it" ticket (since his engine was a bit in the extreem side to say the least) he would remove his motor and put the stock engine and transmission back in the car. He built it so this could be done in about 4 hours! (I think he got a lot of tickets; I know my dad did, hehe)

I'll find out what kind of car it was and get a little more info.

I get what you're saying with the volume issue though.
But what about top fuel dragsters?
I don't know exactly what size their engines are, but they're supplying ~50 pounds boost, so even if the engine were a 2 ltr, thats a hell of a lot of volume at STP! Yet they only run one suppercharger.

Lets keep this conversation going though cause it's interesting.

Tell me more!

[LancasterWannaBe]

Actually Sluttypatton, reading your post again makes me think of something.

I've heard of some people using a turbo and a supercharger.

Now, with typical big block built for high RPM - 10,000 or higher - the 750-3,000 RPM range sucks. A blower can help strengthen this range though. But if a blower is pushing air in the low RPM band, it will be driven to fast in the high RPM band.

Could you use a turbo to help with the low range, and a suppercharger to carry the rest?
Kinda like you said, with the two turbos of different sizes, each reaching peak efficiency at a different RPM.

[Sluttypatton]

You're heading in the right direction but your a little backwards I think. Unless you have a turbo that spools incredibly quickly (Aerocharger makes an amazing VATN turbo with almost zero lag) the supercharger would probably be best for carying the low RPM load, they build boost really quickly. Also, a turbocharger is better suited for high RPM applications as they are capable of delivering larger quantities of air than a supercharger.