Why not more than 2 turbos?

I was just reading one of the posts near the top about turbos.. and i was thinking, why do cars only have "twin turbo" right now, and not like "quad turbo"! Like think about it, just think of the possible configurations. "twin" sequential turbo, so basically 2 steps of 2 different sized pair of turbos. or maybe just 4 turbos in sequence of different size. Wouldn't this be pretty DAMN crazy?

I'm sure some engineers have thought of this before, but why isn't it in any cars? Is it cause there simply isn't enough exhaust gas to push all those turbines?

Plumbing and packaging are the problems. Turbos and the added piping takes up space...space that most engine bays don't have.

There have been and are plans for cars with four turbos. The Bugatti EB110, for example, had four turbos.

Originally posted by BeEfCaKe
I was just reading one of the posts near the top about turbos.. and i was thinking, why do cars only have "twin turbo" right now, and not like "quad turbo"! Like think about it, just think of the possible configurations. "twin" sequential turbo, so basically 2 steps of 2 different sized pair of turbos. or maybe just 4 turbos in sequence of different size. Wouldn't this be pretty DAMN crazy?

I'm sure some engineers have thought of this before, but why isn't it in any cars? Is it cause there simply isn't enough exhaust gas to push all those turbines?

there are a few cars with quad turbo setups. The bugatti veyron is one of them. Go in other cars part of the forum to se it.

Law of diminishing returns. I don't see what four turbos hold over two, anyway. Just the audible ecstasy?

To elucidate... turbos spin up faster and put out higher pressures if the engine sucks in less, but the more the engine sucks in, the more exhaust goes out... so...

i've seen a triple turbo charged inline 6 before but it was being used on a tractor for tractor pull competions so space was not a factor.

Who says they don't!? Take Popular Hot Roddings Quad Turbo Camaro Z28...4000hp at 22lbs! And they had plans to up it to 28lbs!!!
If two turbo's are better than one, four are better than two!:D

Well thx for all the replies. I havne't even heard/seen these crazy cars yet, and didin't know they already had this technology in use.

@Self: 22psi isn't too high is it? I mean wouldn't 2 turbos alone get that pressure? So if 2 can already do it, what would the extra 2 do?... Or are they just sequential so you get that pressure throughout all rpm?

Not so much that the turbo's can't do it, but that the rest of the car CAN'T HANDLE it...That's what I'd guess anyways:cool:

Also, quad turbos just aren't practical on certain engines. It is a waste to even two turbocharge a four cylinder, that is better left for six cylinder and up. I still don't see the advantage to having four unless you are trying to set land speed reccords in certain classes.

Originally posted by Polygon
I still don't see the advantage to having four unless you are trying to set land speed reccords in certain classes.

Or run low 5s in the pro-street class:D

Originally posted by Self


Or run low 5s in the pro-street class:D


Isn't that funny car territory?

Past funny car territory.... "funky" car territory... LoL

Originally posted by Neutrino



Isn't that funny car territory?

HELL YES IT IS. That's the point of the car...I mean, 4000+ hp? That's insane.

Some jet engines can produce in excess of 30,000 hp a piece, and some people drive jet cars.

it's all about packaging and efficiency..

running 4 turbos on a big v8 means they're all smaller, and limited...

if you swapped out for 2 bigger turbos, like doing a single turbo conversion on a skyline or supra or rx7, you'll be able to get more power, but with more lag.

if you ran 4 huge turbos, it would probably never spool. so... 4 decent sized turbos on that motor works well... but if you swapped for 2 larger units... you'd be able to make more power, and the plumbing is easier.

i don't know that you'd need 4 turbos to run that fast either.

all the turbo mustangs that run in the 8s and what not are single turbo... soo... it's not the number, it's all about the flow and the efficiency.

Getaway in Stockholm 4 should be done with one of those jetcars.