superchargers

[HDi fun]

This is all esoteric stuff though.

[petescustompipes]

please explain how it works, because it works (supercharger then turbo) in my head fine but in reality it doesn't... iv been studding this for hours and its all wrong, but why???

[HDi fun]

I'm not going to try and explain it because there is not one simple solution. Using a pair of turbos, regardless of the configuration requires extremely careful design.

Using a mechanical supercharger together with a turbo(super)charger is even more radical. VW has managed this to great effect in the 1.4 TFSi engine but I suspect that the development costs were pretty high and that the oeprating principles are pretty complex. It's not the first of its kind but it's probably the first to hit truly mass market cars.

There is no simple one-size-fits-all configuration.

I steer away from mods to be honest, apart from a decent custom ECU remap I have never modified any cars. Which is not to say that it shouldn't be done, but I can think of easier and cheaper ways to ramp up usable performance, such as buying a different car in the first place.

[claymore]

compound charging will only really work if you have a roots type of supercharger,(which is a compressor) a centrifugal turbo/supercharger is really only an air mover. if the supercharger boosts 7psi, then if you have 12psi going into it from the turbo you will have 19psi coming out (but in practice it will be more like 22psi)

[claymore]

Originally Posted by HDi fun

but I can think of easier and cheaper ways to ramp up usable performance, such as buying a different car in the first place.

Find me a car that has over 350bhp for less than a grand, and I'll bye it. (then I'll start to mod that.......lol)
I find half the fun is doing things my own way.

[HDi fun]

You can't just add absolute or relative boost pressures. Flow rate is more significant. Roots blowers are positive displacement devices. Other types aren't.

At the end of the day airflow is measured by mass divided into time, irrespective of pressures at any point in the intake system.

[jarrus]

So true,

I've been trying to explain this to people for years, (and i'm only 21) just because someone is running more boost on the same engine doesn't mean more power,
For example, if you had say a Garrett GT1549 running 20 psi boost, and a Garrett GT2560 running 15 psi, which turbo is likey to be flowing more air and thus is more likely to make more power on the same engine?

and Claymore what supercharger is that you have? an Eaton E90?