Why do most supercharger setups....

[soopachargen]

seem to run the throttle body before the supercharger??
please give me a bit of discussion on it.

[no_8wire]

Easier to stop the slower air than the fast air?

[SUBARUCONVERT]

then turbo set ups would be the same >?

[fivebob]

Most superchargers are positive displacement pumps, meaning the amount of air in = amount of air out, you can't control the output so you have to control the input.

Turbos and centrifugal supercharger are not positive displacement, and will flow less when the output is restricted. So you can control how much output they produce by controlling the flow after the compressor.

[Mr Revhead]

however with a good dump valve suited to the job you could run the t/b after the charger. but id suggest a plump back system or itll sound like an f16

you may even be able to adapt the stock ABV to do it

[fivebob]

however with a good dump valve suited to the job you could run the t/b after the charger. but id suggest a plump back system or itll sound like an f16

you may even be able to adapt the stock ABV to do it

That'd work, but it's a hell of a waste of energy for no real gain, only really useful if the supercharger isn't sized correctly in the first place.

[Mr Revhead]

it would cure that annoying throttle "hang" the aw11 s/c gets
although a good intake design would lessen that problem as well.


for example you were building a 20v supercharger. and want to use the quad throttles. having it go:

filter-s/c-dump valve-t/bs-engine would be the only way to do it.

[fivebob]

I suppose so, but I can't see any benefit to using quads on a S/C setup in the first place. Though one thing having the throttle after the S/C would help in is intercooler packaging.

However IMO you're wasting your time using a supercharger on a 4A, turbos are a much better option. S/C's come into there own on bigger engines where the drive loss isn't so noticeable, but that discussion is another topic altogether.

[RomanV]

However IMO you're wasting your time using a supercharger on a 4A, turbos are a much better option. S/C's come into there own on bigger engines where the drive loss isn't so noticeable, but that discussion is another topic altogether.

Aaaah, this is something that I have been thinking about for a while.

As such, I have made a new topic about it.

[Mr Revhead]

1800cc should be ok though

[gdsup]

i like the reliability of a supercharged setup, never have problems like most the drift guys do with manifolds cracking etc
just completing my 20v with sc12 now, quads have been ditched for a sizable plenium and single throttle body at the end of the plenium.
i know it is more than likely to be about 20% down power over turbo setups running similar boost, but im not in a class were peak power is always the goal

[Stealer Of Souls]

i like the reliability of a supercharged setup, never have problems like most the drift guys do with manifolds cracking etc
just completing my 20v with sc12 now, quads have been ditched for a sizable plenium and single throttle body at the end of the plenium.
i know it is more than likely to be about 20% down power over turbo setups running similar boost, but im not in a class were peak power is always the goal

I like the mans thinking and reasoning.

How is the 20Vsc coming?

[soopachargen]

I've just bought a 20v head off karl skewes minus the throttles, the plan is to run a plenum and throttle body as tim has done. It looks like the 20v has a higher port exit angle on the head which will give me more room to fit a plenum over my sc14. I've chosen the supercharger coz noone else does it... and coz barry pressured me into it since noone develops it. I believe i will have more power than i need in a front drive anyway and the goal is just to have a quick fun front drive. I'm leaning towards the throttle after the charger coz i already have a frontmount plumbed in and the "lag" is stupid, its taken away the driveability it had. I may eventually go to a water to air and throttle before the charger if it doesnt work this way but at the moment im going with what i have.

[Lanius]

I've always thought a sc set up would be preferable to a turbo one for drifting, as your torque comes in so much lower in the revs. Biggest advantage with the SC12 type s/chargers is that as soon as you start moving, you've got boost. The s/charger pulley is constantly spinning with the crank, ready to deliver boost, but is disconnected via clutch. Instant boost producing buckets of torque low down in the revs ... sounds good for drifting to me ... ?

Of course, I'm not a) a drifter, or b) a mechanic, so if someone (preferably an experienced drifter) could explain why turbo's are preferred, I would be very grateful

[kilowatts]

Mod edit: This is the tech section, please keep to the topic at hand and contribute something useful.

[gdsup]

I've always thought a sc set up would be preferable to a turbo one for drifting, as your torque comes in so much lower in the revs. Biggest advantage with the SC12 type s/chargers is that as soon as you start moving, you've got boost. The s/charger pulley is constantly spinning with the crank, ready to deliver boost, but is disconnected via clutch. Instant boost producing buckets of torque low down in the revs ... sounds good for drifting to me ... ?

Of course, I'm not a) a drifter, or b) a mechanic, so if someone (preferably an experienced drifter) could explain why turbo's are preferred, I would be very grateful

generally you dont spend much time below 5000rpm, so dont need low down tourque of supercharger, even big turbos stay on boost