Chui--

[SlasherX]

Whats your opinion of a centrifugal supercharger on the '99 up 3.8L SEFI V6 block?

[chameleon]

only Chui is allowed to respond :wtc:

[Griffin]

Originally posted by chameleon
only Chui is allowed to respond :wtc:
Ummm.... ah never mind.

Hey slasher - ever heard of PM function?

[SlasherX]

Originally posted by Griffin

Ummm.... ah never mind.

Hey slasher - ever heard of PM function?

no.

[EzRidA]

LOL. I had a 94' V6 Mustang with a centrifgual S/C. However I'm not Chui. :fawk:

[GTS LAID]

no one gets to answer until the black jag-u-are gets a run at it....lol

[Chui]

I'm not fond of superchargers at all, SlasherX, but as long as you kept the pressures within reason it will assist you in achieving a relatively cheap bhp.

[VZV21]

You have to admit, they make a cool whine though.

The centrifugal SC (in its operating range) is more thermally efficient than a Roots one.

[Chui]

I'm not fond of the supercharger whine, either. I much prefer the sound of a well-tuned normally aspirated engine. I do like the sound of turbocharged engines, however, but that bias is partially due to my love of international motorsports. There are no belt-driven superchargers found there.

[VZV21]

I thought you weren't fond of any forced induction methods.

[Chui]

Actually, I do like turbos, but I wouldn't bother turboing a nice normally aspirated engine like the B18C5, F20C or 2ZZ-GE. I used to simply drool for turbo cars, but that was before Honda gave us VTEC which made small displacement engines quite powerful and economical. Then there are cars like the 911, M3, S2000 and 360M... drool! Great engines all.

[Jesse IL]

Centrifugal superchargers are very inefficient at low RPMs. This is due to the fact that they are essentially turbo compressors being driven by the engine. Turbo compressors spin at incredibly high speeds (compared with a positive-displacement supercharger) to create boost. A centrifugal supercharger must be geared in such a way that it will be at the correct speed near the redline of the engine. This forces the compressor to be going too slowly at low engine speeds to make good boost. IMO, a centrifugal supercharger would be a better fit on a large displacement engine with ample low-end torque.

Also, the whine of a supercharger comes from the gears that run it. Although a belt from the engine turns the pulley, a centrifugal (Vortech and Paxton are very common centrifugals) supercharger has internal gearing used to step up the compressor to the necessary speeds. You can actually find centrifugal superchargers with internal belt drives that don't have the whine.

[Griffin]

Rofl - I recently had a very similar conversation to this one with Scott in one of the other forums :) I agree - belt driven centrifugal superchargers basically blow goats.

Griffin

[VZV21]

But, the belt driven centrifugal supercharger is more flexible in packaging, compared to the Roots type distributed by Magnuson.

[Griffin]

Originally posted by VZV21
But, the belt driven centrifugal supercharger is more flexible in packaging, compared to the Roots type distributed by Magnuson.

This is very true. But packaging don't turn the numbers for ya, horesepower and torque do.

Griffin

[autxr]

I still say that a modern turbo engine would rock. Chui doensn't think it is needed as much with the advent of VTEC and VVT(L)-i, but I say it's these technologies that could make a turbo engine incredibly potent!

Imagine being able to use the initial cam profile for one purpose, spooling a turbo. It would be so easy, a nice lift profile to give good sharp high speed exhaust pulses, cam overlap that encourages turbo's to spoool quickly...

Basically, you could set the car up to spool a pretty big turbo *very* quickly. The low speed cam might fall on it's face by 2000 rpm, but it doesn't matter, then you make the switch to the high speed, you are already at 14 psi, and you are moving all the air you need for the high speed cam.

Best of both worlds.

Scott

[Griffin]

Originally posted by autxr
I still say that a modern turbo engine would rock. Chui doensn't think it is needed as much with the advent of VTEC and VVT(L)-i, but I say it's these technologies that could make a turbo engine incredibly potent!

Imagine being able to use the initial cam profile for one purpose, spooling a turbo. It would be so easy, a nice lift profile to give good sharp high speed exhaust pulses, cam overlap that encourages turbo's to spoool quickly...

Basically, you could set the car up to spool a pretty big turbo *very* quickly. The low speed cam might fall on it's face by 2000 rpm, but it doesn't matter, then you make the switch to the high speed, you are already at 14 psi, and you are moving all the air you need for the high speed cam.

Best of both worlds.

Scott

I agree totally - that would be awsome. Tuning it would NOT be easy though and you have to remember the ever-present CARB and emissions demons.

Griffin

[autxr]

Screw the EPA and CARB...

I agree, tuning might be a bear. The manufactures woudl be albe to do it pretty easily though (probalby no harder than NA tuning).

Odds are there are some nice research dyno's out there that make it very easy, not to mention, there are aftermarket ECU's which already incorporate learning functions, imagine the sort of thing the major manufacturers must have...

Scott

[Griffin]

Its just a LOT of variables to consider especially when you don't have a large supply of extra motors to replace any that you cook.

Griffin