For the centri blower guys..

QWKSNKE · 06-25-2007, 08:11 PM

There is a very interesting article in this month's (Aug2007) MM&FF about making a centri blower perform like a turbo.

They setup a wastegate and a boost controller to a blower combo. This allows you to run a smaller pulley on a blower such as a Vortech or Paxton so that you build boost in the lower rpm and then bleed it off in the upper rpm. This also does away with pulley swaps to "race trim" at the track. One pulley all the time and one knob in the passenger compartment to control boost.

Pick up the mag and read the article. It is interesting.

rtusnake · 06-25-2007, 08:36 PM

Sounds like a good idea. Wonder how much it would help out with the tq on those blowers

Sendero · 06-25-2007, 08:37 PM

I've seen something like this years back. I'm looking for the info now, but I believe someone was using a D-1 and a electronic wastegate to do "boost stepping" for the same effect.

uvbnhad · 06-25-2007, 08:50 PM

Interesting

Italian LX · 06-25-2007, 09:43 PM

Sounds interesting, but it seems that it would make the motor very inefficient when bleeding off the boost. The problem I see is that even though you're at lower boost by releasing some of the pressure, you're still generating high-boost heat by spinning the blower at the high boost speeds.

Maybe I'm mistaken.

I guess my next question would be, why not just go with a turbo?

coupe · 06-26-2007, 08:10 AM

Many of the compressor wheels actually make boost between inducer and exducer, so...yes, the heat may very well still be there. And a problem with blowing off the boost is you have to recirculate it within the confines of your air-metering system.

And alot of the drag associated with the centrifugal blowers is in the gear-train and bearings...they overdrive the compressor wheel by up to 10:1 over the crank RPM (I would suspect in this application, maybe more). That is alot of power required, to overcome the bearing loads on the belt, the gear friction, and the boost generated at the wheel.

Sendero · 06-26-2007, 08:38 AM

Quote:

Originally Posted by Italian LX

I guess my next question would be, why not just go with a turbo?

Packaging constraints? Take my car for example.

Quote:

Originally Posted by coupe

And a problem with blowing off the boost is you have to recirculate it within the confines of your air-metering system.

Blow-thru system?

QWKSNKE · 06-26-2007, 09:50 AM

Quote:

Originally Posted by coupe

Many of the compressor wheels actually make boost between inducer and exducer, so...yes, the heat may very well still be there. And a problem with blowing off the boost is you have to recirculate it within the confines of your air-metering system.

.

Not if you blow it off before the metering system.

Intercoolers do away with the heat.

coupe · 06-26-2007, 09:57 AM

It's still a waste of energy. Takes alot of work to spin it up fast, only to release it...sounds like a full-blown lesson in inefficiency. Pun intended!

QWKSNKE · 06-26-2007, 10:57 AM

Quote:

Originally Posted by coupe

It's still a waste of energy. Takes alot of work to spin it up fast, only to release it...sounds like a full-blown lesson in inefficiency. Pun intended!

You guys need to read the article..

we are not talking about overspinning the blower. We are talking about spinning at its efficient rpm which usually is a good bit higher boost than most people would want on the street or on the engines.

Take my old D-1 as an example. I had it pullied for 14psi but it actually was most efficient at a much higher impeller rpm than what I was spinning it at.

06-25-2007, 08:11 PM	#1
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	For the centri blower guys.. There is a very interesting article in this month's (Aug2007) MM&FF about making a centri blower perform like a turbo. They setup a wastegate and a boost controller to a blower combo. This allows you to run a smaller pulley on a blower such as a Vortech or Paxton so that you build boost in the lower rpm and then bleed it off in the upper rpm. This also does away with pulley swaps to "race trim" at the track. One pulley all the time and one knob in the passenger compartment to control boost. Pick up the mag and read the article. It is interesting. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

06-25-2007, 08:36 PM	#2
rtusnake Halfshaft Killer Join Date: Mar 2005 Location: The Kingdom Posts: 3,910	Sounds like a good idea. Wonder how much it would help out with the tq on those blowers __________________ 03 Cobra 06 F250 (\__/) (='.'=) (")_(")

06-25-2007, 08:37 PM	#3
Sendero Im gonna show her my... Join Date: Dec 2004 Location: Somewhere providing FREE tech support. Posts: 4,269	I've seen something like this years back. I'm looking for the info now, but I believe someone was using a D-1 and a electronic wastegate to do "boost stepping" for the same effect. __________________ I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown

06-25-2007, 09:43 PM	#5
Italian LX Daddy x4 ...we're done Join Date: Dec 2004 Location: Oxford, AL Posts: 11,551	Sounds interesting, but it seems that it would make the motor very inefficient when bleeding off the boost. The problem I see is that even though you're at lower boost by releasing some of the pressure, you're still generating high-boost heat by spinning the blower at the high boost speeds. Maybe I'm mistaken. I guess my next question would be, why not just go with a turbo? __________________ -Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring

06-26-2007, 08:10 AM	#6
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Many of the compressor wheels actually make boost between inducer and exducer, so...yes, the heat may very well still be there. And a problem with blowing off the boost is you have to recirculate it within the confines of your air-metering system. And alot of the drag associated with the centrifugal blowers is in the gear-train and bearings...they overdrive the compressor wheel by up to 10:1 over the crank RPM (I would suspect in this application, maybe more). That is alot of power required, to overcome the bearing loads on the belt, the gear friction, and the boost generated at the wheel. __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

06-25-2007, 08:50 PM	#4
uvbnhad Friends Join Date: Mar 2005 Location: McCalla Posts: 1,241	Interesting

06-26-2007, 09:57 AM	#9
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	It's still a waste of energy. Takes alot of work to spin it up fast, only to release it...sounds like a full-blown lesson in inefficiency. Pun intended! __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein