[naynay]

i would think it would over spin it..??

terrible analogy but i would think its like when you pick up something to big for a vacuum hose and it starts to free rev.

but in reverse maybe

 

[Colt]

i would think it would over spin it..??

terrible analogy but i would think its like when you pick up something to big for a vacuum hose and it starts to free rev.

but in reverse maybe

Can't over spin it like that, it's all gear driven internally.. An analogy for that? A turbo is a car with a auto trans going downhill, with no load it'll speed up.. A supercharger is a car with a manual trans going down hill that is able to engine brake.


Boost control with a super charger isn't going to hurt a damn thing, it's not going to increase load on the blower either. Load will decrease with lower pressures.

A BOV isn't what you're looking for though, you'll need to put a wastegate on the intake side. A BOV is going to " pop " open, you need a valve that can be controlled at various position's. Research how the wastegate works, how turbo guys are using them to control boost ( only thing your doing different is putting it in the intake, that's it ), and just apply it to your application.

As to what size wastegate and all the details, unless you can find someone that has done it you're going to have to tinker with it a bit. I have not, I've heard of it a few times however. It'll work, and it won't hurt anything

 

[BENT8]

Boost control with a super charger isn't going to hurt a damn thing, it's not going to increase load on the blower either. Load will decrease with lower pressures.

Here is from the horses mouth...

Yes its more load, however its not a shock load like loosing a tube instantly.

It is hard on a blower, Yes.
It also causes the efficiency of the compressor to fall off.
Because it moves it towards Choke.

Same reason a turbo regulates boost with the exhaust side via RPM.
(and not compressor side)

If a gear box is at its upper HP holding threshold, obviously this is not a good idea.
However lots of smaller street guys with small blowers do it, and don't stress the gear box to hard.

Does it "work" yes, but this helps explain why the ProCharger i-1 supercharger was developed.
To create a centrifugal with a flat boost curve, "correctly"
By changing the speed of the impeller to match the flow/pressure needs.
Allowing the compressor to stay in its efficiency range longer, and less load on the gearbox.

Versus just making our own "wastegate" as people have done for years.



Well thank you! :smile:

 

[Colt]

Here is from the horses mouth...

I won't argue with a manufacturer, but I just can't see that in my head. Seeing more technical data on it would be the only thing that would change my mind on the subject. Thanks for the post though

 

[SAMMY CHRISTIAN]

funny part is, procharger tech doesn't even understand his own stuff.
the speed of the blower does not change or vary by opening a controlled bleed of intake pressure.
it's clear that most commenting on this have zero actual experience, you are not relieving ALL pressure, you are attempting to regulate pressure.
a controlled reduction in resistance has zero effect on the blower or blower speed and negligible effect on blower load. period.
this is getting like the climate change debate, the more people say something, the more they start to believe it.

 

[prost63vette]

funny part is, procharger tech doesn't even understand his own stuff.
the speed of the blower does not change or vary by opening a controlled bleed of intake pressure.
it's clear that most commenting on this have zero actual experience, you are not relieving ALL pressure, you are attempting to regulate pressure.
a controlled reduction in resistance has zero effect on the blower or blower speed and negligible effect on blower load. period.
this is getting like the climate change debate, the more people say something, the more they start to believe it.

Im with this guy ^^^^ I see it done with a bov all the time and no problems. But I will say this you guys need all the boost you can get to keep up with them dammm turbo guys lol

 

[Jn3fj]

funny part is, procharger tech doesn't even understand his own stuff.
the speed of the blower does not change or vary by opening a controlled bleed of intake pressure.
it's clear that most commenting on this have zero actual experience, you are not relieving ALL pressure, you are attempting to regulate pressure.
a controlled reduction in resistance has zero effect on the blower or blower speed and negligible effect on blower load. period.
this is getting like the climate change debate, the more people say something, the more they start to believe it.

We should all run boost controllers because bleeding off power makes us faster. Lmfao

 

[Jn3fj]

funny to read all the know-it-all theories on this.
complete nonsense.
Anyone seen this car before?
controls boost by opening a blow-off to run anywhere from 6.80's to 6.40's and 4.30's to 3.90's
EASILY has won more races and money than all the poster on this thread combined. it works just fine.

There are steel bodied cars going 3.90s without boost control on radial tires. Next

 

[Jn3fj]

Has anyone found a boost controller on a screw blown car? Pretty sure they make a lot of boost very fast, but let's put boost control on a procharger

 

[SAMMY CHRISTIAN]

There are steel bodied cars going 3.90s without boost control on radial tires. Next
yeah, good answer, maybe 1 out every 5 tries.

in the application I'm talking about, these are fast TS cars that run those numbers on a dial-in and repeat unlike the typical small tire or turbo stuff.

 

[BENT8]

Take a look at a compressor map on the right hand side of the chart, thats where you push the blower when you have low pressure ratio, high air flow. Its a centrifical compressor engineering fact.
The more air you move and compress the more heat is generated and load.

Impeller speed is governed by engine rpm so i dont know where the hell guys got the idea it will over spin it.

On my combo pulling 2 degrees of timing out is 180hp..... screw blown big tire guys leave with 30+psi without the need for bleeding boost......

 

[SAMMY CHRISTIAN]

once again, I think most are missing the point. It's not about leaving with less boost, it's about limiting max boost while still being able to make more early. totally geared toward big tire TS dial-in racing.

 

[zbrown]

Lol blower guys that don't even understand blowers lol

There is more load on the blower drive vented than there is at an elevated PR

If you don't think so you need to learn a bit more about a centrifugal compressor


To dumb it way down so you can "grasp" it. Simply think of a centrifugal leaf blower

We have a set amount power to drive the impeller

Open to atmosphere at the lowest PR is the the highest load and hence the lowest RPM achieved


As you start blocking off the outlet and raising the pressure ratio the impeller speeds up from less load

 

[SAMMY CHRISTIAN]

Open to atmosphere at the lowest PR is the the highest load and hence the lowest RPM achieved


As you start blocking off the outlet and raising the pressure ratio the impeller speeds up from less load

did you even read what you wrote? is completely ass-backward to what you are trying to imply.

 

[zbrown]

did you even read what you wrote? is completely ass-backward to what you are trying to imply.

Lol no.. it is correct

You just don't grasp it

 

[Glenn.Payne]

The leaf blower or vacuum cleaner explanation has been around a while. In these cases it only speeds up if you completely or almost completely block off the exit point. This is because there is no air moving to load the impeller. If you partially block off the exit the load goes up and the engine or motor will slow down> yes I tried it to see who was full of shit.

And further proof of centrifugal compressor loads between open exit or making boost can be seen on turbo deal when the charge pipe comes off during a pass>>>>severe over-speed and will knock bearings out of a journal bearing turbo quick> If the load were increased the turbo impeller would have slowed down not over-sped when the charge pipe came off. Accidentally "tried" this ten years ago on my car.

So maybe I can't read a compressor map but these are real world examples.

 

[Disgustang]

Why is blower speed even being discussed here? The blower speed is what it is..... At X engine RPM the blower will be Y RPM no matter if it is blowing through a 1 inch pipe blocked off 100% or an open charge pipe.

 

[zbrown]

Omg it's sad really, very sad

The the rpm was brought up with the leaf blower only because we have a set amount of power to work with..... And as load varies rpm will increase or decrease with load

Yes you ovbiously don't know how to read a compressor map

It shows shaft speed needed for any compressor output...... BUT it doesn't show the required TQ to deliver that shaft speed at any compressor output

 

[zbrown]

. If you partially block off the exit the load goes up and the engine or motor will slow down> yes I tried it to see who was full of shit.

You are so full of shit it isn't even funny

 

[zbrown]

. If you partially block off the exit the load goes up and the engine or motor will slow down> yes I tried it to see who was full of shit.

Bump for your bullshit. As the hand is removed you are dropping the PR across the blower while at the same time increasing volumetric flow

It's absolutely zero difference than a procharger venting to atmosphere