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Boost control with procharger?

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46K views 49 replies 21 participants last post by  rtj  
#1 ·
Is anyone controlling boost with procharger? Like running 2 bov and bleeding off boost? Is their a right way to do this or does it shock the procharger
 
#3 ·
I'm surprised no one has come out with a variable clutch pulley for one yet. Have the ecm control how much it locks up or how much it slips for boost control. Really shouldn't be too hard to develop. The technology is already out there on water pumps and such.
 
#8 ·
Yes.. Wabash. Cannonball..you would think someone have came up with it.. I bought all the pulleys I need now. But I asked a question to someone that had 2 bov's at what point do you need 2. He said some people use the second one to bleed off boost. I didn't know if that was a gear drive thing or what..
 
#11 · (Edited)
If you use a BOV to dump air, it's very hard on the blower, and will cause the drive load to go way up, killing power up top and possibly damaging the blower or trashing belts. Restricting the inlet side is much more efficient. It will still have the same effect by not affecting power down low, but the inlet restriction will reduce how much boost the blower is able to make up top, and doesn't cause near as much stress on the blower or drive system. You will probably have to play with dialing in what diameter restrictor you need to obtain your desired boost: every combo will be different. Take a look at ECS or A&A corvettes. They use inlet restrictors frequently to limit boost.

An air filter can serve as a restrictor as well.....
 
#18 ·
Been running a F3-139 for 12 years. Have tried various ways to control boost levels at different times. Best way was using a turbo wastegate on the intake tube. But all the ways, it's still hard on the blower. Best way is to run the blower speed at what boost you want to run your number.
 
#22 ·
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 ;)
 
#25 ·
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.
 
#31 ·
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......
 
#33 ·
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
 
#36 ·
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.
 
#38 ·
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