I was talking to a friend at work yesterday, and once again discussing the idea of switching out my procharger for turbo(s). I jokingly said I should just do both...and that got me thinking.

I know there are setups with both superchargers and turbos, but they usually involve traditional turbo setups followed by a screw type supercharger. But I was thinking something completely different.

What if I used the Procharger to spool a turbo, instead of my exhast ?

Procharger-> Wastegate ->Turbo -> intercooler -> BoV

With this setup I would have a really adjustable spool(pulley size+wastegate). I wouldn't be dealing with the hot exhaust air or any hot piping for that matter. It would be cake to install this.....


Would this be possible at all? Can the procharger move enough air to spool up a turbo?
What kind of Exhaust manifold pressure do you turbo guys usually need for x-boost?

I know this may seem crazy, but thats just the way I am...never happy to just do it everyone elses way

Looking for constructive(only!) feedback and info

 

A PD blower (Maganacharger or KB) and turbos would work much better. You want low end response from PD (positive displacement) blower and then use turbo to supplement boost. BTW this configuration is and has been used.

Turbo to centrifugal would be extremely peaky and you would be exaggerating weaknesses of both.


Mike

 

Remember that part of what gets a turbo moving is not just air (exhaust), it's the temperature differential across the turbine. Considering that exhaust gas temps are probably north of 800 degrees F for these cars, that's a lot turbine-spinning heat that you wouldn't have in a supercharger fed turbo. I don't think you'd get the typical TT torque this way.

It sounds like you are unhappy with either boost response or how boost is controlled on a centrifugal (since the only reason you mentioned for doing it was boost control). Have you considered pulleying down and then adding a restrictor plate? Or just going turbo altogether?

 

I am not sure if we read the message the same way... I think he is talking about using the compressor side of a centrifugal to feed into a turbo flange, and using the compressor side of the turbo to feed into the motor (not both of them feeding into the motor independently).

Have people really setup multiple FI systems this way?

If so, cool!

 

Damn I misread it... I thought he wanted to feed supercharger with turbo(s), not a hydrostatic drive of sorts.

Efficiency would be so low 10-20% (a guess) that it would not be worth it.

I'll dig up links on some research for constantly variable hydraulic turbine to drive centrifugal supercharger.

I know people have tried CVT with a snowmobile like transmission but even then power transmission efficiency did not exceed 60%. Consider micro-v belt is about 95% efficient.


Mike

 

With a procharger you are going to be maxed out on how much air you can push through the exhaust turbine on a turbo. Once you hit that limit you are going to fall flat on your face. The reason turbos work is because the amount of exhaust gasses that drive the turbine goes up as engine speed increases.

 

Just to clarify I'm totally satisfied with my car currently. But I'm a tinkerer, I love to experiment. Aside form clutches and tires I"m having zero issues. Hence I'm getting bored witht he reliability and need to throw in a challenge

And I'm not looking for max effeciency or power. I"m still on stock bottom end

What I'm wondering is if this would be feesable with the right pulley and turbo. Say I ran the P1SC with a 3.1 pulley(I have one ) which would be like 16psi going into the turbo inlet? Could I get 9psi out of the turbo?

I know this seems really ineffecient...but thats not the point

 

To start with I think you will really be disappointed with results in the end.

I personally don't think you'll even get 1-2 PSI with P1SC going full bore into turbo turbine. As Diynoob pointed the mixed flow turbine relies on hot exhaust gases. Lower temperature and so goes efficiency, but most importantly it is not operating as designed. A turbo turbine with log headers usually has a 2:1 (exhaust pressure to boost pressure) ratio. I'm not even sure were you would wind up being soooooo far off design. Then don't forget standard journal bearings can waste 5-20% of turbine recovered energy, which you are not recovering anything.

Another thing to consider is you are trying to couple two pieces of turbo machinery that can best be described as having a RPM^2 relationship.

Also look at it this way your P1SC depending on boost will require 60 HP to turn it. Now add 20% efficiency 60/(20/100) or 60/.20 or now 300 HP to turn supercharger and make boost even later.

Trying to create a CVT (continuously variable transmission) with a compressible gas is just not a good idea and that's why I just can't think of any example.

Sorry and I applaud you're attempt at trying to accomplish something different.


Mike

 

Thats the info I was after, thanks for the input