# looking for a bypass valve/idea (twin-charged)



## boopizi (Dec 1, 2008)

So this is my progress about two months ago, Its an eaten M62 im putting in series/parallel with a (not yet completely decided) turbo. Whats on it now is a big 16g... Anyways my set up is going to have the turbo feeding the supercharger, feeding my fmi to my intake. 

 

Now since then iv gotten my pulleys straightened out and brackets set in stone. And now im ready to start welding my pluming. Whatever, getting to the point. Im not sure where to get a bypass valve (if such a thing exists, I haven't found it yet) to bypass my supercharger when boost from the turbo picks up. Iv done a little research on vw stock twin-charged motor (the 1.4l tsi) to see how they exactly did it, but to my surprise there is not much info on the technicalities on the web. From what iv found their bypass valve is an electronic engaged type that opens only when the computer sees necessary... heres a little diagram... 

 

In turn my set up will be mostly the same. However, more simple. If I could get a part number for that I may be able to make it work via MS and relays, but it seems more simple to me to just find some type of one way check valve to use in place, seeing as it will only need to be open when the supercharger becomes a restriction. Am I on the right track here? 

Iv read some guys twin-charging other makes using an electronic engaged exhaust cutout such as this, 

 

Im leaning towers this the most right now although it seems like a lot of clutter and id have to see exactly how to use a programable output from MS to make it work properly, but really hoping someone has heard of or seen something different used out there that I'm missing. 


Thanks, 
Austin


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## [email protected] (Jan 2, 2009)

Suggestion: Order the 1.4Tsi unit from the dealer if it's cheap enough and see what comes... 

Those exhaust cut outs might work but anything OE will be much, much more reliable.


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## boopizi (Dec 1, 2008)

Thanks for the reply. 

I think ill at least call the dealer today, get a price and see if they can even get it in. I got a bad feeling since those motors never made it across seas it may be unavailable... I agree the exhaust cutout seems mighty rinky dink...


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## elRey (May 15, 2001)

so, you're looking to sequential charge vs compound charge? 

what's the reason for not compound charging? (i.e. 10psi from turbo into charger and charger compressing the 10psi to 20psi)


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## jettred3 (Aug 5, 2005)

opcorn:opcorn:opcorn:

Watching this..


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## boopizi (Dec 1, 2008)

elRey said:


> so, you're looking to sequential charge vs compound charge?
> 
> what's the reason for not compound charging? (i.e. 10psi from turbo into charger and charger compressing the 10psi to 20psi)


Well, it will be compound to begin with... My set up will be almost exactly like the one in the picture above, except my turbo will be taking in fresh air and them feeding the supercharger. But the worry here isn't about boost its about air flow. While compounding air from both chargers would get me a higher boost number, the supercharger is really going to become more of a restriction at some point in the higher RPM's of the motor. In other words, it'll run out of breath and a big turbo can take over without any lag! ...

Maybe this will help. This was an actual flow chart I found of the 1.4l tsi


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## 1999.5GTIVR6 (Jun 15, 2011)

Possibly bypass ther supercharger when boosting in high rpm?


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## Pat @ Pitt Soundworks (Nov 14, 2008)

Just bypassing the supercharger wouldn't make much sense unless you're also installing a clutch on the supercharger as well.

Just continuous compounding would be the route to go. Just be sure to pull your wastegate pressure source after the supercharger.


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## jettred3 (Aug 5, 2005)

Pat @ Pitt Soundworks said:


> Just bypassing the supercharger wouldn't make much sense unless you're also installing a clutch on the supercharger as well.
> 
> Just continuous compounding would be the route to go. Just be sure to pull your wastegate pressure source after the supercharger.


Isuzu or Suzuki Trucks have clutch driven superchargers...maybe an option.


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## jettred3 (Aug 5, 2005)

Not in this case, though, he has the eaton ready to go.


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## boopizi (Dec 1, 2008)

Yeah, the idea here is that it'll only open up and bypass the supercharger at a certain programable rpm at which a higher volume of air will be moved (via turbo) then what the supercharger can flow. With that being said yes, having a clutched supercharger would be smarter because when the clutch is disengaged (along with the bypass valve) the moter is no longer wasting power to turn the screws... I was looking for the clutched charger from the c230 Benz, but I found this one off a later c230 for 50$... My cheapness won again. (sighs)


Anyways, I ended up buying an exhaust cutout. I never did call the dealer to fun out if they could order the part from the 1.4l I assumed that in the event they could get it, it was going to cost me more then my added on set up. I'll post up pics of everything when it's completely done and running for anyone who might be interested.


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## boopizi (Dec 1, 2008)

I'll have to do some playing around with whats the best Rpm to open the bypass valve, and you might even be correct at this point, compounding both chargers might make me the most power. But I'll leave that up to my 1/4mile time. For now this is just an experiment.


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## sTT eV6 (Oct 26, 2010)

The electric cutout youve shown does not have an inbuilt clutch and will eventually eat teeth.
You would be better going with a vacuum flap setup and solenoid as used on R32s or 3.2 TT exhaust setup.
Here is an aftermarket style..
http://www.oettle-tuning.de/epages/...=/Shops/61293769/Products/"LF-76MM VALVE-180"
I have this in my current exhaust setup.
Steve


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## boopizi (Dec 1, 2008)

sTT eV6 said:


> The electric cutout youve shown does not have an inbuilt clutch and will eventually eat teeth.
> You would be better going with a vacuum flap setup and solenoid as used on R32s or 3.2 TT exhaust setup.
> Here is an aftermarket style..
> http://www.oettle-tuning.de/epages/...=/Shops/61293769/Products/"LF-76MM VALVE-180"
> ...


I'm not sure what you mean by "does not have an inbuilt clutch" I think it should stay normally close and just open up when it sees 12v? No doubt what your using is a better design, but idk how it would work under positive pressure.


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## Rod Ratio (Jun 6, 2012)

Interesting project :thumbup:


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## sTT eV6 (Oct 26, 2010)

boopizi said:


> I'm not sure what you mean by "does not have an inbuilt clutch" I think it should stay normally close and just open up when it sees 12v? No doubt what your using is a better design, but idk how it would work under positive pressure.


It uses hard stops to stop the flap. There is an optional timer that can be incoprorated into the electrical circuit to restrict the hard stops being utilised.

For the vacuum type a pressure switch can be incorporated to swith the flap at a preset pressure.
Steve


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