Blower + Turbo?????

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xThunderbirdSCx

Guest
Ok i was just reading the thread below on the m112 and i got to thinking...

What would happen if i were to run a turbo off the output of the supercharger, then pipe the turbo's output back through our IC and back into the engine, even using the stock lower IC tube and intercooler.

It would save $$ on exhauts manifolds and such.

What would be the problems involved with this kind of set up? Is the 14psi from the supercharger the same as the exhausts psi?

Would this get rid of turbo lag?

How much would it cost and what would i need to do it?
 
Do you know how turbos work??? What would drive the turbo??? What would you do with the SC air once it went through the turbo???

You wouldnt be doing any good like that
 
Huh? How is that going to be any advantage? The output of the SC is TOO low to "power" the turbo. The ONLY way a turbo "works" is to be driven with exhaust gases which are much hotter and less dense that what you would get from the SC alone. Now in the member's forum there is a post I made about using a turbo and SC on the same engine. VW is using this tandem system on the 2006 Golf (in Europe at least). The SC is declutched at higher RPM's where the turbo can effectively supply air to the engine. There is a bypass valve in the system that shunts intake air normally supplied by the SC at lower RPM's over to the turbo at high RPM's for supply to the engine.
 
Tune in if you could Dalke

i was just wondering...instead of using the real exhaust gasses to power the turbo, use the air being driven out of the supercharger as a "pseudo exhaust". The ouput of turbo would go through an intercooler and into the intake manifold, and the exhaust of the turbo into back into the engine bay, or piped below the chassis.

I was wondering if the supercharger would provide more "drive" than the exhaust. Use the 15lbs of boost coming from the supercharger to drive the turbo, and let the turbo make the boosted air for the engine.

With this setup, the only thing the supercharger is acting as is an exhaust basically.

Think of it this way. Is the 15 lbs of boost coming out of my supercharger more than the "boost" coming out of my exhaust that would turn the turbo?

Here is a picture i drew, to kind of represent what i mean...
superturbo8yd.png


Inherently, my idea is to add a turbo onto the car, but drive it using the gas coming from the supercharger. Im going on the assumption (correct me if im wrong) that the superchargers output PSI is more than the exhausts output PSI. This could allow me to keep the engine semi-stock, only replacing the IC and Tubes for custom tubes, a new FMIC and a turbo)
and not require new exhaust manifolds. Also, i could revert it back to a solo supercharger ordeal if i wanted to.

Plus, it would be more efficient (turbo air is cooler and such)

Inherently, i want to turn the supercharger into a "fake" exhaust to drive the turbo. Turn 10PSI from the supercharger into 25 from the turbo.

So i guess my only question would be, what is the PSI of pressure coming out of the exhaust.
 
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I'm correcting you..No No No .....the supercharger output isn't providing nearly enough flow to spool the turbo, it must use the hot exhaust gas. Using something other than exhaust gas to power the turbo would be less efficent. Your design wouldn't work at all.


David
 
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We get the parasitic drag of a supercharger, and the lag of a turbocharger, ALL IN ONE PACKAGE! What could be better?
 
I was thinking something simaler

You cant power the turbo off the supercharger becase its powered off the exhaust, but if you powered the blower with the turbo would you get any more boost? If you run the intake to the turbo and the boost off the turbo through the intercooler to the blower like stock, would it work?
 
Well apparently Dave N. is the only intelligent one whos posted so far. Thanks Dave.

Question though...how is the hot compressed dense air coming out of the supercharger have less flow than the exhaust? Isnt the same amount of air going in as it is coming out (remember the "Conservation of Mass" from chemistry class?" just in a different compound.

This has been buggin me all day and i really wish someone could find out some air flow properties of the exhaust so i can compare it to the superchargers. I really think i could somehow make it work.

Make a custom bracket to fit on the end of the top IC tube, bolt the turbo's exhaust port to that. Add an intake to the turbo, and then route the lower IC tube to the turbos outtake.

For some reason i believe this is possible because i think the supercharger is able to punch more air more powerfully through the turbocharger than the exhaust, and it would do it sooner too, helping eliminate turbo lag. The turbo would then become the forced induction to the engine.

I dont know why but im compelled to try it.... :eek:

It would help alot if someone could give me some Exhaust CFM numbers and Supercharger outlet CFM numbers to compare.
 
You've forgotten the additional energy and volume given to the exhaust by combustion. The same amount of air does go out the tailpipe as goes in the intake but at 1200-1500 deg it has a little more energy than it does at 200-300deg.
 
aha....now i see.

So your telling me i would just fall flat on my face with this setup?

Are ANY gains possible?

It would be cool to go the turbo route, but i really dont want to have to change the engine/exhaust system much.

And since turbo setups arnt even produced for the SC, it would get pretty expensive.
 
xThunderbirdSCx said:
aha....now i see.

So your telling me i would just fall flat on my face with this setup?

Are ANY gains possible?

It would be cool to go the turbo route, but i really dont want to have to change the engine/exhaust system much.

And since turbo setups arnt even produced for the SC, it would get pretty expensive.

Yes flat on your face...no gains only more losses. The reason a turbo makes more power than a supercharger, is because it uses heat energy from the exhaust to spin the turbine and compress the intake air instead of using a belt that takes power off the crankshaft.

David

PS: Visit turbomustang.com for some excellent reading material about turbocharging.
 
"Well apparently Dave N. is the only intelligent one whos posted so far. Thanks Dave. "


Is there an echo in here???? I believe Dave made the exact same point I made in the third post in this thread. Geez.....I wonder why I even try to respond sometimes.:rolleyes:
 
Duffy Floyd said:
"Well apparently Dave N. is the only intelligent one whos posted so far. Thanks Dave. "


Is there an echo in here???? I believe Dave made the exact same point I made in the third post in this thread. Geez.....I wonder why I even try to respond sometimes.:rolleyes:
It seems there is a big echo Duffy everyone has told him NO but yet he keeps asking :rolleyes:
 
Duffy Floyd said:
"Well apparently Dave N. is the only intelligent one whos posted so far. Thanks Dave. "


Is there an echo in here???? I believe Dave made the exact same point I made in the third post in this thread. Geez.....I wonder why I even try to respond sometimes.:rolleyes:

Duffy,

Yes you did, but your post count is so low that many of the noobs don't know you were digging into these cars while they were still in 2nd grade. Or maybe it's like when I ask/tell one of my kids to do something.....they don't really listen until about the 3rd time.

David
 
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David,

Perhaps you're right. Remember our mantra over on the TBSCEC though? Quality over quantity?????? Oh well.....a man's got to know his limitations...right?

It really IS a question of thermodynamics though which I do have some background in.:)
 
dont get all hurt Duffster some of us still love ya.

hell I remember being a noobe we all learn as we go after all this is not your everyday car.

have you guys noticed all the new names the old timers are few now adays, hell Im like a grandpa half the guys here could be my kids.

remember when going 13s was pushing the envelope?

dave just gave a quik clean explaination of it so he was thanked .

some of us forget that not all of the peoples here have the understanding of the real workings of turbo/blower designs.

to tell the truth a blower turbo design is not needed with todays turbos the turbos boost comes on pretty quik and little turbo lag is seen.

a turbo with a good stall converter and intercooler will out do any blower any day. sad but true .

but hey we are still kings of the street. i mean better all around streetable setup with a blower but for all out comp a turbo is the way .

I give this one credit for thinking of a new way to blend the two but alas it wont work but it had me thinking hmmm.

a venturi creating hi volocity aimed at turbo vanes and a ......:eek:
 
Whoops, sorry Duffy, i was talking about the people who had no idea what i was even asking.

Youre right. Thanks for all the help guys.
 
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wow how quickly a thread can get off track when someone gets their toes stepped on a little bit...

What i'd like to say is has anyone who said no ever actually tried it? Have any of them calculated the exact numbers? I doubt that they have. Yes, exhaust gas has much more energy stored in it and slightly more mass from combusted fuel, not to mention it's even more pressurized by the compression of engine, but can a supercharger produce as much flow as a normal engine's compression? I really dont know, but i believe it's possible. You're not going to want to use as thick of tube as we currently have coming off the supercharger, and you wouldn't want a raised top on it, you would want to reduce the volume of space between the supercharger and turbo as much as you could with maybe even as small as 3/4 inch tubing as smaller would be better, but your also goign to have to worrry about adapters to fit the inlet of the exhaust side of the turbo and the outlet of the supercharger.

i dont know exactly what part of ohio you live in, but i'm on the east side in the youngstown area and would love to get my hands in on a part of this if you are seriously concidering it. PM if your interested. Also, I have a long post on the m112 thread that goes into a lot of different scenario options.

besides, if your planning on turboing it anyways, your still going to need the turbo, why not give something different a try?
 
Have any of them calculated the exact numbers?

Thats exactly what im asking for! I believe with some intake tubing, some aluminum block, and a little fabrication by someone with welding experience we could fab something up in no time. Its really actually pretty cheap to make. The only thing that is changing is the IC tubes. If someone wants to actually try this, we should get together sometime this spring and plan accordingly.

I mean, what if, WHAT IF, it turns out this setup could create great leaps and bounds over normal numbers. It may not be as efficient as a normal turbo setup but would sure be cheaper and easier to set up. If it works the way i think it will, it would be a great alternative to a more expensive supercharger, and dare i say it, might even match or surpass that of the mighty autorotor and MPIII, and for a fraction of the cost too!

One question though....would the MAF have to be reloacted to the lower IC tube since the new airflow will be coming from the turbo? Any air being sucked in through the supercharger WILL NOT be used for combustion, it is merely wasted gas to spin the turbo. So a filter wouldnt even be necessary on the supercharger end.

What kind of problems can be run into with this setup?
 
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