Twincharging... Stupid? Awesome?

[Radar]

The idea:
A Twincharger system is a forced induction system, comprised of a combination of both an exhaust-driven turbocharger and a drivetrain-powered supercharger. Forced induction permits high power outputs from small capacity engines by allowing engines of a small displacement to operate at a higher volumetric efficiency. - Wiki

Technical description:
The most common type of twincharging system is a sequentially organized Roots type supercharger, connected to a medium-large sized turbocharger.[citation needed] The supercharger provides near instant manifold pressure, when the turbocharger is otherwise not at its operating speed. Once the turbocharger has reached operating speed, the supercharger can either continue contributing air to the intake (yielding elevated intake pressures), or it can be be bypassed and disconnected from the powertrain (increasing efficiency of the induction system).

It seems all so easy... 3T/2T-GZTE with the fully worked bottom end and head why not but with a fully custom turbo setup

Why are turbo's spooled by exhaust gasses only?

[Gavatron]

Why are turbo's spooled by exhaust gasses only?

What else would you have spool them?

[Radar]

Forced air, through the exhaust housing i.e. a supercharger pushing 25+ PSI

[Gavatron]

a supercharger using 25psi

Twin-charging doesn't spool the turbo blades though. Just allows there to be boost low in the rev range before the turbo is spooled.

[brett_celicacoupe]

the main question is, what are you trying to achieve from twincharging and why do you think you need it?

[Gavatron]

Forced air, through the exhaust housing i.e. a supercharger pushing 25+ PSI

What would be the point in that. You have the parasitic drag on the motor from the supercharger, turning the turbine on the turbo. Why not just use exhaust? It's using a waste product to create boost.

What you're saying is to instead use engine power to compress air, which in turn is used to compress air. Just seems completely pointless to me.

[Radar]

Oh i understand this fact very well, but im saying making a custom pipe setup, so the supercharger leads to where the turbo would normally bolt onto the exhaust manifold, from there the dump pipe leads to the forced air outlet where they join and lead into the intake manifold... NO HEAT! Better boost tuning! More power!

[brett_celicacoupe]

Oh i understand this fact very well, but im saying making a custom pipe setup, so the supercharger leads to where the turbo would normally bolt onto the exhaust manifold, from there the dump pipe leads to the forced air outlet where they join and lead into the intake manifold... NO HEAT! Better boost tuning! More power!

interesting.

care to make any paint diagrams so we understand?

[Gavatron]

I think he means this. Please excuse my mad paint skillz.

[brett_celicacoupe]

interesting indeed.

is that a closed loop hydrogen powered engine by any chance?

i read about them on wiki once and thought it was the best idea ever for my car

[Radar]

here wrap ur minds around this

[Radar]

nah it still uses extractors and an exhaust of corse, its just ran on LPG for the higher octang levels and the way im injecting it, plus the cooler temps

[brett_celicacoupe]

interesting...

so what stops the "forced air from the supercharger" going back into the engine. or creating excessive back pressure?

and what stops the exhaust pressure from the engine going back through the supercharger? or do they create equal pressure all the time?

wow, you might be on to something!

[texasflysuperstar]

What else would you have spool them?

its a bit of track but i thought it was interesting enough to mention.

Alfa Romeo GTA used 2 Turbo Chargers driven by engine oil pressure to get 220 BHP from 1600cc and 2 DCOE Webbers.

[Gavatron]

I don't think the exhaust is used at all. And you'd need a throttle body after all the compression takes place, and a freaking huge BOV.

I don't know if a supercharger would actually turn the turbo. I'm no science whizz, but I thought the superchargers/turbos only compress the air, the don't actually make it move fast like the exhaust does as it comes out the exhaust ports.

[Radar]

The supercharger is driven by a belt so thats what stops it, im sure along the lines somewhere you could adapt a BOV (all you would need) its only compressed air not even emissions from the exhaust.

[Radar]

I don't think the exhaust is used at all. And you'd need a throttle body after all the compression takes place, and a freaking huge BOV.

I don't know if a supercharger would actually turn the turbo. I'm no science whizz, but I thought the superchargers/turbos only compress the air, the don't actually make it move fast like the exhaust does as it comes out the exhaust ports.

Why would there be no exhaust im still exploding a fuel :S

Your confusing the method of condensing the air, theres two different methods: Cooling it, or Forcing as much as you can into a certain spot as fast as you can (Pound per Square Inch)
so basicly your accelerating the air to be able to put more in faster

[brett_celicacoupe]

The supercharger is driven by a belt so thats what stops it, im sure along the lines somewhere you could adapt a BOV (all you would need) its only compressed air not even emissions from the exhaust.

ahhh,

so the belt stops movement of air where there is a pressure difference?

how will you get the car engineered if the BOV is venting emissions from the exhaust?


i wonder if you could feed the external wastegate gasses from the turbo back through where you a feeding the supercharger into? you might get more gains by doing this? you reckon?

[Radar]

Brett I think you could be confused
The rate of air given off by the supercharger is purely dictated by the RPM so in low RPM there is low boost but in high RPM there is huge boost. you could almost have a BOV on the plenum to relax manifold pressure. I think :S turbo guys please help

[brett_celicacoupe]

yeh, i think i am.

what do you think about this idea?
"i wonder if you could feed the external wastegate gasses from the turbo back through where you a feeding the supercharger into? you might get more gains by doing this? you reckon?"