I got a really strange idea, it probably wouldn't work or it would have been made before, but I still wanted to see what people think.


Basically picture a turbo; it's got a compressor side and turbine side. Stick another section between those 2 that is belt driven off the engine crank. At low rpms, when there is not enough exhaust to produce a considerable amount of boost, this unit functions as a supercharger. When the rpms rise and the exhaust flow is enough to make the turbine spin faster then the "supercharger middle section", the belt driven section is bypassed.

You can try to picture it like a rear bicycle wheel (ofcourse the mechanism has to be different and much more durable and heat resistant by design) When the bike is stationary, the rear wheel is powered by the pedals, but when the bike starts moving downhill and is powered by inertia, the pedals are bypassed and the wheel can spin faster then the pedals are able to power it.

The kind of mechanism necessary for this would allow the turbo's shaft to spin if whether the belt in the "supercharger middle section" is moving or not. This is easy to picture if you compare it to a bicycle wheel.

The result of this would be the elimination of turbo lag with the advantage of still providing boost at much higher rpms. There will be some power loss from using the belt to power the turbo at lower rpms, but most of that power loss will disapear after the exhaust gases take over.


Opinions?

 

It could be done. Probablly through in some sort of clutch type gear for the belt drive, b/c after that turbo spools the belt will slide. also a belt next to the turbine might melt. Just some things to consider. But give it a shoot, that is how new ideas arise.

 

That's a lot of moving parts in an extreme heat environment, so costs would be high and reliability low. I can't think of an effective way to run the belt either....especially without moving the turbo to a less than desireable position. I think turbo lag is minimized with a proper setup and isn't an issue anyway (IMO). Superchargers and turbos are 2 different things and I think merging them to get the best of both worlds would be ineffective and a waste of time....but if you have the desire to be innovative, have at 'er.

 

I think it was Turbo Mag., but there was a 1st gen. MR2 with a camry V6 in it, that was turboed and SCed...it was a monster!!!

 

If I'm remembering correctly, the WRC cars use an electric motor connected to the turbo to eliminate turbo lag. Does not spin it real high, just enough to keep the rpm's up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">If I'm remembering correctly, the WRC cars use an electric motor connected to the turbo to eliminate turbo lag. Does not spin it real high, just enough to keep the rpm's up.</TD></TR></TABLE>

From what I have seen, they use a misfiring system, which basically means that when the driver lets off the gas pedal, the ecu advances the timing so that the a/f mixture in one of the cylinders is not burned and passes through to the red hot turbo, which then ignites the mixture, keeping the rpm of the turbo up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nolimits &raquo;</TD></TR><TR><TD CLASS="quote">That's a lot of moving parts in an extreme heat environment, so costs would be high and reliability low.</TD></TR></TABLE> Yep!

 

they also made a turbo that had a third turbine driven by oil pressure that causes the turbo to spool up almost at idle.

It didn't work out to well tho...

 

well the point is, the belt only spins at the engine's speed, not at the speed of the turbo. If the turbo exceeds the speed of the belt because of the exhaust gases, the belt will "free wheel" still going at the speed of the engine.

As for the engine not being able to spin the belt fast enough, That's already already been solved in this type of supercharger:
See how the the belt driven side connects to the compressor? well imagine a turbine side of a turbo being added to that. The shaft would have to go right through and there would have to be some kind of clutch to allow supercharger section to "free wheel"

Temperature is an issue, but I think there's some kind of belt or metal belt that can handle it.