Variable Geometry Turbo random thoughts

I've been wondering how these work ever since I read the new Porsche 997 Turbo has them. They allow you to speed up the exhaust to spin the turbine harder at low RPMs (like a little turbo) but allow more exhaust gas to flow at high RPMs (like a big turbo). I don't think cars with them even need a wastegate.

Apparently there's a few different designs. The one used by the germans is shown on wikipedia. Cummins has a different design that uses a sliding nozzle instead of all the individual moving vanes which is supposed to be more reliable but I would imagine is a little less efficient.

I wonder if it would be possible to fit one of these to a Subaru? I think the position of the moving vanes is controlled by the ECU, so I suppose you'd have to have a completely programmable aftermarket computer running your car to be able to operate it. That, and you'd have to use the one from the Porsche if you wanted all those little moving parts to survive your gas engine's high EGT and that would probably cost as much as a whole WRX.

http://en.wikipedia.org/wiki/Variable_geometry_turbocharger
http://www.everytime.cummins.com/every/misc/video.jsp?s=broadband

There's also a better picture of the one in the BMW 330d in the September issue of Car and Driver (page 106).

 

look up the bell engineering aerocharger. Its a no longer sold variable vane turbo for miatas and foci (the true plural of focus!)

it has mixed reviews. good low end, bad high end, apparenly had an unacceptable failiure rate, but that has been disputed by Bell engineering. It runs in the neighborhood of 8psi usually and has been reported to whine terribly after 5-10k miles of useage in several cars. so far really the only variable vane kit commercially sold AFAIK

also, theyre ungodly expensive, so much so that nobody really tries them much.

http://forums.nasioc.com/forums/archive/index.php/t-45755.html

 

Garret has actually released a few models as well now...
Zak... Dave P. has one he intends to shove into the ass of his little 914

 

http://www.honeywell.com/sites/ts/t...GMKQK64U00ACROYP858GKIH564VY0812155701757.htm

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

 

Then i need to talk to dave P about returning that turbo and talking to some guy i have been dealing with here:

http://www.renegadehybrids.com/914/914subi.html

WRX 914 FTW.

 

They are bad ass. That's all you need to know.

Actually, we just sent out a direct mail piece for Porsche detailing VTG. We also sent a paper weight turbo/turbine that you could demonstrate how it works. It was a pretty cool piece.

The coolest piece we have done was a metal model of the model 550 Spyder that came with a tool kit that you used to piece it together.

You never throw away the "junk" mail you get from us. :biggrin:

 

^ can i get on your mailing list? lol

 

I will talk to your aunt at work today...I figured she would already have you on it.

If not, I will get your address from her...you intend to buy a new vehicle in the next six months and your salary is $150k+ right

 

The new C&D has a good picture of the unit on the BMW. It's an adjustable vane unit.

What unit do they use on a Prodrive WRC car? I hear that keeps the torque up and the turbo spinning at max revs at all times. That's what we all need...

 

Zac,
as you already know, the difference between swapping a motor and turboing the one that's already there is a serious class switch.

going from Street Mod to Prepared sounds painful... but i think you might already know about that...