VNT turbo

[Fast Guy]

Saw this posted on another forum!
(blatent copy and paste )


"VNT technology comes to GT Turbos!
A chap at RTOC who fiddles with turbos has managed to create a VNT turbo for the GTT. Typically used in diesels, these turbos are on the cutting edge of turbo technology and have been adopted by VAG and Renault on their current TD cars. Previously exhaust gas temperatures stopped such turbos from being used on petrol cars, however now with a bit of tinkering here and there it's been sorted...

What does this mean?

Well.. VNT turbos work in a way differently to normal turbos. Rather than having a wastegate which bleeds off boost to stop the turbo overspinning (i.e it limits how much boost it provides by leaking the excess gas), there are vanes in the exhaust housing. These are almost closed at low rpm and open up as more exhaust gases flow, therefore producing a quicker spool up and full boost earlier (i.e. it acts as an exhaust housing that changes size).

So in effect you have a turbo that spools quicker than a T2 yet provides the flow of a huge T3/4..."

Could be a good tuning aid one day

 

[Shaun]

I was thinkin on similar lines a few years ago,was thinking of a design on the lines of the shutter on a camera,but elongating it for better flow so that it was shaped like a nozzle.But never followed it up

 

[JIMMYBACK]

thats would be worth its weight in gold........

 

[ashills]

incredible things as they say are used on the new golf TDs but if they go tits up its 2500 quid for a new one but i think garret do there own range now that very fast then limit them selves to 1.6 bar

 

[MarkMc]

I have seen this one before(2years ago I think) variable AR turbo. I looked at it then and they said petrol exhaust gases are too hot and only really works with diesels. So what has been done to the turbo to make it now work with a petrol engine. The picture you show looks almost identical to what I saw a while back so it may be a material difference. Give it a couple of years and we will all be fitting GT3540 and getting better response than the factory T28(hopefully or maybe just wishful thinking )

Mark

 

[zia]

posted about a this ages ago but had no luck in getting one! what they don,t tell you is the that the vane have tendency to sieze up due to excessive heat build up and your buggered and also the fact you need high pressure actuator to actually to turn the vanes.

zia

 

[AndrewD]

posted about a this ages ago but had no luck in getting one! what they don,t tell you is the that the vane have tendency to sieze up due to excessive heat build up and your buggered and also the fact you need high pressure actuator to actually to turn the vanes.

zia

ahh yes the VNT Turbo, QUITE AWESOME really

we use this on our honda cbr600 engine, and fuck me dead increased power by 20% (nice little increase) but the bloody thing increased torque by 66% compared to NA application

garrets turbo is called the GT15V, and we have had no problems with excessive heat buildup (and we used antilag) and to get around that high pressure actuator we use a high torque servo to actuate the vanes via a student designed pwm controller

nasty little things they are, cause car goes way quick now im talking under 3s to the hundred km/hr => 140metres in about 3.5 sec