Thread: 300TDi turbine exhaust housing size Q

I think Bush65 has a GT2256V (brazillian) on one. Functionally it seems the same spec as the GT2256V I have here from a 2.7l mercedes diesel. But the mercedes housings and flanges are different.

What's the AR of your Benz turbo exhaust housing, Dougal?

Originally Posted by up2nogood

What's the AR of your Benz turbo exhaust housing, Dougal?

I think 0.64.

Had a chat to a bloke at Garrett today, he said the VNT25 would be a sh*t of an idea, with massive lag given the exhaust housing on the 300TDI Garrett has an AR of .47 and the AR of the exhaust housing on the VNT25 is .63.

I think he has a point, but am willing to listen if the Sprinter turbo exhaust housing is the same. And the cartridge is too.

Ideas?

Originally Posted by up2nogood

Had a chat to a bloke at Garrett today, he said the VNT25 would be a sh*t of an idea, with massive lag given the exhaust housing on the 300TDI Garrett has an AR of .47 and the AR of the exhaust housing on the VNT25 is .63.

I think he has a point, but am willing to listen if the Sprinter turbo exhaust housing is the same. And the cartridge is too.

Ideas?

The 0.63 is the biggest the A/R gets, when the vanes close the effective A/R gets much smaller. That is the whole point of a variable vane turbo.
I say either do it, or sell it to me (cheap) and I'll eventually fit it to my 2.2 litre diesel work car.

Hmmm, I wonder what the AR is when the vanes are closed?

Originally Posted by up2nogood

Hmmm, I wonder what the AR is when the vanes are closed?

That bemuses me too.
I gues you could work out the vane angle and the geometry of the resulting vortex. Calculate that back to a theoretical A/R.

Given the higher compression of the diesel, I wonder if there is any greater exhaust pulse being pushed through the exhaust housing than would be the case on a 2.2 petrol?

If there is, then that might compensate for the fact that the turbo only really provided boost from 3000rpm and up on the petrol.