Thread: VNT Turbo Info

Originally Posted by rick130

A little more info (not much) on the GT2556V(S2) 721204-0001

Turbo Build Sheet

I see that the GT2556V has a maximum rating of 168,000 rpm .........it's pretty amazing that they don't just fly to bits.

risk130:

I think they are used in the 530d.. It would interseting to walk into a dealer and ask for a list price...

rijidij:

168 000 rpm... wow. what are the wheels made from?

Originally Posted by rick130

Anyone able to nut out what Garrett wheels are used in that 721204-001 VNT ?

Wheel specs can be accessed through here Products by Turbo Manfacturers - Choose Component Type for Garrett
The only ones they list are BMW ATM. Turbine Wheel, Garrett - GT2556V

A company called Melett are developing service repair components for the Garrett VNT's too. Turbocharger Parts Catalogues

Garrett originally published parts lists for the VNT range, but changed after a few years to only providing complete assembled turbos. I think they had issues with the vane alignment and actuator adjustment when others serviced them.
So they clammed up. Companies like Mellett and other turbo parts suppliers seem to be slowly filling the blanks.

I've got the 130 on the road now, and I can say, I'm pretty impressed with this VNT turbo. It's very responsive, very little lag. Cruising at about 80-90kph, plant the foot and the boost instantly jumps from around 8psi to around 20psi and tops out at 22psi if you keep your right boot into it.
I would love to fit one to the Isuzu. It would be an interesting tuning exercise as the VNT doesn't have a waste gate. After the lag, the Isuzu easily pushes up to my max boost, set at 15psi, so with a VNT I reckon 20-22psi would be effortless considering the extra cubes over the little 300Tdi. Might have to up the size of my intercooler too. I think a VNT would improve the lag between gear changes with the Isuzu.
I shouldn't even be thinking about this at the moment............too many projects on the go already

20-22psi !
What head gasket are you using ?

Be a little careful, I've read that the stock (old type composite ?) gasket doesn't like it when boost exceeds around 18psi.

About 22 psi is boost pressure that the VN turbo from HS2.8 produces. I used slightly higher head bolt tension with composite gasket.

Apparently there is a MLS (multi layer steel) head gasket available now.