Thread: VNT Turbo and Performance Mods - 300 Tdi

Originally Posted by Jock The Rock

Well (...) I was a bit wrong. It is now very fast off the line and accelerating through the gears

HA!!!

The turbo that Allisport and Allard include with their kits is larger than the one used on the HS2.8L - turbine and compressor are both next larger size.

The HS2.8L turbo is a Garrett GT2256V (Garrett part number 724652-0001) - 22 is the turbine series, 56 is the diameter of the exducer (outlet) of the compressor impeller in mm.

IIRC the other turbos are Garrett GT2559V - 25 turbine series and 59mm compressor exducer. A member of this board fitted the Allisport kit to a 300Tdi in a Defender 130. The vehicle was later sold to another board member, and there has been information posted about the turbo including numbers.

The VNT turbos do not have a wastegate. They have an actuator that controls the position of the vanes open/close and effectively the turbine nozzle. The actuator looks like the actuator used to open/close an internal wastegate, which leads to the confusion.

In the case of these particular VNT turbos, the actuator uses boost pressure - the majority of VNT turbos use vacuum or compressed air controlled by computer.

As boost pressure increases, the actuator opens the nozzle vanes. The heat in the exhaust drives the turbo and more heat (increased fuel) is required to increase the boost pressure.

BTW, is it just me or there's a lack of infos about the 2256 on the official Garrett site?

I didn't find any specs sheet.

Originally Posted by Michele

BTW, is it just me or there's a lack of infos about the 2256 on the official Garrett site?

I didn't find any specs sheet.

They don't list a GT2256, only GT2256V (the VNT version).

For whatever reason, Garrett have not released any details of their VNT turbos. Some aftermarket places are starting to list replacement parts for these, but Garrett don't.

can find out what they come off on here http://www.turbotechnics.com/docs/catalogue.pdf.
I have a gt2256v and a couple of gt2260v's in the shed, if the turbo on the d1 dies then i may go down this route, the 2260's are for the isuzu

vern you could always donate one to the dullbirds got a slow 300tdi fund.....

Well the 3" has opened it up a lot, but it needs higher boost pressure than the 15psi it's running atm

To fix that I need more fuel

But before I do that I need to start cooling it down a bit, the EGT temps this thing is pulling is making the head a bit to warm for me.

It was suggested I fit a V8 County radiator, all good I thought. Yep checked with JC; they are a bolt in fitment. Then on the way home today I had a think, the County radiators don't have an engine oil cooler fitted into them like the standard radiator

Anyone have any ideas?

My original plan was to fit the County radiator and have a BIG front mount intercooler made up. Now I'll have to have a rethink

For those that are interested here's where I fitted my pyro probe:

Drilled and tapped


In place

Sorry Jock forgot to mention that bit, we fitted the county rad to a 130 with a 4BD1t, so no engine oil cooler in the rad anyway.
There are a few good quality oil coolers around, but personally I would check the dimensions of a 1980's RX7 engine oil cooler as I think they are a good size to fit across the front, quite a low profile too so won't interfere with anything, and easy to obtain.


JC