Thread: Turbo upgrades

Thanks guys, I had thought of a 2 1/2" pipe mandrel bent, so if i put a small muffler on to reduce the noise that would be better? the T28 turbo do I have to specify the type of wheels, bearings etc for it? as the T25 has a tag with the specs on it.
How do i know what type of T28 to buy? as seen so many diff specs for T28, could i use a 2nd hand 1 from a jap wreckers?

Does any one know of a 200Tdi manifold for sale???????

Originally Posted by philco

Thanks guys, I had thought of a 2 1/2" pipe mandrel bent, so if i put a small muffler on to reduce the noise that would be better? the T28 turbo do I have to specify the type of wheels, bearings etc for it? as the T25 has a tag with the specs on it.
How do i know what type of T28 to buy? as seen so many diff specs for T28, could i use a 2nd hand 1 from a jap wreckers?

I did some quick investigation using the Squirrel Performance Turbo Calculator From several sets of data that I input, a Garrett turbo that looked good to me was the GT2259. More info on the Garrett GT2259 and pdf file with flange data

That Squirrel calculator is based on the methods given by Garrett for sizing turbos. The Garrett info are available as PDF files Part 1, Part 2, Part 3, Part 4, and Part 5 The important parts for sizing are 3 and 4.

If you look at 2nd hand Garrett turbos, the numbers are usually on the compressor housing. They most likely will not have the GT2259 or similar designation, so you need to look up the numbers in a Garrett catalogue.

The designation GT2259 is deciphered as:

The first 2 numbers e.g. 22 is the frame size - dictated by its turbine wheel inducer (inlet side - is the large diameter of the turbine wheel) diameter.
GT22.. is 50.3mm diameter
GT25.. is 53mm diameter
GT28.. is 53.8mm diameter
GT30.. is 60mm diameter
GT.... ..........

The last 2 numbers is the compressor exducer (outlet side - is the large diameter of the compressor wheel) diameter.
GT..54 is 54mm diameter
GT..59 is 59mm diameter
GT..60 is 60mm diameter
GT.... ..........

An 'R' after these 4 numbers designate roller bearings. A roller bearing turbo will spool up quicker. You will need to restrict the oil inlet if fitted in place

Other information you need from the catalogue include:
A/R of the turbine. Smaller A/R will provide more boost at lower rpm - this is what we need with diesel engines. Generally (but not with 300Tdi) it is a simple to replace the turbine housing for a different A/R - a common tuning procedure.
Trim of compressor wheel - enlarging trim will increase air flow capacity of the compressor wheel.

A diesel Mech mentioned that they used to swap out the turbines on the stock 300tdi with those from an isuzu, he mentioned it in passing and I should have questioned him further has any one done this or heard of this before, he did mention "big" increase in performance.
cheers
mal

A bit more info, but sadly I can't find as much information as I would like.

200Tdi turbo is Garrett TB0242, 465171-0001/2 or 465175-0001 - I don't know turbine and compressor wheel sizes.

300Tdi turbo is Garrett T250-4, 452055-4E - I don't know turbine and compressor wheel sizes, except rough measurement of compressor inducer is approx 38mm.

TD5 turbo is Garrett GT2052, 452239-0003/4/5E - compressor wheel - inducer 37.6 mm, exducer 52.2 mm, turbine wheel - inducer 47.0 mm 72 trim A/R 0.5

TD6 (disco 3) turbo is GT2256V - I don't know turbine and compressor wheel sizes except GT22.. should be 50.3 turbine inducer and 56 should be compressor exducer. These are variable geometry turbo - which has similar affect as changing A/R from smaller at low boost to larger at high boost.

The HS2.8TGV engine (2.8 litre development from 300Tdi) also uses a GT2256V turbo - the 300Tdi performs well with these turbos fitted.

The turbo that Murray has on his 130 defender (post above) is a GT2556V - this has a larger turbine wheel (I assume 53mm inducer), but remember it has variable geometry.

IMHO, unless you want to really work the injection pump over and fit 3" mandrel exhaust, and unless you use a variable geometry turbo, you should not go bigger than a GT22.. size turbo with small A/R (around 0.5 A/R). The upgrade will come from using a bigger compressor - something bigger than 52mm exducer as used on TD5 and up to 60mm if you want to push the boost pressure up to around 22psi (so probably between 52 and 60mm).

The 3.0 litre Nissan GU's have a variable geometry turbo - I don't know details, but given they are 3.0 litre diesel, the size will probably be good for upgrading a 300Tdi.

Do we know what vehicles we will find the GT2256V on?

If I was looking for a second hand one I would like to go looking in the right wreckers yard.

The next problem after that will be having to sort out the control of the vanes (I don't know if that is what they are called, I mean the control surface used to maintain gas speed for varying gas volume) as one thread that I saw on a UK forum the control circuit used vacuum and a digital/ECU control signal. Swapping to a pressure driven diaphragm resulted in a lot of experimentation with spring rates.

Originally Posted by slug_burner

Do we know what vehicles we will find the GT2256V on?

If I was looking for a second hand one I would like to go looking in the right wreckers yard.

The next problem after that will be having to sort out the control of the vanes (I don't know if that is what they are called, I mean the control surface used to maintain gas speed for varying gas volume) as one thread that I saw on a UK forum the control circuit used vacuum and a digital/ECU control signal. Swapping to a pressure driven diaphragm resulted in a lot of experimentation with spring rates.

The pics below are cropped screen captures from a garrett 2006 catalogue.

These show all of the GT22..V variable geometry turbos in that catalogue.

AFAIK many computer controlled diesels use a vacuum actuator. The only one I know of that is used without computer control is the HS2.8TGV engine (2.8 litre development from 300Tdi) which uses a GT2256V turbo. It is listed at the top of the 3rd pic under Navistar (current name of the engine manufacturer)part no 724652-0001. This turbo has a boost pressure actuator - I can give you more details.

I can't see why a boost pressure actuator can't be used. I am familiar with the thread you are talking about - IMHO the person made it more difficult than it should be (and it was not a garrett turbo).

Edit: reloaded 1st pic as column titles had been cropped.