Thread: 4BD1T Turbo Sizing and Performance Prediction.

Originally Posted by rar110

TD04HL-19T
Any feedback available on how these perform, particularly in the higher rev range?

Should top out around 200kw (27psi at 4000rpm). Lots of people are currently building with this turbo, but not many up and running.

It is more efficient than the he221, particularly in the mid-range but doesn't have quite the flow range or pressure capacity of the HE221. This is due to the difference in wheel design. The 19T wheel has radically backswept blades at the outer rim, the HE221 compressor is 2mm bigger and has less backsweep so it delivers more pressure at lower wheel speeds but has more turbulence in the diffuser and lower efficiency as a result.
The HE221 compressor is good for ~220kw worth of air (33psi at 4000rpm).

One part I am unsure of is the contribution of pumping losses to power. They are already accounted for somewhat in BSFC dropping at higher rpm, but there is also a power loss due to the drive pressure climbing above boost at high rpm.
The 19T at full power I think has a net pressure loss of about 9.6psi across the engine (boost 26psi, drive pressure 35.6psi) which takes 14kw of power to overcome and could reduce crank power to around 185kw at 4000rpm. But half of this loss could aready be counted in BSFC.
The HE221 has a pumping loss of around 12psi and 19.5kw at 220kw crank power. So total crank power could be likely closer to 200.

Anyone had a look at any of the Garrett Gtx series. They are ballbearing and supposedly have more efficiency under much higher boost.

I am running one on a GQ patrol, gtx 2863. It is a much better turbo than the gt 2860 I was running before. It has better boost response in the low to mid areas and will easily keep boosting right throughout the rev range, but I only have enough fuel to run it to about 22 psi. The previous turbo became inefficient above about 16 psi and would cause a large egt increase after this. The gtx has lowered egt quite considerably.

Originally Posted by Northy

Anyone had a look at any of the Garrett Gtx series. They are ballbearing and supposedly have more efficiency under much higher boost.

All bigger than ideal in turbine sizing. If you only care about 2000rpm and up they have some offerings. But you'll be making big compromises down low.

Cheers Douglas much appreciated

I just found this post from Randy (Carcrafter): I need 35 pounds of boost!!

185cc/1000 shots on a stock but maxed pump.

Hi,
I have been reading this thread with great interest, as I have a 6x6 1989 totally standard as far as motor &"IHI" turbo goes except it has a 3'' exhaust pipe.
It is fitted with 3.54 diffs so normal driving is fine, just a bit slow to come onto boost on take off, also when I get into the hills I need more bottom end power & torque. I can cruise at 100ks all day approx., 2,700rpm but as hills hit I need to change down at about 1900 to 2,000 rpm, no power below 1,800rpm. I was going to fit a GT2259 as it seems to be the one of choice. So went in to order one off my friend & mechanic & the first words he said was "I think you will find that it is too big". Apparently he fitted a similar unit to an Isuzu 4BD1T in a tipper truck & they had to change it to the smaller one, a CA18 Nissan. Starts to come on at 1,000rpm & goes through to 3,000rpm. Has anybody had any testing with this unit in the heavier vehicles? Thanks Paul.

Originally Posted by powerband

Hi,
I have been reading this thread with great interest, as I have a 6x6 1989 totally standard as far as motor &"IHI" turbo goes except it has a 3'' exhaust pipe.
It is fitted with 3.54 diffs so normal driving is fine, just a bit slow to come onto boost on take off, also when I get into the hills I need more bottom end power & torque. I can cruise at 100ks all day approx., 2,700rpm but as hills hit I need to change down at about 1900 to 2,000 rpm, no power below 1,800rpm. I was going to fit a GT2259 as it seems to be the one of choice. So went in to order one off my friend & mechanic & the first words he said was "I think you will find that it is too big". Apparently he fitted a similar unit to an Isuzu 4BD1T in a tipper truck & they had to change it to the smaller one, a CA18 Nissan. Starts to come on at 1,000rpm & goes through to 3,000rpm. Has anybody had any testing with this unit in the heavier vehicles? Thanks Paul.

Sounds like he's referring to a T25. From what others have said, the rev range is about right. However cruising at 2700, it could be getting close to its efficiency limit. Dougal ran a T25 for some time and will be able to comment.