Build Isuzu 4BD1T Lexus LX450 (Land Cruiser) Build

[ForealBoreal]

I vote a TD05H 16G6.
4L diesel engines seem to do good with this combo....

 

[Wheelingnoob]

I vote a TD05H 16G6.
4L diesel engines seem to do good with this combo....

Im kicking myself at the moment. I had 4 of them (new) for DSM's a few years ago and sold them at almost scrap values.

One thing with a TD05h is its hard to find turbine housings that are not strange OEM shapes.

 

[gerg]

Although old, consider the t3 60 trim as it stock has the radial design turbine most diesel turbos come with and a capable compressor. They also almost never fail when pushed hard. I'd still do a 360 bearing, but it's a tuff turbo. It's turbine is in between the td05 and 06. .58 housings are also available now for better tuning.

 

[Dougal]

Yeah my fingers are crossed, I have very little faith in this thing right now so I need to take it slow and build trust again.......like a scornd lover lol.

So far I was shocked to see at 10psi boost that I have almost 20psi drive. At 15psi I had around 22psi drive. I have not opend it up yet though....as much as one can open this slug up.

I still have a feeling I may end up with compounds just somthing proven on this engine that will allow me to max out the pump. Right now I feel this turbo is lacking any real guts.

I want to come up and talk over options and take you for a drive to get your impression in the next week or two.

Your drive/boost numbers are very high. Higher than other people are seeing with the same turbo on the same engine. There's definitely a bottle-neck somewhere which is hurting your boost, power, torque and mpg.
This turbo is capable of maxing out your pump. But you have another issue somewhere.

Can you move your drive pressure pickup to post-turbo for a run?
Alternatively. Pop the wastegate open and go for a drive. See what the drive pressure is with very little boost.

 

[Dougal]

I vote a TD05H 16G6.
4L diesel engines seem to do good with this combo....

The TD04HL-19T isn't the problem. There is another issue to hunt down and I suspect it's exhaust related as Jeremy's drive pressures are far higher than others have measured with the same turbo on a 4BD1+T.
This makes sense going back through his history, poor fuel economy, slow boost (even with the 6cm housing) and poor performance.

But anyway here's a comparison between that and a TD05-8 with the 16G6 compressor.

A TD05 with an 8cm housing is ~20% bigger flow wise than the TD04HL turbine. It won't have the low end pull you want with a 4BD1T. It's a great turbine option if you only want 2000rpm and up. But matching compressors are difficult.
If you find a 6 or 7cm TD05 housing then you'll have surge issues with the 16G6 wheel on this engine.

I've been right through the TD05 compressors and none of them suit the 4BD1T like the 19T compressor does. The 19T has the required surge resistance to run the 6cm housings, it has the same pressure capacity and it even out-flows the 16G6 at the top end (41 lb/min vs 37 lb/min).

 

[Wheelingnoob]

Your drive/boost numbers are very high. Higher than other people are seeing with the same turbo on the same engine. There's definitely a bottle-neck somewhere which is hurting your boost, power, torque and mpg.
This turbo is capable of maxing out your pump. But you have another issue somewhere.

Can you move your drive pressure pickup to post-turbo for a run?
Alternatively. Pop the wastegate open and go for a drive. See what the drive pressure is with very little boost.

Yes they are. The exhaust is 1.5 feet of 2.5" then 3" all the way out the back, mandrel bent no restriction points. I do not have a way to easily check after the turbo.

Im suspect of my intercooler at the moment, im worried its the bottle neck in the system. Not sure how that would relate to drive pressure though. Right now my boost sensor is post intercooler. Im going to try moving it pre to see the effect. If bost and drive are around the same ill be happy and move on to redoing yet another system of this never ending swap.

 

[Dougal]

My drive numbers for comparison. I measured these ~7 years ago running a T25 turbo, no IC and quite restrictive intake piping.

2000rpm cruise. 8-9psi boost, 12-13psi drive.
2000rpm high load, 20psi boost, 18-19psi drive.
1500rpm accelerating from cold, 20psi boost, 40psi drive.

I know my improved intake piping have reduced drive pressures since, but I haven't measured them recently.

What RPM are your measurements at? At 2000rpm and full load you should have drive below boost. As load and EGT drops the boost drops but the drive/boost ratio increases. 1.5:1 at cruise is perfectly fine.

 

[ForealBoreal]

Im kicking myself at the moment. I had 4 of them (new) for DSM's a few years ago and sold them at almost scrap values.

One thing with a TD05h is its hard to find turbine housings that are not strange OEM shapes.

That really sucks

Your drive/boost numbers are very high. Higher than other people are seeing with the same turbo on the same engine. There's definitely a bottle-neck somewhere which is hurting your boost, power, torque and mpg.
This turbo is capable of maxing out your pump. But you have another issue somewhere.

Can you move your drive pressure pickup to post-turbo for a run?
Alternatively. Pop the wastegate open and go for a drive. See what the drive pressure is with very little boost.

Heavier than stock turbine wheel? Aftermarket part?

The TD04HL-19T isn't the problem. There is another issue to hunt down and I suspect it's exhaust related as Jeremy's drive pressures are far higher than others have measured with the same turbo on a 4BD1+T.
This makes sense going back through his history, poor fuel economy, slow boost (even with the 6cm housing) and poor performance.

But anyway here's a comparison between that and a TD05-8 with the 16G6 compressor.

A TD05 with an 8cm housing is ~20% bigger flow wise than the TD04HL turbine. It won't have the low end pull you want with a 4BD1T. It's a great turbine option if you only want 2000rpm and up. But matching compressors are difficult.
If you find a 6 or 7cm TD05 housing then you'll have surge issues with the 16G6 wheel on this engine.

I've been right through the TD05 compressors and none of them suit the 4BD1T like the 19T compressor does. The 19T has the required surge resistance to run the 6cm housings, it has the same pressure capacity and it even out-flows the 16G6 at the top end (41 lb/min vs 37 lb/min).

I know stuff works good on paper and all and I am not down talking it.
But this combination is proven day in and day out to work quite well on the 1H* and TD42 engines.

Your airbox could be a large culprit in turbine inertia.

 

[Dougal]

I know stuff works good on paper and all and I am not down talking it.
But this combination is proven day in and day out to work quite well on the 1H* and TD42 engines.

Your airbox could be a large culprit in turbine inertia.

Yes I know it's proven on plenty of Nissan and Toyota 4.2's. But they have 300cc more displacement, 50-200% more intake valves, shorter stroke and spin a lot quicker.
These three factors combine to make it a higher rpm turbo on the Isuzu. Where the Isuzu by nature is an engine that does it's best work at lower rpm and for best drivability requires full boost earlier than most.

The only sure-fire way to find out what is ailing Jeremy's turbo is a lot of pressure measurements.

 

[Wheelingnoob]

The only sure-fire way to find out what is ailing Jeremy's turbo is a lot of pressure measurements.

I plan to do that on Tuesday/Wendesday this week. I have everything rigged up to test pre and post intercooler pressures and drive pressure. Anything else?

 

[Dougal]

I plan to do that on Tuesday/Wendesday this week. I have everything rigged up to test pre and post intercooler pressures and drive pressure. Anything else?

I'd go exhaust pressure too. Just to be sure. You can probably just move the drive pressure connection.

 

[gerg]

Charge tube leak test?

 

[warezdog]

I'd like to see what kind of flow you're getting thru that intercooler first.

 

[Wheelingnoob]

Well just filled up, granted most of this tank was with a very stogy head gasket. A mind blowing 11.2mpg.....I should have kept the gasser.

 

[Dougal]

That's horrendous. I've never had fuel economy that bad, even towing over 3 ton.

Did you revisit your injection timing? If not I'd do that first, it's easy, then get back to the turbo. The correct timing will help the turbo.

 

[doug720]

Obviously something is very wrong. There have been so many of these swaps into LC's, mine included, and every one of these swaps is getting almost twice that mileage. There is a cause for the low mileage and power.

I won't rehash what has already been said above. But timing is easy and do you have the stock turbo? I'm running the stock waste gated turbo and seeing around 16-18 boost pressure.

There has to be something stupid causing this - blocked inter-cooler, bad turbo, timing off.

I wish I could stop by and lend a hand.

We know your frustration level is off the chart, and the costs...well we all know those too. But you will find the problem!

Doug

 

[Wheelingnoob]

Timing has not changed from when I first got it going and spill timined it. On my first few trips with it I was getting 20ish mpg no mattert if it was hwy or offroad it seemed. I did check to make sure the timming marks are still lined up and they are. The pump timming hash on the timming plate is still in the same location as well.

Ill see today if I can even accsess to inner timming adjustment nuts to lossen them (stupid design).

I do not have the stock turbo, it was a free floater. I have the "hot ticket" turbo that is leaving some to be desired at the moment.

Obviouesly my frusration level is high.

 

[doug720]

If you need to adjust the timing, I made this to get to the nuts! Well worth a wrench and 15 minutes.

 

[Dougal]

Timing has not changed from when I first got it going and spill timined it. On my first few trips with it I was getting 20ish mpg no mattert if it was hwy or offroad it seemed. I did check to make sure the timming marks are still lined up and they are. The pump timming hash on the timming plate is still in the same location as well.

Ill see today if I can even accsess to inner timming adjustment nuts to lossen them (stupid design).

I do not have the stock turbo, it was a free floater. I have the "hot ticket" turbo that is leaving some to be desired at the moment.

Obviouesly my frusration level is high.

The turbo you have is the hot ticket and it's proven on these engines. Normally for drive pressures to be that far out there's a leak or blockage somewhere in the system. Either the compressor is absorbing a lot more power than it should (like 50% more) or the turbine is getting less pressure across it than it should.

The usual list of suspects:
Generally anything which greatly reduces mass flow through the engine.
Specifically:
Incorrect valve clearances.
Intake restriction.
Exhaust restriction.
Eroded compressor wheel.
Damaged turbine wheel.
Turbine shaft not free spinning (coked up or rubbing).
Intercooler blocked or too small for the internal flow.


But I think your injection timing is possibly making this worse.
I know you spill-timed it originally. But I think you need to simply advance timing until it nails, back off until it's only got a crackle under high load and see how this compares to your previous marks.

To put your high drive pressure into perspective. 15psi boost at 2000rpm with 700C EGT requires about 13psi drive pressure.
You had 22psi, but you didn't state rpm or EGT.

 

[Timpanogos Slim]

Can you rent a diesel timing adapter?