Turbo advice for 3L camper cabover rig (1 Viewer)

[DieselSobchak]

Hello diesel crowd,

As the title suggests, I'm in search of guidance for adding a turbo to a Toyota 3L engine, mechanically injected and naturally aspirated. Specifically, a good friend of mine recently purchased a 1997 Dyna 150 with a 3L from a fellow who had imported it directly from Japan. Right hand drive cabover model. I helped them do the timing belt/ water pump/ tensioners and serpentine belts back in January. The exhaust manifold was leaking soot under the cab and into the vehicle, so we replaced the exhaust manifold gasket and used a stud kit instead of bolts. After a 1900 mile road trip, everything was fine but within the last 50 miles it started leaking exhaust from the manifold again. So at the very least the exhaust manifold is warped and needs replacing. Given how the vehicle has only 60,000 kilometers on it I doubt the head is warped.

Given how the truck is really underpowered going up hills, and the exhaust manifold needs replacing, I'm thinking this is a good time to convert to a turbo setup. The goal is simply for better economy and a better breathing engine. Being a camper it's not winning any races and with mechanical injection it's dumping more fuel than is being burned when under load. The transmission is an automatic so that takes away the ability to downshift ahead of time for big climbs. Overheating has not been an issue so far, and if possible I'd really like to have an air to air intercooler plumbed in somehow as well to keep intake temps in check.

So with all that being said, what turbo would be ideal for modest power and general overall economy? What is the maximum safe boost for this engine on stock head bolts when adding a turbo? I know nothing about Toyota diesels, my main experience is with VW TDI cars and GM 6.5 diesels. So I'm no stranger to the general principles of how diesels work. I've seen the CT20 turbo mentioned often as an upgrade. Would this be a good fit for the 3L engine and my desired application? I'd prefer a turbo that is only oil cooled. It seems some CT20s were both water and oil cooled, some just oil. With space under the cab being limited I'd like to avoid additional coolant plumbing if possible. And an external wastegate that can be manually controlled would be great for dialing in maximum boost. If there's another turbo from a different vehicle/ manufacturer that would be similar or better, I'm all ears.

@GTSSportCoupe I see you've got extensive experience with the 2L engine and making power, anything to suggest?

 

[Dougal]

CT20 is old, inefficient and hard to get parts for. Get a MHI TD04-4 which was used on 2.5 litre Mitsubishi and BMW diesels.

Safe boost is single digits (i.e 9psi). Tune it so it doesn't smoke and you'll be fine.

 

[DieselSobchak]

Thank you for the advice Dougal. Any suggested places to source a genuine unit? I don't want to get one off ebay or amazon that is a chinese knock off. Seen too many china clones fail and send shrapnel into an engine. Offhand do you know what size turbo pedestal an OEM unit is?

 

[Dougal]

Thank you for the advice Dougal. Any suggested places to source a genuine unit? I don't want to get one off ebay or amazon that is a chinese knock off. Seen too many china clones fail and send shrapnel into an engine. Offhand do you know what size turbo pedestal an OEM unit is?

I don't think you'll find a genuine unit. I would buy from a reputable seller and you'll get a quality balanced unit. Kinugawa, mambatek etc.

I think it's a unique flange. Part number I have is 49177-06430
There will be other similar size turbos with different flanges. But that's it's own research project.

https://store.kinugawaturbosystems.com/collections/pajero-triton-4d56t-2-5l

 

[John in Utah]

I had a 3L in a ‘90 Hilux I put a CT20 on, and agree there are better turbo options. I liked the CT20 because I could swap it with stock LJ parts- oil cooler and exhaust manifold. I messed with the pump timing a hair, and put in a bigger rad and a water to air intercooler, the Hilux doesn’t have a lot of room for an air to air. It was never fast, but the turbo did help it go at least 70

Some info here: Hilux - '90 Hilux daily driver build - https://forum.ih8mud.com/threads/90-hilux-daily-driver-build.1183010/page-2

 

[KiwiDingo]

Upgrade parts and spare parts are very easy to source for the CT20 turbos.

 

[DieselSobchak]

As far as I can tell the CT20 is both oil and water cooled correct? For that reason I'd prefer another turbo as space is limited and I don't want to mess with running additional water lines.

I am concerned that the TD-04 turbo turbine side is too small for my application. I'm only using the CT20 for reference here, but here are the figures for the CT20 from a thread on alltrac:

CT20:
Compressor size (Inlet diameter) 37mm
Compressor size (Outlet diameter) 62mm
Compressor blade count 10
Compressor material Aluminium
Compressor housing Inlet (ID) 49.8mm
Compressor housing Outlet (ID) 32.4mm
Compressor housing A/R .36

Turbine size (Outlet diameter) 48mm
Turbine size (Inlet diameter) 59.8mm
Turbine blade count 10
Turbine material Ceramic
Turbine housing Inlet (ID) 36mm
Turbine housing Outlet (ID) 50.1mm
Turbine shaft Diameter 10mm
Turbine housing A/R .35

TD04-12T from Kinugawa link in the post above:
Compressor inducer/ exducer: 37.8/ 49.1mm
Turbine inducer/ exducer: 47.1/ 40mm

So the CT20 has a larger compressor wheel, 37/62 mm compared to 37.8/49.1mm, and a larger turbine wheel as well, 59.8/48mm vs 47.1/40mm

Based on my experience on other diesels (and not claiming it to be apples to apples, I appreciate any expertise or correction on my thinking here) a smaller turbine overall can be a restriction in the overall exhaust system and problematic for overheating and creating excessive exhaust backpressure.

I understand that a smaller turbine creates quicker spool up, which is better for race conditions but that's not the goal here. I want to move more air, and have it be safe enough to keep things cool while creating a little more power but more efficiency overall. Seeing as how the CT20 was on the 2L, I'm somewhat skeptical that the smaller TD04 will be sufficient for my needs on the 3L (technically 2.8L displacement) engine.

Thoughts? Appreciate everyone's replies thus far

 

[KiwiDingo]

As far as I can tell the CT20 is both oil and water cooled correct? For that reason I'd prefer another turbo as space is limited and I don't want to mess with running additional water lines.

They have water cooling but you don't have to use it on diesel applications. Journal bearing turbos on diesels don't require the water cooling.

Based on my experience on other diesels (and not claiming it to be apples to apples, I appreciate any expertise or correction on my thinking here) a smaller turbine overall can be a restriction in the overall exhaust system and problematic for overheating and creating excessive exhaust backpressure.

That's also my experience and why I prefer to run larger turbines than others. Way to many people are focused on what the boost gauge is doing.

 

[DieselSobchak]

Thank you for the knowledge that water cooling isn't needed, great to know!

That's also my experience and why I prefer to run larger turbines than others. Way to many people are focused on what the boost gauge is doing.

Is there a variant of turbo with a larger turbine that you'd suggest then?

 

[bj70bc]

Just select further down the kinugawa list, they make quite a few iterations, for instance i have a td04l-13t
you can also pick blade count on the turbine, standard 12 or high flow 9 blade
and you can choose the 6+6 compressor wheel for more low end

 

[DieselSobchak]

Just select further down the kinugawa list, they make quite a few iterations, for instance i have a td04l-13t
you can also pick blade count on the turbine, standard 12 or high flow 9 blade
and you can choose the 6+6 compressor wheel for more low end

I clicked through all the turbos and the turbine size is all the same. Even the turbos for the next size engine up the 3.2L has a smaller turbine than the CT20

 

[Dougal]

As far as I can tell the CT20 is both oil and water cooled correct? For that reason I'd prefer another turbo as space is limited and I don't want to mess with running additional water lines.

I am concerned that the TD-04 turbo turbine side is too small for my application. I'm only using the CT20 for reference here, but here are the figures for the CT20 from a thread on alltrac:

CT20:
Compressor size (Inlet diameter) 37mm
Compressor size (Outlet diameter) 62mm
Compressor blade count 10
Compressor material Aluminium
Compressor housing Inlet (ID) 49.8mm
Compressor housing Outlet (ID) 32.4mm
Compressor housing A/R .36

Turbine size (Outlet diameter) 48mm
Turbine size (Inlet diameter) 59.8mm
Turbine blade count 10
Turbine material Ceramic
Turbine housing Inlet (ID) 36mm
Turbine housing Outlet (ID) 50.1mm
Turbine shaft Diameter 10mm
Turbine housing A/R .35

TD04-12T from Kinugawa link in the post above:
Compressor inducer/ exducer: 37.8/ 49.1mm
Turbine inducer/ exducer: 47.1/ 40mm

So the CT20 has a larger compressor wheel, 37/62 mm compared to 37.8/49.1mm, and a larger turbine wheel as well, 59.8/48mm vs 47.1/40mm

Based on my experience on other diesels (and not claiming it to be apples to apples, I appreciate any expertise or correction on my thinking here) a smaller turbine overall can be a restriction in the overall exhaust system and problematic for overheating and creating excessive exhaust backpressure.

I understand that a smaller turbine creates quicker spool up, which is better for race conditions but that's not the goal here. I want to move more air, and have it be safe enough to keep things cool while creating a little more power but more efficiency overall. Seeing as how the CT20 was on the 2L, I'm somewhat skeptical that the smaller TD04 will be sufficient for my needs on the 3L (technically 2.8L displacement) engine.

Thoughts? Appreciate everyone's replies thus far

A bigger turbine means less boost, hotter EGT, more smoke and worse response. That TD04 was used on 100kW diesels and you'll be nowhere near that. On a diesel boost is cooling.

The CT20 turbine is an old design that is really inefficient and would be an exhaust brake if it was smaller. The MHI is far better and the right size for your engine.

2.5 litre BMW M51 I6 making 136 hp @ 4400 RPM and 270 Nm (199 lb-ft) of torque @ 2300 RPM running a Mitsubishi TD04-13T-4 Turbocharger

 

[KiwiDingo]

Bigger turbine means less EMP, which gives cooler EGT and more power for the same amount of fuelling. Yes it looks like it gives worse response if you only stare at a silly boost gauge but that means very little.

 

[DieselSobchak]

I have a lead on a TD04 that came off a 100 hp kubota tractor, waiting to hear more details on the unit. I'm also curious about the Holset HE200 turbo, which seems to size nicely between the CT20 and TD04. Anyone have firsthand experience with the HE200?

 

[Dougal]

I have a lead on a TD04 that came off a 100 hp kubota tractor, waiting to hear more details on the unit. I'm also curious about the Holset HE200 turbo, which seems to size nicely between the CT20 and TD04. Anyone have firsthand experience with the HE200?

Look up the engine size for a 100hp tractor and the problems will be obvious. Holsets are built for higher boost. You don't need that.

 

[DieselSobchak]

I'm not sure I follow. From all I've seen the TD04 size is mostly consistent across the board, so whether it comes from a tractor or car I'm making an assumption here that it's relatively the same turbo. Given how a tractor wants to make low rpm torque and only has a peak RPM of 2600 I can see why it would be a good turbo for a 100 hp tractor even if its a 3.7 liter engine like a Kubota MX100 compared to the 2.8 liter 3L

Regardless, I've pretty much determined that the TD04 is too small for my application. If the camper was a manual transmission the slightly smaller turbo would help with spooling up on the low end. But as stated the goal here is top end airflow, which is why I'm so focused on the turbine being large enough to move air reasonably without being a restriction.

I see that there is a larger Mitsubishi TD04HL that has a 46/58mm compressor wheel and 52/44.2mm turbine wheel. 6 cm housing. I've been talking to a pump and turbo expert who has extensive experience in the diesel performance world. Can build/ modify pretty much any mechanical pump and knows a thing or two about turbos as well. He's the one who initially suggested looking into the Holset units. He recommends staying with the 5cm housing for the holset turbos. I know I don't need lots of boost, and with a mechanical wastegate I can dial things in to make sure levels stay safe. Just looking for that sweet spot of moving enough air to keep things cooler without over-stressing the engine.

 

[Dougal]

I'm not sure I follow. From all I've seen the TD04 size is mostly consistent across the board, so whether it comes from a tractor or car I'm making an assumption here that it's relatively the same turbo. Given how a tractor wants to make low rpm torque and only has a peak RPM of 2600 I can see why it would be a good turbo for a 100 hp tractor even if its a 3.7 liter engine like a Kubota MX100 compared to the 2.8 liter 3L

Regardless, I've pretty much determined that the TD04 is too small for my application. If the camper was a manual transmission the slightly smaller turbo would help with spooling up on the low end. But as stated the goal here is top end airflow, which is why I'm so focused on the turbine being large enough to move air reasonably without being a restriction.

I see that there is a larger Mitsubishi TD04HL that has a 46/58mm compressor wheel and 52/44.2mm turbine wheel. 6 cm housing. I've been talking to a pump and turbo expert who has extensive experience in the diesel performance world. Can build/ modify pretty much any mechanical pump and knows a thing or two about turbos as well. He's the one who initially suggested looking into the Holset units. He recommends staying with the 5cm housing for the holset turbos. I know I don't need lots of boost, and with a mechanical wastegate I can dial things in to make sure levels stay safe. Just looking for that sweet spot of moving enough air to keep things cooler without over-stressing the engine.

I'm trying to help here but you're making it impossible. There is a lot more to turbo sizing than you've got a grip on. I've calculated out turbo sizes for that size engine using compressor and turbine flows. It's an excellent match. The other Engineers who sized those turbos on BMW and mitsubishi engines reached the same conclusions.

There are hundreds of people worldwide running turbochargers I've calculated and selected on diesels. They all worked great.

How you've decided they're all wrong is not well explained. Putting a turbo sized for "top end airflow" turbo on a diesel makes them absolutely suck. No low end torque, hot, smokey, terrible fuel economy and short engine life.
Your 3L does not need more airflow than a 100kw BMW diesel and never will. It will die early if you try. Especially with a camper shell on top.

TD04 is a frame size with a massive range of turbines and compressors as well as turbine housings. You've been recommended the smallest one and you want the biggest one. I had a Kubota 3.8 diesel turbo, it was completely unsuitable. I have tried to tell you this already.

Your pump and turbo expert doesn't know what he's talking about here. TD04HL will be running in surge if you can get it to boost below 2500rpm. Wastegates only limit boost, they do not let you adjust when it arrives.

 

[DieselSobchak]

I appreciate the help, and I'm by no means trying to be difficult. I fully acknowledge I am no expert on these matters. I have firsthand experience with a turbo being too small on the turbine side, creating insane exhaust backpressure and ultimately killing an engine. Granted it was on a 6.5 diesel, and I know it's not apples to apples here, I'm just not trying to replicate the same scenario.

to be clear, @Dougal are you recommending the smallest TD04 for my application? Am I barking up the wrong tree here with being too worried about turbine size? Is it irrational to speculate that the same turbo on a BMW diesel sedan may perform differently than a 1.25 ton camper fighting all sorts of headwinds? I sincerely don't know and am not trying to be argumentative. I just rode in here on the short bus

Again, no trying to be obstinate, and thank you for the input. I'm learning as I go here and trying to make sense of new things.

 

[KiwiDingo]

I have firsthand experience with a turbo being too small on the turbine side, creating insane exhaust backpressure and ultimately killing an engine. Granted it was on a 6.5 diesel, and I know it's not apples to apples here, I'm just not trying to replicate the same scenario.

Am I barking up the wrong tree here with being too worried about turbine size?

Same here, seen way to many engines destroyed due to tiny turbos creating crazy EMP. You are at the right tree, turbine size is the number one priority for me in turbo selection. EMP:IMP ratio is something that very few take the time to look at and understand when selecting turbos. Most just care about the less important end, the comp wheel size and how low in the RPM they can get it to spin making the boost gauge look good.

 

[Dougal]

I appreciate the help, and I'm by no means trying to be difficult. I fully acknowledge I am no expert on these matters. I have firsthand experience with a turbo being too small on the turbine side, creating insane exhaust backpressure and ultimately killing an engine. Granted it was on a 6.5 diesel, and I know it's not apples to apples here, I'm just not trying to replicate the same scenario.

to be clear, @Dougal are you recommending the smallest TD04 for my application? Am I barking up the wrong tree here with being too worried about turbine size? Is it irrational to speculate that the same turbo on a BMW diesel sedan may perform differently than a 1.25 ton camper fighting all sorts of headwinds? I sincerely don't know and am not trying to be argumentative. I just rode in here on the short bus

Again, no trying to be obstinate, and thank you for the input. I'm learning as I go here and trying to make sense of new things.

I'm suspicous about a turbo that was too small killing your 6.5. Because those things commit suicide often regardless of the turbo. I have run many experiments myself with turbo sizing and purposefully fitted a turbo that caused drive pressure to be 4x boost. 60psi drive pressure for 15psi boost.
As you can imagine it really sucked, no power or driveability.

The biggest factor in the ratio of drive pressure to boost is the turbo efficiency. Both compressor and turbo efficiency multiply together. The more efficient and better matched your turbo the lower drive pressure for the same boost. Matching a turbo is making sure it's best efficiency points match the engine operating points. Going to a bigger turbo than ideal will mean it does less and operates at poorer efficiency. Boost arrives later, more drive pressure for the same boost. Hotter exhaust, more smoke, more engine stress.

The CT20 is an old and inefficient turbo design. The TD04 is more modern design with better efficiency so it spools faster and flows better.

The BMW engine in question was fitted to the Range Rover P38. That thing weighs 2 ton empty and was rated to tow 3.5 tons. It's a higher stressed and higher performance fitment than a Toyota 3L pushing a camper. Same turbo was fitted to mitsubishi 4D56 in Triton utes. Very average engine but good turbo.

The strength limitations of your engine mean you can't run high boost or fuel. That means you can't generate the same exhaust or intake flows of a higher performance engine of the same size.

TD04-4 is the turbine. That's 4cm turbine housing with the 12 blade turbine. Compressors 9T to 11T. 12T will work fine too. Don't go bigger.