Help identifying turbo on 1HDT

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Malahki

Malahki

10 Year 15 Year
Joined
Oct 1, 2006
Threads
81
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1,074
Location
Lethbridge AB
This turbo was on my 1990 HDJ81 when I bought it. Previous owner put this unit on after blowing stock turbo running high boost. He claimed to be running this turbo at 26psi but was set to 16psi with the use of a boost controller at the time of purchase.

Long story short: the motor was toast when I got it. Two years and only 2000kms later I have had the motor completely rebuilt. New head, new cam, .5mm over sized pistons ect.... I am now getting ready to put the motor back in and need to make decisions on what to do about the turbo?? Should I have this one inspected and possibly rebuilt or think about a replacement?

Obviously a G-turbo would be the best but the budget on this truck was blown a long time ago and I am hesitant to invest that much more money until I have it on the road and know their are no more unexpected repairs lurking. Not to mention wanting to run lower boost during break in

My goal is a to use it as a daily driver in nice weather as well as longer road trips and ocasionally pulling my 1000lb Kamparoo tent trailer. It will only see very mild offroad use. Long term reliability is number one.

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That's a factory CT26 .. the issue is the CT26 it's a very popular turbo in Toyota used with variations in many applications from MR2 to HJ61 ..
 
So I just found the number on the mounting flange: 42020. I also just noticed this other cover with the extra threaded hole that is not being used. Adds to my belief this turbo has been altered to fit

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gerg said:
Measure the compressor and turbine, large diameter and small diameter with calipers. get some seraial numbers off the turbine housing. Measuring is the for sure answer to your questions.
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Thanks, just on my way out, I will try and take some measurements later today
 
Supra spec CT26 would support higher than 14psi boost levels, but I'm sure it would not last at 26psi for any amount of time if it's a stock unit.
 
It's definately a stock 7MGTE turbo. The factory wastegate mounting lug spacing doesn't line up with the 1HDT turbo boost actuator, hence the welds.

It's got no business at 26psi. The Exhaust housing isn't suited to diesels which explains why the engine didn't do its usual long mileage.

Cheers
 
gbentink said:
It's definately a stock 7MGTE turbo. The factory wastegate mounting lug spacing doesn't line up with the 1HDT turbo boost actuator, hence the welds.

It's got no business at 26psi. The Exhaust housing isn't suited to diesels which explains why the engine didn't do its usual long mileage.

Cheers
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Are you saying using this turbo on a 1HD-T (any diesel I guess) will reduce it's lifespan due to the exhaust housing design? Can you expand on this a bit?
 
IanB said:
Are you saying using this turbo on a 1HD-T (any diesel I guess) will reduce it's lifespan due to the exhaust housing design? Can you expand on this a bit?
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The stock turbo does not handle the higher boost pressures wheel due to it's design. 15lbs is generally the safe level. With a proper rebuild and a minor upgrade you can sustain the higher boost levels without an issue.

As for the housing it's it's too big and you would only notice it at the higher rpm levels only not down low where you would want it.
 
IanB said:
Are you saying using this turbo on a 1HD-T (any diesel I guess) will reduce it's lifespan due to the exhaust housing design? Can you expand on this a bit?
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Changing to a 58020 housing (ie std 1HD-T) will make this a nice cheap turbo, what Ive suggested for years for those who can't afford more.

The larger housing means that when people tune for power in high rpms, they usually do a poor job at the fueling in sub 2500rpm range and run far too rich (often to get some kind of torque down there where you drive), high egts on light cruise without towing. Since this represents the majority of a vehicles driving, it has a substantial affect on engine life.
 
Ok So what is your definition of sustainable "egts on light cruise without towing" pre turbo for reasonable engine life in degrees?
 
gbentink said:
The larger housing means that when people tune for power in high rpms, they usually do a poor job at the fueling in sub 2500rpm range and run far too rich (often to get some kind of torque down there where you drive), high egts on light cruise without towing. Since this represents the majority of a vehicles driving, it has a substantial affect on engine life.
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I dont recall where the EGT's were running but you called it exactly right on the over fuelling at low RPM's. This motor was pouring clouds of black off the line and any time I put my foot into it until the boost and RPM came up. I thought it was just a case of pour tuning or lack of tuning all together when the boost was dropped down to 16psi
 
sailor said:
Ok So what is your definition of sustainable "egts on light cruise without towing" pre turbo for reasonable engine life in degrees?
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Sub 750. Short term 800.

Your limited to a temp safe 300nm or thereabouts with that turbo around 2000rpm, so the drivers wish frequently exceeds this limit on normal driving.
 
gbentink said:
Sub 750. Short term 800.

Your limited to a temp safe 300nm or thereabouts with that turbo around 2000rpm, so the drivers wish frequently exceeds this limit on normal driving.
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Worth qualifying that those temps are true measurements. Many have probes too short or in a cold spot and read a lot colder than what is actually happening.
 
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