The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread (15 Viewers)

[Dougal]

Well the casting number does match 1HD-FTE, and the size of the CHRA looks like it would be the CT20B too, but it's hard to tell from the pics alone.
You could measure and compare the diameter of the CHRA where the turbine housing clamps on. There's 10 or 15mm difference in diameter (can't remember the diameters) CT26 is larger

My info says CT26 housing of the same casting size would be 17040. If it's the same scroll but with the CT26 wheel machining it would be a corrected flow of ~15 lb/min. Vs ~13.5 for the CT20B (12 earlier was a mistake, skipped a line on the spreadsheet).

 

[Nz Nath]

I thought the 1hdfte housing was 6cm and the ct26 8cm? Either way, this is way smaller than stock, so it would be a fair assumption the hot side isn't the reason why it doesn't want to produce significant boost till high rpm?

The fueling was unchanged. I upped the fuel on the boost compensater a bit (both preload and the off-boost screw). It smokes a bit more and accelerates a bit harder, but it didn't seem to make any difference to the boost levels. I don't want to go overboard with the fuel yet if this isn't the problem. Just based on the hot side, this should spool way better than the ct26 for the same fuel. It doesn't. Egt gets up to about 700 accelerating hard past 100km on the flat. Easily get past 400 accelerating in town without flogging it.

The k and n is because the airbox and snorkel on the truck were horrific (Leakey and restrictive). This is a temporary stopgap, however it doesn't seem to cause any restriction (running up the road with it off performs about the same), and I don't think it's sucking hot air (there is a section of grill either side of the radiator, and this is getting airflow straight from one side). Edit: no it's not new, this is what I ran with the ct26 for a couple of months. The only change in setup is the turbo and bigger fuel lines(8mm), and now running stock crossover pipe rather than fmic to eliminate boost leaks as a possibility

 

[mudgudgeon]

I thought the 1hdfte housing was 6cm and the ct26 8cm? Either way, this is way smaller than stock, so it would be a fair assumption the hot side isn't the reason why it doesn't want to produce significant boost till high rpm?

Yep, correct.

I think @Dougal is saying somewhat cryptically, that if the 17020 housing was machined out to work with CT26 turbine, you'd loose a lot of the benefits of the 6cm housing?

 

[Nz Nath]

It's meant to have the ct20b turbine wheel in it. If it's not raining tomorrow I'll compare the old chra if I still have it.

I'm only seeing two theoretical explanations why this is spooling worse than the ct26. And by worse I mean boost rises at a much slower rate, so even though it starts at slightly lower rpms, it's still at lower figures till 2k+.

1) the comp wheel is mis sized.
2) something has gone wrong or changed on the fuel pump by itself, even though performance up to about 1700rpm is the same.

 

[bjowett]

Delete.

 

[Dougal]

My head is dizzy from reading all the turbocharger sizing and options information... I can read all day long, but always believe there is no replacement for experience... of which I have very little in turbocharger selection. So would anyone care to help size a turbo for my 4.2L 15BFT? Good all arounder with some room to grow? Goal 200hp/400tq.

Holset HE221 with intercooler.

 

[Dougal]

I thought the 1hdfte housing was 6cm and the ct26 8cm? Either way, this is way smaller than stock, so it would be a fair assumption the hot side isn't the reason why it doesn't want to produce significant boost till high rpm?

The fueling was unchanged. I upped the fuel on the boost compensater a bit (both preload and the off-boost screw). It smokes a bit more and accelerates a bit harder, but it didn't seem to make any difference to the boost levels. I don't want to go overboard with the fuel yet if this isn't the problem. Just based on the hot side, this should spool way better than the ct26 for the same fuel. It doesn't. Egt gets up to about 700 accelerating hard past 100km on the flat. Easily get past 400 accelerating in town without flogging it.

The k and n is because the airbox and snorkel on the truck were horrific (Leakey and restrictive). This is a temporary stopgap, however it doesn't seem to cause any restriction (running up the road with it off performs about the same), and I don't think it's sucking hot air (there is a section of grill either side of the radiator, and this is getting airflow straight from one side). Edit: no it's not new, this is what I ran with the ct26 for a couple of months. The only change in setup is the turbo and bigger fuel lines(8mm), and now running stock crossover pipe rather than fmic to eliminate boost leaks as a possibility

I have 6 and 8cm housings in my list for CT26 and the scroll sizes match. But the info I have has come from others so it's not verified personally.

Over summer I changed to a new air-box and didn't have time to do the cold air feed to the front corner of the engine-bay. The result was slow spool, smoke on spoolup, smoke at full load and 3psi down on boost. Drivability sucked.
Put in the cold air feed and instantly sorted.

 

[Dougal]

Yep, correct.

I think @Dougal is saying somewhat cryptically, that if the 17020 housing was machined out to work with CT26 turbine, you'd loose a lot of the benefits of the 6cm housing?

17020 is the 6cm housing for 48mm CT20B (1HD-FTE etc).
58020 should be 6cm CT26 round port.

If anyone can confirm or deny that'd be great as I've never had these in hand.

 

[Mcreight911]

That air box wil make it feel like its lost torque down low even though it feels like it revs better in the upper revs .

Did u change that at the same time as the turbo?

 

[boosted105]

Hey guys, decided I am keeping my td06-20g, I am going to use it as the big turbo in a compound setup but change it from and 8 to 10cm rear. I have lined up a td05-18g 6cm rear to use as my smaller turbo. looking to run around 35psi, do you guys think this will work?

1hz, ceramics, 12mm pump

 

[Dougal]

Hey guys, decided I am keeping my td06-20g, I am going to use it as the big turbo in a compound setup but change it from and 8 to 10cm rear. I have lined up a td05-18g 6cm rear to use as my smaller turbo. looking to run around 35psi, do you guys think this will work?

1hz, ceramics, 12mm pump

You're going to compound charge a high compression 1HZ?

 

[boosted105]

You're going to compound charge a high compression 1HZ?

Yes, it has cermics and 1hdt internals

 

[Dougal]

Yes, it has cermics and 1hdt internals

Does it have 1HD-T pistons, injectors and head?

 

[boosted105]

Does it have 1HD-T pistons, injectors and head?

Negative, whats your point?

 

[Dougal]

Negative, whats your point?

High compression engine with high boost will generate massive mechanical stress on the head, pistons, con-rods, crank, block etc.

There are very good reasons no-one makes them that way.

 

[boosted105]

well the block is the exact same between a 1hz-1hd-fte, my rods are now 1hdt rods and it has ceramic pistons. I understand what you are saying about the stress on parts but everything other than the head is designed for a turbo. Yes the 1hz heads don't flow as much and are prone to cracking but that is from heat and poor tune more than boost. There is a bloke in the 1hz//1hd page running 44 psi through a stock 1hz and been doing so for like 2 years now.

I understand you are trying to warn me and thank you but I wasn't asking if my motor will handle it, I am running 32 psi as it is. I just want to add a little more and have it more responsive. Do you have nay feedback on my turbo choice?

 

[IanB]

Do you have nay feedback on my turbo choice?

Don't compound turbo it, just get one properly sized turbo and accept that a 1HZ is a high compression, indirect injection engine that was never meant to be boosted to the moon. You're heading down an expensive road to heartbreak IMO.

 

[Dougal]

well the block is the exact same between a 1hz-1hd-fte, my rods are now 1hdt rods and it has ceramic pistons. I understand what you are saying about the stress on parts but everything other than the head is designed for a turbo. Yes the 1hz heads don't flow as much and are prone to cracking but that is from heat and poor tune more than boost. There is a bloke in the 1hz//1hd page running 44 psi through a stock 1hz and been doing so for like 2 years now.

I understand you are trying to warn me and thank you but I wasn't asking if my motor will handle it, I am running 32 psi as it is. I just want to add a little more and have it more responsive. Do you have nay feedback on my turbo choice?

It's not the parts that is the problem. It's the mechanical stress of very high compression with high boost.

1HD-T-FT parts are designed to work with ~18:1. Not 22:1

 

[boosted105]

Once again, as I previously stated I didn't ask if you think the motor will handle it. Just because it's not your cup of tea and you are happy running low boost thats fine. I am already running 32 psi, motor is fine I just want to make it more responsive and I can get a tdo5-18g very cheap off a mate.

What I want to know is if you think the TD05-18g Kinugawa will work well With my TD06-20g MMP turbo in a compound set with regards to response and flow.

 

[Dougal]

Once again, as I previously stated I didn't ask if you think the motor will handle it. Just because it's not your cup of tea and you are happy running low boost thats fine. I am already running 32 psi, motor is fine I just want to make it more responsive and I can get a tdo5-18g very cheap off a mate.

What I want to know is if you think the TD05-18g Kinugawa will work well With my TD06-20g MMP turbo in a compound set with regards to response and flow.

You are running 32psi peak. A compound set will run more boost more often and place higher stress on everything. I'm not going to offer any turbo sizing advice on this one. I don't like being part of doomed projects.