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

[absalom]

Same turbo, different ad to market to different vehicle owners.
12HT and 1hd-t share the same exhaust/turbo manifold bolt pattern.

Does it matter if the 1-HDFT turbo is marketed as having a diameter of 2.5", while the 12HT is being sold with 3" diameter?

Sent from my SM-G920V

 

[ForealBoreal]

What do you mean? In terms of compressor inlet?

 

[serenity]

Hi guys, is this the kind of thing I need to do the supra hybrid turbo? Doesn't have any info in the description unfortunately. Am I right in thinking this will help boost earlier? I have a 1hz with a 1hd-t setup, keeping it stockish; currently running 10psi, no inter cooler, 3" exhaust.
Toyota gt26 Turbo Compressor Cover w/compressor wheel

 

[Rob1983]

Does it matter if the 1-HDFT turbo is marketed as having a diameter of 2.5", while the 12HT is being sold with 3" diameter?

Sent from my SM-G920V

If you have a 1HDT, you want a 3" inlet minimum. That Gturbo has the 3" front housing, machined to suit the FTE core. Garret was running a 4" inlet

 

[Dougal]

Well considering driving on a flat highway at 100km/h going with a Gx (td05h16g 7cm) I am looking at 12-14lbs boost. My waste gate is set to 20.

Little high for my likings.

The 18g with the bigger ex housing would be better suited in my opinion for highway trips.
I don't think I will have a problem getting it to boost with a good AFR meter tune and with the hilly environment I live in.

I'm just stuck at this point because it's either get something small for low end or upper end. There is just too much back pressure for my likings with the smaller exhaust housing setup.

What's your rpm and egt at 100km/h? Any idea of a/f ratio?

 

[ForealBoreal]

Don't don't have an afr as of yet.
When I fit a future turbo I'll have one.
2300rpm 650-700f at that speed flat highway

 

[Dougal]

Don't don't have an afr as of yet.
When I fit a future turbo I'll have one.
2300rpm 650-700f at that speed flat highway

So those boost numbers came from other people with similar setup but the GX turbo?

 

[mudgudgeon]

Hi guys, is this the kind of thing I need to do the supra hybrid turbo? Doesn't have any info in the description unfortunately. Am I right in thinking this will help boost earlier? I have a 1hz with a 1hd-t setup, keeping it stockish; currently running 10psi, no inter cooler, 3" exhaust.
Toyota gt26 Turbo Compressor Cover w/compressor wheel

I'd steer well clear of that one. For one, what's a "gt26", and 2, they give no info in the description, and C, the seller has a history of 18 transactions and 90% positive ( or 10%fail) rating.

 

[Dougal]

Here's the deal with the hybrids.

There are two turbos here. The CT26 and the CT20B which is also called the small CT26.
The CT26 has a large turbine and even with the smallest turbine housing it's not going to be that active.
The CT20B has a much smaller turbine and this makes it a lot more active. It spins the compressor harder to produce more boost sooner.
The TD05H-CT20B is slightly smaller than the CT20B but has a turbine design suited to higher flow.

If you simply put a Supra compressor on a CT26 then you're going to get improved top-end, but the low end isn't going to improve in a noticable way. It's the turbine side holding these up.

 

[serenity]

Ok I must have had it all backwards, so which would be the best option to build an early spooling turbo that won't choke out up to 120kph max speeds? A ct20b turbine with 1hdt ct26 compressor side? Or the tdo5h-ct20b? Will they bolt up the factory exhaust manifold?

 

[Ky1e]

Thanks for that dougal. I'm ok with the supra ct26 hybrid I think. See how it goes anyway!

 

[Dougal]

Ok I must have had it all backwards, so which would be the best option to build an early spooling turbo that won't choke out up to 120kph max speeds? A ct20b turbine with 1hdt ct26 compressor side? Or the tdo5h-ct20b? Will they bolt up the factory exhaust manifold?

A CT20B with 1HD-FTE compressor side is an off the shelf 1HD-FTE turbo.

I don't expect any of these turbos to choke out at 120km/h. Compressors choke based on airflow which is boost and rpm. Turbines don't choke, they just require more and more drive pressure as more power is demanded from them. Bigger turbines produce more power with less drive pressure but take more flow to start working.

 

[absalom]

Hypothetical question to all those listening:

Let's say I have $1,000 USD to spend on a turbo for my 1-HDT. How would I best spend my money to make the largest increase in performance and driveability?

 

[ForealBoreal]

So those boost numbers came from other people with similar setup but the GX turbo?

Yeah talking to others running 1hz/hdts the GX turbos all preform very very similar.
All boosting 12-15lbs @ 100km/h and ~350c (650-700f) the 80 series with the h150 seem to cruise at slightly higher Rpms with the lower 5th gear and the last person I talked to was 15lbs at cruise.

There is just too much back pressure for my likings considering I am at 20lbs max currently with this turbo I am running. Even then if I had a GX It would be running ~25lbs.

Any sort of load at this speed and current load the needle snaps to max boost.

The BB would be doing 8lbs on a 1hz or hdt and boost is instant at the highway speeds. Some people say they wouldn't change it for a thing while others wish they did the GX. I don't do a ton of low range stuff to need all that power down low, I'd prefer it to come on a little harder up top.

 

[serenity]

A CT20B with 1HD-FTE compressor side is an off the shelf 1HD-FTE turbo.

I don't expect any of these turbos to choke out at 120km/h. Compressors choke based on airflow which is boost and rpm. Turbines don't choke, they just require more and more drive pressure as more power is demanded from them. Bigger turbines produce more power with less drive pressure but take more flow to start working.

Gotcha, I thought all the 1hd series ran the ct26 variations.
My ct26 has the 58020 housing on it which should give quicker spool than the 17020 variant if I read correctly. From what I can gather, a ct20b or gturbo is going to give me the results I want along with port & polish and a 3" exhaust for that tiny bit extra.

Sorry for the interruption to good tech talk, still trying to learn what I can about turbos!

 

[Dougal]

Gotcha, I thought all the 1hd series ran the ct26 variations.
My ct26 has the 58020 housing on it which should give quicker spool than the 17020 variant if I read correctly. From what I can gather, a ct20b or gturbo is going to give me the results I want along with port & polish and a 3" exhaust for that tiny bit extra.

Sorry for the interruption to good tech talk, still trying to learn what I can about turbos!

The 58020 housing means you've got the bigger and more sluggish CT26. The 17020 is the more active CT20B.

 

[Dougal]

Yeah talking to others running 1hz/hdts the GX turbos all preform very very similar.
All boosting 12-15lbs @ 100km/h and ~350c (650-700f) the 80 series with the h150 seem to cruise at slightly higher Rpms with the lower 5th gear and the last person I talked to was 15lbs at cruise.

There is just too much back pressure for my likings considering I am at 20lbs max currently with this turbo I am running. Even then if I had a GX It would be running ~25lbs.

Any sort of load at this speed and current load the needle snaps to max boost.

The BB would be doing 8lbs on a 1hz or hdt and boost is instant at the highway speeds. Some people say they wouldn't change it for a thing while others wish they did the GX. I don't do a ton of low range stuff to need all that power down low, I'd prefer it to come on a little harder up top.

Back when my 4BD1T was geared at ~2500rpm at 100km/h I would hit 12psi at that speed. I regeared to ~2000rpm at the same speed which dropped boost to 8-9psi and picked up maybe 10% fuel economy. That fuel economy IMO is due all to the engine rpm and not the boost.

A few years back I swapped a t25 (0.49 A/R turbine) for a T28 with 0.64 A/R turbine. My boost at cruise dropped to 4-5psi and my fuel economy tanked. I couldn't get a single fillup at 10km/l in the time I ran that turbo. It was almost 15% worse than usual. I fitted the 0.49 A/R T25 and fuel economy returned to normal.

My takeaway from that was that boost numbers at cruise don't matter much. What does matter is how efficient the turbo is.
I also find it's not low range offroad that I want the torque. It's high range offroad and climbing hills onroad. I've tried a lot of different setups and I always come back to the ones that pull hard between 1500-2500rpm.

 

[mudgudgeon]

Here's the deal with the hybrids.

There are two turbos here. The CT26 and the CT20B which is also called the small CT26.
The CT26 has a large turbine and even with the smallest turbine housing it's not going to be that active.
The CT20B has a much smaller turbine and this makes it a lot more active. It spins the compressor harder to produce more boost sooner.
The TD05H-CT20B is slightly smaller than the CT20B but has a turbine design suited to higher flow.

If you simply put a Supra compressor on a CT26 then you're going to get improved top-end, but the low end isn't going to improve in a noticable way. It's the turbine side holding these up.

View attachment 1195132

So Dougal, based on your comments above, the Sumalaya turbo (as per FBs post) would spool up faster than the 1hd-t turbine, but be capable of greater flow, therefore working over a greater rev range?

My experience with my stock ct26 was that with lots of fuel if would spool up at around 1800 rpm, and boost strongly to around 33-3500 rpm before dropping off. I had it boosting un-wastegated which saw it boost to 22psi. But I know the end result was the compressor was choking.

So you are suggesting the Td05H turbine in 7cm housing will get a large compressor to spool up quick and still flow enough to drive a large compressor at 3500rpm without stupidly high drive pressure?

The sumalaya looks like a good option, but the smaller than 1hd-t turbine housing has me foxed.
Maybe it's not a problem?

 

[mudgudgeon]

Is there data available on comparable components to model performance of the sumalaya turbo on a 4.2 you a diesel?

 

[serenity]

@Dougal the housing on the right is a 17020. It actually is from a JDM 1HD-FT.
Even then the 1hd-fte turbos run a supra compressor wheels and a smaller sized turbine in that same 58020.
The 58020 is actually physically smaller than the 17020 its noticeable when you compare the two. Maybe hard to tell in the photo. They have different casting shapes also. I am unsure how I can accurately get a clean solid measurements on the things. I'll see what I can do.

Either way, I have a setup going on a manual 1hd-ft hopefully in a few weeks time and after May one going on a 1hd-t auto.
Should be a cool comparison and I am excited to play with some of this. Anyone else who's interested pm me.

Thanks, but the bit above you mean the 58020 is smaller than the 17020?

Are they both round port?

To measure them, force some modelling clay or plasticine into the inlet, then cut it off square about the point it is square to the centre-line. Then dividing up that area into cm squares would do.
The radius is from the shaft centre to the centre point of that area you've measured above.

Assuming I am off tomorrow I will see if I can find some plasticine. Might be able to find some playdoh but that may pose a challenge in town.

And yes I mean 58020 is smaller than the 17020 woops.

The 58020 housing means you've got the bigger and more sluggish CT26. The 17020 is the more active CT20B.

Ok this is where I'm getting confused, here you guys are saying that the 58020 is smaller. And foreal sells the 58020 here as a quick spool option. For Sale: - CT26 Compressor Housing/Wheel Hybrid Upgrade Parts

I've also found mention of a 58010 housing, which is bigger than the 17020 according to this.
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