CT12B vs CT26 vs CT15B on 2h (1 Viewer)

[Swifty Devil]

Sorry if its been done to death but its happening.

Im Turbo'ing a 2h

Bought a dump pipe for a CT26/CT12b

As well as a CT12B

My goal is not above 3000rpm. quickest possible spool for more power down low.

Also if im running under 10psi, how do you guys feel about no intercooler as it would make my piping quite short and very easy to do.

I know the CT12B has a really good rear exhaust housing size wise but i know the compressors abit small.

would i be fine for under 3000rpm?

if not just wondering if the CT15B is slightly too big.

please not comments like buy a 12ht thats not going to happen.

 

[GTSSportCoupe]

Is the CT15B off of a 1JZGTE? If so, I think it is too big for the 2H. A CT20B from the 1HDFTE might be more what you want. The CT26 would probably be ok, just slow to spool like all the older turbos. The CT26 is used on the 3.4l 13BT, so you'd think would be usable for a 4.0l 2H. The CT12B is probably on the small side....would spool super fast though.

Have you considered non-Toyota turbos? Maybe the Mitsubishi TD04 series? Garret GT25?

I'm sure @Dougal will chime in with some ideas.

 

[gerg]

Given how the 2H suffers ring land issues if you use the stock CT36 from a 1hdt to keep response sluggish it might akso help avoid the temptation to Jack the boost up. I'd tune it for very conservative egts, like 1000 or less. An intercooler would be a great addition in the future, but only to lower egts even further .

 

[GTSSportCoupe]

For reference, here are some compressor/turbine specs on OEM Toyota Turbochargers (various sources):

Turbo - Compressor(ind/exd) - Turbine(ind/exd)
(engine)

CT26 - 40/65, 65/52
(3SGTE ST165 Celica, single entry)

CT26 - 41/65, 65/52
(3SGTE SW21 MR2, ST185 Celica, twin entry)

CT26 - 42/65, 65/52
(12HT Landcruiser)

CT26 - 43/65, 65/52
(1HDT Landcruiser, single entry)

CT26 - 47/65, 65/52
(7MGTE Supra, single entry, large A/R turbine housing)

CT20 - 36.1/57, 60/48
(2LT, 22RTE Hilux)

CT20A - 39.6/57, 60/44
(2LT-II, 2LTE Hilux, Prado)

CT20A ceramic - 37/62, 60/48
(2JZGTE JDM Supra, Aristo)

CT20B ceramic - 46/65, 60/50
(3SGTE late SW21 MR2, ST205 Celica, twin entry)

CT26 small - 46/65, 60/48
(1HDFTE Landcruiser)

CT15B - 46/65, 60/48
(1JZGTE VVTI Soarer)

CT12A ceramic - 35/54, 51.6/42
(1JZGTE Soarer)

CT12B - 39/58, 52/44
(2JZGTE USDM Supra)

CT12B - 43.1/58, 52/44
(1KZTE Hilux, Prado)

CT9 - 34/48.1, 46/36
(4EFTE Starlet)

 

[FJ601986]

For reference, here are some specs on OEM Toyota Turbochargers:

Turbo - Compressor(ind/exd) - Turbine(ind/exd)
(engine)

CT26 - 40/65, 65/52
(3SGTE ST165 Celica, single entry)

CT26 - 41/65, 65/52
(3SGTE SW21 MR2, ST185 Celica, twin entry)

CT26 - 43/65, 65/52
(1HDT Landcruiser, single entry)

CT26 - 47/65, 65/52
(7MGTE Supra, single entry, large A/R turbine housing)

CT20 - 36.1/57, 60/48
(2LT, 22RTE Hilux)

CT20A - 39.6/57, 60/44
(2LT-II, 2LTE Hilux, Prado)

CT20A ceramic - 37/62, 60/48
(2JZGTE JDM Supra, Aristo)

CT20B ceramic - 46/65, 60/50
(3SGTE late SW21 MR2, ST205 Celica, twin entry)

CT26 small - 46/65, 60/48
(1HDFTE Landcruiser)

CT15B - 46/65, 60/48
(1JZGTE VVTI Soarer)

CT12A ceramic - 35/54, 51.6/42
(1JZGTE Soarer)

CT12B - 39/58, 52/44
(2JZGTE USDM Supra)

CT12B - 43.1/58, 52/44
(1KZTE Hilux, Prado)

CT9 - 34/48.1, 46/36
(4EFTE Starlet)

Do you have the numbers for the CT26 for the 12 HT?

 

[GTSSportCoupe]

Do you have the numbers for the CT26 for the 12 HT?

I've read the 12HT CT26 has a 42mm compressor inducer. So it would be something like:

CT26 - 42/65, 65/52
(12HT Landcruiser)

I'll add it to the list.

I believe the 13BT uses the same turbo....but not sure.

 

[mudgudgeon]

For reference, here are some compressor/turbine specs on OEM Toyota Turbochargers (various sources):

Turbo - Compressor(ind/exd) - Turbine(ind/exd)
(engine)

CT26 - 40/65, 65/52
(3SGTE ST165 Celica, single entry)

CT26 - 41/65, 65/52
(3SGTE SW21 MR2, ST185 Celica, twin entry)

CT26 - 42/65, 65/52
(12HT Landcruiser)

CT26 - 43/65, 65/52
(1HDT Landcruiser, single entry)

CT26 - 47/65, 65/52
(7MGTE Supra, single entry, large A/R turbine housing)

CT20 - 36.1/57, 60/48
(2LT, 22RTE Hilux)

CT20A - 39.6/57, 60/44
(2LT-II, 2LTE Hilux, Prado)

CT20A ceramic - 37/62, 60/48
(2JZGTE JDM Supra, Aristo)

CT20B ceramic - 46/65, 60/50
(3SGTE late SW21 MR2, ST205 Celica, twin entry)

CT26 small - 46/65, 60/48
(1HDFTE Landcruiser)

CT15B - 46/65, 60/48
(1JZGTE VVTI Soarer)

CT12A ceramic - 35/54, 51.6/42
(1JZGTE Soarer)

CT12B - 39/58, 52/44
(2JZGTE USDM Supra)

CT12B - 43.1/58, 52/44
(1KZTE Hilux, Prado)

CT9 - 34/48.1, 46/36
(4EFTE Starlet)

What's your source? Some of those figures are definitely incorrect

 

[GTSSportCoupe]

What's your source? Some of those figures are definitely incorrect

It's a collection I put together a few years ago. Some numbers are from Melett. Other numbers were measured by people who own the turbos. As you know there is no Toyota document with all these numbers. I was doing my best to get the most accurate numbers I could find down in one spot.

So all that said, let me know which numbers you think are out, and I'll research why there is a discrepancy, and fix if necessary.

Edit: Some of the number have been rounded to the nearest mm.... It's meant to be a rough guide.

 

[GooSe77]

The supra should have a bigger comp wheel ... , same with the 1HDTFE I think .....

 

[GTSSportCoupe]

The supra should have a bigger comp wheel ... , same with the 1HDTFE I think .....

I helped my friend upgrade his 1HDT ct26 with a 7MGTE Supra compressor. Having had it in my own hands, I know that number is right.

 

[gerg]

Might be worth it to confirm some of those numbers nick. I dont think I've ever seen a list of Toyota turbos with specs and vehicles they came off of all in one spot. Well done!
g

 

[GooSe77]

I helped my friend upgrade his 1HDT ct26 with a 7MGTE Supra compressor. Having had it in my own hands, I know that number is right.

But isn't putting on the compressor wheel/housing from the Supra 7mgte the budget High Flow conversion for the 12ht/1hdt ?

 

[mudgudgeon]

The supra should have a bigger comp wheel ... , same with the 1HDTFE I think .....

correct. Supra 7MGTE and HD-FTE shared the same compressor, and it is larger than the HD-T CT-26 copressor.
HD-FTE CT20B (or CT26 small??) have a different size turbine too.

I measured the turbines of HD-FTE and HD-T CT26 and recorded it in the gturbo alternative tech thread if someone wants to go digging.

@gerg Mellett turbo had a fairly comprehensive list of Toyota turbo specs and applications. It had some discrepancies, but has a lot of solid info too

 

[gerg]

I too have come accross discrepencies with mellett on occasion. Finding accurate data on the web is so difficult! Who would have ever thought. Very frustrating. Lack of data and aftermarket support for Toyota turbos is why I lean towards MHI.

 

[GTSSportCoupe]

correct. Supra 7MGTE and HD-FTE shared the same compressor, and it is larger than the HD-T CT-26 copressor.
HD-FTE CT20B (or CT26 small??) have a different size turbine too.

I measured the turbines of HD-FTE and HD-T CT26 and recorded it in the gturbo alternative tech thread if someone wants to go digging.

@gerg Mellett turbo had a fairly comprehensive list of Toyota turbo specs and applications. It had some discrepancies, but has a lot of solid info too

I think I know where the Supra compressor confusion is coming from. I'm going to look into it, but I'm certain there are two different compressor sizes used on the 7MGTE. I think North America got a larger one, and that is the spec I put up. The 45.5mm is the smaller one. Suppose I could put both up.

Not sure where I got the 1HDFTE compressor size from. I have the same two Melett documents you have, but for some reason I didn't use their listed compressor size. Will look into it, and correct if necessary.

 

[GTSSportCoupe]

Here is what gbentink (Gturbo) had to say (my specs above match his measurements). These quotes are from this thread: CT26 turbo specs

Melett is "more" correct. I can only suggest that different countries received different specs. I know that in the 1JZGTE the turbo specs were diferent from JDM to USA. The second website is just plan wrong.

In any case, I have measured them with a vernier, thats how I know. Not so easy to measure either, since there is an uneven number of blades.....

I have both types rebuilt in my shed ready for sale and another high flow version. I have had 3 Supra comp wheels and all have been 47mm. I have measure 3 sizes. 43/46/47. The 46mm is from the 1HDFTE.

Melett lists specs which are not found in Australian vehicles as far as I have measured - and I have measured a few. So, for Australia in my experience it is incorrect. As for other countries like UK, it may be correct. Toyota fit different specs for different smog laws in some cases.

45.5mm is not 46mm and will not operate correctly (ie: as efficiently as designed) in a housing machined for 46mm.

The exhaust turbine and CHRA (excl comp wheel) is the same in all cases except for the 1HDFTE and 3rd gen 3SGTE which uses a smaller turbine shaft (48mm exducer vs 52mm exducer for CT26). CT26 is not stamped on the compressor cover of the 3rd gen 3SGTE or the 1HDFTE. These are what many people call "CT20B" however this is not an official name. The 7MGTE went out of production before either the 3rd Gen 3SGTE or the 1HDFTE hence it remains the largest factory configuration of CT26.

It has been said by some that the 7MGTE CT26 47mm inducer is a GT spec. All I can say is that all 3 I have measured have been 47mm, so maybe I am just lucky.

So basically GTurbo's measurements don't match the Melett specs. He thinks it might be because different components were offered to different markets. So both his measurements (my spec list) and the Melett list could be right.

 

[Dougal]

For low end use the CT12B. For high end the CT20B from 1HD-FTE.

That's about it for Toyota turbos.