RC/CS CT26 vs normal st185 CT26

belanger33

New member
Hi,

I heard a lot of rumours that the RC CT26 turbo has some differences with the normal GT-four CT26 for the ST185 version.....Can anybody confirm what differences it may have?

Thanks!
 

l0ch0w

New member
The inducer on the compressor wheel is a few millimeters larger, IIRC its 42mm or something like that instead of 38.

Its in-between the CT20b and the standard USDM CT26.

I used to have one, and I measured it next to a regular one.
 

underscore

Well-known member
"The gen 2 CT26 RC/CS turbo came from the factory with an uprated compressor wheel (which is larger) and it has an inconel wheel instead of the frag happy ceramic JDM standard wheels. I measured the compressor wheel as best I could, and its 46mm which is substantially larger than the stock 38mm. So max power output should be somewhere around 300hp to the wheels. We figured it would be smack between the CT20b and the JDM ct26.

Think of it like a supra ct26 but with a twin entry exhaust housing. Its got the same specifications"
 
I dont know what you guys are talking about, the CT26 on the ST185 only came in one size from factory. The RC/CS GT-Four came with a slightly better turbo known as the CT20b. It has a slightly bigger compressor wheel. The way to tell the difference between the two is that the CT26 has "TOYOTA CT26" on the compressor housing. And the CT20b only has "TOYOTA" on it, also the CT20b has 7 exhaust studs for the downpipe, where as the CT26 only has 6.

If you have a CT26 with a compressor wheel larger than usual then it has been modified by a Turbo shop sometime
 

temperacerguy

New member
loudstealthGT-Four":15ie0n59 said:
I dont know what you guys are talking about, the CT26 on the ST185 only came in one size from factory. The RC/CS GT-Four came with a slightly better turbo known as the CT20b. It has a slightly bigger compressor wheel. The way to tell the difference between the two is that the CT26 has "TOYOTA CT26" on the compressor housing. And the CT20b only has "TOYOTA" on it, also the CT20b has 7 exhaust studs for the downpipe, where as the CT26 only has 6.

If you have a CT26 with a compressor wheel larger than usual then it has been modified by a Turbo shop sometime

Incorrect. the one above is correct.
 

l0ch0w

New member
loudstealthGT-Four":2n8mp0q2 said:
I dont know what you guys are talking about, the CT26 on the ST185 only came in one size from factory. The RC/CS GT-Four came with a slightly better turbo known as the CT20b. It has a slightly bigger compressor wheel. The way to tell the difference between the two is that the CT26 has "TOYOTA CT26" on the compressor housing. And the CT20b only has "TOYOTA" on it, also the CT20b has 7 exhaust studs for the downpipe, where as the CT26 only has 6.

If you have a CT26 with a compressor wheel larger than usual then it has been modified by a Turbo shop sometime

You clearly havent been around long enough to know that the ct20b is only a name that us trolls on the interwebs have invented...

They are ALL ct26 turbos... What we call the ct20b came off the gen 3 motor, and we just call it that to help differentiate it. CT26 is the designator toyota gave to the CHRA... and if you were to compare them, they are all the same... The different parts are the comp/turb housings, and the physical wheels...

From my knowledge, there are at least 7 different variations of the ct26 turbo... There may be more, but these are the ones I know:

-Gen 1 single Entry ct26
-Supra single entry ct26 (i think there may be multiple versions of this, but I dont know)
-gen 2 twin entry USDM inconel ct26
-gen 2 twin entry JDM/FDM ceramic turbine ct26
-gen 2 twin entry JDM RC/CS inconel turbine 46mm compressor ct26
-gen 3 twin entry ceramic turbine ct26 (ct20b)
-gen 3 twin entry inconel turbine ct26 (ct20b from the WRC ST205)
 
Ignore my rant then :lol:. I was aware that a CT20b wasn't actually called a CT20b and is just a nickname. But wasn't aware that this only refers to the turbo on the ST205. Don't hate me im still learning :D
 

l0ch0w

New member
IMHO, the most badass one is the WRC ST205 inconel wheel'd turbo. These are crazy rare though and typically fetch alot of money stateside. The reason people like em is that they are rebuildable, and are freaking sweet... The RC/CS has the same features almost, but is a little smaller and wont flow quite as much, Its sort of in between the "ct20b" and the gen 2 ct26...
 

belanger33

New member
Thanks for the specific info guys i now feel more comfortable rising the boost from stock having a RC CT26 since it doesnt have the ceramic wheel :p!!!
 

Broz

New member
Also - apart from the steel wheel the RC/CS/GroupeA's ECU have higher boost maps with cut off at 17psi as opposed to 12/13? on the std ST185's
Cheers, Mark
 

alltracman78

Active member
No, "stock" boost is normally 8 PSI.
8 - 12 PSI is acceptable in the service manual but 8 is what it normally is.

And I don't think the 185 MAP sensors can read up to 17 PSI. I'm not positive on that, but I'm pretty sure.
I do know the RC has the same MAP sensor as the regular ST185s.
 

Broz

New member
WRC versions have a number of subtle differences to All-tracs & std GT4's the ECU & map sensors is just one of many.

One of the guys here in NZ fully restored his RC & in the process found a large number of parts different to std GT4's so he couldn't just use GT4 parts.

Cheers
 
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