Spot the Differences - 2 "Stock" CT-26's

ImUrOBGYN

NoNameNomad
Mar 30, 2005
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Sorry if this was posted in the wrong place. Wasn't sure whether I should post it here or in the General MKIII section.:1zhelp:
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I made a strange discovery yesterday while pulling two spare ct-26 turbos out to look at them...

1st difference:
The stamping inside the housing. 1st turbo has the number "2" stamped in it, the second turbo has the number "4". (From here on out, the number 2 turbo is always on the left.)
"What are the difference in housing other than the housing to w/g nipple?"[/I
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2nd difference:
The nipple that leaves the housing and goes to the wg is in two different places, albeit, very close to each other. (I placed a small bolt where the nipple would normally be found in the first pic below.)
"I wonder, which one is better if there's a difference?"
(See pics below)

3rd difference (and most notable):
The intake (compressor) wheels are completely different. One is the 5fin design (with large gaps between 1st and secondary fins) and the other is an 8fin design with very little space between 1st and secondary fins.
"Of course this last difference really needs digging into."

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There are a few other minute differences. For example, there is a slight difference in size between the oil inlets and outlets, slight variations in w/g arm design, different wheel fastening nuts, and very small cosmetic difference on the exhaust housings. I have pics of these, as well, if need be.

Now, I know there are actually quite a few ct-26 housings and wheels. But both of these supposedly came off 100% stock 7m's. One an 89 and one a 90 that I owned. I'm not sure anymore which one came from which. Though, I think the 5fin (with the "2" stamp) is from my early '89. Are both these turbos truly stock? Is one a rebuilt ct-26 hybrids, different versions, what? I don't know. Maybe one of them has the ceramic wheels? I don't know yet. I've tried digging for info like crazy and have come up empty-handed. There doesn't appear to be any porting and the compressor wheels both appear to be the same diameter or at least the viewable portion.

And info would be great!
 

MDCmotorsports

Offical SM Expert: Turbochargers
SM Expert
Mar 31, 2005
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www.MDCmotorsports.com
Thats a early VS late turbo.

Also, the turbo with the 8 blades is a typical Garrett style rebuild.

That is a Garrett wheel. Used when toyota wheels were not yet available.

Slight upgrade.

Good strong turbo for making 300hp.
 

ImUrOBGYN

NoNameNomad
Mar 30, 2005
32
0
0
51
Texas
MDCmotorsports;1092760 said:
Thats a early VS late turbo.

Also, the turbo with the 8 blades is a typical Garrett style rebuild.

That is a Garrett wheel. Used when toyota wheels were not yet available.

Slight upgrade.

Good strong turbo for making 300hp.

Hmm, so a Garrett wheel. You know where I could find any more info on it? THanks for the input. First person I've found anywhere with a thought as to what the wheel is.

annoyingrob;1093486 said:
Are they both Supra turbos? Judging by the difference in the nipple location, one of those might have been off of a Celica one point in its life.
The nipple location was changed between 89 and 90, I believe. Also, there seems to be at least 3 different compressor housing with the stamp 1, 2, and 4. I haven't seen a "3", yet. To my knowledge, anyway.

This is a bit of info quoted from bfr1992t on OhioSupras. Another reason why I believe the 90+'s had the housing with the nipple further out.
"The port on Turbo #2 is closer to the compressor wheel. The cross sectional area of the scroll is much smaller, thus pressure will be higher. This might suggest the wastegate would open sooner, or at a lower boost level..."

I know there were w/g related changes between 89 and 90 and the nipple placement may fall under those changes. Along with the other minor differences. The stampings still confuse me and I can only assume that there are at least 3 to 4 possible ct supra compressor housings. I say at least 3 because I have a 2 and 4 and he just posted with a 1, above. You can figure out why I said possibly 4. :)