I received a similar message from Eiji today. What confuses me is that he/they refer to the 9 blade as an upgrade to the 12 blade. In which ways is it an upgrade?Well, there's one less variable in the world
The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread (9 Viewers)
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mudgudgeon
Resident galah
Less restrictive, so it will flow better at higher engine rpm, less back pressure. Turbo will boost later, but will be good for higher rpm
Because the 11 blade turbines are a later style that is better suited to diesel engines. Feel free to go with the stock 12 if you want:
Turbocharger Turbines..
9 blade is a less restrictive version of the 11 blade which IMO is better suited to low boost and high rpm petrol engines.
Well, there's one less variable in the world
Well there we go. They haven't made an 11 blade high torque wheel for the TD05H yet. They have for the TD04HL and TD06H so it can't be long.
Luckily I'm building around the TD04HL and TD06H.
serenity
SILVER Star
And I just found out how gturbo can be great value for money. Got my supra turbo, started stripping it down to prep it for the cruiser. Wasn't careful enough pulling the compressor housing off and bent a blade on the wheel. Now I'm cranky and I'm taking to the whiskey. 
GTSSportCoupe
2LTE abuser
Dougal, just confusing Toyota turbo nomenclature, but you should refer to it as a CT15B, not CT20B. CT20B is dual entry/dual waste gate model from the 3SGTE (Toyota MR2 Turbo). Not as suitable for the diesel manifolds. CT15B is basically the same thing but single entry. This is the unit found on the 1HD-FTE and VVTI 1JZGTE.
serenity
SILVER Star
Can someone explain the difference between 6+6 and 11 blade compressors, seems to be all that I can find for a supra in stock trim is 11 blade.
Interesting. Melett classifies 17201-17040 - Landcruiser 1998+ as a CT20B. Pretty much all the 1HDFTE aftermarket options seem to be refered to as CT20B as well.
Where are you getting CT15B from?
GTSSportCoupe
2LTE abuser
It is completely possible I'm the confused one. The CHRA and compressor/turbine are the same between the two models from my understanding. It's the compressor and turbine housings that are different. I'll look into it a bit more and let you know what I find. I do know that the Melett descriptions can a bit strange also.
I've never heard the CT15B name before. It's not on any of my reliable sources either.
In fact it appears to be only Kinugawa and Alibaba who are using that name.
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The 6/6 blades have 6 full length blades and 6 short splitter blades. The 11 blade wheels have 11 identical blades and are sometimes referred to as GTX style. Though turbos have been using such compressors for decades before the GTX garrett turbos existed.
My thoughts are the 6/6 blades provide less blockage at the inlet while providing more support to the outgoing air at the wheel rim. They should also have a wider operating range as the flow is less constrained.
Garrett have some good compressor maps to view in their GTX range which show how they differ to more conventional. I have bought an 11T wheel for an MHI turbo. But I haven't yet fitted it. I wanted a wheel with extended blade tips and that was my only option.
serenity
SILVER Star
So would an 11 blade be better or should I go for a 6/6 assuming all other factors are equal?
I have read that the equal blades grab more air and can spool a bit sooner but are less effecient at high flow and boost. What is high boost? I dunno. The 6+6 are reported spool slower but have less turbulent flow at the intake, Or less restriction, and are more effecient at high flow. This its all conjecture mind you, but all the old school turbos I've had were equal blades and were coincidently low boost turbos. I personally believe the 6+6 is a way of improving extreme performance within the same blade dimentions. Beware of the diamond shreddie......
GTSSportCoupe
2LTE abuser
Guys, you're right, calling it CT15B is not correct, not sure where I picked that up. I did look closer at supplier naming of the 1HD-FTE turbo part 17201-17040. From legitimate suppliers I'm seeing it called 'CT26 small', CT20B and even CT12B! No real consistency there. At the end of the day, I think using the Toyota part number is the only way to go! The main thing I was trying to prevent was someone ordering a 'CT20B' and ending up with the much more common 3rd gen 3SGTE version which has the dual entry turbine housing. It would be a real disappointment for a Land cruiser owner!
serenity
SILVER Star
So being that the supra compressor flows more than the 1hd-t in theory the 11 blade supra compressor would still have plenty of flow for a 1hz but give better spool up, in theory. I'm not looking for extreme performance just a little fun with a reliable Toyota turbo.
Here is the billet 6/6 I found, the 11 blade I can have cheaper from mamba/kinugawa.
https://www.xsboostturbochargers.co...bocharger-compressor-wheel-toyota-supra-ct26/
CT12B is a completely different turbo. It's the TD04 based turbo used on the 3 litre 1KZ etc.
CT26 small and CT20B are both pretty clear. The housing numbers and photos show which fitment you get.
GTSSportCoupe
2LTE abuser
Yes, I know about the CT12B from the 1KZ. That's why I was surprised one of the companies was using that name for the CT26/CT20B variant.
There's a lot of confusion.
Probably caused by the 15BT engines swapping from the CT26 in earlier variations to the CT12B later on.
There is also a lot of straight out typos and errors that get copied from one turbo sheet to the next. Many have the Toyota 292F as a 3 litre engine. It's the commonrail 1HD-FTE at 4.2 litres.
Any more info on this engine. I've never come across one.
