OK, I am aware that the 20B uses its own special intermediate housing, one that holds the third stationary gear, but are the others (front, rear, intermediate, and rotor housings) just the same as 13B REW parts?
I am thinking of getting a 20B and building a WICKED project...
Sean Cathcart

 

Pretty much...not necessarily 13B-REW housings, but the 13B Cosmo uses the same parts with the exception of the "20B" logo on the rotor housings.



-Ted

 

The side housings on the 20B have bigger intake ports as compared to the 13BREW -- It actualy alternates per rotor. One big one, and one almost same size as the 13BREW. As far as I can remember, I believe the ports from the secondary injectors are the bigger ones.

However the rotor housing exhaust ports on the 20B uses a restrictive sleeves which makes the ports smaller compared with the 13BREW exhaust ports.

 

wow, nice engine bay rx720bt

 

remember the 20b was designed between the s5 and s6, so the rotor housings are more like s5 housings with a special exhaust sleeve. the side housings are unique and feature huge ports on the manifold side.

mike

 

Yeah, a special restrictive exhaust sleeve

Mine have been yanked from the housings and custom fit FD exhaust sleeves in there...

mmmmmm fresh 20b... can't wait

 

Is it expensive to switch out the exhaust sleeves?

 

No. You can do it yourself actually if you have a way to remove the pins that hold them in. Use FD or FC sleeves. They're both the same.

 

Why even bother to replace the sleeves ? , the sleeves in my ports were removed and the ports opened up substantially with no ill effects.

 

The sleaves are designed to direct exhaust gasses at the optimal angle towards the exhaust turbine in the turbocharger(s). It's hard to say if actually using a sleave or not would be better... it'd take a lot of trial and error, test runs, tuning, and specific measurements to tell for sure... to say that there are no ill effects is kind of premature if you ask me. But, I know where you are coming from . I considered not using sleaves at all as well, but after looking at some of the good numbers that 13b-rew motors were putting out with sleaves, i opted to not be a guinea pig on this one.