Can anybody point me to where I can find used 20Bs and the specs on the turbos that come standard on them? Tried a search, but no luck. Thanks.

 

Have you tried posting in the 20B forum?

https://www.rx7club.com/forum/forumd...?s=&forumid=95

 

Sorry, did not know there was one.

 

Used to be an austrailian site with lots of info ... link died.

I recall all 3 rotors initially fed the larger turbo (hitashi-15?) and then the small turbo (-12) kicked in ... fed mostly by the rotor beside it.

 

Thanks KevinK2.

Anybody else?

 

Originally posted by capt. bill1

Can anybody point me to where I can find used 20Bs and the specs on the turbos that come standard on them? Tried a search, but no luck. Thanks.

Hey I are you planning a 20b swap? Just curious, because of all the mods you have on your current car with those M2 ball bearing turbos. I wish I vould help you on your search though! Sorry

 

t-von, yes I am. It looks like I will be coming into a bit of money in the very near future and so I am looking into going 3 rotor. I am tring to find out if the M2 high flow ball bearing turbos flow enough to use on a 3 rotor.

 

Depends on what is enough flow for your application. How much HP are you looking to make?

The stock 20B twins are no bigger than the stock 13B-REW twins, so the M2 BB turbos should push enough to do at least the same as the Pettit Banzai (all else being equal). The Banzai set up is worth 550 bhp.

 

You can try Nippon or fC3S.org for used 20b's Nippon had one a couple weeks ago.

 

Hey capt.bill1. If I were you I would ask Mostly Mazda if they can convert the twin turbos of the 20b to ball bearings. If this possible it would be less hassle when it comes to fitment issues. A 20b project is in my near future also now that I got a job making some serious paper.

Originally posted by mmaragos

The stock 20B twins are no bigger than the stock 13B-REW twins.


Do you mean the turbos themselves are no bigger than the 13b twins, because I was at alamorotary.com's web site and saw comparision pics of the 2 and the 20b turbos looked bigger.

 

the fd turbos wont bolt onto a 20b. the front 20b turbo is like a turbo 2 turbo (big) and the rear one is small like an fd. the fd turbo cartridges may or may not bolt into the cosmo turbo manifold, the rear one might, the front one you could probably upgrade to a t04 stlye wheel.
seems like it might be doable but more hassle than its worth, unless you piggy back something, or use the stock ecu making them sequential is gonna be hard.

mike
running 20b fc

 

You're right they do look bigger in that picture. I never thought they were, but that was a guess. Looking that the output of the stock 20B-REW vs. stock 13B-REW, it just seems like there should be a lot more power there (if everything was equal). Of course there are differences (porting, for one).

 

Originally posted by mmaragos

You're right they do look bigger in that picture. I never thought they were, but that was a guess. Looking that the output of the stock 20B-REW vs. stock 13B-REW, it just seems like there should be a lot more power there (if everything was equal). Of course there are differences (porting, for one).


If i'm not mistaken I think a stock 20b ran lower boost levels compared to the 13b. I believe Peter Farrell claimed they were only designed for 8psi thats why puts big singles in this conversions. Don't hold me to that I may be mistaken.

 

I found out a little more...

The primary is larger, with flat turbine blades. The secondary is similar to the 13B-REW (in size and blade config).

I have read that the stock boost on a Cosmo is .7 bar (a little more than 10 PSI). Not too sure if that is correct.

Pettit changes the stock 20B turbos to non-sequential and turns to boost up to 14.7 psi to get 550 HP.

 

Thanks for the replies. I am in and out of town a lot right now so only get back here every 3 weeks or so.

I was at Pettit and Cam said he runs his conversions at 8-10 psi of boost in a nonsequential mode. He said he has found higher levels of boost to hurt longivity. He also said he is looking at using a single turbo setup in the near future.

 

Use that money to get the one at www.cris.com/~Asam/20B.html

 

http://www.alamorotary.com/images/20...B%20turbos.jpg

mike

 

I have one for sale.

https://www.rx7club.com/forum/showth...threadid=96704