How well does it work on NA 13b's, most notably S4's? I know it works not great, but OK with piston powered engines. I know the tuning window starts getting narrow, but I am not looking for a lot of non-intercooled boost, it will be cooled, and good non-pump fuel is cheap to stave off knock/detonation for how long this thing would have to run.
I did wade in the murky mess of rx7club, but damn all the nuthugging neanderthals spouting the same old tired BS got old fast.
Ranger50 wrote: I did wade in the murky mess of rx7club, but damn all the nuthugging neanderthals spouting the same old tired BS got old fast.
Which was probably "Dude, just put an lsx in it" ....
IDK if the turbo vs. n/a rotaries had different compression ratios....
As long as its tuned correctly I've heard good things about rotaries and bewst.
I'll be adding some to mine next year once I get the chassis sorted.
An S4 NA rotary is 9.0:1, which isn't exactly high compression anyway. S5 is 9.5:1 IIRC.
yamaha wrote: IDK if the turbo vs. n/a rotaries had different compression ratios....
Best I can find is NA at 10:1 and Turbo being 9.4:1? 10:1 is my limit anyways for "stock motor" boost.
Yes there are different rotors between the NA and the Turbo versions. (The dishes are deeper on the turbo rotors = less compression ratio)
It's a very tricky endeavor because with an piston engine you can get away with a little bit of knocking (while you tune the engine...) and not really damage the motor. A Rotary will knock ONCE and you're done/ (From what I understand.)
I'd call some one at corksport or RX7.com and see what their tech's have to say.
DaveEstey wrote: An S4 NA rotary is 9.0:1, which isn't exactly high compression anyway. S5 is 9.5:1 IIRC.
Then why all the pissing and moaning that is doesn't work....
Oh well, thinking outloud as I have a roller, want something different, and "cheap".
Check out some of the comments here: http://grassrootsmotorsports.com/forum/grm/magic-spinning-triangles-and-boost/47943/page1/
Definitely possible to build a boosted rotary, even with a NA S4 or S5 engine. You'll just need a good tune and run the highest octane fuel you can get at the pump. Also, make sure you have a big intercooler and a really robust cooling system. Rotaries run hot NA; with boost it's an inferno in there so you need to run it richer and do more charge cooling and engine cooling than you might think.
I agree with some of the comments that they're not as forgiving with detonation vs piston engines. It's pretty easy to blow out an apex seal with knock, but if you don't get detonation, they'll hold up pretty well in my experience.
for adding a turbo to a S4 N/A have you seen Aaron Cake?
I do believe it works quite well actually.
For compression ratio comparison see second post: here
Good luck 
It can work well. You just have to be more on the ball with tuning and cooling.
In reply to JohnyHachi6:
Cooling system was designed for a V8, so I "should" be safe.
I wouldn't run it on "pump" fuel, unless I can find 104-110 unleaded or leaded somewhere.
Charge cooling was going to be the biggest A2A I could fit, but it I couldn't get the ACT down to a decent level, I would install a A2W instead packed with ice.
In reply to Hungary Bill:
Yes, I have. Can't stand to read what he writes. Too much "God" complex. He has done it all and such and such doesn't work, so don't try it, even though it does work since I did it.
Rotor weights and compression numbers: http://www.mazdatrix.com/r-rtrwgt.htm
The little I know of spinning triangles... I'd go to one of the best... and ask.
Rob Golden - owner, Pineapple Racing - http://www.pineappleracing.com/
Curiosity is killing me, what are you planning on doing with this?
Hungary Bill wrote: Curiosity is killing me, what are you planning on doing with this?
All I will say is "cheap, different, and boost". Reason for asking about the NA's, as the availability is almost 3:1 to a turbo model for easily a third of the money. 
In reply to Wonkothesane:
MegaSquirt.
Don't see the problem as it is only 350HP or so.
Very few stations around here to even buy fuel, so I don't want to run the risk of lunching a motor due to "spoiled" fuel.
A lot of the FD guys have been embracing water/meth injection as of late. I have no personal experience but it might be a useful tool in keeping a boosted NA motor knock-free.
http://www.rx7club.com/3rd-generation-specific-1993-2002-16/making-case-rotary-powered-fd-fix-806104/
Why not run ethanol then?
DaveEstey wrote: Why not run ethanol then?
I can get race fuel by driving 30min-1hr away. E85, as much as I want to run it, is 2hrs plus one way.
In reply to DaveEstey:
I really like the idea of using E85. Only issue is you will need massive fuel injectors, especially with a turbo rotary. Think 1000 cc. You'll almost certainly need an aftermarket fuel pump too.
The GN guys swear by methanol injection, so definitely look into that. Modern boosted boingers are built with 10:1 pretty regularly now, I think an MS'd rotary there will have no issues for you. Do it!
I know meth works, but I just can't get beyond the fact you are injecting water into the chamber.....
JohnyHachi6 wrote: In reply to DaveEstey: I really like the idea of using E85. Only issue is you will need massive fuel injectors, especially with a turbo rotary. Think 1000 cc. You'll almost certainly need an aftermarket fuel pump too.
If you're pushing 400 hp in a boosted rotary you need 1000cc injectors already.
but yeah, you have to throw a ton of E85 into the combustion chamber.
Don't be afraid of methanol injection, the Subaru guys have been using it for a while now and they can lay down some SERIOUS numbers because of it.
I can't believe nobody has posted the "Boost goes in, Apex seals come out" pictureyet. Whats wrong with you guys?
In reply to Streetwiseguy:
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