'79rx7

Because I just went through all the trouble of making my '79 have stock '86 efi! Plus I'm on a budget please talk to me, I'm in no hurry to get this done but I want it done right. But with EFI! So please any ideas on what setup to use, please remember budget.



This is just a side project with spare cash (if there is such a thing)

'79rx7

Also let me add that I'm looking for about 250HP and drivibility, hopefully around 80-100K life expectency



Possible?



Anyone know the limitations of the stock efi, even ported, larger injectors?

Racer X

Did you check that thread I gave you a link to???

pengaru

I purchased one of the rb adapters, it's really crappy. You can find pics here:

http://www.pengaru.com/~swivel/cars/rx-7/03-21-2003/



not to mention it does not seem to be aluminum, and it's chrome is flaking off. Have you ever used an RB intake manifold? before saying it's 'nice' you might want to give it a try.. the one I got is a worse casting than the original mazda stuff.

RotaryRocket219

oops..



my bad.

Node

hmm, looks like nice stuff then

guess its garbage, anyways I never heard of many problems with people who buy stuff from racing beat, probably because I stick mainly to the 2nd gen forums where carbs are rather unheard of.

Node

I guess you could go with an S-AFC for fuel, and just have someone tune it for you.

Maybe you should just go with a 6 port, and bridge the 5/6ports and streetport the others, like judge ito did, that way you can keep N/A EFI (its a 6port now, right?)

Racer X

Yeah he has a the 6-port S4 13B EFI in it right now.I say use the turbo housings but bridge the ports like ito did on that 6 port motor he posted in the 2nd gen forum

88IntegraLS

This would be my ideal NA engine build-up, and it might be what you are looking for:



1. S5 (89-92) rotors because they weigh about a half pound less than S4 or S3 rotors, which means the engine can be revved higher. They also have slightly higher compression which allows combustion to be more efficient; in other words, you will make a little more power with the same amount of air / fuel.



2. S4 rotor housings. Relatively cheap and available compared to other series 13b engines. You can grind off the exhaust diffusers inside the sleeves.



3. Stock S4 manifold (upper and lower), match ported at the joints, S4 throttle body with cold start plates and fast idle stuff removed, ported to remove blunt and sharp edges. The S5 manifold with VDI could also be used but you would need to install an RPM switch to actuate the VDI valve. VDI changes the intake runner length above 5500 rpm to retune the "tournament effect" (slinging of intake charge pressures between the front and back rotor housings as the rotors open and close the ports). The S4 manifold might flow better on a ported engine, however, so any benefit of the S5 manifold is debatable. S4 manifolds are a dime a dozen on Ebay.



4. S4 TII center iron. You can remove more metal in the ports from this vs. an S4 NA center iron before stopping short of the water jacket.



5. S4 NA end irons. Sixth ports are desireable because such large secondary ports without the sixth port separation mechanism (half of them are closed under 3800 rpm) reduces intake velocity which reduces torque and low end power. Working sixth ports allow decent low-end torque (for a non-turbo, that is) yet still allow big ports at high RPM for some upper band power.



6. If you have a cone filter (and you really should) on your mass airflow sensor, it will have an adapter plate with blunt edges around the square opening. If your plate is anything like mine, you can grind a bunch of it back to flush it up with the opening of the MAF sensor. You can also round over these edges. This alone made a noticeable difference in throttle response to my car before taking it apart.



7. The plastic elbow which connects the throttle body to the intake boot has a sharp edge inside it. I would suggest grinding this edge smooth to help airflow smoothness and velocity.





Disclaimer: I have never rebuilt a rotary engine but I have rebuilt a 16 valve twin cam Acura engine, which has 100k miles on it of normal to hard driving, without trouble. The rotary is much simpler and I can't wait to hear mine run again after building it back up with the above parts.

my_jdm_rx7

Humm, this is all so interesting to me..because I am pulling my spare engine apart now to rebuild it, as my mild SP NA is slow(with all mods listed here). I am now wanting to do a Half BP..I have an S4 NA, 6port. With all normal mods(RB header, full 2.5in exhaust, CA-intake, ported MAF, P/Polished,knife edged TB, port matched manifolds, NO 5/6th port sleeves, E-fan, pulley, no AC/PS, NOTHING Emissions wise on a Half BP 6port S4 NA...what HP numbers am I looking at, at the fly? Thanks guys.