91s5narx

iTrader: (6)

ok, i have been searching both rx7club.com and teamfc3s.org for the past 4 hours now trying to figure out what to do to get the most hp out of my n/a engine and all i have gotten is a headache. i've been searching mostly for porting ideas because with my limited knowledge of moding a rotary car, i figured this was the way to go. but in the process i have come accross a throttle body mod that i cant find any info on how to perform and intake and exhaust porting. i am looking to pull my engine this winter and rebuild it cause it has 180,000 miles and isnt acting the same as it used to. just figured it was time to get some power out of it again. thought of porting the actual engine in this process. oringially i was under the inpression that i could do it at home but after some looking it seems that i need a milling machine or something. i dont know, like i said before i am just really confused. most of the threads that i have come across were a year old or more so i didnt know if the poeple that had posted then would still be around to help answer my questions so i figured to start one of my own. i guess any help on moding my car beside the obvious intake filter and exhuast would be great.

RotaryEvolution

iTrader: (30)

porting the intake runners/throttle body is a waste of time IMO, most of your gains will be from porting the housings while you do the rebuild. other gains can be had from replacing the air box with a cold air intake system and opening up the exhaust flow with an aftermarket manifold/full exhaust system, other misc gains can be gotten from advancing the timing a few degrees but aside from those there isn't much else you can do to an n/a aside from install a standalone EMS.

91s5narx

iTrader: (6)

wow so it sounds like i am wasting my time. i met a guy from albany that said he was pushing almost 400 hp out of an 89 na with rx-8 rotors and alot of nothing, and didnt even have the EMS. i thought at the time that he was shitting me but now i totally know that he was

NOPR

200whp is sort of an accepted limit on streetable n/a 6 port 13b's. YES, there are a few different ways to get there and there are a lot of people who have passed it, but it seems in general that thats about as much as you can get without being ridiculous.

as far as porting, all you're doing is opening up the passages into and out of the engine with a porting tool. you can do it with a simple handheld tool porting tool (electric or air powered) in your garage/workshop/kitchen/bathroom whatever.

91s5narx

iTrader: (6)

o ok, i might look into it to get the most out of my car

My5ABaby

iTrader: (7)

Yeah, he's full of ****.

Fc3s88rx7

Convert to turbochargers use a rx6 turbo

SureShot

For best drivable performance, verify that the aux ports are working.
For peak power, you can sacrifice low end torque & remove the aux port sleeves.
If it's an 89-91, verify that the VDI is working.
For bolt-ons, a header & a free flowing exhaust is a good start.
Then a cold air (& ram air) intake.
Then, when you rebuild the motor, give it a nice street port.

Carzy Driver

how bout a tune up while you're at it.

Sideways7

iTrader: (7)

Karak pretty much nailed it. Get a good street port on the intakes and port the exhaust some, get a CAI and a good exhaust system. After that, the only thing left is a standalone. The TB mod is largely a waste of time on NA cars. The only gains youll see is slightly better throttle response from removing the extra secondary butterflies and maybe 1 or 2 hp. Porting the intakes is debatable. According to the people that did it it gives some high end hp, but its quite a bit of work to get right. If you havent already read it, theres a good thread on it in the archives. Also, I would get someone else to port the engine for you. Getting the intake ports optimized can be tricky and easy to screw up.

Sideways7

iTrader: (7)

Also, theres no way to get 400 hp out of a NA 2-rotor short of nitrous and crazy porting. It might theoretically be possible on a renesis with peripheral porting, but I kinda doubt it. Even if it was, it would be undrivable on the street.

snowball

jesus padilla is looking to run 9's on his 2 rotor NA FB. i doubt you would want to street it though.

ericgrau

iTrader: (1)

I read 300HP is limit on N/A, 200HP is practical limit.
I read it involves heavy porting, standalone ECU, rotor balancing for higher redline (?), intake, exhaust and I forget what else.

Good place to start is cold air intake, full performance exhaust, cone intake.

91s5narx

iTrader: (6)

ok, well got a cone filter, working on making a cold air box for it. ive heard ram air intake many times and on many car but what does it really involve? never fully understood it. it is a 91 but no idea what vdi is or how to check it. as for porting, i wouldnt want to screw it up if it is that hard to do so i will just have it done for me.

Sideways7

iTrader: (7)

Yeah, 300 is about the most I've seen for a 2-rotor NA. This is with a peripheral ported motor, either a carb or standalone, and a 10,500+ RPM redline. There was a video of one on a dyno but I can't find the link.