well i own a 85 fb with the 12a carb engine...recently i found out that the front seal is going bad ..this means engine rebuild...well a good buddy of mine has an FC sitting in his garage that runs but also needs rebuilt...he said i could have both engine and tranny for free if i help him prep the car for paint...so i plan on rebuilding the 13b that he is giving me...the 13b is from an 86 non turbo and the tranny is a 5 speed ...i just started getting into rotory engines but i know the basics ...iv always been interested in N/A cars because you never really see turbo cars at a roadcourse and that is where i work...im very interested in building the 13b for street and race use ...not drag race...can you help determine what i need for decent power?

what porting?bridge port? P port?
light weight rotors?....will mine work or should i invest in racing beat or s5 rotors?
carbs?..ITB's?
exaust size?
i just need to be pointed into some type of general direction...the car is going to be for the street and the road course.....thanks for the help

 

I have 1974 RX4 and I run a ’91 S5 engine and you’ll have to do a lot of what I did. First thing you’ll need is a front cover and oil pan from a ’84-’85 GSL-SE 13B, so you can put the 13B you’re putting in a first gen. I would NOT go with a bridge part or anything bigger. It’s too much for the street. Get a nice extend street port. It’s the largest street port and I run it and it’s very streetable; roughly 200-210 HP depending upon the setup. You can go to the higher compression rotors of the S5, but unless you have MONEY I wouldn’t use super expensive stuff when stock is just a good, but they’re thing that the money should be spent on; one upgrading apex seals if you intend on racing hard and high revs. Two mm are good, but some people feel safer with 3mm.
As far as carbs, I certainly run a Holley 750 double pumper on my setup, but I’m going to change to fuel injection from a ’88 N/A . I’m tired of tuning a carb. Also, A lot of people do prefer a side or down draft. I do too. I notice better throttle response, but on the dyno the Holley out performed both above 6800 RPMs. Below that both the side and down draft out performed the Holley.
I also run a 2 ½ “ exhaust but seriously thinking about going up to a 3” but I’m afraid I won’t get enough backpressure. Still looking into it.
The best advice I give is what I go told when I got my first rotary and I tell everyone now, DO THE RESEARCH. See what everyone else is doing. Ask what works and doesn’t work. What works for me may not work for you and vise versa. Keep that in mine.

 

i think im going to stay with fuel injection...but should i go with a bigger throttle body or do an ITB set up...how much work is it to make an itb set up? iv done it with hondas using bike throttles