RotowarySwamp

I was going to do an engine swap for my frist gen and drop a 13b turbo in there but i have sence found parts cars with good rotors and rotor housings so im set on parts. I know the exhaust and carb are going to be my best options for a sustainable power output so whats the scoop? is staright piping going to give a better power boost over say a catback? and what kind of carbs seem to run best with a 12a?

t_g_farrell

iTrader: (1)

A stockport 12A is good for about ~150-160 HP maximum at the flywheel with a good exhaust, performance carb and strong ignition. If you need a cat or to pass emissions you won't see these numbers from a 12A.

Best carbs are weber setups or similiar. For racing, the IDA 48 or the twin 36 DCD setups are
excellent. For the street the DCOE or Dellorto 48 are good for keeping the torque spread down into
the lower RPMs for easier running at low RPMs.

The setup I have in my sig has been measured on a dyno at 134WHP to give you an idea.

Cookboy

iTrader: (10)

Nikki's run best on 12a's!!! A stripped Nikki and a baffle-free exhaust will be your best value for stock port power.
If you can find a dellorto it's a great way to go, certainly more top end. And more dinero, of course.

RotowarySwamp

I don't have to worry about emissions for the year car I have where I live, nice perk for living in the middle of nowhere. I'm sticking with stock ports for this car... I'm going to experiment with that on an 3rd gen that got tunerd to death. Thanks for the info on carbs and I think I'm going to straight pipe it since its not getting driven in a city at all and it really doesn't matter how loud it is lol and I saw how much work its going to be to remove the gas tank and put a fuel cell where the spare would go to justify using a cat back.

Starfox07

Intake and exhaust mods can give pretty strong gains on stockport engines. These engines are pretty plugged up from the factory, lots of restriction.

DreamInRotary

iTrader: (49)

Go the 13bt swap!

Ahh, I'd keep going forward with the better intake and exhaust systems. Porting would be one of the best things that can be done for the 12a in my opinion..

Cookboy

iTrader: (10)

Money is the easiest way to get mo' powah. Ingenuity ain't bad, reading threads is great.

If you are currently stock exhaust and intake, simply ditching the cats for an open pipe from exhaust mani to mid pipe will give a noticeable improvement in response and power. Adding a header will add a little more. Replacing the stock muffler a little more.

Your noise tolerance will ultimately drive your choice, whether you think so or not. I'm an old f&@ker and some noises are more or less tolerable than others. I started last year with an old RB road race header into an old RB collector/presilencer thru a skinny *** mid pipe into the stock muffler. It was a good (cheap) 1st step, but sounded too metallic.

I read dozens, maybe a hundred exhaust threads, and concluded that I wanted to eliminate a. Baffles and b. annoying noise.
I also looked at eBay and amazon. I wound up with an 18" 2" diameter magnaflow pack behind my presilencer as a midpipe and a 2.5" single inlet to dual 2.5 outlet borla as my muffler. No baffles, rich deep tone for an old mans ears. $160 in parts and 110 to a muffler guy to weld it up.

There's no point in thinking about intake til your exhaust is squared away. Once it is, avenues will open to you.

RotowarySwamp

Sorry i haven't been able to get on and post for a few days but... new job equals more cash for the rexy. Keeping the stock port on this car since my dad has to be able to drive it too and even though hes and old man he loves the sound of a well done rotory. Thanks for the tips on the exhaust and carb, definitely going to start with exhaust then work my way up but the first thing that it needs is some new shocks mainly due to the fact that they are still oem and have seen better days. No porting on this 12a... I found a 3rd gen that im going to try and learn porting on sitting in some rednecks lawn that has a blown engine that hes trying to dump for a grand... used 13b Twin Turbo from ebay... and a hell of alot of trial and error lol.