OK here are my 2 options:

1) street ported 12a w/holley Carb

2) Street ported 13b S5

Which should make more power?

I know the S5 would smog much easier.

Your opinon, experience, and advice is much appreciated!

 

a 12B eh? That's a new one...

Personally I'd go for the 13B.... just 'cause of the extra displacement factor.... and the fact that if you want to push more HP, it's easier with an engine that starts with ~130 instead of 100....

Just my 2 bits...

- Jeff

 

A 12B or a 13A would be cool. A 15A would be really cool!

So you're going with the fuel injection of the S5 for smog testing? That is, if you decide to go that route?

The 12A would bolt right in.

 

12a lower weight, stiffer ecc less prone to ecc flex due to shorter block design... custom turbo w/intercooler.

 

Damn it... Thanks for illustrating my typo!

If I go with the S5 13b, I plan on using all the fuel injection components.

I'd like to do a turbo setup, already got a nice 12a mannifold, but I don't really have the money to complete such a setup at the moment.

Pretty much I've got a 12a in there now, but I will have access to a complete S5, all components.

 

Keep the 12A in it for now. Then do the S5 13B if the money for a turbo on the 12A doesn't come through.

 

i would go with the s5 turbo, and this "should" make more power. might as well, since you have access to all the components. then keep it looking stock, and beat the **** outa everybody. just my .02
jeff

 

Well... I'm sorta leaning toward the 12a. The S5 would be a good amount of work and I'm not sure that I'd match the power? But if I keep the 12a I'm not sure how I'll pass smog? Does the alchohol in the tank thing work?

 

The 12a is the safe bet, and from the sounds of it the most reliable bet.

 

well you may remember me from the pm's about the holley stuff; i have officially gone efi on my streetported 13b. i should be done with everything soon enough and have it in eventually. my 12a is just giving too many problems; well actually everything but the block. i think it's a sign to go fuel injection. and since it's the turbo block it'll just be that much easier. and for smog passing and all that. it's almost 200lbs of torque stock!!!! that is what took me to the side of tII. oh wait, are you doing a n/a 13b? if you are doing an n/a 13b then you might as well just keep your 12a. unless your going with a tII it's not worth the trouble.

-magnets

 

S5 13B makes 162 Hp stock..... so even if the streetport on a 6th port sucks, it will still make more than a streeported 12A. Remember, the S5 has lightened rotors, hardened stationary gears, varible intake, so it revs higher and has more torque.

The only issue is getting it in a 1st gen. Honestly, this is the easy part, the wiring and sensor finding is the tough part, but by no means impossible. Staying NA means you won't need to upgrade the tranny, or fiddle much with the fuel tank until your ready to go turbo.

 

yeah I'm reading through older posts... It seems that guys are gettin very nice dyno results with the S5's. 15--175HP at the wheels should be more than adequate for my setup. I'm starting to lean toward S5... at least I woulnd't have to screw with this damn Carb!

Well the donor car is still waiting to picked up so I have some time to think

 

Reading your sig, I see you've got a '79 with a header and no emissions. My REPU also used to have a thermal reactor. The exahust used to stink horribly. A bit rich I guess, but I was used to GSL-SE exhaust with full emissions gear in working order.

The best way I've found to clean up the exhaust without doing any major work is to upgrade the ignition system. After hooking up DLIDFIS, my REPU with a header and dual long primary system no longer stinks. It still smells a little, but it doesn't linger in my clothes and stuff anymore. Who knows, it may even PASS '74 spec emissions now. Well, the sniffer test at least. Luckily, only '78 and later still need to pass in my area. This means I can get an SA next year and mod it.

So I'm still leaning towards the 12A at the moment.

Also, alcohol in the tank just leans the AF mixture, as far as I know.

 

12a all the way!

 

you wnat fi on your 12a? Go megasquirt fi injection takes tweaking but from what I hear the resulsts are impressive.

That means adding parts and using a 13b intermediate plate... or you could go throttle body design. I think RB has something alone those lines

 

https://www.rx7club.com/forum/showth...hreadid=191169

efi for ya