Hello, i looking into boosting my 12a and staying with a carb. I dont wanna produce much power only around 150hp - 200hp. I thinking of pushing around 7-8 psi, do i need to re-jet? i live in miami fl so its not at a high altitude, i heard altitude makes a difference. The turbo manifold which one can i use if i wanna use a t4 turbo, can i use this one on the 12a? what do i need to modify to make it fit? this is the link. http://www.ssautochrome.com/level.itml/icOid/1357

For that psi around what psi should i set my fuel regulator too?How much do i have to advance or retard the dizzy for that amount of boost? I forgot to say can this hp be achieved on stock ports? Is the nikki enough for this amount of boost?

Thanks for the help in advance to everyone

sorry i forgot to put the info, all stock 84 gs 12a.

 

Well, as I've read about it those type of aftermarket manifolds often crack, but I'm not sure. all you would need to do is grind the holes to fit on the bolts. I also heart that you need to space out the manifold from the engine to clear the intake. To run the nikki you'd need to modify it for blow through, yes probably get it rejetted. You need a FPR that adds 1psi fuel for every 1lbs boost. you need a turbo carb hat. its alot of work to say the least. if you want somthing better than a stock 2g turbo, nikkis probably not your best bet.

Also I think you need a wideband.

I'm just going to save and collect parts. I want to do a ITB setup when I go turbo.

 

You should probably talk to Robert at Rotaryshack. Why reinvent the wheel when they've already done all the work?

Sterling might be able to advise you on jetting if you plan to stick with the Nikki: www.sterlingmetalworks.com

Good luck!


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you need a wideband, you will have to rejet, you need a rising rate fuel pressure regulator (and a new pump)

you'll want timing in the 10-15BTDC Leading range (efi we'd be running 15, with a non intercooled carb, 10) YOU need to decide if you can retard it, or just lock it, depends on what the timing is over 5000rpm...

at 8psi, it should be doing right around 190-200hp at the flywheel

 

Here's some reading material for ya. This is the buildup thread on my old 12A blowthrough setup. I had alot of fun with that one. I even pissed of a few 3rd gens with 15 pounds of boost. I kinda miss the old 12A https://www.rx7club.com/showthread.p...roject+updates

 

thanks guys. i was just thinking of the nikki, but maybe i could go with the edelbrock 500 thunder series which has external secondary adjuster and it bolts straight to the rb holley manifold. they dont run expencive, but i would probably still need to get it boost prepped so i was thinking about cost as well, i dont want to spend more than $1500 in parts. oh and i am going to put fmic

how can i find out if i need to retard or lock the dizzy? i am gojng intercooled so what would the trailing be?

 

Everyone I've heard says Lock the dizzy. Like said talk to Rotaryshack or Pineapple Racing.

Definitely intercool it. I'm going to try to boost my nikki first. Then I'm thinking about a 2BBL Holley 500.

I'd stay away from the edelcrap carps myself.

 

sweet, thanks for the info. i decided to go with an s4 turbo, intercooled and the nikki boost prepped and rejetted, going for 7psi.

 

I have ran up to 15 psi blowthrough Nikki on a stock 12A. That was pretty fun.

 

So I can do 10psi on a stock 12a if I rebuild it without a problem?

 

I run 10psi on a stock 12a with just over 100k (never rebuilt) with an S4 and mikuni. Alot of the longevity has to do with the tune. I rebuilt my street port 12A and ran 13lbs of boost before the end plate cracked after a year... which seems to be a common problem boosting the 12A at those levels without having custom reinforcement. While the stock ports in... I will rebuild the street port again in anticipation of the end plate cracking on the stock port.

The fun definately outweighs the work even if I have to rebuild every year. I enjoy the rebuild... Heck I would even go so far as to say I LOVE rotaries... Wish I knew how to add extra dowels...