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-   -   What to do with Nikki carb to turbo12A (https://www.rx7club.com/1st-generation-specific-1979-1985-18/what-do-nikki-carb-turbo12a-229593/)

Mac7 10-04-03 02:15 PM

What to do with Nikki carb to turbo12A
 
What special tricks have to be done to Nikki carb on the 12a to put a turbo on it I have all the rest figured out except that.I know the floats have to be customized and probably other stuff I need this info and Paul Yaw don't wanna give out his recipe..

Sterling 10-04-03 06:44 PM

We don't know yet. It's on our list of things to develop, but my first inclination is to think that sealing things like throttle shafts, idle deceleration valving, and altitude compensation system has to happen first if you're just going to put a carb hat or bonnet on it.

I'm going to be building a carb box for my blow thru Eaton M-90 project, dubbed "The SterlingCharger". :) The boost sensative fuel regulator will go right into the box with the carb, and the only things I'll have to worry about sealing are the throttle cable, fuel inlet, oil lines, and a few special things I'll be doing. ;) But for a carb bonnet, I dunno. Now you've got a whole different ball game because you pretty much need to make that system air-tight. A box is far easier.

Either way, you should get your carburetor fully modified. This is not a plug for business for me or Carl, and it does'nt matter to us who you get it done by, but if you don't have some mods done to that carb, you run the risk of leaning out at hi boost/rpm situations with possibly catastrophic consequences.

I will say this: While shaving down the flow impedances within the carb body (things like half-shafting the throttle shafts, trimming booster venturi support arms, ect) have a great effect on NA engines, the severity of that effect is lessened in a boosted application, or so I've read (a few times). Apparently, that air is gonna be fed into there no matter what. However, on a scientific guess, I'm gonna say that at the very least, doing those things will cut down on the heat that is generated by the air coliding with these obsticals.
I could be worng.
Point is, those mods are not the really important mods for you. What are the important mods for you are boring the main venturis (to get anywheres near the flowability you need), installing appropriate main jets, and installing emulsion tubes that have been drilled and tapped to accept air jets. (Obviously all in addition to sealing up the carb.)

The emulsion tube modification is the most important one that will give you the fuel delivery tunability you need to get the most performance and saftey from your Nikki-turbo application.

In my opinion, if you're boosting with a carb you should know carb tuning INSIDE AND OUT!
I strongly urge you to research this more to get a definite handle on everything about carb tuning that you can. You and others may feel it was presumptuous on my part to suggest that to you, but I feel that if you did have what I believe to be "enough" carb tuning knowledge for your application, then you would'nt have had to post this question.
It's just a dangerous situation for your engine, that's all.
An NA engine with a poorly tuned carb just runs like shit. Add boost, and it can grenade inside.
With a boosted-carb set-up, you have to learn more than the usual "number-punching computer controlled FI sissy-boys" out there. ;)

No matter what you choose to do, if it involves a Nikki, Carl and I will help you with advice any way we can.

wwilliam54 10-04-03 06:53 PM

send it to robert with a check
:D

Defprun 10-04-03 07:03 PM

fuck nikki, if you can, go through the trouble of blow-throughing on a Webber carb, youll see better results.

coldy13 10-04-03 07:18 PM


Originally posted by defprun
fuck nikki, if you can, go through the trouble of blow-throughing on a Webber carb, youll see better results.
But I like my nikki :) http://coldy13.rottenass.com/carb2.jpg

If I had more money I would have gone with a weber, but this nikki is more than good enough for me. I got it from Robert, www.rotaryshack.com

inittab 10-04-03 07:59 PM

coldy13 - what manifold is that?

coldy13 10-04-03 08:01 PM

Ported J-Spec 12aTurbo manifold.

Mac7 10-04-03 08:38 PM

Cools thanks for the info..I also wanted to use Webber carbs,I had seen a setup of that somewhere in a site..But for now gonna try with the Nikki..Ihad planned to build the box out of 1/8th aluminum..I'm a pretty good welder and have acces to all the tools of the trade from Plasma cutters to Migs to argon..For now it's just a matter of collecting all the stuff I need..Someguy in my town had a similar setup but I never got to see it He blew up his motor about 4months after..and went to the 13b N/a instead..I was also thinking of a street port to add to this..My friend wants the same setup but also wants to add NOS..for me I'll skip the Nos, I just want a reliable setup and don't really plan on drag racing it.I'm more into autocross and street courses. The motor I have has less than 110oookm on it..I don't really care If the engine blows I can't get them for pretty cheap(under200$)..and im so use to taking these motors out..and still have few other upgrades for the car like GSL-SE rear end and rear brakes I have all the parts except both manifolds..and planning on using either a Garett or the turbo off one of my MX6GT..:confused:


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