What CFM is the stock nikki? I was thinking of going with a Holley 390 cfm 4 barrel.

http://www.holley.com/products.asp?product=0-8007

Is this over or underkill? I was also considering a sterling carb. I just figures for simplicity a holley might be better. I have all emissions removed.

Thanks...

 

I have a Sterling (not installed yet) so that you know my bias up front. Sterling is cheaper (at least to a Racing Beat Holley). They have the carb pretty well tuned and ready to go when you get it. It IS a Nikki, so its certainly suited for your RX, whereas I've heard Holleys are a bit crude, and being a generic carb, they require a lot of tweeks to get them close to a Sterling, if in fact they ever CAN be made to match?? Also, you don't need to spend the extra $$ on the Holley adapting manifold. And the P&JRacing guys treated me like GOLD, so if you have a problem, they are there to help. Priceless (as VISA sez)
Stu Aull
80GS
Alaska

 

I got a holley 465cfm from racing beat and yeah in the beginning it was a pain to get dialed in but once i got the mixture right and the float levels where i wanted them the thing is sweet. now that my holley is tuned pretty much it starts like a fuel injected no problems and it doesnt matter what temp or humidity it is. I think the holley is the way to go but thats just one opinion, i have not had any problems with it acting wierd in turns or anything so im very pleased with the racing beat holley robert

 

So you got it dialed in now eh ? Any tricks you care to share, coming close to time to tune mine for the season.

 

at first i had no idea what i was doing with my carb. never messed with them or anything. but since it was from racing beat i knew it was jetted right and i knew that some how i could get it tuned. well at first i just messed with about everything on the carb and really ended up screwing a bunch of stuff up. so i started searching and reading about holley perfromance and got a better idea of what was going on when i changed things. since i was so far gone i ended up haveing to completly reset the carb. i had to reset the float levels and mixtures and idle arm, the works.

i first got on the net and found a website (i posted a while back with a link) and went by the holley settings. they were pretty easy to work with. first off get rid of the automatic choke and get a manual choke, i hardly have to choke mine at all so the automatic thing was really causing problems. set the primary and secondary float level to where they just barely were up to the threads in the sight plug, then gently tighten the mixture screws all the way in and backed each side out 2 turns. then set the idle arm where i could fit a .015 inch shim between the arm and the spring. i put the distributor where i thought it looked right and turned the key and for the first time every it cranked the first time. then with the stock ignition on i timed it to 10 advance and then swapped back to the TT 2nd gen direct fire. its cranked everytime since KNOCK ON WOOD and its been could like below freezing in the mornings and i have had no problems,

i first thought i hated that holley but now its working good its really doing GOOD.

 

How is your gas mileage...? I can get a 390 CFM holley carb for $175. And a new holley intake ffor $200.

This is close to the prie of the performance sterling. And I think I might benefit a little more power wise from the intake. But I don't want to think, I'd like to know! And I don't want to do it if it means my MPG wil go down. Although I find that hard to believe because I shoud be able to install what ever jets I need to get the 12A running just like a stocker. Maybe even l little leaner?

 

not sure what the gas milleage of mine is yet, i just got it on the road and inspected last weekend so i have not checked it yet. i will drive it more this week and check the mileage. im not too concerned with the mileage its not my daily driver just a fun car and just drive it. im not sure but i figure the intake will help it breath, and you can adjust those holleys any way you want. if its stock port then a 390 is okay i think, i got a 465 on my streetport. good luck robert

 

well the stock nikki, wheather modded or not, will yield better mileage than the holley since it will flow less air and there for use smaller jets. and those big 2bbl carbs get worse mileage than a holley.

also, why is ppl using carbs ment for stock port(465cfm) on streetported engines. the RB setup is 600cfm whick i use. i can't see that ur getting full potential from the porting using a 465.

 

well, I think the Sterling is around 450 cfm, not 100% sure though. And if you plan to upgrade your carb at all, your MPG is going to go down the tubes.

I would definetly reccomend the Sterling (although I don't have one yet) They can even port your intake manifold, powder coat it, and replate everything.

 

if you go to the racing beat sight on the stock ports it says 465cfm for a 12a and if you go to the streetported place it says its the same carb just small differences. the 600 cfm is for the 13b. unless i am completely reading it wrong

Holley Carburetor (465 CFM)
1974-85 12A Street-Port Engine Application*


Holley Intake System Kit (Non-Ported Engine)*
1976-85 12A Engine

Racing Beat’s Holley Intake System Kit has proven over the years to be an extremely popular carburetor upgrade, with very “streetable” engine smoothness and drivability characteristics. Fuel economy is comparable to the stock carburetor under similar driving conditions.

Each comprehensive package includes a cast aluminum high-rise intake manifold with a vacuum source for power brakes, a Racing Beat-modified Holley carburetor (465 CFM),

Holley Intake System Kit (Street Ported Engine)*
1976-85 12A Engine

The Racing Beat-modified Street Port Holley Intake System Kit includes the same basic components as our non-ported engine Holley Kits; however, the specific modifications to the carburetors are significantly different

Holley Intake System Kit (Street Ported Engine)*
1974-78 13B Engine

The Racing Beat-modified Street Port Holley Intake System Kit includes the same basic components as our non-ported engine Holley Kits; however, the specific modifications to the carburetors are significantly different and the carburetor used for the 13B applications is increased to 600 CFM.

 

Flow Ratings:
Stock Nikki : 313cfm
RB Holley : 465cfm
Sterling Carb : 465cfm

Simplicity rating:
Stock Nikki : Horrendously Complex for no reason
RB Holley : Simple
Sterling Carb : Equally Simple (even moreso if you count the mech secs vs. vac secs)

Price:
Stock Nikki : $50 (replacement from junkyard or good rebuild kit)
RB Holley AND Manifold kit : $770USD for the kit including K&N or ($533.00carb alone + 235.00 intake mani alone)
Sterling Carb : Cheaper than Holley, PM Sterling or Rx7Carl (IIRC the carb rebuild runs somewhere close to $350USD but don't quote me on that!)


Tuneability:
Stock Nikki : Don't even think about it. Jets are expensive and rare (Mazdatrix for those looking) and taking apart the carb is a bugger with all the extra crap on it
Holley : Pretty straightforward, jets available many places, manuals available for tuning Holleys (but mostly for piston engines)
Sterling Carb : Uses Holley Air Bleeds as jets (ingenious!), so they're much easier to find than the stock Nikki jets. Although there are no manuals available, Sterling and Carl offer excellent support and many of the books made for Holleys and other carbs concepts apply. But shhhh.... jetting is the best kept secret to tuning


And of course, I'm biased. I've got an Rx7Carl/Sterling Carb myself, for those reasons.

I also find the 4barrels above more streetable IMHO compared to the 2-barrel carbs. But that's just me.

Jon

 

Im biased also. This will beat the competition on N/A application.

 

Wow whacky, that's forkin' nice !

Jon