OneRotor

iTrader: (3)

So while sitting at work today, my mind wandered to upgrading the performance of my FB. I have RB springs/Tokico struts, and I'm working on getting some Hawk HPS pads for my brakes. I have also done a LSD swap, and I am working on getting some Potenza RE-11's in a 205/50R15 size for my 15x7 4x110 Enkei 92's with a +7 offset. I am pretty good in the handling/stopping department, so now it's time to start thinking about power.

I had a RB 465 setup (now sold) on my old FB, and while (with Mechanical Secondaries, via the screw tick) it was a screamer above 4k, below 4k it was ridiculously flaccid. I am planning on autocrossing with Kentetsu this summer all over the Lower Peninsula, and am thinking about ways to increase my power across my entire rev range (because power under the curve > peak power in autocross). I have settled on a Sterling Nikki, but want to fully utilize its performance by eliminating the factory intake manifold, if possible.

What I'm curious about is this:

Has anyone ever attempted to have an adapter plate machined so the Nikki will bolt to the RB Holley intake? I seem to remember someone saying that the Nikki is taller than the RB Holley 465, thus this setup won't work because of hood clearance. This setup would combine the epicness of the low end of the Sterling carb (small primary venturies = high intake velocity = great fuel atomization = more low end power) with the longer intake runners of the RB intake (longer intake runners = more torque), plus the flow capacity of the RB intake (465 vs. less than 380cfm of the factory 12a intake mani) would make for a hell of an induction setup, ideally suited for autocross (among other types of racing, along with a more streetable powerband).

Just a thought
-Jim

EDIT: Hybrid Intake/Carb setup should be the title. MY BAD.

j9fd3s

iTrader: (3)

back in the 80's they used to sell adaptors to go the other way, put the holley on the stock intake.

i dunno, maybe a 390cfm holley would better suit you?

OneRotor

iTrader: (3)

I'd like to go with the Sterling carb for the smaller primaries, while still flowing the full 465cfm that isn't allowed by the factory intake manifold, hence wanting to know if the Sterling on top of a RB intake manifold would fit under the factory hood.

I would rather stick with the stock Nikki than deal with another Holley (I had all sorts of trouble with my 465).

Jeff20B

iTrader: (13)

What you need is an intake manifold from the '70s. They flow like dominos compared to FB manifolds. They even flow better than the sought-after '79-'80 manifold AND posses the correct casting to cover the ACV port below the intermediate ports. They're sickiningly rare, though. Maybe an old schooler around here will have one. It'll need to have channels or as j9fd3s calls them (and probably more correctly), balance ports at the top of the runners. I mention this because some old manifolds are seperate runner like your typical RB holley manifold, and it may not provide a proper vacuum signal on a Sterling-prepped Nikki or any other later Nikki unless you mess with the slow air bleeds or whatever else was changed when Mazda went from independant runner manifolds to channeled manifolds.

If all this is way over year head, sorry. Others can probably fill in the blanks.

PercentSevenC got to experience one of these awesome old school manifolds on a mild ported 12A for about a year before we swapped him over to a streetported 13B, and he has some fond memories.

To add icing on the cake, I swapped in an RB light steel flywheel and their dual pipe "Streetport" exhaust system on his car and drove it around for a summer. Man it was nice! Those RB systems are great and not restrictive at all on an NA 12A. The only things lacking from that equation were direct fire and a Sterling carb, although my stripped Nikki did a pretty good job on that excellent manifold.

OneRotor

iTrader: (3)

I am rocking the SP exhaust, as well as a pair of MSD Blaster 2 coils (thinking about a 6AL box to compliment them, but besides the rev limiter, i don't think there is much to gain).

I know I could use a lighter flywheel as well.

I *think* I have a 1980 mani sitting around somewhere, but it could have just gone with the '82 EUDM SA22C that I just sold.

So basically what you're saying Jeff is that if I could find a machine shop that was equipped with an extrude-hone machine, that would be the best course of action with matching the intake manifold's flow with the flow of the Sterling Nikki, to extract as much performance as possible from the Sterling, and that the RB Holley intake mani. wouldn't allow the Nikki to function properly because of a poor vacuum signal?

-Jim

Jeff20B

iTrader: (13)

I didn't say that at all. But if all you can find is an SA manifold, then I suppose you could have it extrude honed and have a piece of aluminum added to the bottom to block the ACV port on your engine. Or just clean the port in the engine really well and fill it full of quicksteel or some other decent quality putty.

The problem with the RB manifolds is they are pretty tall. The Nikki carb is pretty tall. Put them together and your air filter may touch the hood. You'd also need to cut channels in the RB manifold rendering it less desirable for future use with a Holley. Maybe someone else will know more about independant runner vs channeld runners and whether you can get away with a Sterling on one more easily than the other. Ask Sterling.

I do have an SA intake manifold if you need one.

OneRotor

iTrader: (3)

I have a FB manifold (the stock one), with my factory nikki mounted on it. I was just thinking of using the RB manifold for the Sterling Nikki. I am in contact with Sterling about the use of a RB intake, I was basically looking for your second paragraph, stating that the Nikki + RB intake = hood clearance issues.

Thanks.

84stock

iTrader: (5)

I would do a 500cfm edelbrock thunder series. This with give you completely adjustable secondary actuation and eliminate the cornering issues familiar with the holley. No offense to sterling of course. Oooooooor, port your fb intake and use the sterling.

OneRotor

iTrader: (3)

I'm thinking about finding a machine shop with the capacity to extrude hone and pay them to properly hone my intake mani.

Kentetsu

Interesting ideas. What exactly can extrude honing do for you?

One of the issues with using the RB mani on a Nikki carb is the change in diameter between the openings. The RB has a wider opening than the Nikki does, so to avoid having a huge step in there, which would disrupt the airflow, you'd have to have some sort of sleeve that reachs down into the mani providing a gradual change in diameter. Hmm, not sure I explained that very well.

Looking foward to tearing up the courses with you this year!



.

OneRotor

iTrader: (3)

Extrude honing is a process where an abrasive putty is forced through an orifice to remove material and polish the path the putty takes.

http://www.extrudehone.com/auto/auto-performance.php


http://www.directindustry.com/prod/e...shing-system-b
y-abrasive-flow-machining-afm-32425-181247.html

It'll be a fun summer. Hopefully I'll be able to dominate E-stock, or be put in the proper class and have some people to chase down.

-Jim