struhall

i was thinking today... i know, scary to hear.

i was thinking about taking a racing beat peripheral port intake, turning it upside down, and bolting it on top of a weber downdraft manifold, and using the rubber hose part of the p port manifold to mount a couple of mikuni side draft motorcycle carbs. of course i would have some way of supporting the carbs so they wouldnt move.

but does this sound like a good idea to anyone other than me? and has anyone ever thought of this or tried this before.

and another question, how exactly do they measure the size of a carb? ive seen 48 and 51mm weber carbs, and i dont know where or how they measure this.

i know someone will say i should just find a side-draft manifold, but the only way i have done that, i would have to use a stock lower manifold (which i do not have), and the stock manifold will not clear a stock s5 turbo and manifold without a spacer.

struhall

forgot to mention that this is on a gslse 6port 13b.

Yellow '79

is there any gain to this mod or is it just to say i did that?

struhall

because i want to eventually do a blow through setup, and i hate my holley carb. i figure it would be easier to do it on a side draft, than with a downdraft or a holley like i have now.

and i just think it would be fun to try something new.

Naegleria_Fowleri

I'm not quite sure why you would really want to do this. If there was really anything to gain from doing this, don't you think people would have already?

And if you want a sidedraft, they do make a kit for side drafts through Racing Beat. I can slightly understand the allure of doing something new; however, the things people do now are tried, and proven to work. It is foolish to start trying to do new things to a car that is this old, unless its modifications that haven't been available until recently. (ie: 13BEEF making carbon fiber stuff)

May I ask why you hate your Holley though?

Midwest 7's

iTrader: (4)

https://www.rx7club.com/1st-generation-specific-1979-1985-18/whats-best-aftermarket-carb-setup-463766/

some guys talking about 500ex carbs or something.

im gona say not a good idea though.

Naegleria_Fowleri

I really think the Webers are probably the best carb to buy. I bought a Holley because it came as a complete kit and I needed something then. I wish I would have been a bit smarter in buying it and went with the Weber now, but overall my Holley isn't a bad carb either.

Midwest 7's

iTrader: (4)

they're like the only sidedraft you can buy new thats setup for a rotary. the mikuni and dellortos are just as good but nobody makes them rotary specific anymore, at least not to my knowledge.
i guess wolf creek racing sells mikunis, i think.

struhall

i dont like the holley because i have problems driving really curvy roads, and having the car start to buck in the middle of a corner is something i do not like. i have about 10 years experience with mikuni bike carbs, and i know how to do just about anything with a mikuni. plus i can get new ones cheap through my shop.

if i would have started with a stock car, i wouldnt have bought a holley setup, but the car came with a holley manifold and bad holley carb on it when i got it. im just making it work with what i have now, and im getting tired of it, and i want to do something new.

the link midwest 7's posted is very similar to what i was thinking. i dont know, i was on the racing beat site, and saw the p port manifold and the idea just popped into my head. if anyone knows of a site that has complete side draft manifolds for the 13b that dont use the factory lower manifold, i might consider that, because i dont have the stock manifold, i just wanna do something new.

Naegleria_Fowleri

The whole bucking around corners thing is why I wish I would have went with a different setup myself. Mine doesn't really do it all the time, just depends; however, I've also taken a turn so hard that it ran my engine so lean it killed it thanks to the Holley carb. Someday in the future I will change carbs, but right now I'll work with my choice, as good or bad as it may have been.

I was just curious as to whether or not you were having a different problem than that with your Holley.

struhall

thats really the only problem i am having other than running rich, and i know how to fix that. i have noticed that the car doesnt do anything really strange when im taking it easy, just when im getting close to 85-90% of what i wanna do that it will buck on me, and i dont want to find out how well the car stands up to a tree.

struhall

another question. how do you measure the size of a carb, like the racing beat 48 ida carbs?

trochoid

iTrader: (6)

That's the inner diameter of the throttle bore, from there chokes are added inside to change the diameter and add more venture effect. My Mikuni 44 PHH has 39 mm chokes for example.