Crispin38

iTrader: (3)

I'm also swapping my 12A for a 13B. But, i'm going with a 91 6 port, street ported, maybe even bridged. I'm still debating on what kind of intake i'm going to run.
I currently am running a 48 IDF on my 12A monster port, i love it. It's been good to me, i have it jetted and haven't had to touch it. Just change the idle mixture every once in a while. And i could go the same route with the 13B and just buy and intake and use my 48 IDF but i'm thinking about going to a Holley.
Here's why:
-Cheaper
-Thinking it would get better fuel mileage if get it jetted correctly
-More torque and upper end being a four barrel.. Maybe. I think power will be same.
-Much easier to find/buy jets and other misc parts. I mean hell, you can buy just about anything for them at an oreilly's. And the parts are fairly inexpensive. Where as most weber parts are expensive, and sometimes hard to find depending on what you're looking for.
-Just looking for something different i guess.

What's everyone's opinion/results on Webers + Holleys on 6 ports? Stock/Ported/Bridged?

Thanks,
Crispin

rxtasy3

iTrader: (2)

well u should be able to use the current carb, just get the intake to put it on the 91 engine. i currently run a holley but have used both a holley and mikuni on a stock 12a, and the holley did get better mileage over the big 2 bbl carb to me simply cause ur running off much smaller primary throttle blades. but with those smaller throttle blades, the throttle response is no where near as much as with the larger ones. but at WOT, to me they're the same.

clubber

Does someone even make carb intakes for six port motors? And will it actuate the ports like the fuel injected motors will?

j9fd3s

iTrader: (3)

it might get better mpg, you can jet it lean on the primaries, and then tune for power on the secondaries.
my friend used to get 26mpg on his full bridge 13B.

power, http://www.twminduction.com/ThrottleBody/carb_vs_fi.pdf page 4 there is a graph of the EFI vs holley VS 2 barrel carb

84stock

iTrader: (5)

Only if you get the racing beat upper to mount to the factory lower intake and use a side draft carb. A great option though for an auxillary bridge n/a engine with atkins sleeves!

rxtasy3

iTrader: (2)

yes and yes. it's just an upper intake change for the side draft carbs which will retain the lower intake and actuators. now u can get a holley intake for the 6 port but it will eliminate the actuators.

Crispin38

iTrader: (3)

Yeah, i've thought about using my current carb but i really want to get a Holley. Simply for the better fuel mileage, and parts availabilty like i stated.
I also think that i can make it much more 'streetable' I just need to find an intake and a carb now.. Something close to the RB 6-port kit.

j9fd3s: Wow, 26mpg? I'm going to shoot for that. Lol. And, interesting link you posted. I would've thought the fuel injection would've blown the holley and dellerto away, but, it's mainly throttle response and some torque that you gain with fuel injection.
I'm still not convinced that FI is just way better then Carb. It is better, but that's a whole nother debate.

rxtasy3

iTrader: (2)

jaytech has similar intakes for the holley. i'm wanting to try an edelbrock carb.

Crispin38

iTrader: (3)

I'm thinking the same thing, but, i'd be reinventing the wheel if i did.

Directfreak

iTrader: (2)

I've had both, and on a normally aspirated setup, I prefer the
IDF setup. The IDF doesn't smell as bad, has decent top end,
very clean install, and also compatible with the 6 port actuators (which you definitely want). The car will feel quick and nimble.

The Holley setup is mounted 90 degrees different than every other car, and has tendencies to slosh fuel and shut off on hard turns. Holley is good for all out drag race/top end. You will lose the 6 port actuators if you go Holley. Plus, the Holley seems to always have a strong Gas smell because of the large bowls.
The throttle response of the Holley can't compare to the IDF.

One real advantage for the Holley - it is a great way to eventually upgrade to a blow-through turbo setup.

Just my 2 cents. YMMV

Crispin38

iTrader: (3)

Hmm.. I'm still thinking about it. Thanks for your opinion.

Jobro

iTrader: (2)

Fuel injected stock manifold will make the best power and best spread of power. All you need is a fuel only MT4 a handset and a stock SE pump in good nick.

Directfreak

iTrader: (2)

^^^ Another good alternative. ^^^

bumpstart

adapters like this can be found in australia ( ASK ) to convert s4/5 4 port or 6 port to 13b hitachi or 12a nikki carb manifolds
( and by default to any weber manifolds )

i see you only requiring this adapter ( 6 port 13b to 12a manifold ) and a set of 13b extractors
as the cheapest and easiest solution to your conversion
it will deny you the 6 p actuators ,, as will most other choices aside those that retain the OEM lower inlet manifold

will it matter much?? no,, i have run 6 p engines with 48 IDA weber and found that its quite a good combo
i dont expect the IDF to be any worse here , in fact a little better

yes,, with unstaged carbs you lose out below 2500 in throttle response compared to staged EFI or four barrel carb
-- easily fixed with a 4.44 rear gear,, more bottom end than you can handle and response everywhere at the tip of the throttle

personally my experiences with weber on s4/5 6 p engines and that with a holley intake and manifold ( also on a 6p engine ) are chalk and cheese

the holley was out and out a fiddly pain in the **** that never worked 100% ever,, and with lots of nasty traits
and the webers ( 48 IDA ) just worked,, worked well, and where exceedingly easy to service

i would be tempted again by another 6p /weber combo,,,but if offered a free holley setup i would turn my back on it .

Crispin38

iTrader: (3)

Thats an interested piece bumpstart. But like i've stated, i've thought about getting an adaptor and just using an 12A 4 port intake.
I just really think the Holley would be much more drivable on the street than my weber day to day, being that it's a four barrel.. My Rex is my DD. If it was something i drove once a week or once in forever then i wouldn't hesitate to put my weber back on. It's been good to me. TBO, it was better than my nikki..

bumpstart

and when i had a weber , 6port and 4.44 it was in an rx2,, and was also a DD

you need to look at that EFI dyno results in the link above again

dellorto ( the closest equivilent to your weber ) is absolutley raping it for power curve
( just doenst have the same peak as EFI and holley )

the EFI,, second,, the holley a distant third

this power curve,, while not peaking to the extremes of the holley and EFI
demonstrates that the dellorto ( and likely your weber ) is a much more responsive drive at low to mid range rpms over the other two

this is what you look for in DD's

Crispin38

iTrader: (3)

I understand that.
But, the graph is comparing at WOT.

Crispin38

iTrader: (3)

Here's what i'm thinking:
Carb: http://www.webercarbsdirect.com/40_DCOE_p/19550.174.htm

Intake: http://www.racingbeat.com/RX7-1975-1...ake/18100.html

Then i can use the original 6-Port lower manifold, and the carb being 300$ and the upper man only 150$ i don't think this setup can be beat now that i really think about it. I mean, i know how to tune the weber, and i've always wanted a 40 DCOE side draft. So, i think this will be perfect.

Japan2LA

iTrader: (256)

Here are a few options

I have the TII LIM (modified to work on a 6 port block) if you want to go fuel injection

$275.00 Shipped outright or $230.00 shipped if you send in your own TII lim

Also

I have weber IDF manifold ( modified from 13B 4 port to 13B 6 port) if you want to go with an IDF weber

Brand New $350.00 Shipped

theNeanderthol

iTrader: (1)

Sounds like a good setup to me. Although I'd use a 45 dcoe at least. Actually I remember a few carb gurus here saying that even a 45 is too small for a 13b.

Robert from rotary shack (I know some folks don't like him, but no-one can refute that he knows his stuff) says a 13b always needs a 48 (ish) in weber style carbs and a 45 is always too small for a 13b.

I remember Hyper4mance once stated that even with the same venturis, a larger carb will have more of a pressure drop, across the venturi, than a smaller carb. (and better performance) Maybe he'll chime in and clarify, cause I'd love to learn more about this. (Hope I'm not misquoting you, Hyper)

WackyRicer is always preaching big carbs and venturis and has magical carb tuning skills.

I realize you are looking at the 40 cause it's cheap, but the 45 dcoe is the same price. I also have a dellorto 48 dhla (racing beat modified) with the rb upper manifold you were talking about that you might be able to pry out of my hands. And a weber 48 IDA (the original italian one) too.

Also OER makes a weber copy in the 47 mm size. Robert uses it a lot on the 13b. Last time I checked you can find them for a pretty good price.

j9fd3s

iTrader: (3)

the 40 is too small! even the stock FC runs 3x45mm throttles!

it does seem like the rotary wants a 40-42mm venturi, if not a little bigger. it seems to be pretty ideal when the venturi is about 80% of the size of the throttle plate, so a 40-42mm venturi gives you a 48-50mm throttle plate...

theNeanderthol

iTrader: (1)

Cool! great little jewel of info there

Crispin38

iTrader: (3)

Was just looking at the 40 DCOE for better torque and fuel mileage over a 45 or 48..
I wish i remembered what chokes are in my 48 currently. I know they're big.

Siraniko

iTrader: (13)

concerned about fuel mileage? buy a honda civic or toyota corolla

orion84gsl

iTrader: (5)

^ This. Why do I not complain about rising fuel costs? My car is a sports car, and while good fuel mileage is nice, it's not on the top of the list. I bought and built it to drive the **** out of it. You can get good fuel mileage by keeping your foot out of it.