What size carby???

[kane_coro]

I live up in Coromandel and work 6 days a week.Nearly every one i know is either chev or mopar.Haha im the only "sick" holden fan as they call me.
Haha got offered a 750 double pumper but im guessing that would be way to much...
So if i dont go the quaddy way a holley 600 would be ample

 

[VNracer34G]

If you must run with a holley just go for a 600vac. list#1850,(the old blister pack carb) out of the box with minor acc. pump adjustment they give acceptable performance but wont be any where near as efficient or as hard as a HQ type factory intake with the secondary divider milled down and a well set up Q-jet.

 

[old mate]

quadrajet is epic for holden v8s, just set them up. and a peformer manifold may be better than the torker. depending on how many revs you pull, but for the street the peformer is way better.

 

[383 hatch]

Why does everyone think the performer is so good? It's pretty much just a stock replacement manifold....The Torker is fine for the street, it's not a high reving monster single plain.

 

[kane_coro]

For now ive got my hands on a holley 600,but will probly look into going down the quaddy path later on in life.Theres obviously a few different views on the manifokld side of things but surely the torker has to be better tha a stock manifold?

 

[ari666]

yeah the torker will be a good manifold, to be honest i am looking for one to replace my performer, but the ones to suit VK black are big $$$

the 600 will be a good carb and you will be happy with it, but the problem is it over carburates something cronic down low. because the quaddy uses vacuum for both primary and secondary metering the carburation goes up as the engine needs it, and you can do a couple of 'tweaks' to it to get a bit more fuel or air if you find you need it.

the primary metering on a DP is basically "put your foot down, primary pump will shoot a measured amount of fuel straight down the throat of the carb, power valve opens allowing even MORE fuel through, then metering takes over" which after mucking around with mine for AGGGGES i had to decide if i wanted to launch well or get good top end. fuel economy suffered both ways. lol.

the quaddy was just; tighten that spring, change this spring, change these rods, drill out this hole, set the idle, and BAM! it was awesome off the line and keeps pulling all the way through the rev range.

someone mentioned the 600 vac holley too, and after reading a really good post from delcowizid...

CFM = (CID x RPM x CF) / (2 x 1728)

CFM = cubic feet per minute
CID = displacmente
RPM = well if you don't know this one you may as well go to a different site
CF = correction factor. this is based on the VE% (volumetric efficiency) of the engine. i have a nice chart here for that in relation to cam duration but for stock heads and cams in the 240-250 duration @ .050 use .9

these numbers are all based on the standard 1.5" pressure drop across the carby. this is the part where it gets interesting because it doesn't take a lot of effort to get a decent intake to have less then 1.5" drop which changes the CFM rating of the carb.

there is however a formula for that too.

CFM / square root of( old pressure drop/ new pressure drop)

or 800cfm / sqaure root of 1.5/.5

= 800/1.732

= 462 CFM so a 800cfm carb (measured at 1.5" drop) only flows 462CFM @ .5" drop

(told ya i'd save it)
it would seem like that would also be an awesome carb for a mild 308, but the thing is, the quaddy can be setup to go above 800 cfm if modded right. so once again, out of the two i would still go quaddy.

but yeah. all that is useless info cos you have a holley

ok, well. setup your power valve, get your primary shot set right (there is a changeable cam on the pump arm) set your jets right and really take the time to tune it properley and itll run well. if a little thirsty.

i made this thread a while ago: https://forums.justcommodores.com.a...odify-quadrajets-also-vac-hose-diagram.121828 if you do land one and wanna play with it. they are pretty easy as long as you know what each bit does.

 

[old mate]

Why does everyone think the performer is so good? It's pretty much just a stock replacement manifold....The Torker is fine for the street, it's not a high reving monster single plain.

it does depend on the engine, but in my experience with both the manifolds on the same engine the performer was the better all round package for the street. sure it made more peak horsepower at higher revs but it lost too much down the bottom end to make it worthwhile. this was in a heavy car with tall gearing though, so torque losses are felt quite alot.

 

[kane_coro]

In my experience so far any holden parts are big bucks in comparison to chev or ford.I managed to get my torker for 250,was fairly happy with that.

but yeah. all that is useless info cos you have a holley

Theres no such thing as useless info ari666!I might save that qoute as well.
Got the Holley on today,600 vac secondarys.Just slapped it on and hooked it up and its already heaps better.My old one was poked.
I thought the only adjustment was on the accelerator pump and your idle mixture??

 

[ari666]

Got the Holley on today,600 vac secondarys.Just slapped it on and hooked it up and its already heaps better.My old one was poked.
I thought the only adjustment was on the accelerator pump and your idle mixture??

ah cool! i think that will be pretty good actually.

i dont know much about the vac secondary 600's to be honest, as i have only played with the 6150 sorta' series. but on a 600dp there is so much freakin adjustment itll drive you nuts. jets and secondary metering springs and powervalves and pump shots and pump cams and linkages and floats and vent whistles etc etc etc. i must say its fun playing with them all, but sometimes you just want a bit of fuel economy

 

[kane_coro]

Damn it....Just wrote a reply,clicked the wrong button and its gone.
It felt better instantly.Ive ben through the holley website and there is a little tweaking ot be done.A mission for the weekend maybe.
What sort of ignition timing do you run on yours?