bestcarb for mpg???

[jasonsnova]

ok seeing how gas prices are soaring and i just dropped tons of cash into my car putting a 6 speed in, i refuse to not drive it even though it might break the bank....so i am thinking about doing a carb swap or one atleast for around town and normal driving while keeping my holley hp double pumper for the track... so what would be the best choice ? i know double pumpers are nortoriously bad mpg... thinking maybe vac secondary holley or one of their street avenger carb? or maybe a edlerbrock? years ago i had a quadrajet on a v8s10 i had and that was good but ...man they are ugly! lol! while i would like to get a bit more mpg i dont want to totally kill my performance......so im open to suggestions!!!!!!

[Steve68]

They say the q-jet is the closest thing to F.I. and work really good when tuned right and not worn out,

[jasonsnova]

haha, ya but anyone know how to tune one? lol! not to mention ugly!!!!

[6'9"Witha69]

Use a spreadbore holley Vac Secondary. Or a smaller squarebore.

I have a 600 cfm vac Secondary carb I use for long distance cruising. I conversted it to a dual feed center float and it has it's own rail. I keep the big one (780) in the trunk and it is only 2 clips, 4 nuts and a hose clamp to swap 'em. MPG is vastly improved this way. Also make sure your vacuum advance is dialed in well.

[jasonsnova]

well not sure if a 600 would be ok??? i have a 355 9.75comp, bowtie heads, vic jr bowtieII intake, and a big solid lifter lunati cam it .528 int lift and .534 ex...forget the dur but the poweband is 3500-7000 so its alot... wishing i swapped the cam out when i had the motor out this winter but... im open to suggestions?? i noticed that the holley street avengers take the same fuel line as my 4150 so swaping back and forth would be easy with one of those.

[6'9"Witha69]

My 383 runs 10.8:1, has a roller cam w/ ~.540 lift and ~.235 dur @ 0.050. Dart Pro 1 alum heads (215) and an RPM with a 1" spacer. You just need to set the 600 up right. Then again, my 114 lsa helps with the vacuum stuff.

[JMarsa]

I second the Quadrajet. Get one built for your combo and it'll do great for power and economy. And yes you can tune them.

--JMarsa

[jasonsnova]

ya problem is a quadrajet is like reading russian......i dont have a clue!!!! .....holleys are easy

[Steve68]

I have 2 Q jets stashed in the attic both off big 455 and a 425, just for that special occasion.

[Karch]

Contact Cliff Ruggles for qjet's. He has a long waiting list. He also just wrote a book on it.

[Adam's 55 Chevy]

Edelbrock 600. fit it and forget it.

[jasonsnova]

i had a edlebrock on another truck for a bit i couldnt get the dang thing to run for crap, but i think something was screwed on it. another friend had one on a mustang and he said it got 2x the mpg of a holley double pump. also whats everyone think of the holley street avengers????

[PTAddict]

I've used a bunch of carbs - Holley, Edelbrock, Q-jet - and the Q-jet is definitely the best I've used for MPG and around-town drivability. And they're actually not so difficult to tune - you can usually dial them in just using idle screws and mixture rods. Some tuners think they're easier than Holleys ...

[73ta]

An 800 CFM Quadrajet. Stay on the small primaries good gas mileage and good throttle response, like a 600 CFM carb. Open the secondaries big CFM carb without having two carbs. I've got one from Cliff, runs like fuel injection. Best carb I've ever run and I've had stock Quadrajet, 800 Vacuum Sec spreadbore and 850 double pumper holley on my motor.

[Goatman]

Use a small Holley (650cfm would be my recomendation) with vacuum secondaries...


Q-junks have a gay factor of at least 1,000,000....While the Holley vac. secondaries are around 10.........

Alternatively, the Q-junk makes an excellent shot-put-into-the-dumpster toy for you and your friends... Fun for the whole family, really.

[DusterRT]

Thoughts on adapters to put a Q-Jet on a square bore intake?

[Goatman]

Only thing gay-er than a Q-junk on a Q-junk intake...........

[jasonsnova]

wow you really dont like q-jets huh? ....i will admit they are extremely ugly. but their seems to be alot of support for them here!
by the way who is this cliff guy that builds them ? does he have a web site or something???

[Goatman]

Ugly and useless. Two things they accel at.... Never been a fast car with one on it and the gas milage is the same.

There's a reason they aren't made anymore.


And most Pontiac guys like them because they're numbers matching stuff... See my sig for the deal on matching numbers...

[Karch]

Goatman, while I don't use one, I disagree with your comments.

There are plenty of people who swear by them. They definately have their place.

They aren't made because e-brock couldn't get them right, though Cliff says that if tweaked, the e-brocks are really, really good.

Also, GM stopped making them after what, 16 years or more? Hmm, perhaps because they decided to go to efi?

Cliff is Cliff Ruggles...

http://www.cliffshighperformance.com/

http://forums.performanceyears.com/f...r.php?u=140049

http://www.pontiacstreetperformance....uild455cr.html

You can't just go by one or two bad apples. When I started with Pontiacs, it was taboo to port the heads or change the intake seat to 45 degrees from 30.

Q-jets are good when matched right, and usually don't flow enough to support more than 600 hp...and around 500-550 they start to reach their max efficiency versus other carbs. But, if you are after mileage, throttle response, and good street performance, call Cliff.