Carb and Intake upgrade

[jcarle]

Hello all,
I was looking into putting a carb and intake into my 79 L82 Vette. I was mainly looking at the Edelbrock Performer carb (600cfm) and Performer intake. I know my car already has a stock aluminum intake, and the quadrajet runs fine. Will I get any Horsepower or performance increase from the upgrade. I was told that it may not make a difference at all. Or, would I be better off with just a carb upgrade. I read a forum that the Performer Intake was one of the few that will fit under the L-82 hood.

Thanks for any help anyone can give.
Jon

 

[MaineShark]

The QuadraJet is a pretty good carb. They can be tricky to set up properly, but once they are, the air-valve-secondary configuration flows a lot of air.

Switching the inatke, but keeping the Q-Jet, is probably better.

Or, to put it another way: based on the advice I've gotten, I'm keeping my stock Q-Jet when I build my 406", 425hp engine.

Joe

 

[rpounds]

I agree with Joe. Switching to an Edelbrock is not an 'upgrade' from a well set up Quadra Jet. You probably will not gain any power by going to the Edelbrock. However, you may gain some throttle response due to the smaller secondary venturis.

Personally, I love the Q-jet and continue to run mine on my '75 vette and '68 Firebird 400. Set it up right and you can hardly beat it.

 

[Stallion]

I have heard about this Q-jet all around, but I never knew what it was. Is this a stock carb for early C3s or something? What's so special about it? A lot of people seem to rave about this.

 

[Mike Carter]

I love Qjets, I have a 69 Qjet on my 72 with an Edelbrock Performer, I chose the 69 Qjet due to metering rod size. Runs great, next I'm going to LT1 aluminum with same carb.

Mike

 

[Jack]

Jon:
Weiand makes dimensional equivalent to Edelbrock Performer 2101 ... Weiand Action Plus pn 8004. It fits under a stock low-rise base L48 71 hood with stock Qjet & stock air cleaner. Functionally, 8004 is as good ... maybe a teeny bit better than 2101 ... and it's a bit cheaper. No difference in quality. Just as 2101 .. 8004 will mate w/ most any brand carb.

Frankly, if your Qjet is in good shape & tuned properly ... I don't think you'd see any noticeable difference in either carb and/or intake swap. But there's one thing that will that's VERY cheap, quick & easy ... recurve your distributor. There's other threads/posts on distributor recurve/curve ... do a search. There's a fellow CACC member (Lars) here that'll sell you a kit w/ all needed parts & instructions for about $40 ... there are also papers here on recurve authored by Lars ... do a search. Changes to ignition curve do affect emissions ... sometimes better ... sometimes worse.

Stallion:
Qjet came on your vette when new. Like any carb, it's only good when it's in good shape & tuned. IMHO, Qjet is the best street carb for vette.

FYI:
Edelbrock makes (I think Weber makes em for edelbrock) two distinctly different series of "Performer" carbs. Those with part number beginning "14" are clones of Carter AFB. Those with pn beginning "19" are clones of Rochester Qjet. The 14's (afb) are cheaper but alotta guys love em. I recall several here w/ E AFB ... & others w/ E Qjet. I prefer the Qjet. As with any performance mod ... the potential for emissions-testing failure exists ... may or may not be an issue in your jurisdiction. Not an issue here in SC ... yet.
JACK:gap

 

[jcarle]

Thanks

I used all of your research. I think I am just going to rebuild the Quadra Jet. Still debating on the Intake.

Thanks for all of the help.
Jon

 

[JohnZ]

Q-Jets flow about 750CFM wide open, which is more than enough; rebuild it and set it up properly and you'll be happy with it. The small primaries generate a good metering signal for good throttle response and fuel economy, and it has all the secondaries you'll ever need when you stomp on it.

 

[FERL 73]

Don't rebuild the carb if it's running fine. You could try playing with the jets but I bet you wont see much improvement. Replacing the intake wont do much for you either. If it's running good leave it alone. Wait until you're ready to play with the cam and the heads and then look at the intake and carb. I don't know anything about the HEI distributor but the best bang for my buck was getting my distributor set up right. I agree with the others on the Qjet. It's a great carb when set up right. If you want to play with the carb look for one on ebay and rebuild it. It's nice to have one that you can plop back on with no down time.

 

[billybob]

Being a sucker for anything that shines....and is made by Edelbrock

This is what I got going on under the hood of the 75 as far as carb and intake

Edelbrock 21011 Intake Manifold
Edelbrock 8113 Thunder Series AVS Carb (800cfm)

And in case you were wondering... edelbrock valve covers, air cleaner, mini cleaner, performer cam kit, performer link timing chain, sure seat springs.

And to toss in a bit of other makers, holly fuel pump, stewart s3 water pump, power master mini starter, power master 140 amp alt, 4" hook side pipes, 10k rpm flex fan... and the list goes on.....

Can you guess the overall look... sparkling


Bill

 

[jcarle]

Very Nice. Someday mine will look like that I hope.

Do you drive it?

Jon

 

[billybob]

DRIVE!?!?! Whats that??? I havent even started it since I started the oh I'll just do a quick tune up and a few minor fixups

Thanks for the comments, I like the look of chrome/polished, just makes me all warms and fuzzy inside

If its not one thing its another the vettes, my wife is starting to think I'm opening a parts store, I've got 2 more piles like this out in the garage, most of the parts are of the I'll get to it eventually or I wonder what that would look like category. With 3 babies I find myself having to go back through all the old receipts due to the fact that my mind is not as sharp as it once was and I keep getting parts mixed.

They are a curse and the blackholes of the pocketbooks, I've told my son either own a vette or get wife/girl friend.. not both too expensive

My wife says I have an obsessive compulsive disorder, what can I say

Bill

 

[clar2001]

Edelbrock makes a Q-jet stock replacement I am running this with the performer manifold also smoge legal:bang

 

[Vader]

It's pretty easy to tune a Quadrajet for serious performance. Soem of the early- mid-'70s Q-Jets flowed at 800+ SCFM from the factory. These could be found on Olds and Poncho 455s in big trailer-towing wagons and sedans. The "regular" Q-Jet is really no different, except for a minor difference in teh primary treatment. The rest can be "equalized" by altering the secondary AV stop.

Tuning can be accomplished with AV spring windup adjustment, secondary metering rod and rod hanger changes, and a little dilligence. The 'B' hanger and "DR" rods are usually a good starting point for a relatively stock or mildly built 350 .

 

[Vette/Berlina-coupe]

-toward perfection of the beast...

-glad to see nobody advised installing any of the other brands of adaptable Carbs, because what you've got is unbeatable; --just install an overhaul-kit if need be, and then while you're at it pull-off the stock aluminum/Intake-manifold, grind-off all of the unwanted rough-casting portions and take to a chrome-shop and have it buffed--up real pretty-like...
~Bob vH

 

[jcarle]

Recurve

I just wanted to let you all know that I did the distributor recurve kit offered by Lars, and it rocks. I couldn't believe the difference it makes.

I put it into a ZZ3 345 HP GM Crate engine, and it made a big, fun, nice difference. I would recommend it, and it was an easy install. I was a little concerned about pulling out the distributor, but it was easy. Requires two people for the whole timing thing, but easy.

Thanks to all of you for your help.
Jon

 

[phxraptor]

Vader, Can a 81 Q Jet that is computer controlled be used on a built engine without being hooked up to the computer ? Thanks

 

[clar2001]

Question Bill not to change subjects but how did the 4" hook side pipes work hard install ...........any pics ?

75 stingray 350/400 project in works