CamaroMan81

I have an 82 Z28 305 stock setup. QJ needs rebuilt. So I have decided to replace it. I know the 305 is not the best engine for performance but I would like at least alittle more ***** out of. Any suggestions would be great.
Thanks. PS this car has only 48,000 original miles if that is of any help

midias

There is NO other carb you can just bolt on and get more power than a Q jet on a stock 305.

Rebuild the Qjet, add headers and exhaust and tune it right.

RedLeader289

iTrader: (2)

There are many carb selection calculators/etc on most carb company's websites. Sounds like a 600 cfm would do you just fine though. Perhaps some exhaust w/headers and a better air filter too?

naf

iTrader: (7)

Again. the stock carburetor is not holding your motor back. properly functioning, the stock ccc-qjet system will support much more power than you're likely to get out of that 305 until you go with a fairly radical cam.

changing out the stock carb renders the ECM useless. since the ECM also controls the electronic distributor, you'll also have to swap to a mechanical distributor. you'll also need some other mechanism for torque converter lock up if you have an automatic.

the money and effort to swap all of that stuff on top will, in the end, yield no power increase and likely worse mileage. put that effort towards fixing what you've got and the mileage increase alone will likely pay for itself fairly quickly.

CamaroMan81

The mechanic I took it to told me the Q jet carb is garbage and I'd be better off replacing it rather then going with the rebuild. I'm not looking to make this car a monster just alittle more power, since at the moment I drive this car everyday.

midias

You mechanic probably does not know how to rebuild a Q Jet and he is covering his ***. THERE IS NO CARB THAT CAN REPLACE THE Q JET AND WILL MAKE MORE POWER ON A STOCK OR NEAR STOCK 305

Get the Q jet rebuilt and add headers and an exhaust.

RedLeader289

iTrader: (2)

I don't know much about quadrojets, and you and I have agreed on some things in the past, so please just take this as my own curiosity (and for further enlightenment of the OP): Why do you say that? as in, what's your backing on the statement?

naf

iTrader: (7)

The carburetor is not the bottleneck in the 305. The qjet is just as capable of supporting a streetable build as any other carburetor (with an automatic trans, anyway).

The carb just mixes gas and air, and provided each is tuned correctly, swapping one type for another on a 305 isn't going to make a noticeable difference in power. The ccc-qjet has the advantage that it is, to a degree, self tuning for the primaries. The secondaries operate exactly as the mechanical qjet model and respond to the same mods and tuning requirements. The ccc-qjet only has some trouble when a non-computer friendly cam is used, although it is much more tolerant than many other FI induction systems. I use the system on a 350/vortec/xe262 motor with excellent driveability and 19-21 mpg. Many other users have similar experiences.

It's a shame to go backwards in technology, especially farther back from a system that is already 30+ years old. I might recommend it if the existing system is completely shot and I already had most of the parts. But buying new carb/dist/etc. can be a hefty chunk that could possibly be spent on a more modern FI system. Just saying.

midias

First here is a nice link about rebuilding them.

http://www.carcraft.com/techarticles...d/viewall.html

Second besides the cost of having to buy a new intake manifold, distributor and Tq converter lock up kit you are not replacing any type of bottleneck.

First off the Qjet is a 750cfm spread bore. This means the primaries are smaller and it allows for great low end and MPG that a standard square bore of similar size would never be able to achieve on such a small engine.

Because it can flow to 750cfm any modifications you do to the 305 you will still not bottleneck the system. It also has vacuum secondaries so when the carb is properly tuned it provides really impressive streetability and MPG.

The computer controlled aspect of the Qjet is superior to a mechanical distributor.

Basically what I am saying is any factory or near factory 305 cannot pull in more air than a factory Q jet can deliver. A 600 Holley will allow the exact same amount of air into the system because the cam, heads and exhaust are dictating how much the engine wants to breath. And both can be properly tuned to achieve the same A/F mixture but the small primaries of the Qjet will give it the edge on the street.

CamaroMan81

I'm trying to find a new qjet carb to replace the existing one all together. I haven't had much luck so far. I can't even find the exact name of the it other then qjet lol. I know jack about cars but I'm trying to learn. You mentioned headers and exhaust what would be some good ones to go with??

RedLeader289

iTrader: (2)

There are many headers that would work, I have hedman longtube hedders on mine, alot of people run shortys. Exhaust depends on your taste and local laws regarding emissions (do you have to have a cat or not, etc).

midias

You can order rebuilt carbs from autozone or send it out to be rebuilt. Some people around here like karbking.

Or these people they have done well in the past for a few friends

http://quadrajetcarburetors.com/quad...g-service.html


What type of emissions do you have? Do your headers need airtubes? How about a converter?