Edelbrock carb vs. Holley

[mike561]

For those of you who dont know my engine, i got the 83 caprice, 5.0 305 engine all stock only with an edlebrock intake manifold and dual flowmaster 50s (still have the stock headers though) i have a few questions:

1. Which will i get better performance from holley or edelbrock?

2. which one if not both, will hookup to the electrical connectors that are currently connected to my 4bbl quadrajet? (choke, tps sensor etc)

and last, will i notice any power gain at all and decrease in fuel economy from the two?

[Blt2Lst]

Originally Posted by mike561

For those of you who dont know my engine, i got the 83 caprice, 5.0 305 engine all stock only with an edlebrock intake manifold and dual flowmaster 50s (still have the stock headers though) i have a few questions:

1. Which will i get better performance from holley or edelbrock?

2. which one if not both, will hookup to the electrical connectors that are currently connected to my 4bbl quadrajet? (choke, tps sensor etc)

and last, will i notice any power gain at all and decrease in fuel economy from the two?

If you are going to retain the electronic functions of the carb, you are pretty much stuck using an electronic Qjet carb. The Holley and Edelbrock do not have any provisions for those components. Holley does make a spread bore carb like the Qjet design but they are totally mechanical and do not have electrical components.

If you want a Hi-Po electronic Qjet, check these guys out.
Normally, they modify the secondaries for better performance and leave the primary side stock to pass emissions. However since you do not have to pass emissions, they can rework the primary side for better performance also. They can rebuild yours or you can buy one of theirs. Give them a call and tell them what you are trying to accomplish.
http://www.smicarburetor.com/product.../productID/433

[mike561]

ok ill look into that, if i were to go with an edlebrock or holly which one would be the best for performance gain? also if i were to install one what do people do with the wires that connected to the qjet just throw em aside? i know the edlebrock and holley have the connection for an electronic choke though...

[NOVAZ27]

If you have the COMPUTER CONTROLED Q jet your dist is a CC HEI. dist. If you should change out the carb to a non CC HEI. carb the dist. will have to be changed out as well. I just did this on my SILVERADO. What tranny do you have? If you have the 700r4 overdrive you will probably need to retain the CC QJET, CC HEI, COMPUTER ETC. since the computer controls the transmisson. There is a stand alone circuit available to control the transmisson. Lots of factors to consider here.

HOPE THIS HELPS NOT HINDER.

[96capricemgr]

Everyone hate the Qjet mostly because it is complicated and easily screwed up. Long as they are in good shape and you don't mess it up "adjusting" it they are great carbs. Tiny primaries for cruising and huge secondaries for WOT operation. Most of them were 750cfm, not that a 305 can use that. A 600cfm aftermarket like you are looking at will do the job but is NOT an upgrade.

[mike561]

yeah i got the 700r4 trans

[MagicRat]

Originally Posted by mike561

yeah i got the 700r4 trans

Your transmission is not computer controlled, so you have no problem there.

I'm not sure if you need to replace the distroubutor with a non-computer HEI, though. But they are pretty easy to find and install.

Here is a thread that addresses the Holley vs. Edelbrock issue. Note my incredibly well-informed post in the thread.

http://www.automotiveforums.com/vbul...d.php?t=331440

[Blue Bowtie]

Actually, while the trans is not shifted through the ranges via solenoids like later models with full electronic control, the TCC is controlled by the ECM. Running without a lockup will increase transmission heat, but there are vacuum switches and stand-alone controls which can replace the ECM in that regard. Moreover, the ECM relies upon the inputs of the 3/4 range switch, TPS, BARO, and CTS to operate the TCC and to trim timing and fuel for more efficient highway driving. This happens even on an '83 Caprice (unless it is an export model). As we all know, the E4ME can be altered to flow upwards of 780 SCFM without touching the die castings and meter fuel correctly all the way through the range. Some Pontiacs got 840 SCM units, and heavy work will get you 890 SFM out of the "lowly" QuadrJet.

Thankfully, we can no longer purchase any street vehicle with a carburetor. I've been through enough one-, two-, and four hole Autolite, Carter, Edlebrock, Ford Three-barrels, Holley OEMs and aftermarkets (including Detroit Aero carbs), Mikuni, Motorcraft (and Holley and Carter) variable venturis, Nikki, Rochesters from BCs to E4MEs, Solex, Tillotsen, Walbro, Weber, and Zenith carbs. That includes updrafts, sidedrafts, downdrafts, leakers, squeakers, leaners, burners, and LP and natural gas carbs for industrial and stationary engines.

Finding a place where the words "sophisticated" and "carburetor" are linked is always a source of humor. While many of the better designs from the past were indeed complex and quite intricate, the end result of all the artistry and detail is that they don't hold a candle to the much more simple and flexible injection systems currently available (except those programmed by Toyota).

In terms of accuracy and flexibility, probably the best automotive version of a carburetor designed was the Carter ThermoQuad with temperature and barometric compensation. In terms of reliability and best all-around performance, the QuadraJet stands above all others. In terms of all-out fuel delivery, Holley takes the crown, but with a substantial penalty in driving manners and fuel metering finesse. When the QuadraJet introduced the mixture control solenoid, the game was over for everyone else. Even the last versions of carbureted Dodge trucks used QuadraJets in order to meet emissions standards and make decent power and mileage.

In short (even though it's far too late for that) if you have the E4ME already installed, stick with it, learn about it, and make it work. Anything aftermarket you install will only be a step backward. If it were mine and the vehicle is worth keeping, I'd consider a TPI conversion given the weight of the vehicle, likely low gearing, and typical output of the 305. An LT1 conversion with a modified (Millican style) intake would a close second choice.

[MagicRat]

^^ Good post.

As I mentioned in the other thread linked above,
If one has a stock or near-stock GM car with a Q-jet, keep it and tune it right; it will be just fine.

I like carbs, but as mentioned above, factory-stock EFI systems are great. The old TBI (OBD 1) systems are relatively easy to convert to your 305 and are superior to a carb in almost every way.

IMO if it were my car, I would simply tune the stock carb and leave it alone, or replace the entire engine with a TPI 350.

[mike561]

speaking of the lockup solenoid in the 700r4 trans, is there any danger disabling that via the wire at the brake pedal? I am getting so aggraveted at having to stomp down on the gas for a moment to get it out of lockup at cruising speeds, its bogging down acceleration (thats another issue im having)

[MagicRat]

Originally Posted by mike561

speaking of the lockup solenoid in the 700r4 trans, is there any danger disabling that via the wire at the brake pedal? I am getting so aggraveted at having to stomp down on the gas for a moment to get it out of lockup at cruising speeds, its bogging down acceleration (thats another issue im having)

No, you can drive around with an unlocked TC without difficulty, so long as you have a decent auxiliary transmission cooler (which you should have anyways).

You ca add a simple toggle switch to the existing TCC circuit so you can flip a switch and disable the lock up entirely at-will.

[mike561]

ok i will do that, when would i need lockup anyway and what is it for? (i live in FL so we have no hills if that makes any difference)

[Blue Bowtie]

When the torque converter clutch locks the engine and transmission are directly coupled. There is no slip (stall, or K-Factor) in the torque converter and thus no oil shear and heating caused by the TC. This improves fuel mileage and helps sustain the stator and turbine in the TC for longer service life.

The down side is that through about 1987 many cars had programming which locked the TCC too soon and released it too late, causing frustrating driveability on slight inclines and in passing. My '85 Caprice was just awful that way.

A custom PROM can solve this by adjusting the TCC setpoints and LV8 factor for releasing the TCC. I did this on my '86 TA and it acted like an entirely different vehicle, really waking up the car from a rolling start under 45 MPH and making the higher speed TCC operation smoother. With the factory program it held on to the TCC and lugged like a lumber truck until the throttle was depressed enough to drop from OD to 2nd at which point the engine hit excessive RPM and went berserk. The new program made for a lot better transition from lockup to OD to 3rd and back.

You can burn your own PROM and convert your MEMCAL or get an aftermarket MEMCAL such as this:

http://www.jegs.com/i/JET+Performanc...18301/10002/-1


Your other option is to manually lock it out with a switch as the Rat suggested - It's probably faster. You can also just slightly tap the brake pedal to release the TCC without kicking down a gear.

[mike561]

yeah i have been tapping the brake just enough to release it, makes a great difference but i wanna just be able to disable/enable it on command. If i were to put a toggle switch to lock it out (which i probably will) when would i need to enable and disable the tcc with the switch? or would i just leave it disabled?

[Blue Bowtie]

I would use the TCC where practical, such as sustained highway driving. When traveling around on short trips, lots of slow-and-go driving, and under 45-50 MPH it may be better to just turn it off.