What carb to get??
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 3,264
Likes: 3
From: Toms River NJ
What carb to get??
Ive been contemplating upgrading carbs recently...I have a Edelbrock 750 right now with vacuum secondaries, but a friend of mine was telling about how when i launch the car it looses its vacuum some and causes the secondaries to close, which makes sense cause i can sense what hes saying when im just cruising around on the streets cause if i dont let the clutch out slow or give it a lot of gas, itll bog down...
So i was thinking of going with mechanical secondary carb...As far as i can tell Edelbrock doesnt make a mech. secondary carb :bs . So what would be the best carb to go with?? If its a matter of gas mileage, i dont really car since its not my every day driver.If there is one with a electric choke i would rather get that, but if not id put one on after the fact.
Thanks....I appreciate your help...
Chris
[Modified by 74VETTE, 2:38 AM 11/24/2001]
So i was thinking of going with mechanical secondary carb...As far as i can tell Edelbrock doesnt make a mech. secondary carb :bs . So what would be the best carb to go with?? If its a matter of gas mileage, i dont really car since its not my every day driver.If there is one with a electric choke i would rather get that, but if not id put one on after the fact.
Thanks....I appreciate your help...
Chris
[Modified by 74VETTE, 2:38 AM 11/24/2001]
Senior Member since 1492
Joined: Aug 2000
Posts: 87,932
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Re: What carb to get?? (pats406nitrovette)
I switched from Edelbrock to a Holley 3310 750 vac sec. This carb is a dual feed and not the double pumper. I was pleased with the ease of setup and outa the box plug and play traits of the Holley. It needs less tinkering than the Edelbrock which could never hold the idle speed?? I too question the value of the vac secondaries. Eventually I'm going to switch to a 750 double pumper with mechanical sec.
I don't remember exactly, but I think the Demon's were much more $$.
I don't remember exactly, but I think the Demon's were much more $$.
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: What carb to get?? (74VETTE)
What is wrong with vacuum secondaries? If they are set right, they work great..... Especially on the steet. When you open the throttle, the vacuum does get lower but so does air velocity through the carb. This air velocity is what "pulls" fuel through the jets and delivery system of the carb. With a huge vacuum drop(like wide open throttle with mechanical secondaries) there is no air flow through the venturi's so performance is terrible (That is why a BIG one barrel won't work.). As the engine speed increases so does air/fuel flow through the carb. when the vacuum gets high enough to add more air fuel ( via the secondaries) they begin to open. This timing/rate is adjustable by the secondary diaphram on Holley's. On others they are adjusted by the air valve spring tension. So you have a "demand system" that will control the fuel/air flow as needed. When the secondaries open all at once, you will get a huge "bog" unless the engine is running fast enough to handle that much flow.On the strip you are revving the engine and pretty much keeping it wide open and mechanical secondaries work OK.
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Re: What carb to get?? (silvervetteman)
Why not a Q-Jet? Mine feeds my mildly modded L-48 (see sig) and still gets 18-20 mpg on the highway. It is actually a very sophisticated design.
Primary fuel flow is controlled by a power piston with a spring. Less vacuum more gas, like it should be. Secondarys are mechanical but with a large air valve door that only lets in as much air as the engine needs.
Primary fuel flow is controlled by a power piston with a spring. Less vacuum more gas, like it should be. Secondarys are mechanical but with a large air valve door that only lets in as much air as the engine needs.
Instructor
Joined: Nov 2000
Posts: 220
Likes: 0
From: Overlandpark Kansas
Re: What carb to get?? (silvervetteman)
When I add my Demon with mec secondaries the diference was big. If set up right there is no bog. But you have to spend some time to get it right but when you do there are great.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
