4 barrel or webers?

[dlampe]

I realize that there is a price difference, but is there a performance difference? I have seen huge gains with webers on off road racers based on the VW motor, but is the performance gains as great on a well built 427. There are a lot of great intakes and carbs out there today. The webers look so good it is hard to pass up. I do race more than I cruise but I want to look good. Jay and Clois should stop laughing now! What are the pros and the cons?

[Bob In Ct]

Webers tend to like lots of RPMs so as to get some air flow. They look great at the shows and cruise nights but in a street car they need very mild cams and such. They tend to cost a bunch as well.

Bob

[Big-Foot]

Webers look awesome but they are a brass-plated-b!tch to keep in tune... The slightest bit of dirt in an emulsion tube will give you a carb that sputters, burps, backfires and generally runs like cr@p.
Now that iI've given you the bad news - The throttle response is pretty good, but not as good as a single 4bbl that is setup right. These carbs are meant for mid-range to top-end and really don't like low RPM use. When tuned right they are sweet as you can find. When in the proper RPM range, they will pull you off a corner like nothing else short of a good EFI system as they are darned near immune to cornering forces..

[Cal Metal]

The range of these carbs depends entirely on what you want the application to be. The big mistake is that people want the best of both worlds---a racing carburetor that will run like a kitten on the street. They can do both, but you need to set them up as either one or the other. Most often this is accomplished by either necking down the chokes and jet size for the street; for the track, just the opposite.

[SCOBRAC]

Webers are for cheese eating surrender monky's and guys who wear blue sports coats with gold buttons with mechanics named antionio...

That said webers offer a greater tunability over a wider spectrum than MOST (not all) 4 and 8v configurations. They look pretty cool too. The thing is what's great at 6000 rpm may not be great at 2500 rpm.

Big foot is right. Nothing beats an EFI. You can do a retro efi that looks like a set of 48 IDAs and you will be very happy. But you will look like a cheese eating surrender monkey (IMHO).

[lineslinger]

I had the same question when I started my FE build and ended up having a long phone conversation with CRACKER who has run both setups mentioned above. He offered up a lot of really helpful information and I finally decided to go with a dual quad configuratinon. TWM EFI was also a consideration, but for starters I decided to stay in a realm of which I had a better understanding. Who knows, one of these days I may get a blue coat with gold buttons and a set of "stacks" to go with it.
Mark

[trularin]

I believe CalMetal stated it best; what is your application.

For a car that is designed to be run in the 2500 to 6000 RPM ( or more ) range these are a good, but expensive, choice. Some formula car or a track car where there are a number of turns and bends.

For a car that will be driven on the street, oftten, these can be a headache. They are very sensitive to dirt, fingers ( people playing with them ) and gunk. They are a true racing atomizer, but can be a low RPM problem.

Just my $0.02

[dlampe]

This motor is a 427 so built to run between 2500 and 6500 mostly on the track. I do drive on the street but I would be willing to give up some performance on the street to be faster on the track.

To through another option in the mix, how about a tunnel wedge setup? Is this a good alternative? I would guess that the webers would be worth an extra $3000 to $4000 on resale.

[Cal Metal]

The problem with Webers that most people experience, for street applications anyway, is the transition at around 2,200-2,500 rpm. This often results in a slight hesitation or stumble.

There is a remedy for this, but it isn't much of a problem if the set up is to be used for racing applications, as the car is being run above that range almost all of the time, anyway.

The Webers will increase torque by around 20%, which is good when using a SB. They will increase the value on resale, but one has to remember that some people are wary of buying cars with a multiple carburetion set up if they feel that there is going to be a never ending "tuneability" issue. It cuts both ways.

The Webers are not hard to tune--the important issue is getting the initial set up (jetting, chokes, idles, cam) right for your specific application. To tune them is no harder than doing ignition timing.

As a visual stimulus, they are very hard to beat in the looks department. They are so massive on a SB, that it is the one big magnet that people point to when displaying your car.

[Adrian472]

Cal so whats the remedy for the hesitation or stumble?
thanks
Adrian

[MOTORHEAD]

Hey guys:
Click on the Inglese link to the left of the thread area, then click on "Weber-o-logy 101", and in 15/20 min you will be Weber experts!!

[Cal Metal]

Adrian:

Getting the idle/idle holders correct. Making sure your exhaust valve (sits in the float bowl) is correct.

The cure for some people is to drill a third progression hole in the idle circuit. It works well and is what the VW guys used to do on their high performance doonbuggies. You just need the correct jig in which to drill the hole.

[Big-Foot]

Originally posted by Cal Metal


The Webers will increase torque by around 20%, which is good when using a SB.

An increase of 20% over what and with what parameter engine?

[Lew Ledyard]

Do the available Webers flow enough for a BB? I thought that you need 58s for a BB.

[Mohuska]

I have 58mm throttle bodies from twm induction.....fuel injected and they are fantastic! .....They have throttle bodies for most engines...

With a good controller..you can make separate settings for street, track and strip. I think you get better throttle response from fuel injection also...

just my 2c....try twminduction.com

[RICK LAKE]

Mohuska I know that TWM says 58mm, thats on the inlet, what is the size of the throttle plate at the base. I understand that the manifolds had to be special or the webers to seal, not enought sealing surface. 48mm manifolds where hogged out. Next time you take one off measure the throttle plate. 2 3/8 is 58mm , theopening in the manifold needs to be 2 7/16 to cleareverything when WOT and the engine at operating temp. The only person I know running 58MM Olbergs has had this problem with gasket seals. I am looking at the same setup. I like the 10-30 hp in mid range over a carb. And the tork. Rick Lake