Need Some advice - Weber 48 IDA...
 

I got a 86' 13B 2-Port (for top end) with 12A Sides. All motor. I switched from a Holley 600 to a Weber 48 IDA.

I was wondering if anybody has a weber or has some knowledge about weber.

What kind of setup do you have:
Air Jets:
Main Jets:
Emulsion Tube:
Idle Jets:
Venturies:
Ball and Seat:


PS: Thanks in advance. The weber is a pain in my @ss. But I think it will be worth it.

Actually, the Weber should be pretty straightforward to tune, and once set up properly they don't change. First things first, I guess. What are you tuning the car to do? What are you calling a "two-port"? Are you refferring to a four port 13b as opposed to a six port? If you are using 12a "sides" does that mean 12a cast irons? Since the intake ports are located in the irons, all 12as are four ports as far as I know.

Start with fuel pressure - it needs to be really low with IDA's - in the range of 3.5.

For a street-ported motor, the old recommendations for a 13b are:
Air Jets: 160
Main Jets: 190
Emulsion Tube: F11
Idle Jets:
Venturis: 38 mm
Ball and Seat: 250 needle valve (I prefer grosse jets though!)

Believe it or not, on a bridgeport 13b the weber IDA 48 is not recommended because it needs to flow more. A machined carb or Gene Berg copy IDA 51 is considered more appropriate.

It's not really clear to me exactly hat quetion you are asking, but I can make some suggestions based on my experience. IDA's are great for racecars, but are a lot less desireable on street cars. They have no choke, and no provision for one so they are a real pain to get started and warmed up. In these days of expensive gas, it seems foolish to have to restart the car 4 to 10 times before you can even sit and rev an IDA equipped car repeatedly just to keep it running until it builds some heat. If it is for pure wide open horsepower with few partial throttle applications it is awesome for flow, but it is like stripping out your interior for weight. It makes you a little faster, but makes the car a bitch as a daily driver. Make sure the car never has to pass emissions with one of these.

Wackyracer will provide you all the info you need...search his name.
But...on my 13B 4-port...it has...

Air: 165
Main: 220
E-Tube: F-11
Idle: 70F9
Vents: 40mm
"0" discharge
250 needle.
Carter black/Holley reg. at 5 psi. (IDA's need at least 4.5psi)

Since you're in FLA...no cold starting probs...just like L.A. I daily drive IDA's without a hiccup. I get better mileage on my IDA than my 48 DCO...YOU'LL LOVE IT!!!!

Boswoj: Thanks for the info. What I meant by 2-Port was a I got two of my side topas bridged and the middle one streetport. Maybe I should have explained it better.

Jaime F: Thanks for the info. I was talking with my mechanic and he told the same thing you said. But he wanted to try out a couple things first. Like more gas less air. I just got some MSD 6AL's. So that should change it a little.

My Mechanic wants to do:
Air: 160
Main: 260
Idle: Stock
Emlusion: F11
Venturies: 44MM
Needle and seat: 3.3

I also have a muffler mid pipe that i can unbolt and bolt onto a stock muffler. So yesterday bolted on the mid muffler to the stock muffler and the car was hard to start. I think it's because of air flowing through. Sounded like back preasure.

If anybody has a setup with a weber 48 IDA. Please let me know what you have tried and what works for your engine. Thanks

Ummm? That really helps... :confused: lol. Sounds like 4 port 13b using 12a irons. 1/2 bridge. :icon_tup:

if you have an 86 13b with 12a irons, I dont think those will work well (if at all) because of the coolant passages were switched around.

PM sent

RB's recommendations are for "track use only" but for street, you will loose. You will get low-end but no top end at all. Its like having a rev-limiter using 38mm venturies. For street use, you need at least 42/43mm, 300 needle/seat or a grosse jet. Also, the discharge valve in the bottom of float bowl must be changed to "close" or "0"; otherwise, at top end, gas will dump back to the fuel bowl instead of the carb. The squirters need to be enlarged slightly and you need 3 progression holes (typical off the shelf items OR used VW IDA carbs came with 2 progression holes per barrel).

For idle jet, go with at least a 70 to eliminate the bogging/surging. Once the air/fuel mixture is fully seated, back off 3/4 turn and adjust it 1/4 turn at a time (either in/out) to you get it right.