Weber, 44 IDA's Options

[Randal]

Does anyone have a altitude chart that shows which jets you should use?

[914forme]

So Sisyphus, I have said it once I will say it again, you can't tune a carb via an AFR gauge. You will chase your tail all day long, and the next and the next etc. AFR, was perfected via electronics for an electronic subsystem, it is just a sensor, and we know that the magic number isn't so magic. If you where running EFI, I would say go for a wideband AFR. Put your money into EGT, and data logging.

EFI uses a cool little device called a MAP, carbs do not, the MAP tells the efi to compensate for barometric pressure. Which we all know changes. This is why racing teams that are required by the rules to run carbs will have a weather station, and a guy who knows how to use it, and adjust carbs right before the race. Top Fuel guys will rebuild the engine and re-jet the carb for each run. Crazy I know, but in the world of winning or losing by 1000th of a second, every little bit helps.

Reality is you would be better off tuning via EGT, than AFR. AFR does not mean crap to you anyway it is just a number.

No easy way out, you need dyno time, and somebody who knows weber carbs.

To me carbs have 3 advantages, cheap ( somewhat ) maximum Power ( one given Point) and reliability you can almost always limp home. EFI kills it in every other way, drivability, broader torque band usally close to 10% increase, and that translate into more horsepower across the board, and last flexibility.

I will look tonight when I get home and see what the old weber manual says. What's the displacement and elevation your running? Oh and lets not forget what is the top end RPM wise your engine will see, as choke size (Ventures) effects jet size.