As the title states, what exactly does it do. I understand its part of tuning carbs/ITB's. I also understand that it basically give out a reading of how much vacumm is being pulled through the opening of the Carbs/ITBs. But what do you do with that reading? How would you change things from one opening to the other? I'm just curious if it would really help in tuning and what not. Thanks

 

It shows you how much air is entering the carb. You need to tune each barrel until they're the same. If it happens to run worse once you do this, fine tune one or the other until it's smooth.

As for measuring vacuum, I don't know about that. It just sits on top of the air horn thing and shows you on a guage how much air is flowing.

That's all I know about them. I could be mistaken. A local Weber expert used one on the black '83 with the 48 IDF and the above was my personal observation of the tuning process.

 

It is usually refeered to as a manometer when used on carbs. It is designed to measure pressure of gasses and vapors. Normally used in multi-carb applications to syncronize them.

That's the best explanation I can offer.

 

does it actually calculate how much CFM flow through it? I thought it would be like a big vaccum meter. Also what exactly do you adjust to alter the flow of each single carb? The butterflies can't be changed positions (unless you "twist" the rod that holds them"

 

The A/F mixture screw can make small observable changes in the meter.

 

well I was considering htis for my ITB setup, for fully tuning it. Not sure how the A/F ratio would make a notable change in flow though. When you took your car in to get tuned Jeff, what was the outcome of it before and after the syncrometer adjustments. I'm sure he probably did more things too it but curious on what kind of real HP output it would of given you. I would image a smoother idle, and smoother all around engine would do something too.

 

They're are really only needed in multi carb setups to tune the idle settings. Making changes to the a/f mixutre changes how much air is entering the carb. The better the mixture, the stronger the vacuum and more airflow.

 

Thr engine was a fresh rebuild so who knows how much power it was putting down. It did run better though after the tuning.