I was reading how the annular boosters on a carb seem to have a very noticeable throttle response, better down low power with the cost of affecting power up top. Though with a turbo, I think that top end issue would get countered any way. Was hoping any one had any experience with this and give any advice. Thanks.

 

annular boosters that have the proper air bleed config will not cost any top end power.
The bleed is there to maintain air fuel throughout the rpm range.

If the transition circuit, accel pump and jet are all playing nice, response down low will be great.

Annular booster create more signal to draw fuel because they have a bigger I.D. so more air flows thru it.
The size also reduces cfm flow of the carb.
They also can have more holes so the fuel vaporizes better.

The increased signal works well in blow thru applications.

 

Appreciate it ! Im new to carburetors and I am finding them to be... pretty impressive. I was thinking the better vaporization would allow for better air cooling. I wish I could see a dyno comparing the two but theoretically it should be better. Though if a carb that is rated at 750, with annular boosters, will it actually flow 700 cfms, for example ? Or is it already taken into consideration ?

 

The flow varies on what booster is used. There are various sizes out there.
Seems like a 950 with annular is 850cfm. Dont quote me on that.

But dont chase carb size in the blow thru world. If its not max effort, smaller responds better.

 

Okay I see what you mean, guess the restriction isnt taken into consideration. With a 355, I found that a 650- 750 will work. Thanks !