Fuel pressure on boost with carbs

[jonny1bump]

Gents hope we are all well.

Quick question for those who have carbs with boost reference reg, what fuel pressure do you see a full chat with idle setting at 1.5 to 2 psi.

Cheers Jonny.

[jonny1bump]

Is there formula or is it as simple as max boost pressure plus your 2 psi starting pressure.

Cheers.

[MeanBean49]

1 hour ago, jonny1bump said:

Gents hope we are all well.

Quick question for those who have carbs with boost reference reg, what fuel pressure do you see a full chat with idle setting at 1.5 to 2 psi.

Cheers Jonny.

It will be boost pressure + base pressure

[Gixer1460]

As MB49 says - you are trying to equalise the pressure applied over the surface of the fuel in the bowl with the pressure required to force fuel into the bowl. Ideally Normal atmospheric ie. gravity + boost but that never works LOL! You are trying to make the carb think it is running NA so it functions exactly the same.

[Reinhoud]

With 2 psi my carbs just flowed over, 1 to 1.5 psi should be good.

I had to cut a bit from the spring in the FPR to lower the pressure.

 

The boost raises the fuel pressure to the right level.

Edited June 8, 2021 by Reinhoud

[jonny1bump]

Guys thanks for the info all makes very good sense.