Help! I am running 0.6bar/8.7psi boost what fuel pump/pressure must i run.Iam runnig 7psi fuel pres, its nice til 4500RPM and then nothing. Blow through weber 38 dgas stoc A14 motor

I'm no carb expers But I'd imaine the fule would hafto be at a greater presure then the air flowing through the carb?

from memory fuel pressure is surpose to be 2-3psi above boost pressure, something like that.

Sounds about right, what you would run an ordinary carb above your post pressure!

ill second that steveo this is right at least 2psi above boost this can also be regulated wit a rising rate regulator or by using a hobbs switch to start boost fule pump

Thanks ! for the input

Or use a rising rate fuel regulator.

I'm posting this twice.

I am running 10psi boost on a supercharger (boosting through my carbs). My fuel pressure is at 7psi but I am running 2 weber 32/36's. So I'm running twice the amount of fuel.
I am using the stock fuel line from the tank but removed the mechanical fuel pump and installed an electric pump next to the passenger side (USA) engine mount. I then installed a second identical pump just prior to the carbs to boost the pressure. With only one pump running I get 3 psi, with the second pump running it boosts it to 7 psi. 3 psi was not cutting it with the supercharger engaged and in full boost. I am also injecting a little fuel when the nitrous is applied.
All of this seems to be working fine.
Still working on the rearend. H165 axles are at the machine shop dealing with the bearings.

as a14force said you need a rising rate fuel reg because. the satndard carby needs 4 psi any more or less and it will have a hissy fit but for every pound of boost you need another pound of fuel so.... 2pounds boost 6 psi fuel.... 7 psi boost = 12 psi fuel. but you shouldnt have 12 psi when its not at full boost thus use a rising rate fuel reg, it will do all this for you

as most have said, you need to run 3-4 psi more fuel pressure then boost. you need a high pressure fuel pump, like a fuel injection pump and a rising rate regulator with a return line back to the swirl pot or tee it into the fuel line betwen tank and pump for a getto cheap way out. look at a factory blow throu carb set up. renault 5/11. mg metro turbo. lotus etc