high speed

i can put high speed valve before barrel valve

 

I run mine on top of the shut off

 

Does this can caused problems in the burnout

 

I see most all hilborn pump equipped cars with the high speeds at the pump. Seems to work fine.

 

Thats where mine is, tee'd right in the line from the pump to the BV.

 

I'm new to the high speed as well, I am going to install one for the season. My question is, putting it between the shutoff and the barrel valve wil take fuel out of the entire sytem is this correct? Is this better that putting it in the port OR hat nozzles alone and pulling fuel from just one area?

Corey

 

The reason most high speeds are plumbed in behind the barrel valve is that the pressure responds a bit slower there, so your high speed opens up from 60 to 100 feet off the starting line, depending on the poppet pressure. If you plumb it off the pump, it will open almost instantaneously, it is more of a pump loop than a high speed.

 

Definitely. Sometimes you don't want it to open right away though, due to tire spin or tire shake issues.

 

No, it would then be a LOW speed.

 

A pump loop on a roots blown car is usually at 40 or 50 psi and opens before staging, if a loop is used on a screw it's usually 15 psi because the screw doesn't need as much fuel below 5000 rpm. If a high (engine) speed (opens after leaving )is before the barrel valve it needs to be about 20 psi higher than if its after it to have it open at the same distance from the stating line (100') because there's a pressure drop across the barrel valve. Also the pump pressure can be quite high staging (5000 or 6000rpm) because the pump speed is up and the barrel valve is restricting the flow.