"Hotwiring" Shurflo pressure switch.

[keithmac]

I`ve been running my port injection setup for a few months now with no problems but I`ve reached the flow limit of my primered Erl pump, and I`m looking into experimenting with more methanol and more flow.

I`ve had a read on here and it seems the pressure switch on the Shurflo pumps is pretty bad, causes pulsing etc and read one person has bypassed the pressure switch all together?.

My first target is to get near 1l/min combined and try tuning at that point, with the Surflo switch bypassed and the pump active under boost only is there a chance of wearing the pump out prematurely?.

Would be interested to here from anyone using the Shurflo pump, pro and cons. I`m keeping all the Aqamist fittings just changing the pump.

[Richard L]

The Shurflo pump used on the latest Aquamist HFS (High flow system) range utilises three internal by-pass valves, set at 125psi. The pressure does not fluctuate . This is our solution in combating pulsing characteristics of the "demand switch" arrange use on all shurflo based systems. The pump is available separately, complete with 22cc accumulator:



If you look carefully, there is no demand switch on the front.