Double Pumper

[aquickv6]

How does the Hobb Switch hook up on the Double Pumper?? Two wires and a vacuum hose. On the pump end there is a ground and power wire. Thanks

 

[Lynn D. Brown]

Hobbs switch

I think the power to the pump has to go thru the Hobbs switch. So, one side goes to one of the terminals - I don't think it matters which one - and the other continues the circuit to the relay. U then crank down on the adjusting screw to set the pressure where the switch closes. U will also need a light to come on (preferably in the car) to show when the switch closes. Then U read the manifold pressure (boost) pressure when it activates.

 

[aquickv6]

One side is a red fused wire, I guess this would go to the alternator. The other side is a larger guage wire that would go to a relay and then to the pump? Where is the vacuum spliced in?

 

[Lynn D. Brown]

Hobbs

The vacuum would just be spliced into the intake manifold somewhere. Make sure there is no vac check valve between the IM and the Hobbs. I think I spliced it into the line to the EGR. The Hobbs has to break the circuit to the fuel pump. My double pumper is an ATR model and has a relay for the 2nd pump also. Now I may need one for my Typhoon and w ATR OOB, I don't where I'll get it. I may have to make my own.

 

[Quick6'n'-K.C.]

Either run both pumps at the same time so you know they are both working.
Or run one pump all the time, the second pump to kick in at a set boost pressure with the hobbs switch.

First question, do you really need both pumps? I know alot of people running 10s with pump gas/meth and only one intank walboro 307/340 fuel pump.

If you want to run 2 pumps, then use the hobbs switch to kick the second pump in around 18psi so you can leave the line at 15psi and not be too rich during spooolup.
I would have the hobbs switch anywhere where there is a pressure source under a load, and use it to trip the relay/switch to the closed position to kick the pump on.
Any hobbs switch is adjustable, do a search here and they give the part numbers for any, but its all the same switch, just set to a different psi.

BW

 

[gnxis]

If you want to run 2 pumps, then use the hobbs switch to kick the second pump in arou

If you want to run 2 pumps, then use the hobbs switch to kick the second pump in around 18psi so you can leave the line at 15psi and not be too rich during spooolup.

with a return style fuel system it wont matter if both pumps are on or not.
My RA double pumper dosent have a relay for 2nd pump as it only runs from 18 psi & up. so its only on for a few seconds at a time.