Questions on running a dual walbro system

Heys Guys,

First a little info on the setup. It's a forged 383 with a s-trim. It will hopefully make around 550 rwhp with methanol involved. I'm also going to be running a 75 wet shot when better fuel/timing retard comes into factor. Now I already have a single 255 walbro and racetronix HW kit with 57 pound siemens. I want to make sure this thing doesn't go lean on me. I was thinking of running the dual walbros but have 3 questions about the setup.

First wiring side of it. Are you guys just splicing into the existing wiring and running both pumps off of that? If not how are you wiring the new pump in.

Secondly. Do HAVE to run the hobbs switch for this setup or can both pumps be running all of the time. I heard two heat up the fuel but I dunno if I believe it or not. If you don't need one I was just thinking of buying a y junction and using steel braided lines for the pressure to the y block.

Third. Do I need this system? I know I could just put on a BOP but I plan on upgrading the blower to a t-trim in the future and it would be nice just to take care of it once and for all.

Mikey

Thanks for the replies :D

Rich Krause has made I believe 700rwhp on a single in tank with a good harness and a boost-a-pump. Would you have a problem? I dont know enough to really say if the single would do it without a boost a pump.

Personally, I went with the twin intake route myself. I have one in the stock bucket and another attached to the bucket as well with a y block. The 2nd comes on only with boost via a hobbs switch. You will not only get more heat in the lines with running both at all times, you will also wear your pumps faster AND you may be pushing more to the rail then the fpr can easily feed back at idle. Also the other advantage to my system (call me paranoid) is if for some reason the pump in the bucket fails, I can switch the "primary" pump to the non-bucket and limp it home. Probably never would come to be an issue, but you never know.

I have mine set up very similar to Geoff's. If you try running 2 - 255's, the regulator can't keep the pressure down at idle.

Mike

Thanks for the responses guys. :bow: Ok so the hobbs switch, where are you guys mounting it. Are you running a wire from the alt back or are you just tapping the hotwire kit. Thinking about it, it would seems to make sense that you'd mount it near the engine because of the switch being boost/pressure referanced. Less 1/8th line to deal with. Then wiring in the other pump. Is it as simple as finding a good ground and running a wire back from the alternator like the HW kit? Lastly I want to keep the stock lines. What Y junction are you guys using? I found posts on the russel but I don't want to convert over to a -8 line.

Thanks again

mikey

the hot wire taps off the alternator. I see 70 psi with both pumps on :eek: Thats with stock lines and regulator.

I have an oil pressure switch screwed directly into the intake manifold. It triggers a relay mounted near the Positive (+) distribution block by the battery. Then, the power wire runs all the way from the relay to the tank, into the top of the tank, to the 2nd fuel pump.

Thanks a bunch guys cleared a lot of things up for me thanks.

Mikey