[Syty] Double-pumper (was Re: Syty Digest, Vol 19, Issue 6)

[Dig]

I don't think the hobbs really adds much either, particularly in an environment where you can tune stuff.
Back in the old days, it was sort of seen as a way to combat fuel loading on the low end, while providing more at the top.

It would save wear/tear on the second pump, however.

I never saw more than a 2-3 psi jump by activating the second pump, which wouldn't even amount to a .1 AFR change with stock injectors. It would likely be more significant with larger injectors.

I wouldn't dream of running both pumps with the same wiring. Personally, I wouldn't run *either* pump with the OEM wiring. Get some nice weatherpack connectors from waytek, and make a nice 10-ga harness, with really good grounds to the frame.

I've seen stock fuel line setups support mid 10 second vehicles, so the line capacity is there. Generally, if you go faster than that, you're going to be doing more with the fuel system anyway.


Side topic... is really odd digest operation normal? Or does it digest by kb?
Nothing for a week, then 4 all on the same day?

Later,
Dig
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Message: 1
Date: Tue, 24 Oct 2006 11:49:46 -0400
From: "tydriver at gmail.com" <tydriver at turbols6.com>
Subject: Re: [Syty] Re: Syty Digest, Vol 19, Issue 3
To: "Brian Dourty" <dourtyb at got-boost.net>
Cc: syty at syty.org
Message-ID: <002701c6f784$0a0f0ca0$6401a8c0 at laptop>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=response

I am not 100 % on the wiring but I know that Nolan did this setup before on 
a truck or two he was building..Personally I dont like the idea of running a 
hobbs type switch to kick the 2nd pump on (like the ATR setup) but thats 
just me. I would be interested in seeing how many problems you'd run into by 
running them both continuously. The setup that Nolan made had a Y adapter 
from the 2 pumps into the single feed line. I had some pictures of it around 
here somewhere but lost it with the most recent HD crash otherwise I'd 
forward them.. I checked canadiansyty.com and its no longer up anymore, so I 
dont know what happened to the information.. Maybe email Nolan directly ??

I would most definitely run a thicker gauge wire off the alternator back 
there with a relay of some sort to turn the pumps on when they'd normally 
run (similar to the boost-a-pump/or racetronix setup), using the stock fuel 
pump wire to trigger the relay.

HTH,

Todd




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