idahoBLKss Posted May 12, 2011 Report Share Posted May 12, 2011 Need so help on how to wire my dual intank set up. I was looking into a dual hot wire kit from racetronix but they wont sell one to the public. How would you guys wire this up? Could I use there single pump harness and just wire the second pump to the first pump? Let me know what you guys would do. Quote Link to comment Share on other sites More sharing options...
Cramer Posted May 12, 2011 Report Share Posted May 12, 2011 Jon. I found that wiring diagram for the dual pumps. When i get home tomm I will email it to you. Yes you can use the hotwire kit. You will have to wire in a relay between the two pumps almost the same as the relay in the kit is wired. I will get back to you asap Quote Link to comment Share on other sites More sharing options...
misterp Posted May 12, 2011 Report Share Posted May 12, 2011 I would run a single fused big hot wire (#10 maybe?) to the rear of the truck, and wire it to two relays; the first relay I would trigger off the existing pump wires, the second relay triggered off a 0-psi Hobbs switch on the intake manifold. From the relays I would run heavier hot leads to the pumps themselves (14-gauge maybe?). For ground I would solder together a "Y" from a couple black wires (same size as hot leads from relays) and then have a single large ground lead exiting the tank and grounding at the factory pump/tank ground point (at the front of the truck bed). That way, one pump is 'primary' and runs all the time, the second pump kicks on when you go into boost, and the pumps get plenty of power especially on the aenemic wiring they use on the 04+ trucks. For extra credit you can house the relays in a $6 ABS plastic box, and source factory weatherpack connectors so that you don't have to cut the original tank harness connector. You would have to provide for the larger wiring to safely enter/exit the tank bulkhead, IMO this would be the biggest challenge. Your project is complicated enough that I would get a fuel pump module from a 2004+ truck (wrecking yard, $50) and build it for your truck, and separately test the modified pump module using a bucket & gas can. Outside. Mr. P. Quote Link to comment Share on other sites More sharing options...
idahoBLKss Posted May 13, 2011 Author Report Share Posted May 13, 2011 Is it bad to wire both pumps to be on all the time? Where do you get a hobbs switch from ? And yeah ryan pm me a link of what you found. Quote Link to comment Share on other sites More sharing options...
misterp Posted May 13, 2011 Report Share Posted May 13, 2011 Is it bad to wire both pumps to be on all the time? Where do you get a hobbs switch from ? And yeah ryan pm me a link of what you found. Any un-used gasoline returned from the engine will be hot - it heats the fuel in the tank, not to mention that the pumps themselves heat the fuel. One pump is plenty of fuel for cruising; you put the second pump on a switch (Hobbs switch) that turns the pump on at a certain PSI in the intake manifold. You can get a 0-psi switch, that way the 'stiffening' pump kicks-in as you cross into boost, or you can get a -4 PSI switch, so the pump kicks on under heavy load but before boost, etc. Mr. P. Quote Link to comment Share on other sites More sharing options...
chpspecial Posted May 13, 2011 Report Share Posted May 13, 2011 you can get hobbs switches at your local NAPA store. I don't know if any other parts stores carry them. there are also two types, normally open, what you want, and normally closed switches. they are pricy mofos too. Quote Link to comment Share on other sites More sharing options...
Quik Posted May 15, 2011 Report Share Posted May 15, 2011 Is it bad to wire both pumps to be on all the time? Where do you get a hobbs switch from ? And yeah ryan pm me a link of what you found. for past 3 yrs ive had both my pumps running together at same time. ppl are so concerned about fuel being heated up with dual pumps running together. something to think about youll have a regulator to control that pressure. another thing to think about is when you go race pump that flows more then 2 walboros whats any different then that? ive had no issues Quote Link to comment Share on other sites More sharing options...
idahoBLKss Posted May 15, 2011 Author Report Share Posted May 15, 2011 for past 3 yrs ive had both my pumps running together at same time. ppl are so concerned about fuel being heated up with dual pumps running together. something to think about youll have a regulator to control that pressure. another thing to think about is when you go race pump that flows more then 2 walboros whats any different then that? ive had no issues Do you have a diagram on how you wired them? Quote Link to comment Share on other sites More sharing options...
Quik Posted May 15, 2011 Report Share Posted May 15, 2011 Do you have a diagram on how you wired them? i did the following i used the stock wiring to trigger my 40 amp relay i have mounted by the tank. i have a single 10 gauge industrial wire going from battery to relay with a 30amp fuse since each 255 draws 12 amps max now times 2 you have plenty of amp even for inrush current. when wiring this way, if a pump fails it blows the fuse. once the pump opens up then you replace the fuse and limp home on 1 pump ppl say with dual pumps you have no idea when you lose a pump, well how i have mine i do know. ive done this way on a few builds and all have same results sorry i dont have a diagram or anythng as i just got at it as i need to this way you can still pull the factory fuel relay when troubleshooting the setup or priming the motor Quote Link to comment Share on other sites More sharing options...
Cramer Posted May 18, 2011 Report Share Posted May 18, 2011 Hope this helps Jon. I will get my Racetronix harness and some relays out to see the exact pin out and color wires is needed to wire this up. This is with the Hobbs switch setup. IMO this is the way I would go. Quote Link to comment Share on other sites More sharing options...
Warden Posted May 18, 2011 Report Share Posted May 18, 2011 I know of a number of big power FI cars running both pumps all the time with no issues.If it makes you uneasy you can add a Hobs switch.My new fuel system is setup to run all the time.The majority of dual pump kits come with a Hobs switch so it's your choice. I have been close friends with the owner of Racetrnx for years and his shop is just down the street.If you give me a part # I may be able to help you.They used my SS for some measurements when they made that harness.They are having a charity dinner is about 3 weeks.Maybe I can get the owner a little hammered and talk him into it.Racetrnx also makes a universal wiring harness for twin pumps,but I don't know if it is long enough.I used it in my C5 but sold it with my old fuel system. I am spelling the name wrong because the owner sometimes does a search of the web for his company name just to keep up on things. Quote Link to comment Share on other sites More sharing options...
idahoBLKss Posted May 18, 2011 Author Report Share Posted May 18, 2011 (edited) I know of a number of big power FI cars running both pumps all the time with no issues.If it makes you uneasy you can add a Hobs switch.My new fuel system is setup to run all the time.The majority of dual pump kits come with a Hobs switch so it's your choice. I have been close friends with the owner of Racetrnx for years and his shop is just down the street.If you give me a part # I may be able to help you.They used my SS for some measurements when they made that harness.They are having a charity dinner is about 3 weeks.Maybe I can get the owner a little hammered and talk him into it.Racetrnx also makes a universal wiring harness for twin pumps,but I don't know if it is long enough.I used it in my C5 but sold it with my old fuel system. I am spelling the name wrong because the owner sometimes does a search of the web for his company name just to keep up on things. To me it wouldn't make a differance if one or two were working but it seems like the majority go with a hobbs switch so it looks like that's what ill be doing. Racetronix has been name dropped in this thread a ton so I don't know why you are trying to hid he'll find this thread anyway...lol. that cool that you would try and help me out buy talking to him but im not about to wait another 3 weeks parts will be ordered one way or another by the end of this week it just would of been a hell of allot easier if they would just sell the stupid harness they make for the dual pumps to the public instead of pushing people off to lonnies performance where he doesn't want to help you unless you buy a whole fuel system from him. Today with all of the forums and info out there people want to do it them selves to know that it gets done right and to tell a customer that your not going to sell the a harness cause its to involved I think is BS let the customer make that call you don't know what that person is capable of . I noticed that some of the harnesses where label a do at own risk type of thing so I don't know why this would be any different ... sorry im done lol Edited May 18, 2011 by idahoBLKss (see edit history) Quote Link to comment Share on other sites More sharing options...
Cramer Posted May 20, 2011 Report Share Posted May 20, 2011 I will get that pinout for the Racetronx harness to run with another weather proof relay and hobbs switch for you tomm Jon. Quote Link to comment Share on other sites More sharing options...
Warden Posted May 20, 2011 Report Share Posted May 20, 2011 It turns out the Racetronix universal double pumper harness is the same length as the one needed for our trucks. Quote Link to comment Share on other sites More sharing options...
Cramer Posted May 20, 2011 Report Share Posted May 20, 2011 Do the ends have the 280 series connectors for the sending unit? If so that should be a plug and play harness. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.