Return system sanity check

[04MystiCobra]

Switching over to return from a 3 GT pump Lethal returnless setup to a twin 465 deadhead return. Read up on Malcombs fuel heating thread as well as his pump module and came up with the following.
twin 465s
Division X hat
-10 feed to filter
-10 from filter to Magnafuel regulator in the fender
"T" w/-8s to front of rails
-8 crossover
-8 return from regulator
MD Racing pump module
twin 25a relays triggered by FPDM so pumps prime as stock and don't remain on during uploading of tunes or engine stalling.

 

[Bdubbs]

What are your hp goals? I have my pumps running full time with zero issues. Probably going on 3 years like that.

 

[04MystiCobra]

850ish. The module provides a few attractive benefits such as reduced electrical load at idle/low rpm and reduced requirement on the return line size.

 

[Bdubbs]

850ish. The module provides a few attractive benefits such as reduced electrical load at idle/low rpm and reduced requirement on the return line size.

Sounds good. I prefer to keep things simple. I'm running a dead head setup as well. I had my head spinning endlessly trying to come up with a return system. Your looking to make more hp than me. I'm around 675-700.

Reduced electrical load at low rpms doesn't seem like a huge factor or a problem. It's the higher rpm voltage drop that's a common problem on these cars.

Sounds like it will be a fun car.

 

[bigmoose]

Why not run the same size return as the feed. At idle and part throttle almost all that fuel is going back to the tank.

Also why the magnafuel FPR? Malcolm did indicate the fore regulator was the best when using staged pumps.

 

[04MystiCobra]

Having one less item drawing power during idle is a concern as much as is the high rpm history. I can control the power demand more at idle with the fuel pump module. If the low high rpm power presents itself that's a completely different approach/solution.

The regulator was recommended by others as well. As for running the same size return line as the feed, it should not be needed as only one pump is running 99% of the time.

 

[cj428mach]

Save yourself some headache and buy a Fore Setup.

 

[MG0h3]

If youre buying the module from Malcolm Id have him piece a kit together for you like I did. Sure itll save you money and youll end up with the best stuff from Fore.

 

[Bdubbs]

Another vote for fore innovation fuel setup. My volts at idle are 14.7-15.3 when engine is warmed up. I have two aem 320e pumps running full time. I do have a nations alternator with an adjustable regulator.

 

[04MystiCobra]

Thanks for the suggestions on hardware but I have it all already. Just throwing the schematic out there for folks to review and possible use.

 

[MalcolmV8]

Sorry I'm just seeing this. Your schematic is wrong. The red and black wires coming from the fuel pump module go to key on 12 volts and the black wire to battery negative.

That second relay (top right corner of your diagram) have those two pins 85 & 86 connected to your FPDM pins 10 & 3.

Also your LED positive and negative are reversed.

Dbubbs the electrical drain from dual 465s is very real. A touch over 30 amps. Lots of short drives daily driving the car will show it struggling to keep the battery fully charged with the extra load. It's not detrimental by any means but is a huge electrical load for no reason at low loads. Also it is to reduce all the fuel you're pumping up to the engine and back to the tank constantly at idle and low load driving. No reason to have your gas tank turn into a whirlpool for no reason.

 

[04MystiCobra]

thank you sir. That's why I put it up there. I'll update with the correct one shortly.

 

[MalcolmV8]

thank you sir. That's why I put it up there.

No problem. You have the majority of it right. Just correct those few things and you'll be in business.

 

[04MystiCobra]

Take 2

 

[MalcolmV8]

Looks good. You got it.

 

[04MystiCobra]

Updated 1st post. Thanks Malcolm. I really appreciate it.

 

[MalcolmV8]

I just noticed on the second relay (bottom left) you have written in words "FPDM positions 10 & 3" by the 85/86 terminals. That is incorrect and conflicts with the actual wiring schematic. Just remove that wording to avoid confusion.

 

[04MystiCobra]

Got it. Updated.