Dual Intank Pump Information...

[GREG O'Brien]

hey guys.

I am just trying to track down some information, instructions, and/or pictures of some of the dual intank pump setups alot of people appear to be using.

I have a hot-wired single 340 walbro in the tank of my Turbo 2.3L mustang, but I think it is going to run out of capacity with the new aluminum headed motor. Not that I am disappointed, just that i need a plan to keep everything going full steam

I am trying to see how everyone has been doing these dual pump setups. I've heard rumors of a few twin turbo 5.0 guys doing dual intanks and they have the same fuel tanks as me - but I haven't found any pictures or good descriptions.

I have somewhat of an idea of what is involved - but it would be great to get some SOLID information to see if one of these setups will translate to my application.

thanks
GREG

 

[V6 Beast]

You can buy a coupler and hobbs switch from atr(http://www.atrperformance.com/). Basically they way most of them work is you drive around on only 1 pump and have the 2nd pump cut on when under boost. The hobbs switch will control when 2nd pump cuts on. The coupler is basically a Y connector that connects both pumps to your single fuel line. The Hobbs switch sits between the 2nd pump and the alternator so when a certain boost level is achieved then the circuit is closed supplying power to 2nd pump.

Hope that helps

Sully

 

[TurboTR]

Well the thing is, generally you can safely get to the 600 flywheel hp range with the single pump and good lines and filter. Do you plan to go past 600 hp with it?

TurboTR

 

[TRENT THOMPSON]

what lines are on the car. I am a former mustang guy and most of the fuel problems they have are the lines and then again where it goes into the fuel rail. You may have too upgrade these as the TR's have much better lines

 

[GREG O'Brien]

hmmm.


well with the current setup (not in the car yet) it will be nearing 500 flywheel hp on pump gas... i have NO idea what it'll do with race gas, propane injection, or water/alky injection - but i plan to try them all and see.

i will be limited to about 500-550 flywheel hp by turbo size - so that is what i am going by for now since a larger T series turbo will probably kill the cars streetability.

the longblock, as it sits now, is good for 600+hp to the wheels though - but i don't know if it will ever see it. i'd rather have 500 on pump gas that purrs like a kitten than 600 that need a trailer and race gas. the chassis only has a 2500# race weight (full interior 1979 with a bunch of aluminum and chromoly parts) - so it won't take much for me to get kicked of the track (9's) which i want to avoid.

right now it has

1) a stock mustang tank and pickup (more or less the same as the 5.0 stuff)
2) the lines are routed different (driver side) but i am pretty sure the sizes are the same
3) the fuel rail is stock - but i may get a aluminum one from www.svpu.com down the road (it looks like AN8 - but i've got to call)
4) stock regulator
5) 96#/hr injectors
6) Walbro 340 pump

i am going to break in the new motor on the stock computer, rail, lines, injectors, regulator, etc. and then get into modifying that stuff after all the mechanical bugs are worked out and the motor has a 1000 miles on it.

it is going to have either an SDS system or a FAST system for managment.

I guess what I am really looking for is has the pumps are physically setup? I definitely understand the hobbs switch (but i think i would just buy a larger regulator and run them both all the time so that there is one less part to fail) and I think I understanding the plumbing after the pumps.

BUT I am REALLY confused about the pickups and how the pumps PHYSICALLY fit in the tank!

thanks for all the help so far guys.
greg

PS - could you give me an idea of what page those parts are on in the ATR catalogue? that thing is HUGE and my connection speed is REALLY slow.

 

[TRENT THOMPSON]

please here me... More fuel pump and lines....you will be so grateful for going mean the first time.. you must understand that forced induction requires LOTS of fuel.. but you will have done yourself a huge favor

 

[GNVAIR]

Hey Greg,
To answer your questions, a single Walbro 340 is good into the very high 10's on an average weight Buick (approx 3500-3800 lb's) which is well over 500 horses. Many guys at that point will switch to a double pumper or an Aeromotive or a Weldon. Our stock fuel lines are 3/8" and the fuel rails are huge approx 1/2" throughout.
Now, the main problem you will run into is fitting 2 pumps into the Mustang tank as the hole is only maybe 4" inches in diameter (or barely large enough for 1 pump to fit into. On most of the fuel injected GM products, the fuel pump and gas gauge sender are built into 1 unit. The hole on the Buick tanks is about 7 inches in diameter so, squeezing 2 pumps is not an issue. A single 340 should be fine for high 10's on a lighter car putting out 500 horses. What I would concentrate is running a dedicated 4 gauge wire off the battery back to the trunk to a junction block (like car stereo guys do) with an 8 gauge powering the pump. Use the stock trigger wire to trigger a relay. I would forget about the stock lines on the Mustang as they are something like 5/16" which is probably good for return lines at best. Run atleast a -8AN up to the rails. The stock 4 cylinder turbo rails are about the same size as the stock 5.0 rails and are very restrictive...especially were the injectors plug in. Consider making a billet fuel rail so you have no restrictions.
The best way to tell if you have enough fuel (via pump and injectors) would be with the FAST or similar DFI software by measuring duty cycle on the injectors.
Good luck with your project.

 

[V6 Beast]

I don't see any way a Single Walbro 340 could begin to supply fuel for 8 96#ers. In fact you could max it out with 6 50's or 55's depending on who you ask. The pumps sit side by side each other on a modified stock hanger. I have never really looked at their online catalog so I can't help ya... The coupler is on page 29 of their regular catalog. Part # is RP354-4 The Hobbs switch may not be in there. They also have a picture of the double pumper which kinda shows the 2 pumps right beside each other on the stock hanger.


HTH
Sully

 

[GNVAIR]

Originally posted by V6 Beast
I don't see any way a Single Walbro 340 could begin to supply fuel for 8 96#ers. In fact you could max it out with 6 50's or 55's depending on who you ask. The pumps sit side by side each other on a modified stock hanger. I have never really looked at their online catalog so I can't help ya... The coupler is on page 29 of their regular catalog. Part # is RP354-4 The Hobbs switch may not be in there. They also have a picture of the double pumper which kinda shows the 2 pumps right beside each other on the stock hanger.


HTH
Sully

I believe he is talking 4 of the 96lb injectors not 8.

 

[TurboTR]

The pumps are just tie wrapped together into a tight cluster around the hangar tube. Only way they'll fit (barely- scraping) through the stock GN tank opening. They use the stock type pickup socks. ATR uses a billet coupler piece, Red's uses a Y piece to couple the 2 oututs together. I still use the ATR double setup and have recently upgraded to a -8 feed path and an Aeromotive filter. But IME just a single 307 was good to the low/mid 120's mph in a 3650 lb turbo car w/ driver, through the stock GN lines and filter. FWIW.

With a decent feed path and filter the single hotwired 340 pump should support you safely to your < 600 hp goal, if you prefer to keep it simple. If you have the FAST w/ wb o2 it's even safer of course. If the volume flow falls off for whatever reason (clogged filter? etc) the a/f ratio feedback will do quite a bit towards keeping it real. We've seen this happen a few times around here in practice over the years with varous cars In fact that's how some guys discover a clogged filter in the 1st place, seeing the O2 correction or inj duty cycle swing way positive all of a sudden

Sounds to me like Lee is right on, per above...

TurboTR

 

[GREG O'Brien]

DOUBLE POST!

(mumbling to self) "stupid dial-up connection errors - GRRRRR."

 

[GREG O'Brien]

yup - it is "only" 2.3L motor...

little know fact of the day - the stock 2.3L block and crank are FAR stronger than any *production* 5.0 ford unit - it has been tested to 700+hp and 7000+ RPM. The only reason people go to anything aftermarket is to get more cubes or to run REALLY high RPM (read 9-10k rpm). All the connecting rods, pistons, and heads can be had for reasonable prices because of the sprint/circle track history of the 2.3L. And all the turbo/chassis stuff is just hand me downs from the 5.0 and GN market places Thus why I am here.

hey Lee nice to bump into you (i'm the guy that sold your buddy the SVO and bought an intercooler from you) - looks like you got even more turbo projects on the way - i'd love to see the Monte.

i sold the blue notch and bought a cleaner chassis - as you can see the program has been stepped up quite a bit from the junkyard rendition.

first off - thanks for the advice everyone!

I think I've got a plan...

1) since i am moving my battery to the trunk - i'll redo my hotwire setup using some really thick cable to get REALLY low resistance.

2) i'll keep the single 340 in the tank and clean the sock real good.

3) i'll feed the fuel out through a 'Y' to the pressure AND return line fittings in the tank and then plumb another return line fitting elsewhere.

4) i'll run 8 AN to the fuel rail with an Aeromotive 10 micron filter.

5) i'll use a billet aluminum fuel rail from svpu.com

6) i'll use a 6AN return line

7) any recommendations for a regulator? - i am thinking Aeromotive.

8) I'll hook up a fuel pressure gauge so i can keep an eye on pump capacity.



If I EVER run out of pump capacity I'll either:

A) plumb in an aeromotive pump and use the Walbro as a feeder rather than sumping the tank for the aeromotive. the flow of the walbro at 10psi as a feeder is enough for ANY streetable car.

or

B) Cut the top of the tank open - hang double walbro's and then make a new hanger/cover for the opening i cut.



THANKS EVERYONE

I'll stop by sometime and let 'yall know how it works out.

GREG

 

[TRENT THOMPSON]

that a baby, someone who isn't scared too do it right