asubennett

This may have a real simple answer. I am not an expert with our fuel systems however I have seen double and even triple Walbro 255 fuel pumps used in Supra's, Mustangs, etc.... to support 1000whp and up.

However, everyone seems to strongly discourage the use of more than one pump when getting over 650whp which requires the use of an expensive Aeromotive or Bosch versus purchasing another Walbro 255.

Thoughts and comments appreciated. Thanks.

rudebwoy

iTrader: (1)

how would you get 2 to work? you would have to install another fuel pump holder in the tank and run bigger lines to the fuel rail or run 2 fuel rails on a edelbrock type manifold

Turbo-charged

all of the supra guys i have known to run 2 pumps use 2 OEM pumps. ive had issues with walbro pumps in the past and prefer not to use them on my zillion dollar motor haha.

asubennett

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rudebwoy &raquo;</TD></TR><TR><TD CLASS="quote">how would you get 2 to work? you would have to install another fuel pump holder in the tank and run bigger lines to the fuel rail or run 2 fuel rails on a edelbrock type manifold</TD></TR></TABLE>

But running two fuel rails and 8 injectors is more expensive than just buying the Aeromotive pump in the first place.

The Supra guys pushing 1000rwhp that I have seen using the Walbros run two in tank and one in line.

Axle

I saw mention of this on another car forum somewhere and they talked about the difference between running two pumps in series and in parallel. The idea was that running them in series would double the pressure and running them in parallel would double the flow at the same-as-original pressure. It was then clarified that running them in series does not automatically double the fuel pressure but if you wanted to raise it, you would have the potential to up it to nearly twice as much. It's an alternative to running one large noisy external fuel pump. Oh, yea, almost forgot that they mentioned the pump closer to the engine would be at least as big as the first (from the gas tank) pump because it (pump closer to engine) would otherwise just be limiting the flow to as much as it can send thru.

asubennett

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Axle &raquo;</TD></TR><TR><TD CLASS="quote">I saw mention of this on another car forum somewhere and they talked about the difference between running two pumps in series and in parallel. The idea was that running them in series would double the pressure and running them in parallel would double the flow at the same-as-original pressure. It was then clarified that running them in series does not automatically double the fuel pressure but if you wanted to raise it, you would have the potential to up it to nearly twice as much. It's an alternative to running one large noisy external fuel pump. Oh, yea, almost forgot that they mentioned the pump closer to the engine would be at least as big as the first (from the gas tank) pump because it (pump closer to engine) would otherwise just be limiting the flow to as much as it can send thru.</TD></TR></TABLE>

Running an inline Walbro as I understand still makes the max whp achievable only as high as the pump in the tank.

Has anyone installed two Walbros in their tank, then have them tee together into one feed line and one fuel rail, etc..... Honda Application only please.

asubennett

TTT

igy

Maybe the reason it's not done in a Honduh is because it is hard enough just to fit one pump through the fuel pump access hole. I have run 2 walbro's on an fd in parallel and y'd 2 smaller lines into one bigger line. The fd access hole is almost twice as big as the one on my honda and it was still a bitch getting 2 pumps through it.

asubennett

I have installed a few Walbros and am quite aware of the size constraints. However, I am sure there has been a workaround by someone on this board and I would like to see the fabrication associated with doing so.

TheThiefTheKnife'NTheGun

are you talking about a pump in take and an inline pump. I am running two pumps.. A 255 HP in the tank and an MSD Inline the reason behind it is if you datalog fuel pressure in high hp cars that are just using an in take pump you will most likely watch your fuel pressure dip at higher rpms.. I think 3 pumps might be overkill but I would definatly run two pumps in FI cars just to be on the safe side..

asubennett

I was actuall talking about having two in tank pumps if that is possible at all. Your right though even all motor one pump has a hard time maintaining the same fuel pressure in fourth gear at the track.

93LSivic

I was going to do it. Mocked up a fuel tank with the troth, simulated the top of the tank with the exact size opening. Basically spent a lot of time trying to figure it out.....which I did. But didnt go ahead and put it all together cause it was just easier to sump and run a big inline

The sweed

I have run 2 walbros in paralell on an engine dyno... (b16 turbo) We were trying to get it to run on E85 (85%ethanol and 15% petrol) E85 has a stoich ratio of 9,5:1 so it needs hugh fuel systems. 2 walbro in tank pumps flowed 7,22 liters / min at 5 bar fuel pressure (~73psi) @ 12,5 volts. I had a an 8 feed line and a AN6 return and a sx fuel pressure regulatorand Golden eagle fuel rail. If u realy need 2 pumps think of what would hgappen if one fail? it takes a lot of effort to make a warning system to see that coming otherwise there will always be a risk for kaboom... If you have one pump and it fails the car wount run. But with 2 it runs, but leans out when u put the pedal to the ground if your engine needs more fuel than one pump can deliver. = kaboom

I also had an aeromotive I bought from summit and I think that pump sux.. It is extremly loud in my messures and it only flowed 3,65 liter per min @5bar fuel pressure @12,5 volt. I bet just one walbro flows just as much..

One idé could be running 3 walbros to have one incase one fail.. But the fuel pressure regulator has to have the flow capabilitys to flow so the fuel pressure is steady at idle..

I hope i make sence I´m from sweden and i´m not the best in english.

Bspec18

I am using 2 Aeromotive A1000 Fuel pumps with a stock tank, just made a sump for it. with -10 lines from the tank to the rail. Sounds over kill but on the previous racecar we ran only one fuel pump and noticed and high rpms we were running out of fuel. Our last option was to add a fuel pump. Injectors, Rail and even pump were replaced and still same problem. Pump even had a steady 13.5 volts all the way thru. Now with 2 pumps we are makin 680+ and no fuel problems what so ever.

Dee

Search engine seems to be working fine to me

https://honda-tech.com/zerothread?id=1125419

asubennett

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dee &raquo;</TD></TR><TR><TD CLASS="quote">Search engine seems to be working fine to me

https://honda-tech.com/zerothread?id=1125419</TD></TR></TABLE>

Thanks Mr. Dee. I don't really see a need for a frowny face or smart *** remark though. If Honda-Tech Search engine worked all the time I would have found it myself. However, it wasn't working for me at the time of the post.

Dee

Geez.... I get called a smart *** for helping someone. Yep, that's H-T for ya.

traction issuez

STi and WRX guys been doing this but the problem is you have to make a seperate wiring system for it because for subarus, it seem to draw in too much for the fuse/relay to handle.

shouldn't be too hard to do just get yourself an automotive relay and set it up with a 12v source.

-mike

traction issuez

here is a website that i read on awhile ago when i was trying to do the same thing.

http://www.stealth316.com/2-fuelpumpguide.htm

asubennett

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedrotary &raquo;</TD></TR><TR><TD CLASS="quote">STi and WRX guys been doing this but the problem is you have to make a seperate wiring system for it because for subarus, it seem to draw in too much for the fuse/relay to handle.

shouldn't be too hard to do just get yourself an automotive relay and set it up with a 12v source.

-mike</TD></TR></TABLE>

I'll have to take a look at some of the Suby set ups. I really want to see how one would go about mounting two walbros in the tank.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dee &raquo;</TD></TR><TR><TD CLASS="quote">Geez.... I get called a smart *** for helping someone. Yep, that's H-T for ya. </TD></TR></TABLE>

LOL, Don't play the beaten wife now. You could have posted, "Hey man I found this thread on the search engine and it may help you get some answers for your question. Hope that helps." But instead you made Honda-Tech exactly what you are complaining about now. -A place to be negative with frowny faces and all.