Jump to content
SAU Community

Aftermarket Fuel Pump = Less Fuel Capacity?

sonicz

By sonicz,
in General Maintenance

 Share

Recommended Posts

sonicz Rising Star

sonicz

Posted
  • Author
Posted (edited)

Is that supra denso the same pump that came with some of the r33 skylines?

Mine is a Jecs.

So according to that the walbro 255 flows less than the stock pump?

Edited by sonicz
battery Mentor

battery

Posted
Posted

Is that supra denso the same pump that came with some of the r33 skylines?

Mine is a Jecs.

So according to that the walbro 255 flows less than the stock pump?

Not the same pump.

Forget about which flows more, the stock pump is 20 years old, pick the pump which will supply enough fuel for your application. If your running stock injectors then a 255lph @ battery voltage will.

Ben C34 Grand Master

Ben C34

Posted
Posted

op dunno what youre concerned about, i only ever fill up to half a tank cuz it saves weight = more power

what???

It still fits in the same amount of fuel its just that the intake was higher so couldn't use it. That would mean your awesome method of going fast (light weight) would mean you can only access 1/4 of a tank.

And sorry to burst your bubble, but a 50kg weight saving is worth 0.1 seconds at the drags. You might as well fill your tank up man.

discoPumpkin Community Regular

discoPumpkin

Posted
Posted


And sorry to burst your bubble, but a 50kg weight saving is worth 0.1 seconds at the drags. You might as well fill your tank up man.

Do u know

Thats over 400 metres only, on a race track that would be a second slower a lap, and a second is a HUGE difference, a second a lap slower then anyone else would have u almost being lapped at the sned of the race.

But youre right doesnt make much of a difference, hell might aswell throw in barbell plates and dumbells for even more weight gain...wait wot

sonicz Rising Star

sonicz

Posted
  • Author
Posted (edited)

op dunno what youre concerned about, i only ever fill up to half a tank cuz it saves weight = more power

g9pepl.jpg

Lol. The only way that would make any sense is if gravity worked upside down just in the petrol tank.

Moving on, I have a quick question hopefully can be answered here without starting a new thread.

Is it at all possible to run a dual walbro setup with the stock wiring and piping?

BY this I mean just splice in power to the second walbo 255 from the wiring going to the 1st then fit both pumps into a "Y" piece in tank.

Its ok if the voltage drops off a bit because there will be 2 pumps pumping.

Edited by sonicz
discoPumpkin Community Regular

discoPumpkin

Posted
Posted

g9pepl.jpg

Lol. The only way that would make any sense is if gravity worked upside down just in the petrol tank.

If u fill youre car only half full VS full tank, which do u think is gona make the go go faster? C if u can work that equation out lol

ps i don't know how u brought gravity into this.

If he really wants extra fuel capacity, might as well make it duel fuel tanks like my dads Hilux, again pointless tho i mean its hardly a 500hp fuelaholic rotary were talkin about here. So many mods for so little gain.. but its you're ride

Ben C34 Grand Master

Ben C34

Posted
Posted

g9pepl.jpg

Lol. The only way that would make any sense is if gravity worked upside down just in the petrol tank.

Moving on, I have a quick question hopefully can be answered here without starting a new thread.

Is it at all possible to run a dual walbro setup with the stock wiring and piping?

BY this I mean just splice in power to the second walbo 255 from the wiring going to the 1st then fit both pumps into a "Y" piece in tank.

Its ok if the voltage drops off a bit because there will be 2 pumps pumping.

No, you will melt your wiring.

http://www.skylinesaustralia.com/forums/topic/423664-melted-connector-plug-due-to-larger-in-tank-pump-pics/?fromsearch=1

sonicz Rising Star

sonicz

Posted
  • Author
Posted

Hmm well thats a walbro 460 not 2x 255s. The walbro 255s take about 7-9 amps, and these guys are saying the 460 takes 25A? Its possible the stock wiring could handle 2x 7-9amps ?

Furthermore this guy did the direct battery feed mod, which would raise the volage above the stock 12v, further drawing more amps than my setup would.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

You need to learn some electronics basics, raising the voltage will lower the current draw, which is why the Walbro's fail at the low cruise voltage. That stalling your car is doing while idling and cruising is the pump stalling out, bad news for the pump.

Ben C34 Grand Master

Ben C34

Posted
Posted

You need to learn some electronics basics, raising the voltage will lower the current draw, which is why the Walbro's fail at the low cruise voltage. That stalling your car is doing while idling and cruising is the pump stalling out, bad news for the pump.

+1

watts=volts x amps

watts are constant. higher volts = less amp draw.

mad082 Grand Master

mad082

Posted
Posted

I understand the walbro is not designed to run at 9v, but its still just a DC motor in there just like the stock pump which runs at 9v like a champ.

Are people actually saying when both pumps are at 9v, the walbro flows hugely less than the stock, so little in fact my car almost stalls, but when both pumps are at 12v suddenly the 255 overtakes the stock pump and flows more?

of course a pump designed to run at 12v may not run that well. hell, a big turbo that is designed to run on large capacity engine isn't going to spool up like a champ when bolted into corolla. it's all about effeciency. sure the stock pump may run fine at 9v, but that is probably because of it's design. 9v might be enough to have it work efficiently. but something designed to work at only 12v may have more resistance in the internals to allow it to flow more, but that means that at 9v it isn't able to overcome this, so it doesn't work very well.

GTRsean Grand Master

GTRsean

Posted
Posted

I wouldn't be using rubber items such as radiator hose in the tank. The rubber breaks down. You can only use butyl rubber fuel hose inside the tank (inner and outer layers are butyl rubber, $100 a metre roughly) as it is designed to be immeresed in fuel.

Even efi fuel hose, not to be used in the tank, just outside.

It will break down and harden and clog shit.. My 2cents...

sonicz Rising Star

sonicz

Posted
  • Author
Posted (edited)

I wouldn't be using rubber items such as radiator hose in the tank. The rubber breaks down. You can only use butyl rubber fuel hose inside the tank (inner and outer layers are butyl rubber, $100 a metre roughly) as it is designed to be immeresed in fuel.

Even efi fuel hose, not to be used in the tank, just outside.

It will break down and harden and clog shit.. My 2cents...

Yes i agree, this is an important issue.

I too, had the same concern before i went out and bought a radiator hose for my second fitting attempt.

I went ahead and fitted it because I figured, if the fuel is strong enough to dissolve the hose at the source, It will be strong enough to keep any of the dissolved debris from building up or clogging anything. Worst case scenario I will be burning small amounts of dissolved rubber in the combustion chamber mixed in with the fuel.

I would appreciate your thoughts on this reasoning.

I plan to check the state of the rubbers after a few weeks.

Edited by sonicz
Ben C34 Grand Master

Ben C34

Posted
Posted (edited)

Yes i agree, this is an important issue.

I too, had the same concern before i went out and bought a radiator hose for my second fitting attempt.

I went ahead and fitted it because I figured, if the fuel is strong enough to dissolve the hose at the source, It will be strong enough to keep any of the dissolved debris from building up or clogging anything. Worst case scenario I will be burning small amounts of dissolved rubber in the combustion chamber mixed in with the fuel.

I would appreciate your thoughts on this reasoning.

I plan to check the state of the rubbers after a few weeks.

not sure on your thoughts there man, radiator hose has fibres reinforcing it,i doubt the petrol would dissolve them.

Also, that is some freaky stuff with the current draw getting higher with more voltage, really can't get my head around that....

Edited by superben
  • 3 months later...
suwidji Experienced

suwidji

Posted
Posted

Just the thread i was after!!

I mounted my walbro in the exact location as the stock one, but I was provided with a vertical strainer/filter, but it's still about an inch shorter than the stock.

I didn't realise i had to install it lower, and therefore my car would just crank and try and try and try to start up, but just wouldn't fire up when I got down to about 1/4 tank.

I was supplied with a black sock that i didn't know what i needed it for, but now I'm assuming it's to cover the pump. I'm not exactly sure what material it is though, and I don't want it to dissolve or whatnot in my fuel. I may have a go at just lowering it without the sock, and just maybe try my luck at using just one hose clamp? :\

Can anyone tell me what size hose clamp is needed to tighten the pump onto the cradle thing? Also, will I need to cut off the metal round thing on the cradle where the stock pump used to sit on the rubber mount?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • JC71
      new 1.5 LSD issues/concerns

      By JC71 · Posted

      sold listed as a Tomei LSD 1.5 Way For 1998+ Nissan Skyline ER34 25GT RB25DE w/Open R200 https://www.ebay.com/itm/174006114594?campid=5338967980&mkevt=1&mkcid=1&toolid=10050&customid=&mkrid=711-53200-19255-0&loc_physical_ms=108689&loc_interest_ms=&campid=5338967980&mkevt=1&mkcid=1&toolid=10050&customid=71883f2ccc571356e0a757bc7adfdde2&mkrid=710-53481-19255-0&loc_physical_ms=108689&loc_interest_ms= it went in like butter all gears, alignment, back lash etc, rotation and clearances correct, and if rolling all rotates smooth and free when coasting down road , clutch in or out over 10 mph smooth... its the binding, clunking and jerking from a stop that is most concerning, also seems like its going to tear the tires off in 10 miles of normal road driving. 
    • Kinkstaah
      new 1.5 LSD issues/concerns

      By Kinkstaah · Posted

      What 1.5 way? There's no such thing really as a 1.5 way, just different ways of explaining 2 ways with different ramp rates. HOWEVER. In any driving in a straight line your 1.5 or 2 or 1.7 way should have no clunking at all. With the clutch fully depressed the diff should be silent (unless it's welded but I'm assuming it's not). Something aint right here.
    • JC71
      new 1.5 LSD issues/concerns

      By JC71 · Posted

      Clutch is a spec brand, new clutch system,( PP, flywheel, friction disc, etc. pull type) installed 100 miles ago, with no problems.
    • JC71
      new 1.5 LSD issues/concerns

      By JC71 · Posted

      looking for some help and maybe some insight on others experience with a new LSD. R34 GT ran and drove beautifully, but always alot of grip loss due to the open R200 rear end, so I just installed a new 1.5 LSD way into the stock open R200 for a ER34. Simple. Everything seemed right. I test drove for the first time this weekend. as I started to back out the garage the first time slowly with tires straight it sounded and felt like I had a loose or half disconnected drive shaft...that was clucking around loose and shaking entire vehicle, and making it feel like the trans clutch was spontaneously slipping then grabbing very roughly while just letting out pedal slowly. I backed it out went to pull forward with the same noise, shake and slip grab feeling with hesitation, I turned the tires to back out more and then pulled ahead some same thing but worst because of added wheel resistance (which that I expected) puzzled … pulling it back in checking everything over and finding nothing wrong, I tried it the next day. same thing, couldn’t believe how it shook everything again making a terrible noise and making it feel like the trans clutch was slipping and grabbing, but I got it out of garage into the driveway, got it straight, drove forward and then reveres a few times in a straight line everything shaking , causing what felt like clutch slip and grab every time, sounded like right behind front driver tire and I could feel it in the floor board with my feet,... worst right when beginning to let clutch pedal out to engage slightly, shuttering and sounding terrible along the way…I managed to slowly get down the road, babying it the whole way, once I was rolling (out of 1st) seemed to be better and between shifts, then clutch felt closer to normal…not slip/ grab etc., but back down to any stop, straight road or turning, same thing. Made no difference if all tires were straight or if I was turning. All other gauge read out correct. with in 2 miles as planned I reached the empty parking lot and performed the break in procedure that came with lsd, essentially to drive in a figure 8 a bunch.  Did this, binding chattering, and shaking the car the whole way. I drove it back home seemed somewhat normal once I was in straight line and past 10 mph or so, and I know it will “bind” on corners and cause some tires squeal when turning especially from a stop, but when I begin to move it still causes what feels like the trans clutch to slip and jerk badly as well as shaking the entire car, and sounds terrible, that I didn’t expect. I used the fluid they supplied with LSD kit and did the breaking, planning to change fluid as they suggest after breaking, but wondering will it get smoother or less aggressive with use? maybe a 1.5 is just too aggressive for normal road driving?   I have a LSD that I put in my 71 cuda when I restored it, with amazing smooth , quite yet effective results. Different style LSD but that ones a joy to drive. maybe expecting too much from this R200?
    • Matt Z
      SAU NSW - Archies Flame Grille Meet & Cruise to Kurnell

      By Matt Z · Posted

      Join SAU NSW for a flame-grilled feed & flame-spitting cruise! Sunday 17th August 2025 3:30PM Meeting Archies Flame Grille Sylvania Waters 4:45PM Cruise Departure 5:15PM Arrival at Cape Solander Kurnell Meet Location: Archies Flame Grille Final Destination: Cape Solander Kurnell *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
×
×
  • Create New...