Jump to content
SAU Community

How To Install Walbro Gss-341 In An R34?

Hanaldo

By Hanaldo,
in Engines & Forced Induction

 Share

Recommended Posts

Hanaldo Grand Master

Hanaldo

Posted
  • Author
Posted

Man that was quick :)

I don't understand that though, why would it not? Voltage drop on 2.5mm wire that is 3 maybe 4 meters long would be minimal. Resistance in series would reduce current flow, wouldn't do much to voltage. Telephone wire can flow 125v down the wire the size of a string, just low current.

I don't see how there can be anything wrong with the wiring if the pump isn't blowing fuses?

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

StealthX Veteran

StealthX

Posted
Posted

Nah man maybe it refers to the pump need more voltage I.e. Stock pump - 12v, walbro - 14v.

And yeah didn't mean those thng as literal suggestions, just that 'rewire' could mean anything, need specifics. I wanna know too, I've got the same pump and have installed it with standard wiring.

TriniGT Experienced

TriniGT

Posted
Posted

What most do is use the stock wiring to power a relay and then run a direct wire from the battery to the relay and then from the relay to the pump. Idea is that once the ignition is triggered it will power the relay and from there the voltage from the direct wire from the battery is sent to the pump. You will notice the difference in the pump, it will sound angry with buzzing and the voltage which would have varied from say 11-13 volts should be somewhere from 14-15V. Remember a 255lph pump getting 11V will not push the same amount that one with 14V. On my GTT when I used the stock wiring my pressure would fluctuate due to the circuitry and my reading for my pressure was 20psi, now I get 40psi constant and my walbro makes a nice buzzing sound. Check the rating of the walbro to see as well, the recommended voltage should be 14.3V or somewhere up there.

Hanaldo Grand Master

Hanaldo

Posted
  • Author
Posted

I don't see why it would vary so much though ^ You shouldn't see a voltage drop of more than 1v from your battery. You would never see as high as 15v unless the regulator in your alternator is stuffed. Optimal charging is between 13.8v to 14.2v, so that is the max you would see at the pump. But even so, with the stock wiring you should not lose more than 1v, if that. So you should be getting between 12.8v to 14.2v at the pump, wouldn't matter what wiring you have.

Maybe if we were talking about current it would make sense, but voltage is the same.

TriniGT Experienced

TriniGT

Posted
Posted

The GTT has a built-in voltage regulator for the pump, what happens on idle and in traffic is fluctuates the voltage. You can check for yourself if you want simple measure the voltage you get through the circuitry to the pump and measure the voltage from running a direct to it, let me know the difference, this is a known problem not something that was unique to me :).

Socrates Mentor

Socrates

Posted
Posted (edited)

From what i understand the aftermarket pump requires more voltage than the stock pump does (12v), the ecu is only sending that much voltage down to the pump.You're not getting the full performance out of your pump even though it runs the car fine now.

Edit due to replies: I have also read that the aftermarket pumps don't take the ecu voltage changes well (idle, WOT) and another reason to run a relay.

Edited by Socrates
StealthX Veteran

StealthX

Posted
Posted

Nah man it's not varying or loosing power, the computer gives the pump variable voltage, but they need constant 12v to be tuned/used correctly...

TriniGT solved it for me, I get it now...

Hanaldo Grand Master

Hanaldo

Posted
  • Author
Posted
The GTT has a built-in voltage regulator for the pump, what happens on idle and in traffic is fluctuates the voltage. You can check for yourself if you want simple measure the voltage you get through the circuitry to the pump and measure the voltage from running a direct to it, let me know the difference, this is a known problem not something that was unique to me :( .

Ahaa, that's what I was looking for. That regulator would be the reason that I couldn't find lol.

But, who says that aftermarket fuel pumps require higher voltage? I can't find anything written by Walbro stating that they need a higher voltage, you would think that if it was going to make their pumps run better then they would make sure you knew about it.

Thanks for the replies, they are answering my questions :)

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
Yeah, but Martin's question is, how does one re-wire the pump to provide moar power?

i.e. 'rewiring' could just mean replacing the wires that feed the current to the pump, or changing the voltage source to a constant 12v, using a voltage amplifier, adding resistors etc...

No, that is not what he asked. :)

I don't see why it would vary so much though ^ You shouldn't see a voltage drop of more than 1v from your battery. You would never see as high as 15v unless the regulator in your alternator is stuffed. Optimal charging is between 13.8v to 14.2v, so that is the max you would see at the pump. But even so, with the stock wiring you should not lose more than 1v, if that. So you should be getting between 12.8v to 14.2v at the pump, wouldn't matter what wiring you have.

Maybe if we were talking about current it would make sense, but voltage is the same.

Get the mutlimeter out then, and see for yourself @ idle, under load etc. It's not always enough.

1volt loss to the pump can mean quite a bit in terms of volume.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
Ahaa, that's what I was looking for. That regulator would be the reason that I couldn't find lol.

But, who says that aftermarket fuel pumps require higher voltage? I can't find anything written by Walbro stating that they need a higher voltage, you would think that if it was going to make their pumps run better then they would make sure you knew about it.

Thanks for the replies, they are answering my questions :)

Check the manufactuers info.

Bosch quote thier pumps running voltage that is higher than factory.

Walbro are the same, they need more juice.

Hanaldo Grand Master

Hanaldo

Posted
  • Author
Posted

Thanks guys, makes sense to me now :)

I wasn't aware of the voltage regulator, which is why I couldn't understand how there would be such a high voltage drop. Unless you had a regulator, the voltage is always going to be the same.

Will look into rewiring my pump now :(

Randon_I_Am Veteran

Randon_I_Am

Posted
Posted

I'm in the same boat. I have the walbro installed at the moment with stock wiring (I've also seen my car make 266rwkw on this pump setup with 12-1 afr's)

But maybe I've one of the lucky dip good pumps that can supply that kinda fuel at ECU supplied voltage...

I've got some cable and a relay and on the cards is take the car apart and run that cable to the boot for the pump, sigh.

Does anyone know the current draw of these pumps? would hate to have a relay not capable of switching the current and fuse together, or worse blow out :)

Rolls Grand Master

Rolls

Posted
Posted
This is why the nismo drop ins are the best no issues no hassles just drop it in like the stock one and your all done.

You can just drop these pumps in and you are done but they won't function optimally, the nismo one might operate at a slightly lower voltage but old dodgy wiring can still be an issue. Personally I would spend the 30 minutes running a new 12V cable from the fuse box and then power a relay via the stock wiring, gives you piece of mind and you know it will last, really isn't any work at all, a few crimp connections, pull the carpet sides up and cable tie all the cables up.

  • 2 weeks later...
StealthX Veteran

StealthX

Posted
Posted

No, that is not what he asked. :dry:

Did you really need to point that out mate?

All I was saying is that Martin didn't understand the concept of 'rewiring' the stock pump, cos no one had explained that it needed DIFFERENT voltage.

It seems you just went out of your way to shut me down.

Just sayin'!

Apologies for barking up the wrong tree in advance.

Hanaldo Grand Master

Hanaldo

Posted
  • Author
Posted

I did understand that it needed different voltage, I just didn't understand how the voltage at the pump could be less than what was at the battery because I didn't know about the regulator :dry:

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

    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      I neglected to respond to this previously. Get it up to 100 psi, and then you'll be OK.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      I agree with everything else, except (and I'm rethinking this as it wasn't setup how my brain first though) if the sensor is at the end of a hose which is how it has been recommended to isolate it from vibrations, then if that line had a small hole in, I could foresee potentially (not a fluid dynamic specialist) the ability for it to see a lower pressure at the sensor. But thinking through, said sensor was in the actual block, HOWEVER it was also the sensor itself that broke, so oil pressure may not have been fully reaching the sensor still. So I'm still in my same theory.   However, I 100% would be saying COOL THE OIL DOWN if it's at 125c. That would be an epic concern of mine.   Im now thinking as you did Brad that the knock detection is likely due to the bearings giving a bit more noise as pressure dropped away. Kinkstah, drop your oil, and get a sample of it (as you're draining it) and send it off for analysis.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      I myself AM TOTALLY UNPREPARED TO BELIEVE that the load is higher on the track than on the dyno. If it is not happening on the dyno, I cannot see it happening on the track. The difference you are seeing is because it is hot on the track, and I am pretty sure your tuner is not belting the crap out of it on teh dyno when it starts to get hot. The only way that being hot on the track can lead to real ping, that I can think of, is if you are getting more oil (from mist in the inlet tract, or going up past the oil control rings) reducing the effective octane rating of the fuel and causing ping that way. Yeah, nah. Look at this graph which I will helpfully show you zoomed back in. As an engineer, I look at the difference in viscocity at (in your case, 125°C) and say "they're all the same number". Even though those lines are not completely collapsed down onto each other, the oil grades you are talking about (40, 50 and 60) are teh top three lines (150, 220 and 320) and as far as I am concerned, there is not enough difference between them at that temperature to be meaningful. The viscosity of 60 at 125°C is teh same as 40 at 100°C. You should not operate it under high load at high temperature. That is purely because the only way they can achieve their emissions numbers is with thin-arse oil in it, so they have to tell you to put thin oil in it for the street. They know that no-one can drive the car & engine hard enough on the street to reach the operating regime that demands the actual correct oil that the engine needs on the track. And so they tell you to put that oil in for the track. Find a way to get more air into it, or, more likely, out of it. Or add a water spray for when it's hot. Or something.   As to the leak --- a small leak that cannot cause near catastrophic volume loss in a few seconds cannot cause a low pressure condition in the engine. If the leak is large enough to drop oil pressure, then you will only get one or two shots at it before the sump is drained.
    • GTSBoy
      Help! Leak coming under transmission

      By GTSBoy · Posted

      So..... it's going to be a heater hose or other coolant hose at the rear of the head/plenum. Or it's going to be one of the welch plugs on the back of the motor, which is a motor out thing to fix.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      The oil pressure sensor for logging, does it happen to be the one that was slowly breaking out of the oil block? If it is,I would be ignoring your logs. You had a leak at the sensor which would mean it can't read accurately. It's a small hole at the sensor, and you had a small hole just before it, meaning you could have lost significant pressure reading.   As for brakes, if it's just fluid getting old, you won't necessarily end up with air sitting in the line. Bleed a shit tonne of fluid through so you effectively replace it and go again. Oh and, pay close attention to the pressure gauge while on track!
×
×
  • Create New...