Fuel pump testing - see results inside
Feb 16, 2013, 12:53 AM
#1
Fuel pump testing - see results inside
Since I was experiencing lean issues with my personal car, i took it upon myself to thoroughly test and inspect and upgrade if necessary my current fuel system.
I sent my fuel pumps & FPR to Kinsler, and my injectors to Fuel injector clinic. Everything tested perfect to my surprise. The only thing that was malfunctioning was the hobb switch / pressure switch failing to kick on the secondary fuel pump resulting in severe lean conditions randomly.
It seems odd, because ever since i used an old grenade pin off a timing belt hydraulic tensioner to push in the valve on the hobb switch to trick it to kick on without having to pressurize it, it seemed to start failing. After 4 years of working perfect right after i stuck something in it to trigger it, it seemed to fail. Maybe that semi shorted it out!
So I figured id help the community and give some information along the way as i had my testing done.
The modified walbro 255 is no joke. as others know that have already tested these years ago from modifying them. I had some flow tested I modified and gathered the rest of the information off of a very reputable source of further testing at Kinsler as well.
All Testing was done at 13.2 Volts
GSS342 (walbro 255lph rated hp unmodified)
50psi: 209lph - 8.6 amp
70psi: 177lph - 11.1 amp
100psi: 68lph - 15.1 amp
GSS340 (walbro 255lph rated hp modified relief valve)
50psi: 242lph - 8.1 amp
70psi: 208lph - 10.4 amp
100psi: 153lph - 14.6 amp
Aeromotive Stealth 11142 (340lph rated)
50psi: 284lph - 12.7 amp
70psi: 228lph - 14.3 amp
100psi: 155lph - 16.9 amp
Bosch 044 universal/inline
50psi: 277lph - 11.7 amp
70psi: 263lph - 12.8 amp
100psi: 239lph - 14.7 amp
As you can see, modifying the walbro 255 hp turns it into a hardcore competitor to pumps rated much higher then it.
keep in mind, 45psi is the pressure the stock FPR cracks open at, so 45psi + your boost pressure would be your total fuel pressure.
100psi for example would be 55psi of boost.
70psi for example would be 25psi of boost.
I sent my fuel pumps & FPR to Kinsler, and my injectors to Fuel injector clinic. Everything tested perfect to my surprise. The only thing that was malfunctioning was the hobb switch / pressure switch failing to kick on the secondary fuel pump resulting in severe lean conditions randomly.
It seems odd, because ever since i used an old grenade pin off a timing belt hydraulic tensioner to push in the valve on the hobb switch to trick it to kick on without having to pressurize it, it seemed to start failing. After 4 years of working perfect right after i stuck something in it to trigger it, it seemed to fail. Maybe that semi shorted it out!
So I figured id help the community and give some information along the way as i had my testing done.
The modified walbro 255 is no joke. as others know that have already tested these years ago from modifying them. I had some flow tested I modified and gathered the rest of the information off of a very reputable source of further testing at Kinsler as well.
All Testing was done at 13.2 Volts
GSS342 (walbro 255lph rated hp unmodified)
50psi: 209lph - 8.6 amp
70psi: 177lph - 11.1 amp
100psi: 68lph - 15.1 amp
GSS340 (walbro 255lph rated hp modified relief valve)
50psi: 242lph - 8.1 amp
70psi: 208lph - 10.4 amp
100psi: 153lph - 14.6 amp
Aeromotive Stealth 11142 (340lph rated)
50psi: 284lph - 12.7 amp
70psi: 228lph - 14.3 amp
100psi: 155lph - 16.9 amp
Bosch 044 universal/inline
50psi: 277lph - 11.7 amp
70psi: 263lph - 12.8 amp
100psi: 239lph - 14.7 amp
As you can see, modifying the walbro 255 hp turns it into a hardcore competitor to pumps rated much higher then it.
keep in mind, 45psi is the pressure the stock FPR cracks open at, so 45psi + your boost pressure would be your total fuel pressure.
100psi for example would be 55psi of boost.
70psi for example would be 25psi of boost.
Last edited by tscompusa; Feb 19, 2013 at 04:54 PM.
Feb 16, 2013, 01:55 AM
#2
You are right about the modified 255. I have played around with the e85 Walbro 400 and basically think that the upgrade was pointless after modding the 7+ year old Walbro in my re-wired eclipse and having probably provide the same amount of fuel as my E85 Walbro 400 in my evo with a voltage amplifier at 14.5 volts.
I am curious to see the E85 400's numbers and wouldn't be surprised if the modded Walbro 255 outflows it or comes near.
Great post.
I am curious to see the E85 400's numbers and wouldn't be surprised if the modded Walbro 255 outflows it or comes near.
Great post.
Feb 16, 2013, 10:14 AM
#4
Have you considered running a new fuel line? I just changed out the line on a local car and we went from staving fuel to having more than enough with a -6AN line. We didn't hard wire the pump, change the fuel rail, or add an AFPR.
Total cost was under $150 for the hose and fittings and I think it is a better solution than buying Walbro 400 with hard wiring kit.
Total cost was under $150 for the hose and fittings and I think it is a better solution than buying Walbro 400 with hard wiring kit.
Feb 16, 2013, 04:52 PM
#5
Have you considered running a new fuel line? I just changed out the line on a local car and we went from staving fuel to having more than enough with a -6AN line. We didn't hard wire the pump, change the fuel rail, or add an AFPR.
Total cost was under $150 for the hose and fittings and I think it is a better solution than buying Walbro 400 with hard wiring kit.
Total cost was under $150 for the hose and fittings and I think it is a better solution than buying Walbro 400 with hard wiring kit.
I agree keeping it simple with the evo's seems to be the best bet. the only thing i don't like is relying on a pressure switch to kick on the secondary pump for my car.
My old setup was -6 aeroquip aqp socketless hose with the regular kinsler paper filter which this setup worked fine. After a year of using the line is still in great condition and never had any fuel smell when the car sat in the garage overnight.
My new setup is;
stock FPR on the same AMS rail as before, -8 (.405" ID due to carbon coating) techafx blackwrap ptfe/teflon feedline to a fuelab 6 micron inline fuel filter post pump to a standard Y fitting attached to barb on fuelab filter (fiberglass e85 safe) to gates 225 PSI Barricade Fuel Injection Hose w/ GreenShield Technology then the modified pump housing has AN fittings with barbs for easy disconnect if need be.
I was thinking about just getting it 100% done in 910 kevlar goodridge ptfe hose but that would be extremely overkill. the gates barricade fuel hose is more then safe for the Y portion to the dual walbros.
The techafx hose is really nice stuff. it has a outer protective layer, then inside that is the SS braided line, then the teflon carbon coated material inside. perfect for running under the car.
aside from extremely high quality teflon/ptfe hose i would recommend stainless steel hard lines. the ptfe/teflon hose will last forever though just like the hardlines. the only downfall is, its way more expensive.
Feb 16, 2013, 05:59 PM
#7
That I cant really answer, but the Bosch 044 is the loudest. I didn't do this test, I sent my stuff to kinsler to be tested. www.kinsler.com.
I will say this from experience. If you hear your walbro whining or sounding like its sucking through a straw or changing pitches from high to low then you better either inspect your fuel filters for clogging or change out the pump because its bad.
When walbros work properly they are silent. With my rear seats out and the black cover off the fuel pump housing area i still cant hear them at idle.
I will say this from experience. If you hear your walbro whining or sounding like its sucking through a straw or changing pitches from high to low then you better either inspect your fuel filters for clogging or change out the pump because its bad.
When walbros work properly they are silent. With my rear seats out and the black cover off the fuel pump housing area i still cant hear them at idle.
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Feb 16, 2013, 06:12 PM
#8
Hmm...interesting and Im kind of confused? Tom remember the setup I mentioned to you? I was planning on reinforcing that with an aeromotive stealth to drop in and replace the primary pump to support the power I was planning on.
I doubt 100psi of fuel pressure would be needed lol, so the Aero does perform better at more normal fuel pressures than the modified 255's in terms of flow.
I doubt 100psi of fuel pressure would be needed lol, so the Aero does perform better at more normal fuel pressures than the modified 255's in terms of flow.
Feb 16, 2013, 07:14 PM
#9
Hmm...interesting and Im kind of confused? Tom remember the setup I mentioned to you? I was planning on reinforcing that with an aeromotive stealth to drop in and replace the primary pump to support the power I was planning on.
I doubt 100psi of fuel pressure would be needed lol, so the Aero does perform better at more normal fuel pressures than the modified 255's in terms of flow.
I doubt 100psi of fuel pressure would be needed lol, so the Aero does perform better at more normal fuel pressures than the modified 255's in terms of flow.
I would just stick with the walbro 255! the higher the pressure, the more the walbro 255 benefits. it really doesn't matter what the aeromotive can do at 0psi of boost, because we are turbo cars.
you figure about 40psi of boost, thats around 85psi of fuel pressure, the aeromotive might be 10lph or so more then the walbro at that pressure, but is the price worth it? i don't think it is. also if you notice, the aeromotive is power hungry and will put more load on your electrical system.
Feb 16, 2013, 08:38 PM
#11
I also forgot to mention that im going to use the factory feed line as the return.
the evap line is the same ID as the feed? i never checked into it. If you're not sure ill put a digital caliper on it later tonight and check the OD.
Feb 16, 2013, 09:15 PM
#12
Ya and a simple -8 or -10 upgrade will net you in the 1000whp (dynojet) mark on 2 modded walbros.
I also forgot to mention that im going to use the factory feed line as the return.
the evap line is the same ID as the feed? i never checked into it. If you're not sure ill put a digital caliper on it later tonight and check the OD.
I also forgot to mention that im going to use the factory feed line as the return.
the evap line is the same ID as the feed? i never checked into it. If you're not sure ill put a digital caliper on it later tonight and check the OD.
I didn't want to cut my stock lines so I removed them as a whole. I didn't care about the evap line so I flared it and used it
You are more than welcome to check and report back for the others that might be curious.
Feb 16, 2013, 09:34 PM
#13
It wont on ethanol and 2 walbros IMO, I know when it comes to that power I wont be running two pumps, hell I'm done running two pumps before I switch to make 800. I simply don't trust it, if one pump fails you still have enough fuel to melt an engine. I also don't trust hobb switches, they fail often especially with some good vibrations lol. I have an aem so I run my second pump switched off my aem. If your one and only pump fails usually it goes lean enough to die without causing damage.
I didn't want to cut my stock lines so I removed them as a whole. I didn't care about the evap line so I flared it and used it You are more than welcome to check and report back for the others that might be curious.
I didn't want to cut my stock lines so I removed them as a whole. I didn't care about the evap line so I flared it and used it
You are more than welcome to check and report back for the others that might be curious.why wouldn't two walbro 255 modified be enough to push over 900whp dynojet if one can do over 500 by itself? i have dozens of cars on modified walbros on dynojets with STD correction that can pass 500whp. so if one pump can pass 500whp on e85 why cant two do 1000whp? dont forget were tuning e85 into the 12 afr's uptop.
there is however a limitation on how much two walbros can do though based on the feed line diameter. i think if you open the ID to much you can actually reach a point of diminishing returns where the pumps become not as effective for the job.
Feb 16, 2013, 09:50 PM
#15
I agree with the pressure switch stuff. its definitely taking a chance. you can lose 50% of the fuel supply out of no where during a WOT pull. I mount my switch inside the car now, because i don't trust the heat/vibration under the hood. there are however fail safes i can utilize with the stock ecu. once it surpasses for example 13 AFR at a given load i can request the ecu to drop boost via the 3 port.
why wouldn't two walbro 255 modified be enough to push over 900whp dynojet if one can do over 500 by itself? i have dozens of cars on modified walbros on dynojets with STD correction that can pass 500whp. so if one pump can pass 500whp on e85 why cant two do 1000whp? dont forget were tuning e85 into the 12 afr's uptop.
there is however a limitation on how much two walbros can do though based on the feed line diameter. i think if you open the ID to much you can actually reach a point of diminishing returns where the pumps become not as effective for the job.
why wouldn't two walbro 255 modified be enough to push over 900whp dynojet if one can do over 500 by itself? i have dozens of cars on modified walbros on dynojets with STD correction that can pass 500whp. so if one pump can pass 500whp on e85 why cant two do 1000whp? dont forget were tuning e85 into the 12 afr's uptop.
there is however a limitation on how much two walbros can do though based on the feed line diameter. i think if you open the ID to much you can actually reach a point of diminishing returns where the pumps become not as effective for the job.
Ask everyone that tries and runs out of fuel lol. There might be a reason why you don't see any 1k hp cars running e85 and twin walbros. Im assuming its not because everyone wants to spend 500+ on a pump. I wont pretend to act like Ive done the research or the match because I haven't. I would assume that the volume required to make power up there isn't linear with the power at 500.