tested 545whp on stock fuel lines with walbro pumps
#1
Senior Member
Thread Starter
tested 545whp on stock fuel lines with walbro pumps
Hi guys, I ran into a problem with running lean on my 13b. I was only running 1 walbro intank pump, I was really impressed with how much that little pump could flow. Anyway something was running dry my injectors, stock lines or pump.
I have always been unsure of the flow limits with stock 3/16 lines. Some experts told me that this is the first thing to upgrade while others have said it can support 1000hp at the engine. hmm who do you believe?
So I decided to do a test with a......
2L container
Pressure gauge
Stop watch
Stock fuel reg
Syringe (to simulate boost on the reg)
Gate valve (to simulate a large injector)
I first tested a single intank walbro pump with the stock lines. What I did was turn on the pump on, I measured an instant base fuel pressure of 45psi then pressed the syringe to simulate 1.3bar boost. The fuel pressure rose to 65psi. I then open the gate slowly to see how much I could flow before the fuel pressure would drop.
The more the gate opened the more the pressure would drop.
I measured....
Base fuel pressure 45psi
60psi fuel pressure. 2L 36sec = 3.3L/min with 5psi pressure drop
55psi 2L 30sec = 4L/min with 10psi pressure drop
CONCLUSSION
from this I concluded that with one intank pump and stock lines assuming 5psi fuel pressure drop is acceptable, then this pump can support 375whp at 1.3bar boost.
I noticed that the pump would really start to struggle with flow as the reg pressure would increase with boost (simulated) and more than 1.3bar showed the pump flow slow dramatically. (I didn’t measure this just observed the flow from the gate as I increase the boost on the reg.) So I conclude that one walbro flow is only stable with 1.3bar boost applications.
My next test was with the two walbros installed. The results....
Base fuel pressure 65psi (stock reg is really struggling)
1.3bar boost simulated fuel pressures....
60psi 2L 25sec = 4.8L/min with 5psi fuel pressure drop
55psi 2L 24sec = 5L/min with 10psi drop
50psi 2L 22sec = 5.5L/min with 15psi drop.
CONCLUSSION
With 1.3bar boost pressure and two intank walbro, stock fuel lines are able to support 545whp. An aftermarket pressure reg is also needed with two pumps as the stock cant regulate accurately, with base pressure tested as high as 65psi.
I have always been unsure of the flow limits with stock 3/16 lines. Some experts told me that this is the first thing to upgrade while others have said it can support 1000hp at the engine. hmm who do you believe?
So I decided to do a test with a......
2L container
Pressure gauge
Stop watch
Stock fuel reg
Syringe (to simulate boost on the reg)
Gate valve (to simulate a large injector)
I first tested a single intank walbro pump with the stock lines. What I did was turn on the pump on, I measured an instant base fuel pressure of 45psi then pressed the syringe to simulate 1.3bar boost. The fuel pressure rose to 65psi. I then open the gate slowly to see how much I could flow before the fuel pressure would drop.
The more the gate opened the more the pressure would drop.
I measured....
Base fuel pressure 45psi
60psi fuel pressure. 2L 36sec = 3.3L/min with 5psi pressure drop
55psi 2L 30sec = 4L/min with 10psi pressure drop
CONCLUSSION
from this I concluded that with one intank pump and stock lines assuming 5psi fuel pressure drop is acceptable, then this pump can support 375whp at 1.3bar boost.
I noticed that the pump would really start to struggle with flow as the reg pressure would increase with boost (simulated) and more than 1.3bar showed the pump flow slow dramatically. (I didn’t measure this just observed the flow from the gate as I increase the boost on the reg.) So I conclude that one walbro flow is only stable with 1.3bar boost applications.
My next test was with the two walbros installed. The results....
Base fuel pressure 65psi (stock reg is really struggling)
1.3bar boost simulated fuel pressures....
60psi 2L 25sec = 4.8L/min with 5psi fuel pressure drop
55psi 2L 24sec = 5L/min with 10psi drop
50psi 2L 22sec = 5.5L/min with 15psi drop.
CONCLUSSION
With 1.3bar boost pressure and two intank walbro, stock fuel lines are able to support 545whp. An aftermarket pressure reg is also needed with two pumps as the stock cant regulate accurately, with base pressure tested as high as 65psi.
Last edited by bobybeach; 04-13-06 at 09:11 PM.
#3
Senior Member
Thread Starter
Originally Posted by OMGWTFBBQ
thats amazing you did that testing yourself.
Good to know !
Good to know !
#5
Senior Member
Thread Starter
Originally Posted by rotorforce
That's genius even if it is in theory you have quite the intelligence.
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#9
Not to knock your test or anything, however those tests don't factor in other variables that are IRL; for example acceleration Gs.
If you are going to run that much power, why cheap out on runner larger diameter lines? I know some people are going to bring up the debate on overkill and the necessity but still...
If you are going to run that much power, why cheap out on runner larger diameter lines? I know some people are going to bring up the debate on overkill and the necessity but still...
#10
Senior Member
Thread Starter
Originally Posted by 1Revvin7
Not to knock your test or anything, however those tests don't factor in other variables that are IRL; for example acceleration Gs.
If you are going to run that much power, why cheap out on runner larger diameter lines? I know some people are going to bring up the debate on overkill and the necessity but still...
If you are going to run that much power, why cheap out on runner larger diameter lines? I know some people are going to bring up the debate on overkill and the necessity but still...
and as far as cheaping out, why waste money on unnecessary upgrades like fuel lines if simple testing like this proves that stock are fine. id rather save that money and put in into tuning or real hp upgrades.
but still the dyno could prove me wrong.
#17
Senior Member
Thread Starter
Originally Posted by ilike2eatricers
cool. what kind of voltage was (were) the walbro seeing?
#18
Senior Member
Thread Starter
update! pressure reg problems solved
Hi guys here's an update on the fuel system, If youve all read the original post you will know that i was having trouble with the stock fuel reg, It was not able to maintain 42psi base presure with the twin walbros installed. infact base presure jumped to 65psi.
I have over come this by running 2 stock fuel regs as the picture shows. The polsation dampner was removed and a second stock fuel reg has replaced it. they use the same thread. the only modification needed was a slight bevel machined in with a tapered grind stone to set the o ring. now with the stock twin regs the fuel pressure has droped back to 42psi and under simulated boost rose to aprox 70psi at 2bar (simulated with suringe)
CONCLUSION
twin walbro and twin stock fuel regs with stock fuel lines can support 545whp and maintain stable fuel pressure.
I have over come this by running 2 stock fuel regs as the picture shows. The polsation dampner was removed and a second stock fuel reg has replaced it. they use the same thread. the only modification needed was a slight bevel machined in with a tapered grind stone to set the o ring. now with the stock twin regs the fuel pressure has droped back to 42psi and under simulated boost rose to aprox 70psi at 2bar (simulated with suringe)
CONCLUSION
twin walbro and twin stock fuel regs with stock fuel lines can support 545whp and maintain stable fuel pressure.
#21
Senior Member
Thread Starter
Originally Posted by RXciting
Hey Oliver,
Just out of curiosity, what are you currently running for a turbo and what are you upgrading to?
Frank
Just out of curiosity, what are you currently running for a turbo and what are you upgrading to?
Frank
not sure what i will upgrade to yet ethier the similer flow but faster spoiling mp t-60 with the larger gt spec q trim wheel, or go the larger mp T-64 or T-70 and gt q trim turbine with higher boost levels.
hows your t-70 working out?
#22
Senior Member
Thread Starter
Originally Posted by ilike2eatricers
just for the record adding an extra stock regulator is only an option for S4s since S5's have the PD welded to the rail
#24
NorCal 7's Co-founder
This is a great thread Oliver!! And after you get more testing done, including dyno time I'll be sure to clean up the random posts and put this in the 2nd gen archives! Good on you bro.
Zach
Zach
#25
GrapefruitRacing?
Join Date: Apr 2003
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Originally Posted by bobybeach
i was running mp t-61 with p trim turbine at 1.3bar on bridgeport, one intank walbro wasnt quite enough fuel supply.
not sure what i will upgrade to yet ethier the similer flow but faster spoiling mp t-60 with the larger gt spec q trim wheel, or go the larger mp T-64 or T-70 and gt q trim turbine with higher boost levels.
hows your t-70 working out?
not sure what i will upgrade to yet ethier the similer flow but faster spoiling mp t-60 with the larger gt spec q trim wheel, or go the larger mp T-64 or T-70 and gt q trim turbine with higher boost levels.
hows your t-70 working out?
It's coming, slowly but surely. I'm just solving the problems as they come. Turns out the flange was not only the wrong type, but also the wrong size , imagine my face when i tried installing the newly machined flange only to figure out it's a 4".
So when i got home from work I welded the flange I had bought for the downpipe to the housing. Now I just need another flange.
I'll have that turbo permanently installed in that car yet!
I'll let you know how it goes.