How much boost can one walbro support?
09-25-2010, 01:54 PM
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How much boost can one walbro support? I have a LQ4, MP-T76, 60 lbs injectors and ZO6 cam. I just upped the bosst to about 14 psi and noticed that my AFR started going waaay lean on me (like 13.4-1) as I climbed in the RPM range. I tried making adjustments using my PE table but nothing seems to help. When I was runing about 6 psi things seemed ok. I could get 11.5-1 all the way with no problems.
I planned on adding a second pump I just didn't know how soon I would need to. Thanks in advance!
I planned on adding a second pump I just didn't know how soon I would need to. Thanks in advance!
09-25-2010, 02:32 PM
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I wouldn't push beyond 500rwhp with boost and a single walbro.
your very lucky you didn't pop your engine running that lean in boost, get a second pump in there !
your very lucky you didn't pop your engine running that lean in boost, get a second pump in there !
09-25-2010, 02:42 PM
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Interesting I run one 255 with a msd boost a pump and see 17lbs boost on a built 383 (lq motor) with a ST80 turbo. My afr's are good, they respond to adjustments in the VE table (speed density). My 60lb injectors are close to max.
But my pump set seems to be keeping up, I'm surprised from reading the above responses.
But my pump set seems to be keeping up, I'm surprised from reading the above responses.
09-25-2010, 02:49 PM
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Interesting I run one 255 with a msd boost a pump and see 17lbs boost on a built 383 (lq motor) with a ST80 turbo. My afr's are good, they respond to adjustments in the VE table (speed density). My 60lb injectors are close to max.
But my pump set seems to be keeping up, I'm surprised from reading the above responses.
But my pump set seems to be keeping up, I'm surprised from reading the above responses.
09-25-2010, 03:21 PM
#7
Save the time and trouble and get 2 pumps!!! Ask me how I know I have already been through this. One pump running out, only trying to push 8psi. and this was with a SD tune. Also had 60pd injectors but they were fine.
Setup I went with:
2 pump setup from Lonnies
I ran my own lines on feed and return -8 feed -6 return Weldon fuel pressure regulator, also changed fuel rails. Runiing 8pds without a glich at over 600RWHP
Setup I went with:
2 pump setup from Lonnies
I ran my own lines on feed and return -8 feed -6 return Weldon fuel pressure regulator, also changed fuel rails. Runiing 8pds without a glich at over 600RWHP
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09-25-2010, 04:30 PM
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speed density isn't related to your fueling requirements.
09-25-2010, 11:13 PM
#12
The Z06 pump is quite larger than a 255lph Walbro. I regularly see them work at over 600rwhp. Higher with a boost-a-pump, but they are typically short lived at increased voltages.
The GSS340 Walbro pump is generally good to 550rwhp. Above this, it is a crap shoot.
If you are looking for a dual pump setup, I'll be gald to help you out.
Mine are completely assembled, tested & guaranteed to work.
Let me know if I can help.
The GSS340 Walbro pump is generally good to 550rwhp. Above this, it is a crap shoot.
If you are looking for a dual pump setup, I'll be gald to help you out.
Mine are completely assembled, tested & guaranteed to work.
Let me know if I can help.
09-26-2010, 01:15 AM
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Theres probably literally 100 different 255l walbros.....thats why youll see them cheap sometimes......with no model number. Just "255l"
Along long time ago.........the turbo buick guys tested the pumps a lot. The gss340 was good for about 650 chp, the 307 about 550.....
I ran a 99 camaro with a 340, 60's a 76, and z06 cam into the 16 psi area on 116 octane.
Along long time ago.........the turbo buick guys tested the pumps a lot. The gss340 was good for about 650 chp, the 307 about 550.....
I ran a 99 camaro with a 340, 60's a 76, and z06 cam into the 16 psi area on 116 octane.
09-27-2010, 01:34 PM
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Theres probably literally 100 different 255l walbros.....thats why youll see them cheap sometimes......with no model number. Just "255l"
Along long time ago.........the turbo buick guys tested the pumps a lot. The gss340 was good for about 650 chp, the 307 about 550.....
I ran a 99 camaro with a 340, 60's a 76, and z06 cam into the 16 psi area on 116 octane.
Along long time ago.........the turbo buick guys tested the pumps a lot. The gss340 was good for about 650 chp, the 307 about 550.....
I ran a 99 camaro with a 340, 60's a 76, and z06 cam into the 16 psi area on 116 octane.
09-28-2010, 04:27 PM
#18
mine drops pressure to 43-46psi at 10psi of boost but then again it is 5 years old just ordered 2 new ones.
stock ls1 bottom end 317 heads ls9 cam no dyno numbers
afr 11.5 @ 5200 then 12.8@ 6300
stock ls1 bottom end 317 heads ls9 cam no dyno numbers
afr 11.5 @ 5200 then 12.8@ 6300 