Who thinks 12 psi is too much for stock injectors?
12-08-02, 11:02 PM
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Who thinks 12 psi is too much for stock injectors?
Hi... OK, The turbo NA is running well.... but I am not getting enough fuel.
1st and second gear are fine, getting only to 8-9 psi.
3rd hits about 10 psi, but 4th gear goes to 12+
It keeps pinging a bit around 5500 rpms (so I let off immediately of course), there is a lean spot (goes up to around 13:1)
This is on my high-comp S5 N/A rotors too! Not cool. I want around 11:1 at most
Anyways, I can set my S-AFC to full (50% more) rich at 5000, and it doesn't get any richer.... the 12 psi is definatly too much for the stock TII fuel system, I guess 9 psi is about the limit.
Question is... is it the fuel pump or the injectors that need to be upgraded??
1st and second gear are fine, getting only to 8-9 psi.
3rd hits about 10 psi, but 4th gear goes to 12+
It keeps pinging a bit around 5500 rpms (so I let off immediately of course), there is a lean spot (goes up to around 13:1)
This is on my high-comp S5 N/A rotors too! Not cool. I want around 11:1 at most
Anyways, I can set my S-AFC to full (50% more) rich at 5000, and it doesn't get any richer.... the 12 psi is definatly too much for the stock TII fuel system, I guess 9 psi is about the limit.
Question is... is it the fuel pump or the injectors that need to be upgraded??
12-09-02, 12:07 AM
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what pump are you using?? please don't say the N/A pump?!?! that flows 1/2 as much as the turbo pump flows. and the turbo one is barly enough.
what ecu? turbo or N/A ? if N/A you probbaly have way to much timming.
13 is way too lean. should be 11.7:1 or so.
stock injectors are good for 12psi or 280hp or so.
I asume you are running 94 oct? or the highest in your area?
what ecu? turbo or N/A ? if N/A you probbaly have way to much timming.
13 is way too lean. should be 11.7:1 or so.
stock injectors are good for 12psi or 280hp or so.
I asume you are running 94 oct? or the highest in your area?
12-09-02, 12:15 AM
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you can also bypass the fuel pressure regulator solenoid, that will give you a little more fuel under boost
mike
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12-09-02, 12:27 AM
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I am running a TII pump. I thought that this, with the 4 550's would be enough.. I guess not!
I havn't rewired the pump yet, using a direct battery connection, and a relay. I will do that ASAP.
I have backed the timing off about 3-4 degrees. (N/A ECU) If I back it off any more it KILLS power under 2000 rpms.
Well, I'll probably rewire, and then just wrap some duct tape around the air filter to keep things in check untill I get an FD pump and some 720's or something.....
Thanks for the input!
I havn't rewired the pump yet, using a direct battery connection, and a relay. I will do that ASAP.
I have backed the timing off about 3-4 degrees. (N/A ECU) If I back it off any more it KILLS power under 2000 rpms.
Well, I'll probably rewire, and then just wrap some duct tape around the air filter to keep things in check untill I get an FD pump and some 720's or something.....
Thanks for the input!
12-09-02, 01:09 AM
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oh ya you are probably running the N/A FPR right??? you are missing 10 psi of fuel pressure at 10psi boost!! so you are running around 20% less fuel then a TII would at 10psi...
the stock TII FPR increases FP 1 psi for every psi of boost.
the stock TII FPR increases FP 1 psi for every psi of boost.
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12-09-02, 01:12 AM
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Originally posted by Bambam7
I have backed the timing off about 3-4 degrees. (N/A ECU) If I back it off any more it KILLS power under 2000 rpms.
I have backed the timing off about 3-4 degrees. (N/A ECU) If I back it off any more it KILLS power under 2000 rpms.
turbo or standalone ECU will give timming at the low end, while retarding the top end 
12-11-02, 02:03 AM
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Originally posted by j9fd3s
you can also bypass the fuel pressure regulator solenoid, that will give you a little more fuel under boost
you can also bypass the fuel pressure regulator solenoid, that will give you a little more fuel under boost
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