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Old 02-04-2007, 09:02 PM   #1
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Default couple weird problems ive been having... help!

i have a stock greddy kit on my 93 with a bipes and rx7 afm. running at 5 psi

got two questions

1) i will hit 5 psi at 3.5 rpm but i dont get that surge of power till i hit 4k

my gauge is reading boost at one of the fittings that used to go to the charcoal canister. if im in 4th gear ill floor it and get 5psi at 3.5 but there is no increase in pull, then once it gos past 4k it will begin to accelerate much more rapidly is this just the camshaft timing or do i not have my bipes setup correctly

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi

again it this just something with my timing or what?
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Old 02-04-2007, 09:09 PM   #2
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Fuel pressure gauge?
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Old 02-04-2007, 10:04 PM   #3
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Your getting your boost reading from where ?
You should be getting the reading from the top of the injector manifold, the little metal nipple thingy.
Why are you running down at 5psi ?
Tighten up that wastegate a few turns and get up to or over 6PSI !!
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Old 02-04-2007, 10:18 PM   #4
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Quote:
Originally Posted by Dlaitini View Post
i have a stock greddy kit on my 93 with a bipes and rx7 afm. running at 5 psi

got two questions

1) i will hit 5 psi at 3.5 rpm but i dont get that surge of power till i hit 4k

my gauge is reading boost at one of the fittings that used to go to the charcoal canister. if im in 4th gear ill floor it and get 5psi at 3.5 but there is no increase in pull, then once it gos past 4k it will begin to accelerate much more rapidly is this just the camshaft timing or do i not have my bipes setup correctly

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi

again it this just something with my timing or what?

1. Lean tip-in (research o2 clamp)
2. In your head....you're seeing a fast increase in Tq and then it plateus quickly at only around 130rwtq or so.
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Old 02-04-2007, 11:57 PM   #5
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Brainack is right.. should be a lean tip in...needing O2 clamp.

Could also be the Vortech not clamping down fuel pressure till 1.5psi as said on POP's test. http://home.bellsouth.net/p/s/commun...pid=224302&ck=
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Old 02-05-2007, 02:23 AM   #6
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im going out on a limb here, but i think maybe your wastegate actuator hose popped off....i think i had similar problems once and i figured out that it was that......
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Old 02-05-2007, 03:56 PM   #7
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Just to be obnoxious: o2 clamp

People say the Greddy is like an on/off switch
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Old 02-05-2007, 04:12 PM   #8
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I don't think it's a lean tip in. That's just how the greddy kit is.

Check out this screen capture of a Feb 04, 2007 datalog:

The yellow line is engine speed (RPM). The blue line is MAP. The Y axis is marked for RPM, not pressure, sorry. The engine reached atmsopheric pressure at 1900 rpm, and 1 psi positive pressure by 2100 rpm. You can see how long the turbo takes to spool, as it doesn't reach 10 psi until 5k rpm.

Don't underestimate the need to downshift. It's usually better to be in a gear too low than in a gear too high.
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Old 02-05-2007, 04:27 PM   #9
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Quote:
Originally Posted by Dlaitini View Post
got two questions

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi
Do you have stock exhaust?
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