Losing boost higher RPM's The more boost I lose
12-14-2002, 10:24 PM
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Losing boost higher RPM's The more boost I lose
99.5 A4 1.8 70k miles GIAC Chipped;Tuboxs Bypass;KN; Boost gauge;
problem
n WOT at 3,000 rpm I am making full 14.5 psi of boost holds boost for a sec around 4000 rpms boost start to full and at 7,000 I am only making about 7 PSI.
trouble shooting: I have checked the three hoses that go to the bypass valve. So I checked the "T" from the Boost gauge the line from the T to the intake manifold it is very brittle heat from the cooling line most have got to it.
Do you guys think I am on the right track.
problem
n WOT at 3,000 rpm I am making full 14.5 psi of boost holds boost for a sec around 4000 rpms boost start to full and at 7,000 I am only making about 7 PSI.trouble shooting: I have checked the three hoses that go to the bypass valve. So I checked the "T" from the Boost gauge the line from the T to the intake manifold it is very brittle heat from the cooling line most have got to it.
Do you guys think I am on the right track.
12-15-2002, 07:45 AM
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By the time you hit 5500 rpms you are well past the
tq and hp peaks since the K03 has hit full spool by then, which means the boost pressure will drop off fast at that time. By the time you reach 7K rpms your making much less power then you are at 5000 rpms.
12-15-2002, 08:12 AM
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Re: By the time you hit 5500 rpms you are well past the
This engine is based on torque management. when the engine hits it's nm of torque it expects it gets rid of power by dropping off boost to keep it at the spec. Pretty normal to see it drop off.
12-15-2002, 09:17 AM
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Re: Losing boost higher RPM's The more boost I lose (fixed)
Sorry forgot one thing that the runs are in 4 th gear. I replace the hose going from the intake to the T. Did another run hold 14 psi to 6,0000 then I backed off. 1st gear run goes to 14 psi then around 4K dropp to 10 psi and holds. Thanks for all your help
12-15-2002, 11:25 AM
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You see a drop in boost because the K03 cant spool up any more
after a set rpms. A turbo can only spool so fast, when it hits that limit the boost drops off and the air volume peaks.
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