again a boost question?

vtecthis349pony

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I have a RPM outlet 2.82 upper pulley and LFP #2 lower. I am only seeing 13.5 psi. I have no kinks in my lines and Have used different Autometer gauges. What is wrong? Stiegemeier's chart says 16.0 PSI. Any one got an idea?

:pop:
 

04CobraMatt

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well the obvious question is belt slip?

2nd, 13.5psi would be normal for 5k/6k rpm

what psi are you at @ 4k rpm?
 

CobraRyan

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Its because of your headers and no cats. That combo should make about 14 psi. So 13.5 sounds alright
 

04CobraMatt

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no slip and it hits 13.5-14 psi at 4k and holds to 6k RPM

The fact that your boost holds over 13.5psi to the redlines says your setup is working. You should be peaking a little higher around 4k but it doesn't seem like a big problem. As mentioned your off-road setup is definatly lowering your max boost.
 
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CobraBob

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Its because of your headers and no cats. That combo should make about 14 psi. So 13.5 sounds alright

Exactly! Boost charts (I have one on my site as well) are only a guide.

Actual boost will vary depending on your mods (ie. headers), as pointed out by CobraRyan. And remember that less boost and more power is always better.
 

vtecthis349pony

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oh ok. so when i get the stageV port will i still not see 16? will it lower even more?

Cause I do have a #4 LOWER i would like on
 

CobraBob

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You'll see a more boost than you are seeing now. Add the 4 lb. lower and I'll guess you'll see around 17 lbs. total.
 

CobraBob

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Not if the blower is ported. Unported I would stay at 15 lbs. max.
 

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