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Discussion Starter #1
I have a Jackson Racing Supercharger running 8 lbs of boost. But i can only really feel the boost at around 5500 RPM. How would I get more boost in the lower RPM range?
 

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Smaller pulley on the SC to overdrive it faster is the traditional way with roots type blowers. If the blower is up in miles, it may need a freshening up.
 

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if you have 8# at 5000rpm, what do you have a WOT at 2000 rpm. you should get 7 or 8 too. if you don't, then you are leaking boost, maybe your bypass valve.

Roots blowers should reach near full boost at all rpm. at least mine did
 

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Discussion Starter #14
Yeah i just looked more into the functions of it. I think the boost is fine because its a linear boost climb. Where full boost is being generated at red-line. But the slightly jumpy idle is a problem? I also run rich so i backfire whilst coasting. Could that be the upstream o2 sensor then?
 

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Yes. Before cat is the more important one. You might be even in limp mode which isn't good for to long.
 

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if you have 8# at 5000rpm, what do you have a WOT at 2000 rpm. you should get 7 or 8 too. if you don't, then you are leaking boost, maybe your bypass valve.

Roots blowers should reach near full boost at all rpm. at least mine did
The ones I have experience with, peak boost is at the highest rpm. It might make 12# at 6500rpm, but it sure isn't making 12#@ 3000rpm.

My experience is mostly just 6-71's and 8-71's on V8's though, nothing with a bypass valve either.
 
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