I have a chevy ss with the 6.0L awd and a whipple supercharger on it but lately i have been haveing problems with low boost psi dont know why and dont see any thing that could cause a leak in maniford psi is there anything i can check? I have tryed to talk to whipple dirrectly and have not had much sucess called and no call back and email and no email back.

any advice would be great thanks
BAD.ASS.SS

thats too bad about the info request, i can try to help you out.

Are you running a boost gauge? how many psi is missing? Does it feel underpowered? i typically see about a 1psi change according to temperature, in winter months i may see 6-6.5psi and only 5 psi summer due to air desity.

do you hear any belt squeal? maby checkout your tensioner and all the pulleys to see it they are in good shape, also remove the belt and see if it is shiny and glazed. i know the tensioner used on my setup is one tough tensioner!!! takes lot of omph to release tension to change the belt. the originall could be weak.

other things to consider is a leak, one way to tell is put a mix of dish soap and water in a spray condtainer and idle the truck and spray everywere you can around the intake and any pasages after the charger, if there is a leak it should suck in the bubbles. another thing to do is to remove the vacuum line to the dump valve, plug off the truck end of the hose and go for a drive, this will eliminate the actuator from dumping acces boost, this SHOULD increase the boost you see, if not the valve could be stuck, or have failed open.

another thing is the condition of the engine, maybe a tune up is in order? supercharging an engine requires shorter tune up scedules. have you perfomed a compression test? i know it has low miles but its a good thing to keep track of.
Just a few ideas, letme know what you think.

Stump.

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Thats a great idea i did not think to check the belt or tensioner.it has new pulgs in it and a clean k&n. The charger use to make 9 to 10 psi on stock pulley it is a 2300ax by whipple. it has new dule exhaust but it is still running the cats could a cloged cat be causing a restriction that would lower boost?

It is the origonal belt and tensioner

I will look in to checking the ducting and intake with soap and water

Thanks for the help if you can think of anything else let me know

bad.ass.ss

by the way nice sleeper have fun makeing the imports look stupid stumppuller454

how much boost does it make now? and this happend after the exhaust?
I was going to mention something about exhaust restriction but i`m not sure if it would cause low boost, for sure on a turbo situation it would but i don`t know on a belt driven supercharger if it would reduce boost, it would be a good thing to check though, an exhaust shop would (or should) be compitent enough to know how much restriction is too much and how to check it.

stump

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it makes about 3psi now a huge drop in proformance.
no it ran great with the new exhaust then had issues.

still runs ok

the two injectors that are on the back of the supercharger are not working
I took a injector pulser and tested the injectors and they work but the
EFI computer is not fireing them ran a test with a wide band o2 sensor in and no different with them hooked up or not

ah i see, you know, i don`t know if you have warranty but your owners manual might have some basic things to troubleshoot for that problem. With my charger i ditched the auxillarys and module and upsized my stock injectors and went with a custom tune. its just an option. it may cost the same as a new computer.(if thats the case) i would assume there must be some fuses or relays that could be checked in the unit. I guess you could start checking all the wiring to that baby, something could have come un-attached or shorted.

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Hey Stumpuller454 - Tried to respond to your PM but got a message ssaying you don't accept PM's. Anyways, here's my reply. Sorry for jacking this thresd....

Hey Clancy,

I have upgraded injectors (60lbs?). Also water/meth injection. Smaller pully to get me to 11 lbs boost. MSD ignition, headers and a custom tune. I believed it dyno'd 600+ RWT and 440 RWHP.

Mike

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2002 996TT: EVOMS GT700 - Big Throttle Body - EVO Intercoolers - Europipe 92mm Custom - Moton Club Sports - GT3 Swaybars - Big Brakes - BBS Racing Wheels 21 psi = 600 4WHP & 4WTQ

1999 7.4L Whipple: 11PSI 440 WHP 660 WTQ

2007 Escalade: 0 PSI -> Where's the BOOST?