So I think the next thing for me to check for causing me to not be able to boost over 7-8psi and to not be able to get over 0-2 psi in first could be the bypass on the supercharger? I tried plugging the bottom hose (the one that is open to the air) and it seems to be a little easier to create boost. Also when I try to open the bypass it kind of makes a creaking sound like something is loose bad. It still has a little spring action in it but it is really easy to move. Does this sound like it could be the problem? The charger I bought had 45k on it and the original hose from the bypass to the charger had dry rot. So who knows how long it was sitting. Any feedback is appreciated. I just don't want to waste $45 on it if I don't need it.
Mine creaks.
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Not seeing over 8 psi on the stock pulley isn't unheard of, I only saw 8 a very few times on my stock pulley and that was on a really cold night . The first gear thing is definitely weird though
Yeah the 8psi isn't bothering me so much as the 1st gear. Im pretty sure I don't have a vacuum leak. ( my guage reads 20 hg at idle and it idles fine) I can't even break the tires loose in 1st
depends on the gauge too i am seeing 10 to 11 on my stock pulley
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David wrote:depends on the gauge too i am seeing 10 to 11 on my stock pulley
Sounds like your gauge is way off. A 3.1" pulley would put you at 10-10.5psi.
To the OP, sounds like it may be the bypass valve. I had the same problem shortly after installing my blower, wouldn't make past 3-4 psi. Put on a replacement unit from ZZP and problem solved. After some reading, it seems they aren't the best construction, basically a runner diagram and spring inside, and it's prone to tearing. Took apart the original valve afterwards and sure enough the diaphragm inside the valve had a 1" tear in it.
Ok I'll just go ahead and order one. Probably a good idea to replace it with the mileage the old one has anyways. I really hope this is it. It's fun in 3rd and up but 1 and 2 just aren't doing it.
1st gear should practically be useless with the charger on there. Something is definitely wrong and I think in one of your other posts I even mentioned to check your bypass valve. The only real way to diagnose the bypass valve is to hook it up to a vacuum pump but I am guessing that is not an option for you. Typically when there is a diaphragm issue in the bypass valve it will affect all gears but if yours has been busted since the beginning you are likely not familiar with what it should be doing in the first place. It sounds like a bypass issue but it could be several other things as well. Trying to diagnose an issue over the internet is always a challenge.
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yeah i dont have a air compressor. I just went ahead and bought the new bypass. Yeah I was taking your advice to check the bypass. It should be here mid next week so I guess we'll see if that was it.
EVILution (KGM Godfather) wrote:David wrote:depends on the gauge too i am seeing 10 to 11 on my stock pulley
Sounds like your gauge is way off. A 3.1" pulley would put you at 10-10.5psi.
To the OP, sounds like it may be the bypass valve. I had the same problem shortly after installing my blower, wouldn't make past 3-4 psi. Put on a replacement unit from ZZP and problem solved. After some reading, it seems they aren't the best construction, basically a runner diagram and spring inside, and it's prone to tearing. Took apart the original valve afterwards and sure enough the diaphragm inside the valve had a 1" tear in it.
I barely see 10psi on a 3.1. Damn altitude! Haha
Im at sea level and I see 11 psi daily on the stock pulley
Philly D wrote:Im at sea level and I see 11 psi daily on the stock pulley
What gauge are you using?? I was seeing 11ish on a mechanical Autometer gauge, but now I'm dead on at 10 psi with an AEM digital.
^ On a 3.1 I mean. No way you should be making 11 on a stocker.
I have a Autometer cobalt series mechanical gauge.
I see 10-11 lsj on stock pulley too
z28guy(KGM BEOTCH)
z28guy wrote:I see 10-11 lsj on stock pulley too
Wow Sam, you see 10-11 LSJs?! Give me one!!
Wtf I don't know how my auto correct put lsj instead of psi lol
z28guy(KGM BEOTCH)
i see 12-13 on my 3 inch.
when my bypass valve was bad i couldn't make boost in any gear. In first I rarely see boost, I tac out too fast. Boost is definitely there though as i can shred tires bouncing off the rev limiter.
Well the new bypass came in today. Getting ready to go put it on the charger after I put my daughter to bed. Hopefully, this fixes my issues.
Well 15 minutes and 1 bolt lost in the engine bay later, I have installed the new bypass. Haven't taken her out for an actual drive yet, but I was able to hit 5psi with 1/2 throttle in 1st. Looks like my issue may be fixed. The old bypass didn't look like there was anything wrong externally. The spring tension was def sloppier on the old one. I guess I'll have to open her up to see what went wrong. Thanks for your help guys. Can't wait to drive to work tomorrow to see how much boost I get.
FTW!
Well I didn't get to see what my max psi was today (DAMN HIGHWAY TRAFFIC!!!), but I def was able to break the tires loose in first and got at least 8 psi. So looks like the bypass was def the problem.
Glad you got it fixed, and I'm glad I replaced the one on my charger that's sitting in a box ready to go on my car, better safe than sorry.
Yeah true that, I'm just glad it was something so simple.
