saleen supercharger question

[89hatchlx]

hello everyone im new to the sn197 had plenty of fox bodys but this is all new to me. Ok here it goes. Bought a 2007 GT 5 Speed it has a stage 1 sallen supercharger. Day 1 car built 8 psi anywhere. Day 2 car would only hit like 4 psi, and the gage flutters like a butterfly.. I know from past experince it should be steady not jumping all over the place. Does anyone have any idea what could cause this and what i can do to fix it? All the work and tuning was done at JDM Engineering in Jersey. Thanks for any info you can throw at..

 

[o0Dan0o]

I'd call them (JDM), but that is most likely either belt slip or a bad bypass valve actuator.
Dan

EDIT: But to make sure, you should buy a new unit and send me that one for "diagnostics"...

 

[89hatchlx]

Yes, Thanks for the info i'll start taking it all apart now get it ready for shipping lol. I'm going to call JDM tomorrow morning and see what they have to say. Thanks again i'll keep you updated.

 

[89hatchlx]

talked to JDM they said they have never heard of the boost actuator going bad they said the only thing it could be is either a fouled plug or a vacum leak?? Check all vac lines they are great havent pulled any plugs yet. Any input?

 

[ct07gt]

Was there a performance difference between day one a day two? It may be a dumb question, but you didn't mention that it ran poorly. If it runs the same, then you probably have a bad gauge or a hole in the line running to it.

 

[89hatchlx]

the car seems a little sluggish in the lower RPMs but pulls bout the same up top..

 

[o0Dan0o]

Double check the wiring from the sending unit to the gage, could just be something got knocked loose causing the erratic gage.
Dan

 

[ct07gt]

I would say its a gauge problem then, you would probably notice a very large performance difference between 4 psi and 8 psi, especially when the tune is for 8.

 

[Steel Horse]

I would agree that something is wrong with the gauge. Wouldn't hurt to check for vaccum leaks too.

 

[89hatchlx]

found the answer to all my problems.. Car started making crazy howling sound today. called JDM and they said it had a blocked off vac line took two min to fix and no more gauge issues. The line coming off the inlet tube to the passenger side valve conver is molded into the hard plastic from the facotry its the size of a pin needle. and it becomes clogged. Reemed it out to match the size of the hose and TADA no more issues. Thanks for all the input guys.