lifegrddude Posted January 25, 2005 Share Posted January 25, 2005 Hey everyone, I've got a slight problem with my 82ZXT. I've noticed it only when my boost controller is powered on (Greddy Profec B old style). During part throttle boosting, (~.3-.5 BAR out of a max of .7) I can hear this cyclic fluttering and the power will sag/surge along with the boost gauge fluttering. When I turn the controller off and do part throttle boosting, it's fine. WOT runs show no problems either, it's only during light boosting such as merging onto the freeway. For those of you running with a Profec B, have you had this problem? Or is there something else I'm missing here? I'm going to mess with the balance knob once I'm done with my classes today, but have any of you actually had to have changed the dipswitches on the side of the box to the other internal wastegate setting? This surging/oscillating problem isn't major since I don't boost often, but it is annoying, and I don't think it's healthy for the turbo when it occurs. I am running a blow off valve too btw. Thanks. John 82ZXT Quote Link to comment Share on other sites More sharing options...
Thumper Posted January 26, 2005 Share Posted January 26, 2005 Hope this helps. http://home.flash.net/~joeao/greg/adjpopoff.html Quote Link to comment Share on other sites More sharing options...
Guest jjohart Posted January 26, 2005 Share Posted January 26, 2005 I have the same Greddy Profec B, and my installing mechanic spent about an hour of tech time after he first installed it, winding up telling me it was messed up, b/c he saw the boost going way, way up, like 13+ pounds! I was driving to the only authorized Greddy dealer the next day to get it sent out, when yes, I tried playing with the switches, which he'd stupidly set for "external wastegate", and found it made all the difference. Believe it or not, if you have it set for the incorrect wastegate (and I could be wrong/reversed even now, but the ZX has a "internal"one, AFAICR), the dial settings for boost amount work backwards, so you get more overboost (dangerous amounts, actually) with lesser settings! I also have a boost increased adjustable 280ZXT pop off valve which I got off of Ebay last year...I removed it b/c it seemed to release at 12.5psi boost, when I wanted to try higher amounts, so I just did the bolt/cap thing. Just for comparison, when I tried the original non-modded pop off a few months ago, I found that it indeed dropped off the boost after about 10psi, and it also made a rather clickety sucking metallic sound as it relased. I have reasonable confidence in the Greddy, now that it's been set and functioning properly for a year. Try the 1 inch plumbers cap, or try an adjustable pop off valve (I'll sell mine for $15-bought for $52), or build your own, but BE CAREFUL to be sure of your max boost settings before you put the cap on it! Good luck! Quote Link to comment Share on other sites More sharing options...
lifegrddude Posted January 27, 2005 Author Share Posted January 27, 2005 Thanks for the replies, I double checked the pop off valve's spring tension (forgot to mention I was running an HKS adjustable one) and it's set at 14psi, higher than I will boost in my current state of tune. (max I do is ~12) I had noticed this oscillating/surge was only occuring during mid throttle corners and it was severely affecting the car's attitude, making kinda unstable and scary since weight transfer kept shifting. I checked the dip switch positions and it checked out, so I adjusted the wastegate response via the balance knob on the boost controller. After a few late night blasts on an empty freeway, the part throttle surge has been eliminated. I had to slow down the boost controller's response to the wastegate. Thanks again for the ideas and suggestions! John 82ZXT Quote Link to comment Share on other sites More sharing options...
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