98Z28CobraKiller

iTrader: (17)

Are there obvious ways to tell the different reasons for being down on boost? I mean does cold side leak behave different than a wastegate leak (torn diaphram) or hot side leak?

My problem is simple enough. The car is making 2 lbs less boost on the spring and 4-6 lbs less on the manual controller. Consistant. Doesn't fluctuate. Otherwise runs great. I have verified the boost via mechanical gage and thru the MAP sensor reading in my logs. I checked the cold side and didnt find any leaks except some air getting around the injectors. My rails were a little loose. I tightend them down but I still have the same problem.

Thanks in advance for any pointers and things to look for.

TurboZ28408

iTrader: (18)

look for exhaust leaks any leaks will KILL spool time. and look for cuts or tears in couplers

OUTLAWZ RACING

iTrader: (9)

Check the bov for leaks.I just had my manual controller take a dump. It was blowing air through the adj ****. What type of intake set up? Oh and if you can hear it dose the gate open befor your set boost level? My old controller made it do that to mine. The wastegate valve may not be fully seated. Other than that any leak will show exhaust leaks will cause longer spool and cold side leaks depending on the size will spike and drop fast as the controller try to maintain the boost level.

98Z28CobraKiller

iTrader: (17)

There doesnt seem to be a delay in spooling. Once it gets to it's max boost at any given setting it holds just fine. I'm just down on boost. Can I rule out the cold side with these symptoms?

slow67

iTrader: (2)

What does it do on the gate only? Your foam depot boost controller could be whacky again.

98Camarod

iTrader: (43)

Does it bleed the boost off ie reach the maximum and then go down from there or what?

98Z28CobraKiller

iTrader: (17)

I took the wastegate off today and pulled it apart. Looks like the el cheapo diaphram on this X02 wastegate got pinched and got a little tear in it. The shinny part just to the right of my thumb.

Will this cause the symptoms that I described in the first post? Again, boost goes up to 7 psi on the spring and 12-13 on the MBC all the way open. It doesn't drop from there. It's just down about 2 psi and 4 psi respectably from what I was seeing before.

I've heard that the Tial diaphram can be used on these. I know that when I took apart my Tial 44mm wastegate (that was too small), it had a much nicer diaphram and everything else for that matter. Unfortunately, I couldn't swing the price tag on the 60mm.