my boost gauge works properly between -20 to around 4-5psi, but when the turbo starts to spool fast the gauge bounces from like 4-9psi really fast, then at full boost its steady at 9, just wondering what could be causing this?

 

how is the car itself responding accordingly? (Really, that's the more important question).

 

If your able to access your tuning software run datalog and make a pull, check the datalog and see if boost is spiking on the map sensor or if its just a faulty gauge. What kind of boost gauge is it?

 

the car is running great, i dont notice any extra lag, or any problems, and the gauge is an autometer, im just unsure of what would cause this, or if it is normal, its an sc61, with tial wastegate.

 

the autometer gauge should have come with a t-piece vac connector. one of the three ports is restricted greatly this steadies the gauges. Some need it some dont.

 

Neither one of my Autometer's came with this. Both where brand new in the box. Neither had this prob though.

 

call autometer they should supply it for you. Ive had problems with autometer boost gauges in the past with the reading being off but thats nto to say all of their products are bad just my experience.

 

I have had some funky autometer gauges before so it wouldn't surprise me if it was a little off.

 

I have heard of alot of people having probs with their Auto-meter boost gauges being off I was just lucky to have 2 that worked great with no probs I think.

 

my concern is that the gauge has been working great for about a year now, and now all of a sudden, its doing this, nothing has really changed since its started going crazy

 

Are you A/F chaing when it does this or like Turbo-LS said check what the map says see if its reading the spiking and stuff or if its just the gauge. Gauge might just be wearing out.

 

That would be consistent with what surge would do, but if it never used to do it before I doubt it's that. Also, you'd hear it if it was.

Check some datalogs?

 

Any chance you have some bolts either before the turbo on the exhaust side or clamps after compressor on the charge side?

 

datalog, or get another gauge.

could be problems holding boost, spikes or a leak, etc.