Ok so under boost or load my boost guage goes crazy.. The needle shakes eraticly between 2psi. like my max boost is set at 6 psi it will shake super eraticly between 6-4psi.. the performance doesnt seem to be affected. I have changed all of the vaccum lines and i have a brand new guage thinking it was that. I took apart my wastegate and tehre doesn't seemto be a problem with that. When I data log it shows the same thing .. the weird "psi shake" is it something mechaincal? does anyone have this problem? if so how do I fix?
2000 RS with an sti short block and FAT stage 3 turbo kit.
also I thought it was my MBC but I took it off and the problem still persisted?HELP

 

I had the same problem. change your vaccum location!

 

My boost guage was seeing to much air. I used a piece of super 883M elec. tape with a pin hole in it.. this restricted the air flow and there is no more flutter..

 

the whole point of the guage is to see how much air is entering the intake. if you block the path to the guage, than your not really seeing whats going into it! your not fixing the problem, your just covering it up so you don't see it.(not safe)! please just change the location, for running a NA/turbo car , you really need your guages to be accurate!

 

YOu probably just mounted the gauge in the wrong place. There's a really convenient place to plumb it in near the stock boost controller that will make it behave exactly as you have said, because it is NOT the right place to put it in. As someone else suggested, T it into the fuel pressure regulator.

 

actually all that was wrong, was thebguage was seeing to much prerssure. It needed a restrictor... Black electric tape worked well, and now its is smooth again.. Makes me wonder about the quality of some guages out there???? hmmmmmm.....

 

the boost guage is supposed to read pressure. you totally missed my point! your boost guage is only gonna tell you wants going on in your intake! if your boost guage is fluttering than the boost pressure in your intake is fluttering! if your intake is seeing 15psi would you put a piece of tape over the guage so it would only read 7psi in the car and tune it for what the guage is reading? I hope not, but that is what your doing. all you have to do is change the vaccuum location!

 

if your wastegate is not hooked up properly it could cause erratic boost. IIRC you should have the wastegate connected between the turbo and the throttle body so when you get off the throttle and the throttle plate closes, the wastegate is not seeing manifold vaccum but the boost in the charge pipe. the boost gauge and blow-off valve should be connected to the intake manifold.

 

I have a 2004 STi and i put the Utec in it the other week and new Defi gauges and im getting "BOOST FLUTTER" or what ever it is like crazy. Where do i start trying to fix it. I had K N Typhoon intake on, took it off. Reset everything that not it. Whats the deal here or does the TURBO XS UTEC cause this alot?