Stuttering Boost with Exhaust Bung Out

[malcster]

I have a Rev 2 with a 5Zigen border exhaust, stock CT26 & a Greddy I/C with the boost set to 1 Bar.
When I run the exhaust with the bung in, the power delivery is smooth throughout the rev range.

However, if I remove the bung, and run the car through full boost up the rev range, it feels kind of stuttery.
Not to the point of it miss-firing etc, its just as if the boost is stuttering very slightly.

Any ideas?

[Steve-O 2007]

what boost is it hitting now with the bung out?

you might have to turn your gain / duty right down as you have now changed the exhaust flow in a big way making it less restrictive.

either that or check your ignition components, dizzy cap, rotor arm, plugs, leads etc.

[JDM-MAT]

do you have a strait through exhaust? no cat? could be over spooling this may explain why its okay with the bung in. the bug creates a bit of back pressure on the turbo which stops it over spooling. on my supra i had to fit a restrictive ring in my exhaust to create back pressure so my turbo's would not over spool.