2003cobra

Hi guys. I previously had a zzp intake tube with a k&n drop in filter and had no flutter. Now after I installed my k&n sri I get a flutter in boost while letting off of the gas. It flutters in every gear. I have a forge bpv but I don't think that matters. I am still not tuned for the new intake so could that cause flutter? Thanks

FLASH1970

sometimes i get flutter too. sometimes a loud sneeze, sometimes a long hiss if i just ease up on the throttle. i think it all depends on how much boost/vacuum is built up. i wasnt tuned for a couple years when i put mine on. now that im working on the tune, the sounds havent changed. i read somewhere about angling the filter a certain way but cant remember what position to angle it. it lessens the corrections the ECU has to make for fuel trims.

umrdyldo

iTrader: (1)

Flutter is 100% normal. It's just more audible with the K&N filter.

Filter should clocked with the metal strip at 11 or 1, don't remember which. On GMS1 my LTFT is around +-3% which isn't awful.

Now untuned the fuel trims are off by 8-10% under heavy acceleration, which I don't consider acceptable.

ECaulk

iTrader: (6)

I second this.

zeeky420

3rd if you don't like it then don't let off throttle so quick

tomj77

iTrader: (2)

Ya u get flutter with the forge, if u wanna stop it, use green spring if ur not, and u can drill the bpv port a little bigger, extremely carefully. That should make it almost non existent. Also regrease if bpv

63 Nova SS

iTrader: (3)

Or you could just do what I did and get rid of the forge and go back to the stocker. Waisted money on the forge.

tomj77

iTrader: (2)

Stock was worse on zfr

nutty21

iTrader: (1)

I drilled mine out. Still flutter. Don't know where to go from here.
Read forge has flutter issues, which is what I've always gotten, and read it leaks.
Read stock leaks.
Out of everything I read, seems like no actual good options or solutions.
What works for one, some how the exact opposite works for another...

user 72239

iTrader: (4)

Whats wrong with the flutter?

nutty21

iTrader: (1)

You mean besides the fact that it's not suppose to be how it functions? It's annoying.

ECaulk

iTrader: (6)

I'm going to refer you to post #3. Flutter is a 100% normal thing with a turbocharged engine. Don't confuse flutter with compressor surge, they are two completely different things.

tomj77

iTrader: (2)

k04 / zfr problems

nutty21

iTrader: (1)

I'm not, just because it's "normal", doesn't mean that it's functioning properly, or good. I'd rather have it work properly.

ECaulk

iTrader: (6)

It is functioning correctly, lower pressure release causes it in combination with how the car is tuned.

nutty21

iTrader: (1)

"Lower" than what? Proper pressure release? Which would be my point.

ECaulk

iTrader: (6)

So a 1-5psi can cause it, so can the tune calling for the valve to open and close rapidly due to the configuration of the tune. Trust me they function correctly and I've got my adjusted in the tune so it doesn't do that build release build release back and forth.

user 72239

iTrader: (4)

someone say turbo flutter?

63 Nova SS

iTrader: (3)

^ is that the subi?

user 72239

iTrader: (4)

Si

tomj77

iTrader: (2)

I got 0 flutter