Help Me Get Rid Of This Fluttering Noise When I'm At 1/2 Throttle

[PHANTASM]

i get a fluttering noise from the air filter when i get to 1/2 throttle.
sounds like air perculating out of the air filter.
car kinda slows way down.

any help is appreciated.

SEE SIG FOR DETAILS

 

[speedfreakv6]

stupid question but is it when you are letting off gas to hold at 1/2 throttle???if after seing boost ???

 

[PHANTASM]

WHEN IT STARTS TO BUILD MORE THAN 4-5 LBS IT SOUNDS LIKE A HOSE POPS OFF AND A LOUD FLUTTERING NOISE.


could it be some adjustment in the wastegate?
i have an adjustable actuator and a knob type adjuster valve for manually adjusting when the actuator opens.

i also get a whisle noise while at part throttle, sounds like it is coming from the t.b upper plenum area.

 

[LV GN]

could it be your waste gate has a weak spring and its bounching open and close??

 

[PHANTASM]

not sure i have the vac lines routed right.
it is a new h.d. actuator from cottons.

i have the lines this way.
knob type adjuster then hose goes to "y" connector, then one line goes to comp housing(line with restrictor) and the other one to wastegate actuator.

i really haven't tried to turn the knob that much but i haven't taken it over 5 lbs being a new motor and all.

just want to make sure i have the boost line hooked up right.
jack cotton says the noise is normal, but the car slows down when the fluttering occurs.

 

[LV GN]

well you never really stay at 4 or 5 lbs of boost and the h.d. actuator is made to control high level's of boost. how is it at full throttel?

 

[JDSfastGN]

well mine does the same thing with my 44. At around 13-14 psi at half throttle it flutters loudly out of the filter. I believe its because there is too much air flowing from the turbo compared to the amount that the throttlebody is allowing it, causing it to go out the filter. Could be wrong but once you get the right amount of boost it should be fine

 

[PHANTASM]

i will have to check it past 5lbs.

so do i have the hoses hooked up correctly? how do i adjust the boost level? by turning the knob?

 

[bruce]

i get a fluttering noise from the air filter when i get to 1/2 throttle.
sounds like air perculating out of the air filter.
car kinda slows way down.
any help is appreciated.
SEE SIG FOR DETAILS

Going back to my stock Throttle Body, all but got rid of that in my car. I have to go into boost, and throttle back, and really try to get it to *surge* now.

In my case as it *surged*, it's repeatedly going between way too rich and slightly too lean. Too rich can quickly kill making HP.

 

[GNVYUS 1]

Compressor surge, pretty common on modded cars. As long as you keep getting into it it will not be as bad, but holding boost part throttle is not going to happen. That horse will run right through the filter every time and sneeze at you.

 

[turbo2nr]

Dial in a BOV for good street manners. Mine opens a little at every shift and sometimes messing around with med. boost. Never at WOT (of course). Had to get one with a T70.

 

[scot w.]

compressor surge!

Did you change anything to your set up? your's is doing exactly what mine did after installing the P.T.E. stock location I.C, what ended up fixing mine was a bad MAF, it was only getting 188grams of air per second as to what it should be getting 255grm's that's 67grm's short. when I switched MAF's the scanmaster read 255 and the mid throttle surge went away. what was happening was I could get the air out the exhaust, I could get the air into the throttle body but I could'nt get the cold air in. hope I could help.

 

[JKessler]

I would have to go and try a new MAF senser.I had got some thing loged in the hole on the MAF sensor and it ran like that.

 

[Mike Licht]

Does it go away when you press on the gas a bit? If so it is compressor surge.
Mike

 

[PHANTASM]

Yes it goes away as long as your foot is in the gas.
if you go from a stop and wait till you feel the turbo start kickin in and if you leave off the gas a little to cruise it flutters bad as well as if you leave off completely.

maybe i should install a b.o.v.
what brand and style should i get and where to put it?

i also get a whistle noise during cruising. part throttle.
any help on that one? seems to go away when colder out though.
wierd.

 

[bgn87]

I think it's compressor surge, mine's been doing it also. Just bought a new wastegate as I think my ATR external has a bad diaphragm. I also just ordered a Greddy electronic boost controller so hopefully I can eliminate some of this.