boost 'flutter'

gentlyharsh · Oct 6, 2009, 11:04 AM

Weird problem with my 9:
at full throttle the boost does a ... 'flutter' for lack of a better term. It'll be steady until about 10psi, then start wavering and by the time its at peak the needle on the gauge is going between 25 and 20 or so. (its the most extreme at peak boost, lower than that it fluctuates between about 2psi then grows as the boost grows).

I've had my guy check it multiple times, boost leak test, checked all lines, even replaced the throttle body, but the problem still persists.
I'm beginning to think it might just be with the gauge itself because I do not FEEL a loss of power or boost in the car, it only seems to appear on the gauge.

Thoughts?

huevosrancheros · Oct 13, 2009, 05:12 AM

change the gauge or check you BOV

gentlyharsh · Oct 13, 2009, 08:48 AM

changed out the BOV completely with another one that we knew for sure worked, so it's not that.

The gauge is the next thing to swap out, just need to buy a new one first

CBRD · Oct 13, 2009, 08:49 AM

what boost controller?

cb

gentlyharsh · Oct 13, 2009, 08:50 AM

Not positive, it's ECU controlled though

CBRD · Oct 13, 2009, 09:19 AM

depending on how its set up, the boost correction could be causing your duty cycles to be going up and down and making it fluctuate.

cb

gentlyharsh · Oct 13, 2009, 09:22 AM

Quote:

Originally Posted by CBRD

depending on how its set up, the boost correction could be causing your duty cycles to be going up and down and making it fluctuate.

cb

those are a lot of words put together that i know nothing about

but I'll definitely look into it, i really appreciate the feed back!
My car will be at the shop today so i'll ask about it.

gentlyharsh · Oct 14, 2009, 09:27 PM

So I got my car back from the shop, got new cams springs and retainers a aquamist meth kit and a tune and now it doesn't do the flutter anymore...sooo... yay!

Evo_IX_Guy · Oct 14, 2009, 09:44 PM

What you put down on the dyno?

gentlyharsh · Oct 15, 2009, 08:39 AM

Don't know numbers yet, all I know is it's fast as ****!!

Bluefire · Oct 16, 2009, 10:38 PM

hmm odd, i would have guessed the wastegate might have been fluttering

gentlyharsh · Oct 16, 2009, 11:16 PM

I don't know what a wastegate flutter would have done, but like I said in the original post, I didnt feel any loss in power or that it was lagging in anyway :/

but its all good now so I don't have anything to worry about...yet haha

1badgsex · Oct 18, 2009, 06:19 AM

Quote:

Originally Posted by CBRD

depending on how its set up, the boost correction could be causing your duty cycles to be going up and down and making it fluctuate.

cb

totally agree ^, i had my blitz dsbc elec boost controller set wrong the duty cycles were off and war doing exactly what u are describing, played with the settings and probally the best boost cont i ever used !!!!

sgt_petty_210 · Oct 18, 2009, 07:20 AM

im assuming your boost controller is a three port in which the stock ecu controls. If you are tuned that shouldnt be an issue. You can rule out the bov since you said you changed to one that works. My guess, and its only a guess, is since you are not feeling any power loss, but your gauge is being retarded, change the boost gauge then. What kind of gauge are you using right now? Also to, can you hear any fluttering when you are on boost. IE the turbo making weird noises when you are wot. There could be many factors to causing this issue. What sucks is you are going to have to use the elimination process. But def change out your gauge and see if that works.

gentlyharsh · Oct 18, 2009, 09:20 AM

i appreciate all the feed back guys. If the problem did persist, I would have changed out the gauge cause it's a cheap-o Autometer boost gauge. But as I said in post 8, I got a re-tune with the addition of some new parts and now it doesn't flutter at all anymore. So i guess it must have been the boost controller.