Hello all,

I recently switched to E85(like this week), and was tunning yesterday and everything was wonderful, until I did some 4th gear pulls(6 speed so tunning in 3rd) at 28 psi. At WOT, full load, full boost, 2500-4000 k rpms, it sounds like my bov is fluttering and then it goes away. I was concerned that this was compressor surge so of course I found some video clips and I am kind of sure thats not the problem cuz every clip showed basically when the turbo surged an almost stallish condition of the car. My car on the other hand stutters/hesitates a little as the flutter is happening, which leads me to belive that the bov is flutttering, but to me that makes no sense cuz it holds the boost after 4k. I tried adjusting my APS twin vent, which should hold that boost, and that did not solve the problem. I am kind of at a loss here, so maybe somebody has a solution out there.

 

Flint do you think it could be a leak somewhere? When at full throttle I am having a similiar problem. It sounds almsot as if the BOV has opened then shut, this is seen as a drop in pressure on my boost gauge.

 

Incadescent...watch this video.

http://youtube.com/watch?v=OuNTnA5A2Fo


My car doesnt stall like his car, it more or less hesitates a little with each flutter.

 

dang work computer .. ill check it out when i get home

 

My car does the same thing. It is killing the power bigtime. We had it on the dyno yesterday and was able to confirm it is the BOV.

 

Bump, for some help.

 

After 4k, are you under 28psi?

You might have found the limit for your bov.

 

That is BOV flutter, not compressor surge. I'd say check for a leak around the BOV somewhere, or adjust the spring on the BOV.

 

friend had a similar problem when he did his race gas tune...ended up being the BOV just couldnt hold the boost, im running a FORGE as my aftermarket and i havnt had a problem, just use the right spring

 

Crush it... use a pair of channel locks and slowly/smoothly crush the BOV in slightly and retest

 

I am thinking this has to do with the umpteen million mods you have to do with your factory ecu. I am going to start fresh with only the absolute minimum of ecu mods to get the car running and see if it happens then. I know it is not due to the boost I am running cuz it does the same thing at lower psi.

I will keep you guys posted and thanks for your help.

 

Metal intake pipes will also compound this problem.

 

What do you mean exactly.

 

Explain please oh wise one...

-E

 

You just need to adjust the BOV, sometimes you need to get another spring and sometimes you need to get a full new one. I have 3 BOV's and One flutters like that allot, another not at all because I have it fine tunned to the right strength on the spring and another is the stock Evo9 BOV which does it a little but not as much, the more boost you run on the Stock BOV the more flutter you are going to get its not made for much more than stock, thats why its none adjustable. What BOV do you have?? Flutter is not all bad, just letting you know its time to adjust, but its a fine line in setting up a BOV, you most of the time either have to have it set to high boost with flutter at times when you are only on the throttle part way, or climbing hills with low throttle, or you make it go off more and it will not hold the high boost that you want but it will leak then.