What would cause my stock bpv to flutter. It seems to do it more in the lower rpm.
I have the airbox mod with a k&n filter, full 3" turbo back, synapse intercooler, dejon upper charge pipe, gm stage 1.

I'm pretty sure it's fluttering. Even when I'm in full boost and let off it doesn't sound like it used to. It's kinda like woosh woosh. Maybe im not used to the air box mod and k&n filter. I used to have the dejon Sri on my car.

Can someone chime in.

Bump anyone........ I just went out for a drive and you can hear it during low boost vacume......

 

the airbox mod and K&N... mine does it a little... it could probably most be tuned out but with the GMS1 or like I have the superchips tune, it'll do it... though mine isn't as bad as your is(or maybe i'm just used to it)... I seem to notice most of mine before the temps get completely up on the car(under light boost its the most noticeable)


one of the many reasons I am ditching the SC tune

i'm thinking about just going with the Hahn when I get tuned as much as Hahn catches flack about being "overpriced" that intake seems to react the best with this car

 

Yours does it too.... Seems to be when I'm in vacume close to 0 psi. Kinda worries me. Wondering if I should not drive it until I get it figured out. Or if I should throw the stock filter back in

 

yelp but mine seems to go away when the car gets completely warmed... for the most part

I wouldn't really worry about it, if its like mine its minimum anyway, besides you should be out of the vacuum much until the car gets warmed anyway

i've never seen an engine as temperature dependent as the LNF, its very finicky

 

is the black thing on the inside of the bpv ripped

 

The thing is that my car is fully up to operating temp.

what black thing inside the stock bpv????

Should I take it apart to see what's wrong

 

yea mines ripped and its on national back order

 

i believe its called the bypass valve diaphram

 

Morning bump......looking for term, or byt to chime in here

Is yours doing the same as mine

How would I check this. Just take those 3 bolts out and take the bpv out.

 

what is the part #? and can you get just the spring as well? I lost my stock spring and have the Dejon, but would like to put the stock one back in

 

There is your issue right there.

 

ive yet to have a problem with the dejon spring... i suppose if you were to add washers in it it could cause problems but i have yet to have any...

 

It is the AEM elbow. It cannot be tuned out. I have tried for months in the past to no avail. Get rid of the AEM elbow and all issues with flutter and choke/surge will disappear.

 

Bump

Got an appt at the dealership tomorrow but I doubt they will know what to look for...

 

Try putting the stock elbow back on the airbox. I bet your issue disappears.

 

I have the stock full intake back onto the car with a k&n drop in.

 

Again, I tuned a car with that elbow and he has 0 issues.

 

you have to be kidding? if you are tuned for it sure, but if you arent..it causes issues.

 

Bump...... Any suggestions.... I don't have the aem elbow, I have the stock

 

Check the BPV diaphram and spring as well as the vac lines on the car. I never had any surging unless the AEM elbow was on there.

 

I'll get the dealer to check tomorrow. Would charge pipes or intercooler have anything to do with the surge.....I don't hear any boost leaks.

 

i have had the dejon spring for 11000 miles and no single issue to report from it

 

Pfft so you say, I just had stuck my stock BPV spring back in for the last 2 weeks, I've had the Dejon since I had 600 miles on the car I have about 5k now, I switched back to the Dejon BPV spring this week. The car feels much stronger again at WOT pulls.

Every single person that rode in my car since I switched back to the stock BPV spring has asked me if I turned my boost back down because the car didn't feel like it pulled as hard at WOT. None of those people even knew I switched back to the stock BPV spring.
Every person on this board can call it placebo effect or butt dyno but when 5 different people tell me the car feels slower at WOT without telling them I did anything to it, then something is going on.

The Dejon spring will give you very slight flutter for the 1st 500 miles, then mine went away.
You do get faster boost recovery with the stock bpv, but the stock bpv spring pulls no where as hard at WOT pulls (at least for me).
I barely had minimal torque steer with the stock BPV spring back in (these last 2 weeks), with the Dejon BPV spring I have to keep 2 hands on the wheel and pay attention at WoT pulls.

I have no way of proving any of this, I'm just going by how the car felt to me and then all the people that rode with me (without them knowing I switched springs) aka butt dyno.

 

I noticed no difference in power with he Dejon Spring in the car. The only way you would notice was if you need to take the BPV apart and clean and reseat the diaphram.

 

Bump....deff does this when I'm in vacume....I just checked all the vacume hoses and everything is connected. It either has to be the diaphram or the k&n filter or I'm my head lol, which I know it's not.

Could be a vacume leak that I just can't see, I'll probably end up teaching the techs a thing or two.

What If I try that tank bypass. Maybe that will work?

Also will this hurt my car, is it still safe to drive ?

How hard is it to take the bpv apart to check the diaphram