When getting on the freeway and holding the throttle steady the psi seems to bounce 2-4 psi about three times then levels off and relaxes. Only seems to do it when the engine is still warming up. I'm wondering if its a problem with the BPV and if the Forge BPV would fix this?

 

The question is can you "feel" the surge in the engine? If you don't feel a surge or hesitation, then it may be a gauge reading issue.

 

I can definitely feel it. It doesn't stumble or anything just seems like it struggles to hold the boost for a few seconds.

 

mine does this too, i would just upgrade the BOV to the forge, its just the spring and rubber diaphragm not coping very well with the pressure

 

I think that condition, is related to the stock BOV. I just updated to a Forge valve[along with a humungous air filter], and the stock Bov spring is really weak, compared to the Forge springs, both green and yellow.
I just took a 75 mile trip, mosly out on the highway, and I seemed that the Forge valve, made the throttle response much better[I'm running yellow spring-Trifecta tuned]. At freeway speed[80MPH], I was just giving it less throttle than normal, and seemed like the boost came in both quicker, and held , when WOT.
I know a noticable difference was made, but not sure what the large air filer/Forge vale combo, which one made the most difference.
I know, I sure like the quicker throttle response, I'm getting now. It's like you have to pay more attention now, to keep from running up someones rear end, with the better throttle responce. "Moon"

 

double post, sorry

 

Almost 1 year since installl, and last fall I was getting that same turbo flutter, where there is slight hesitation under moderate/passing acceleration. Of course running premium, and wasn't just happening on a colder engine.

The boost guage flutters, as do the RPM's just a bit, enough to hear the engine hesitation and notice the gauges, but nothing to jolt the car, but enough to make you wonder what's going on and why its not holding the rpms and boost.

No big clunk or anything when I let off the gas or anything, just the engine hesitating for a half second while I am under the constant acceleration.

Driving winters, I don't have the ability to have too many opportunities to re-create the issue, but now that weather is nicer, notice the same issue.

So its going in two days to the dealer before the 1 year warranty is up on the install before it costs me anything out of pocket (other then the front brakes, which magically have worn down to need replacement in the last year )

So, from this it looks to be a blow off valve issue. What specifically should I have the dealer look for/replace with regards to the issue? There are no codes to reflash or anything, right? This is likely just a hardware issue, with the stock blow off valve assembly that needs replacement?

TIA

 

Bypass valve is mechanical. Might have dealer make sure there are no other boost leaks.

 

Thanks.

Upon further reflection, I guess I am also assuming that this BOV issue is a result of the LNF upgrade (which is why I said "A year since install"), but I guess that may be presumptive on my part, and it may just be coincidence that it's happened since the LNF upgrade this time last year.

Have other LNF owners seen this happen after the upgrade? For purposes of the dealer I am going to blame this issue on the upgrade so that its covered under the install warranty, as I am not sure if something like that is covered under the powertrain warranty or not (since the car is now going to be 4 years old and the regular warranty expired).

Certainly though, the LNF upgrade has increased the pressure on the turbo system and likely been the main reason for the BOV assembly to be put under more strain then the non-Stage 1 SS cars.

 

It's the tune, or blow off valve, or both. Mine does it, but only when the engine is cold and hasn't warmed up for 20 minutes.

IMO