Different than the lash or the turkey
Thanks Geezer. Let me just say that I am Purple and Proud brother...LOL!
Anyway, the surging sensation is more of the issue here. I will post pix of my setup. At the present I have a custom 2.5" CAI recirculated, a custom 3" mandrel-bent exhaust with single hi-flow cat. I am running stock boost. I have a Joe P MBC and FPR, but have not installed either yet. I am still waiting to receive my FPR from Joe (see my other threads for that story). When I mash it I hit 7 PSI peak and then return to 6.5 PSI steady. I have been flashed, but prior to the exhaust and CAI install. I have reset my ECU twice since the CAI install to try to resolve the issue. I really should have dynoed the car before the CAI install as it is really hard to get a sense of whether I have made any HP/TQ gains. With the surging it almost feels slower, but it is hard to clearly tell. My wife says that it is faster, but that is only because the CAI whooshing and turkey sound scare the s*** out of her....LOL! Of course, while I was on vacation and I took it by Essential Speed to have Ian take a look at it, it never once misbehaved, even though it was hot and humid and we did 4-5 WOT runs. Ian thought I was smoking something or spending too much time in the sun.
When I first installed the CAI, it was not recirculating. I had the usual stalling issues. However, I also had this surging sensation on heavy load then as I do now. I think that it might have been a bit worse when I was vented atmospheric than it is now, but then again it just might have felt worse as it was totally unexpected then and now I have become a bit used to it. I have had to adjust my driving style a bit to avoid it, but it still does happen. At normal city speeds it isn't a problem, but it is a bit disconcerting when you are cruising along at 140 kmh at the front of a line of cars on an incline and then your car starts to buck when you step on the gas harder. Surging might not be a good way to describe it as it seems to ? "backfire/burp" (for lack of a better description as I do get true backfires that are completely different) and falter BEFORE it momentarily surges.
I also wondered about the fuel cut issue, but with only a 3" exhaust and the CAI that seemed unlikely. The sensation is almost like hitting fuel cut as it is as if the engine momentarily dies, but it is also different as it usually happens 3-4 times very quickly (within 1-2 sec) before it settles when I lift off. Sometimes I can lift off slightly and it resolves. Other times I have to get off the gas completely.
I hear everyone's argument about the turkey sound. This I see and have noticed like everyone else, but here I am talking more about the sensation although it does have a sound associated with it. It is also different than the drivetrain lash that people mention although if you put your car into 1st and depress and release the gas pedal quickly 3-4 times in 1 second you will get a rough idea of what I experience although when it happens in my car my foot is not moving on the pedal. I will try to take a video of it happening so that everyone can see what I am talking about.
R
Geezer000 said:
If all you "TURKEY" fans read his posts properly you will notice that he is talking about the FEELING of the surges, Not the SOUND of the surges. I'm not trying to start something here, just trying to get this post going on the right track....
I think Rainman has the right idea, but I also get it with my stock airbox just not as predominantly as with your cai. So I don't think it's FCD fixable. That just fixes the fuel cut (or whatever you want to call it) because he said he also got it before full throttle.