BigSteve

im gonna try to make this as simple as possible. this has been stressing me out like crraaazzzyyyy. Maybe someone on here can shed some light/give me peace of mind/help me find a solution.

I was recently protuned, I was running cobb AMS stage 2 OTS map. I did some logs and I didnt like the knock count I was getting but the car ran strong, and pulled hard.

The day of my protune I had my tuner install a perrin v2 3 port, he tuned the car to spike at 28 1/2 but im holding 26/27. The tuner did a great job with the tune but on my way home from their shop I was accelerating on the highway in 4th gear around 3.5K and I hear this "ch ch ch ch ch" coming from my intake. I put the car in 5th around the same rpm and got the same thing "ch ch ch ch ch" After making some calls and doing some reading I decided to take my car back to my tuner and have him turn the boost down. I figured what I was hearing was compressor surge and lowering the boost would fix the flutter im getting in low rpm high load.

the flutter mainly happens when 4th and 5th and a little in 3rd. I can hear the flutter up till about 5K but my exhaust could be covering the sound at that RPM. So I took my car in and he turned the boost down to 19!!! The same "ch ch ch ch ch" was still present in 3,4,5th.

The car drives GREAT at quarter throttle just normal daily driving, but when im on the highway and want to pass some one or if im in 4th and accelerate thru a traffic light I hear the surge. I cant hear the surge at quarter throttle, I hear it at half throttle and full throttle and any where in between.

This is interesting as well.. if I WOT 1,2,3,4,5 I wont hear flutter, its only when im half/full throttle on the highway or something similar.

So heres my concerns...

-The "surge,flutter,ch ch ch" wasnt there when I took the car in, it started after the 3port and protune.

-Is this a tune issue, or a 3 port issue?

Please, if you can help me out I would really appreciate it. This is driving me nuts and ruining the fun in my car.


I was thinking about removing the 3 port and putting back the stock solenoid and flashing back to my cobb map to see if I still hear surge.. but that doesn't help me narrow what the problem is.. because im changing the map and removing the 3 port.. so im still getting nowhere with diagnosing the problem.

one last thing, when I hear the ch ch ch sound the car doesnt act funny or jerk at all. it pulls hard but when I hear the surge it doesnt sound healthy. The car holds 26/27 psi very well and tapers to about 22 23 so the 3 port is doing its job and its holding boost but something just isnt right....

tephra

iTrader: (6)

its either too much MIVEC causing turbo surge.

or the WGDC maps arn't smooth, and there might be a big jump from 1 cell to another...

probably the former thou

BigSteve

How do I fix it? What do I have to change?

tephra

iTrader: (6)

post up pics of your #2 MIVEC maps (both intake and exhaust)

BigSteve

not exactly sure how to do that... do u want me to just upload the tune/map im running? or logs with the ap?

Piper747

iTrader: (2)

Are sure the sound is not just the 3-port itself? I have a Perrin 3-port and have a sound similar to what you describe. You'll hear it or not hear it depending on the WGDC being used. Just a thought.