Okay so I switched the N75J back tot he stock N75 and now it idles much nicer and runs a little better. It was spooling like a fricken 737 before. Anyway now when I hit high rpm I hear a thumping sound from under the car. It scares the crap out of me. It does it if I floor it in D or in tip. It almost sounds like exhaust popping but under the middle of the car. Any ideas????

 

Also (and I dont know if this means anything) I noticed that everything in my engine bay by my turbo is moved up a bit so I can assume my exhasut move bit too right? Anyway I ask because my exhaust is really deep now for some reason and I am wondering if the thudding is the exhaust vibrating really hard and hitting the frame or something. Please help guys!!! The fluttering is gone the weird spooling is gone now I just have an ultra deep exhasut and weird thumping at high rpms. Please help PLEASE!!!

 

wut do you mean everything is moved up a bit? and what doesit sound like? like its backfiring? im guessin you might have an exhaust leak somewhere, but i wouldn't take my word on it.

 

Everything up by the intake is closer together now like the turbo took up some more room or something. Like the N75 and everything is all more tight. Maybe it is an exhaust leak. It is hella deep right now. Any other thoughts

 

Who installed it? Check for codes and/or take it back to the tuner to double check his work.

 

I thought the k03 and k04 are near the same external dimensions?

 

It could be compressor surge, I have this problem when my BOV doesn’t dump the air properly, it’s a big thud right as you begin to let off the gas. It feels like its coming from the middle of the car. One other thing is, it could be a boost leak, the extra PSI could be forcing the pipes apart, then as u loose PSI the engine floods and gas starts exploding in your cat, and you hear a bang.
If you do have compressor surge you want to be careful until you get it fixed, because it can slowly damage the turbo shaft. In fact compressor surge is why I went BOV in the first place, with the DV it was happening almost every time I shifted. Now it almost never happens. Maybe 3-4 times in the last 5 months. I know everyone on here bitches about BOV but I have 9K on mine with no real probs now.
Also the K04 and the K03 shouldn’t have changed the dimensions under the hood. Only if you also did an exhaust manifold.

 

Were you tripping on acid??? Did you get new glasses/contacts? Check at end of the down pipe. If your exhaust is much louder and you hear a thumping under the car, you might have a broken joint in the pipng or it could be off a hanger. Just take a look under there.

 

No acid and my vision is 20/15 even my cousin noticed everything shifted a bit. That sound could only ybe exhaust right?

 

Also I dont think its a compressor surge, it happens when accelerating not lettingoff the gas.