S3 with downpipe - exhaust note changed

[ved789]

Hi,

I drove down to coast 3 weeks ago from Johannesburg (1600m above sea level). I have a downpipe, Forge Intake, Forge DV on my 8P S3. The car obviously got louder as I approached Durban ( coast - due to the denser air). I did 1500 km in Durban itself during the week, doing mainly highway driving. Anyway, after driving about 900-1000 km at the coast, the exhaust had changed dramatically. The car became quiet quiet quiet. It actually became softer than stock. The normal raspy noise had dissappeared. I logged the car, and all was perfect, boost, timing, ... The airflow was actually the best I have ever got. I drove back to Jhb from Dbn, and the car is even quieter in Jhb (obviously, with the air being thinner). I can actually here the turbo spooling now.

I am confused now !!! What do you think could have changed my exhaust note from a nice raspy D/P sound to very quiet ???? I can not work it out. The only variable that changed during the time the sound changed while I was at the coast, was that I ran a small bit of octane booster in half a tank.

At high rpm now, I pretty much only here the turbo spinning. Even if I open the windows to hear the car, the turbo noise has increased as compared to the way the car sounded previously.

Any ideas?

 

[Staz]

I can only assume it's something to do with the ECU adapting to the change in the air it's getting and not re-changing once you're gone back up in altitude. How long have you been back?

 

[ved789]

nope - intially I also thought that it was a function of some sort of adaptation. I have however reset the ECU on the VCDS, and also disconnected the battery. Neither has helped with this change. I am back to Johannesburg for 2 and half weeks now.

I think, I will need to put the car on a ramp to physically look at the exhaust.

tx

 

[Staz]

Hmm weird!

 

[ved789]

exactly - it is really really bugging me. Something tells me that something is gone wrong with the car. To be honest, despite the logs being bang in line, the car does not feel as strong as it usually does.

 

[Spin140]

Reminds me of the beverly hills cop film, have you checked noone has inserted a banana, little help I know but thought I'd share it with you anyway, goes away humming the Axle F tune....