ReMap 997T Swirlling Noise!

[Robtheloop]

I have a Gen1 997T. It has a Kline exhaust with 200 cell cats and BNC air filter. I took it to SuperChips for a remap. After the map it is most definitely pulling more torque and very smooth, however, under boost it makes a very odd, but loud swirling/swishing noise. The noise is coming from the rear of the car. It sounds like any excess boost is escaping via a valve. I know the 997T doesn't have conventional waste gates so am not sure how this pressure is escaping. It's just odd because it's not a constant single tone pressure, but this swirling/swishing noise. The dash boost gauge is reading 1.0 bar solid and the delivery of boost is very linear, as too is the torque. The motor runs perfectly - just this odd noise - a noise not there prior to the remap.

Any light from experts please?!?

IMIA - any thoughts?

Cheers,

[s3nick]

It's hard to tell without being in the car. It does sound like a hose has popped off but then you say the car has power so it could be just the turbo spool you could be hearing.

Are you local to London?

[IMIA]

s3nick said:

It's hard to tell without being in the car. It does sound like a hose has popped off but then you say the car has power so it could be just the turbo spool you could be hearing.

Are you local to London?

+1 its a loose hose somewhere imo. probably one of the hoses connecting to y pipe

[Robtheloop]

IMIA said:

+1 its a loose hose somewhere imo. probably one of the hoses connecting to y pipe

I've checked all the hoses. It's 100% not a loose hose. There are very few on the car and I've checked turbo to intercooler - intercooler to y pipe and y pipe to throttle body.

It didn't make the noise at all before pulling up at SuperChips and as soon as we left it started making it. I'm sure it's not a hose problem as the boost holds perfectly and smoothly through the range. Under load it holds 1.0 bar no problem. It's a really odd swirling noise - never heard from a turbo car before! Performance is perfect though!

[DasChin]

If performance is spot on then it's probably turbo and spool up noise. Plus on way down.

You will be running more boost so they are working harder. Plus you have uprated filter and cats/exhaust so you are going to get more noises when the blowers are wound up a bit.

Is the noise under load or off load with the gas ? Or both?