Wastegate flutter?

[rhanchard]

I have recently bought a Cupra ST300 with Stage 1 map and I am getting a wastegate type chatter noise sometimes when lifting off the throttle at low revs or downshifting from the passenger side. It might be making the noise when driving hard but I can't hear it above the other engine noise.

Not a great recording but around 3/4 through the recording you should be able to hear the noise here : Cupra flutter It sounds much louder in person

I can't see any obvious mods so wanted to check if I have an issue. The car drives fine but worried there might be a problem or I am causing damage driving it like this.

Thanks

 

[SuperV8]

I can't hear the noise very well from your recording but usually a turbo noise when you accelerate then lift of the throttle to change gear is when the turbo surges - basically the pressurised air from the turbo hits the closed throttle plate and reverses back through the spinning turbine 'the wrong way'.

Generally not good for the turbo, and what dump valves try to eliminate, i'm sure there will be people who have had no issues though with mild turbo surge/flutter.

 

[rhanchard]

I can't hear the noise very well from your recording but usually a turbo noise when you accelerate then lift of the throttle to change gear is when the turbo surges - basically the pressurised air from the turbo hits the closed throttle plate and reverses back through the spinning turbine 'the wrong way'.

Generally not good for the turbo, and what dump valves try to eliminate, i'm sure there will be people who have had no issues though with mild turbo surge/flutter.

Thanks it's not very clear in the file. Yeah that's what I am worried about.

This happens even when downshifting after coasting from 2nd gear down to 1st so wouldn't have thought it's a surging turbo as hardly any boost has been applied

 

[queen]

It's most likely diverter flutter that has become more apparent because of the increased boost of the tune, don't worry about it at all, it's normal, mine does it too. If you like it you can "amplify" it with an intake.

 

[rhanchard]

It's most likely diverter flutter that has become more apparent because of the increased boost of the tune, don't worry about it at all, it's normal, mine does it too. If you like it you can "amplify" it with an intake.

Thanks that's good to know.