Low power

[C4PRA.AD]

My Seat Leon Cupra MK2 2009 CDL K04 was remapped to stage2+ by the previous owner. It's got the supporting mods for a stage 2: downpipe, custom 3 inch turbo back decat exhaust, oversized ramair intake, R8 coil packs, NGK8 spark plugs. Always run on 99 octane.
Dyno figures show 239whp, around 270bhp and 400nm of torque.
What could be wrong? Anything mechanical to look at?

 

[R3k1355]

Boost leak

 

[James_R]

What kind of diverter valve are you using?

 

[C4PRA.AD]

What kind of diverter valve are you using?

OEM but I’ve just ordered a GFB DV+ VTA. I’ve checked the one I got and it looked fine. I have attached pictures of it.

 

[James_R]

that one you have is the best of a bad bunch and could well be the cause of the power loss. Have you had any codes logged in the ECU? pressure drop between turbo and throttle for example?

 

[C4PRA.AD]

that one you have is the best of a bad bunch and could well be the cause of the power loss. Have you had any codes logged in the ECU? pressure drop between turbo and throttle for example?

No no codes at all I checked it for any rips but there were none. Judging by its state, could it be the reason behind it? I thought it looked okay

 

[James_R]

From previous experience, those ones warp and become weak. It was the type with the big orange diaphragm that used to visibly split.

 

[C4PRA.AD]

Should I expect any difference with the new one? This is the one I got.

 

[James_R]

I'd opt for another internal diverter valve rather than a blown off valve.

 

[C4PRA.AD]

What are the chances the DV could be the culprit judging by its state in the pictures?

 

[James_R]

Difficult to tell off the picture alone, you could always replace it with an OEM part to test before upgrading? I recall the difference being night and day once they were replaced, they were less than £50 at the time.

 

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I’ll replace it with the new one and test if there’s any difference. Thank you.