Strange Behaviour

[h100vw]

I reckon the PCV system is a likely candidate. Can lend you a BSH plate if you want to try that after the ECU gets back.

Gavin

[pinkgti]

Righto. After some investigations with the vernier calipers this afternoon I have found an issue with the DP that has been installed. It's a straight through 2.5" system. Not that it's a problem in itself as it's a long piece of stainless tube with some nice blue/purple hues - eye candy for the mechanic.



The issue is the tune file in my ECU is set for a 3" DP

Now just wondering what effect that's going to have and whether that explains the flat spot from 2,000-3,000RPM.

And you can be assured I'll be talking to my tuner on Monday at 9am!!!!

[pinkgti]

I reckon the PCV system is a likely candidate. Can lend you a BSH plate if you want to try that after the ECU gets back.

Gavin as always going above and beyond the call of duty. If it doesn't get sorted will definitely be asking for a full refund and will be giving you a call. Either way I'm up for a DSG tune so I'll give you a call or maybe you can let us know when you're next down this way.

[h100vw]

Gavin as always going above and beyond the call of duty. If it doesn't get sorted will definitely be asking for a full refund and will be giving you a call. Either way I'm up for a DSG tune so I'll give you a call or maybe you can let us know when you're next down this way.

The important bit of the DP is right after the turbo. The gases contract to an extent afterwards, so dropping to a 2.5 system is unlikely to restrict flow.

Can you see the diameter of that?

Logging would be the answer to the flat spot. Surely they need to see that before writing up another tune?

Gavin

[pinkgti]

The important bit of the DP is right after the turbo. The gases contract to an extent afterwards, so dropping to a 2.5 system is unlikely to restrict flow.

Can you see the diameter of that?

Logging would be the answer to the flat spot. Surely they need to see that before writing up another tune?

Gavin

Yep 2.5" straight off the turbo. Managed to get the verniers onto it and confirmed diameter before the weld onto the flex section.



I'm going to go back to the tuner as they were meant to put a 3" system on.

It's 2.5" behind the cat so that it can connect up to the standard muffler which is OK but it's meant to be 3" out of the turbo.

Anyway not sure what effect putting a smaller exhaust on a tune for larger exhaust would have anyone???

Yes so new DP and then logging in that order.

Anyone after a 2.5" straight through DP as I know where there'll be one going cheap.

[parso_rex]

DP diameter is not going to cause that issue and 2.5" is more than adequate for the stock turbo but yes a 3" tapering to 2.5" (or 2.25" is ideal). If you have no leaks and everything else is mechanically sound then it would appear that the set duty cycle is too low for the turbo to produce enough boost reach the specified target but there's so many other things that need to be modified in the file that could cause the same thing.
Do your logs in 4th gear 3K rpm to redline and post it up that's all you need to do (apart from find a nice bit of M4/M5 )

Mark

[parso_rex]

not a nice colour for an exhaust to be either, looks like its been very hot under there .........

[pinkgti]

DP diameter is not going to cause that issue and 2.5" is more than adequate for the stock turbo but yes a 3" tapering to 2.5" (or 2.25" is ideal). If you have no leaks and everything else is mechanically sound then it would appear that the set duty cycle is too low for the turbo to produce enough boost reach the specified target but there's so many other things that need to be modified in the file that could cause the same thing.
Do your logs in 4th gear 3K rpm to redline and post it up that's all you need to do (apart from find a nice bit of M4/M5 )

Mark

Thanks Mark,

I'll start with matching tune file and DP to eliminate this first. It's meant to have 3" going to 2.5" to match the stock muffler.

Sounds like the guys bolting the hardware on weren't talking to the software guys or something. Anyway I'll get this sorted first and then go from there.

Anyone have a favoured section of road? I'm guessing flat and do a few runs plus leave a good few minutes between each to let temps get back to "normal"?

[h100vw]

Thanks Mark,

Anyone have a favoured section of road? I'm guessing flat and do a few runs plus leave a good few minutes between each to let temps get back to "normal"?

After a bit of a coast down and by the time you have changed the blocks on the laptop, it'll have recovered.

Gavin

[pinkgti]

After a bit of a coast down and by the time you have changed the blocks on the laptop, it'll have recovered.

Gavin

So which blocks do you usually log? There's quite a few to choose from and often parameters are repeated between blocks.

I imagine you recommend only do 1 block (4 parameters) at a time on turbo so you get the greatest resolution?

Sorry this info is probably on other threads - should do some more trawling....