I think the sudden power change at 3000rpm has a bit to do with open loop boost control upto 3000rpm controlled from vnt map using revs and injection quantity. After 3000rpm it switches to closed loop control of vnt from boost actual and desired value.
The more car is changed from standard this jump will possibly increase, decat ring probably affecting it the most but inlet mods also will affect slightly I'm guessing.
appologies if any of this is wrong i think we are always learning more
The vnt map looks basic compared to other maps,
I,ll put a pic up of map.


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So will I pass mot with the new regulations out this year if I smash the inside of my cat out

Chris017 said:

So will I pass mot with the new regulations out this year if I smash the inside of my cat out

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I can't guarantee it for you but I didn't have any problem at all

Owen.

I have passed the smoke test at mot 2 years running with no cats, it is unclear from the new rules if testers will look under your car see no cats and fail it on technicality of the new rules.just phone and ask I'm sure they will be honest and tell you if they would fail it ring another mot station.
Of course if you bash out the insides yours will still look normal so no worries anyway.
No cats and tuning box I've had smoke results of approx 1.2 and 0.8 limit is 1.5.
I'm not sure if scale is linear? Or how smoky 1.5 is.