First topic in the forums!
I'm Adriano from Italy, I own a 406 saloon 2.2HDi from 2001. I'm a physics student in Trieste, Italy.
I'm looking to defap and remap it soon!
I'm eager to learn how to do it.

happy tuning!

Welcome OdinEidolon,

defap is quite easy, now you are on half way to do it.

For this ECU you can safely use ECUSafe program. It will do the trick.
After flashing your car you have to disable FAP system computer in BSI with pp2000.

Then just remove things from your fap/dpf filter but leave the catalyst as it is - because of turbo back pressure... :)

For remap, we can start new topic.

ecuedit wrote:Welcome OdinEidolon,

defap is quite easy, now you are on half way to do it.

For this ECU you can safely use ECUSafe program. It will do the trick.
After flashing your car you have to disable FAP system computer in BSI with pp2000.

Then just remove things from your fap/dpf filter but leave the catalyst as it is - because of turbo back pressure... :)

For remap, we can start new topic.

Thank you, I'll open a topic about that in the DPF section.

ecuedit wrote:.....

Then just remove things from your fap/dpf filter but leave the catalyst as it is - because of turbo back pressure... :)

....

I believe a few 406 HDi owners have removed the catalyst and report success.
It is my understanding that:
... back pressure in the exhaust system of a turbo diesel is not a good thing, but in non turbo engines can be successfully used to aid "scavenging" which increases power output by in-phase re-enforcement of exhaust pulses through the exhaust manifold. The turbocharger "chops up" any pulses so the exhaust stream is more uniform. The most reactive and efficient way to boost with a turbo is to maximise the flow potential across the turbo trainer and this can best be achieved with as freely flowing exhaust as possible and minimum back pressure.
I have been considering porting and polishing my exhaust manifold to test if this has a positive effect as in theory it should minimize exhaust gas retardation caused by flow restriction through the head and manifold to the turbocharger inlet, so with a ported and polished manifold the gas is moving as quickly as possibly when it meets the turbo blades....at least that is the theory!
A turbocharger can be analogous to a water wheel which turn faster when the water falling onto it is moving faster and if the water can flow away from it freely and does not prevent the wheel turning.

...but I am only an amateur (OK I studied fluid dynamics as part of my Physics degree at University but that was a long time ago...) so I would be willing to take corrections from someone who really knows.....

Martin I did not know you were a fellow physicist!

MrH wrote:

ecuedit wrote:.....

Then just remove things from your fap/dpf filter but leave the catalyst as it is - because of turbo back pressure... :)

....

I believe a few 406 HDi owners have removed the catalyst and report success.
It is my understanding that:
... back pressure in the exhaust system of a turbo diesel is not a good thing, but in non turbo engines can be successfully used to aid "scavenging" which increases power output by in-phase re-enforcement of exhaust pulses through the exhaust manifold. The turbocharger "chops up" any pulses so the exhaust stream is more uniform. The most reactive and efficient way to boost with a turbo is to maximise the flow potential across the turbo trainer and this can best be achieved with as freely flowing exhaust as possible and minimum back pressure.
I have been considering porting and polishing my exhaust manifold to test if this has a positive effect as in theory it should minimize exhaust gas retardation caused by flow restriction through the head and manifold to the turbocharger inlet, so with a ported and polished manifold the gas is moving as quickly as possibly when it meets the turbo blades....at least that is the theory!
A turbocharger can be analogous to a water wheel which turn faster when the water falling onto it is moving faster and if the water can flow away from it freely and does not prevent the wheel turning.

...but I am only an amateur (OK I studied fluid dynamics as part of my Physics degree at University but that was a long time ago...) so I would be willing to take corrections from someone who really knows.....

hi there, nice post ;) everything seems fine and logical,
to this post I can only add the practical results.

There have been made a practical test with and without the catalyst part at this engine (2.2 HDI 4HX) - personally tested.
No noticeable differences were achieved or measured. With pro-tune, this would be unnecessary work.
De-fap yes, but catalyst can stay as it is.

For a standard remap you can leave the cat on and just remove the FAP. For a harder remap with new hardware you must remove the cat also.

OdinEidolon wrote:Martin I did not know you were a fellow physicist!

I would not say I deserve the title "physicist" - I studied it at University and have worked for 20 years in a manufacuring environment from polymer engineering to logic and control systems so suppose that means I have lurched more towards "engineering". But I still like to understand how things work which I always thought was the basis of physics in general.
Quantum mechanics and Fourier transforms seem a long way away now..... :?

MrH wrote:

OdinEidolon wrote:Martin I did not know you were a fellow physicist!

I would not say I deserve the title "physicist" - I studied it at University and have worked for 20 years in a manufacuring environment from polymer engineering to logic and control systems so suppose that means I have lurched more towards "engineering". But I still like to understand how things work which I always thought was the basis of physics in general.
Quantum mechanics and Fourier transforms seem a long way away now..... :?

A scientist remains a scientist ;) no matter what. Yours seems a nice field to work in, by the way. Never been a theritician myself.

Hi my name is Daniel and i am electrician !