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  #1  
Old 1st October 2017, 08:26 PM
GlynH GlynH is offline
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Default 4.2 TDi - difference between 350PS & 385PS?

Hi there, a quick question hopefully!

Just what is the difference between the 2010 A8 4.2TDi putting out 350PS and the 2013 A8 4.2TDi that puts out 385PS?

Apart from 35PS of course!

Is it simply a different map using the same components or are there any physical changes such as different/bigger turbos, cams, heads etc?

Curious to know what changes Audi have made to the engine to achieve the extra 35PS...

Thanks & kind regards,
-=Glyn=-
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  #2  
Old 1st October 2017, 09:36 PM
paulrstaylor paulrstaylor is offline
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I think the later engine is EU6, i.e. has and ad-blue system, so I suspect there is more than a map in play.....
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  #3  
Old 5th October 2017, 08:20 PM
GlynH GlynH is offline
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Ah but nothing that a remap wouldn't overcome then I guess? Would be good starting from 385 rather than 350 though...

Thanks for the reply Paul.

Kind regards,
-=Glyn=-
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  #4  
Old 5th October 2017, 08:57 PM
paulrstaylor paulrstaylor is offline
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Yeah a remap would make up the difference for sure, but having driven both back to back the difference isn't noticeable and mine remains at 350
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  #5  
Old 19th October 2017, 11:53 AM
GlynH GlynH is offline
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Well Paul as I just mentioned in the introduction sub-forum I had mine remapped at MRC on Tuesday.

The health check showed the standard car producing 340.2 PS / 830Nm which is @10PS down and 30Nm up on Audi's quoted spec.

Both ECU's were removed from the car and fully read and the profile saved as a reference should I ever decide to go back.

They were then unlocked so any future performance only updates can be flashed directly in @30 seconds instead of 30 minutes to overwrite everything through the OBD port.

The ECU's were refitted and the dyno runs began to custom map the software curves to the car.

It wasn't a quick process and took about 3 hours in total but any future updates as mentioned above will be much easier/quicker.

I have seen various figures banded about including 425 / 1000+Nm of torque and I had this figure in my mind and so was slightly disappointed to 'only' achieve 415 & 966Nm torque.

However on driving the car it was obvious that it was much smoother and appeared quieter also and the power just surged like a turbine and the car felt like it just wanted to get up and go.

My W12 had this same 'get up and go' feeling but felt quicker off the mark. You just had to have your foot close to the throttle pedal and the layer of dust on the sole of your shoe just made it leap away with no effort. Those lucky enough to have experienced the superlative W12 first hand will know what I mean.

The diesel has @ an inch of throttle free play before anything happens and although that couldn't be mapped out it now has a similar urgency to just get up and go where before there was almost a disconnect between brain, foot & the car starting to move. Difficult to describe but quite obvious when sat in the car probably made more apparent by coming straight from the W12.

It's like the car now is a 'hybrid' between petrol and diesel now and although I haven't had my foot down (I seem to spend most of my driving just wafting along these days) the remap has definitely improved the car for the better.

The speed limiter was also removed but I value acceleration (and stopping power) more than top speed these days.

IMHO the remap was most definitely worth it as even the cold start this morning seemed smoother & quieter although I would concede that some of this may be down to the placebo effect and it could be that by clearing the ECU and it relearning my driving style that it has somehow becomes smoother.

Whichever way I would highly recommend Doug at MRC for his patience, knowledge and performance in working on my TDi, a friends S8 and doing a heath check for another friend with an S8 that has previously been mapped!

For me a very worthwhile exercise but your mileage may vary of course.

-=Glyn=-
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  #6  
Old 10th November 2017, 11:52 AM
mondie mondie is offline
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Great post thanks, Glyn. I was all set to have our 4.2 done when we bought it 2 years ago but we have now decided to sell it early next year. Alas, I found your experience interesting and I wish now we had done it.

Did you notice any change in mpg or are you pushing it too hard to notice
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  #7  
Old 11th November 2017, 03:17 AM
Lui Lui is offline
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Quote:
Originally Posted by GlynH View Post
Well Paul as I just mentioned in the introduction sub-forum I had mine remapped at MRC on Tuesday.

The health check showed the standard car producing 340.2 PS / 830Nm which is @10PS down and 30Nm up on Audi's quoted spec.

Both ECU's were removed from the car and fully read and the profile saved as a reference should I ever decide to go back.

They were then unlocked so any future performance only updates can be flashed directly in @30 seconds instead of 30 minutes to overwrite everything through the OBD port.

The ECU's were refitted and the dyno runs began to custom map the software curves to the car.

It wasn't a quick process and took about 3 hours in total but any future updates as mentioned above will be much easier/quicker.

I have seen various figures banded about including 425 / 1000+Nm of torque and I had this figure in my mind and so was slightly disappointed to 'only' achieve 415 & 966Nm torque.

However on driving the car it was obvious that it was much smoother and appeared quieter also and the power just surged like a turbine and the car felt like it just wanted to get up and go.

My W12 had this same 'get up and go' feeling but felt quicker off the mark. You just had to have your foot close to the throttle pedal and the layer of dust on the sole of your shoe just made it leap away with no effort. Those lucky enough to have experienced the superlative W12 first hand will know what I mean.

The diesel has @ an inch of throttle free play before anything happens and although that couldn't be mapped out it now has a similar urgency to just get up and go where before there was almost a disconnect between brain, foot & the car starting to move. Difficult to describe but quite obvious when sat in the car probably made more apparent by coming straight from the W12.

It's like the car now is a 'hybrid' between petrol and diesel now and although I haven't had my foot down (I seem to spend most of my driving just wafting along these days) the remap has definitely improved the car for the better.

The speed limiter was also removed but I value acceleration (and stopping power) more than top speed these days.

IMHO the remap was most definitely worth it as even the cold start this morning seemed smoother & quieter although I would concede that some of this may be down to the placebo effect and it could be that by clearing the ECU and it relearning my driving style that it has somehow becomes smoother.

Whichever way I would highly recommend Doug at MRC for his patience, knowledge and performance in working on my TDi, a friends S8 and doing a heath check for another friend with an S8 that has previously been mapped!

For me a very worthwhile exercise but your mileage may vary of course.

-=Glyn=-
What sort of cost did this set you back glyn to have done ??? & where are Marc based & do you have a link for them regards lui
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