What is remapping? Is it really beneficial?

[chris200]

....take the c200 and c220 CDI's (W204007 and W204008), there is absolutely no difference between the 2 other than the map on the ecu, with this in mind there is no reason to expect a moderate remap of the 200 to have a detrimental effect over standard....

I've changed my mind again!

 

[Dieselman]

The turbo is different as well.

 

[John Jones Jr]

remapping is also often undertaken in order to smooth the power delivery and provide a more driveable car, the headline torque and bhp figures are not what you should be looking for, more the area that is under the curves.....

If the aim of a remap is better driveability alone without chasing power, I think it should be considered for any mass produced car. I find that big low end slug of torque from modern diesels annoying, so if a remap can smooth that out somewhat (don't know if it can) it's got to be worth it.

 

[MattDC]

The turbo is different as well.

Wrong......

The W204007 (C200 CDI non BE) and W204008 (C220 CDI non BE) both use the following part number as per the EPC:

A646 090 10 80

 

[Dieselman]

So we have one detuned model that might be safe to remap.

As a rule, it's not a good idea unless the EGT is monitored.

 

[chris200]

On this note......should I consider getting a new ECU for my C200 W204 or having it remapped? Any idea of likely costs?

 

[MattDC]

But as stated, the 220 should also be fairly safe, as all major components on the 4 pots are pretty much the same across the differing power levels........

I think it was the German taxi drivers that all used to buy the E200 instead of the 220 (big price difference) and then fit the 220 injectors and remap, basically getting a 220 for little more than a 200......

 

[V12]

Recently helping my bro in law buy a passat estate.
Drove the 140bhp 2.0D and it was pleasant enough (for a 4 pot diesel).
Then drove a 170bhp version and the lag was terrible.
Both cars were 2 or 3 years old with around 40k on the clock, same dealer so the experience was back to back with the same roads driven that I know very well.

It was the first time I've witnessed the sacrifice of driveability for power in a production car.

 

[Dieselman]

It was the first time I've witnessed the sacrifice of driveability for power in a production car.

Try a 1.9 TDi 150. Very laggy compared to the 130.

The lag is caused by the turbo being larger and taking longer to spool up, so not an issue on a remapped car. What is more likely there is turbine tip melt due to the high EGT.

 

[MattDC]

On this note......should I consider getting a new ECU for my C200 W204 or having it remapped? Any idea of likely costs?

remap - although get a reputable one - I would steer clear of the tuning boxes (unless Brabus) and the cheapo £200 maps.....

Once funds allow I'll be getting the superchips remap, unless I can be even more patient and save a bit more to get a custom map to push slightly more than the standard 220......

 

[MattDC]

Recently helping my bro in law buy a passat estate.
Drove the 140bhp 2.0D and it was pleasant enough (for a 4 pot diesel).
Then drove a 170bhp version and the lag was terrible.
Both cars were 2 or 3 years old with around 40k on the clock, same dealer so the experience was back to back with the same roads driven that I know very well.

It was the first time I've witnessed the sacrifice of driveability for power in a production car.

Which is where I refer to my earlier post - the headline figures aren't what matter - its the curve and the area beneath it that matter....

the 170 will more than likely have a curve which gives lower power lower down the rev range than the 140 all in an effort to raise the bhp figure in order to sell cars.....

 

[Howard]

Nothing to add from me as I know nothing about anything , but I would just like to say how nice it is to see a discussion , by members who are actually knowledgeable about what they are talking about.

Not been much of that lately.

 

[John Jones Jr]

Recently helping my bro in law buy a passat estate.
Drove the 140bhp 2.0D and it was pleasant enough (for a 4 pot diesel).
Then drove a 170bhp version and the lag was terrible.
Both cars were 2 or 3 years old with around 40k on the clock, same dealer so the experience was back to back with the same roads driven that I know very well.

It was the first time I've witnessed the sacrifice of driveability for power in a production car.

I exactly know what you mean. Found the same issue driving one of those Golf Tdigti'sRedi, 180Bhp or something, quick car but I bet the lower powered version was a better alrounder.

 

[HumberMart]

remaps taken to extremes and done unsafely can and will cause damage..... but take the Mercedes engine lineups for example, some of these are restricted by the map to give lesser performance in order to meet insurance groupings and other targets for certain markets.... take the c200 and c220 CDI's (W204007 and W204008), there is absolutely no difference between the 2 other than the map on the ecu, with this in mind there is no reason to expect a moderate remap of the 200 to have a detrimental effect over standard. In fact other than the turbo and injectors there is no difference in other components when you move up the range further to the c250! remapping is also often undertaken in order to smooth the power delivery and provide a more driveable car, the headline torque and bhp figures are not what you should be looking for, more the area that is under the curves.....

Matt DC. It's nice to find someone else talking sense on here. It's a bit ironic that my post gets lambasted for a lack of knowledge about CO2 and combustion since I am a consulting engineer in that very field!

There's so much misleading info on this thread it's unbelievable. Most diesels can benefit from a remap with no effect on reliability and the manufacturers do not supply optimum maps across the rev range. FACT.

Just to make it clear as well. None of my cars have been mapped and I have no connection with any mapping company. I am well qualified to comment though.

 

[V12]

There's so much misleading info on this thread it's unbelievable. Most diesels can benefit from a remap with no effect on reliability and the manufacturers do not supply optimum maps across the rev range. FACT.

What benefits?
No effect on Short term or long term reliability?

Let's face it, if the internet is representative, people get a remap for more power, not for better driveability.

More power = more diesel = higher temperature = reduced longevity.

Now, the next point is debatable.
Do the manufacturers leave such a large margin that they can safely be run at these higher temps?

 

[Dieselman]

Do the manufacturers leave such a large margin that they can safely be run at these higher temps?

My old sludgeburner isn't remapped and can readily pull 780c as an EGT, I've once seen 820c.

I wouldn't fancy going any higher as the head, valves, piston crowns and turbo are on borrowed time then.

 

[SavMan]

One major point to take into account regarding remapping petrol engines is that the Lambda sensor always holds the mixture very close to stoichiometric, so other than advancing the ignition timing, or letting in more air by opening the throttle more what can a remap do? Diesel engines an have the fuel volume increased, which yields more power at the expense of engine longevity due to turbo and piston crowns suffering from excess EGT.

The voltage from the Lambda sensors is used by the ECU but not when under high load it then refers to the tables and cells defined within the map. It is possible with some ECU's to modify both open and closed loop tables.

 

[SavMan]

My old sludgeburner isn't remapped and can readily pull 780c as an EGT, I've once seen 820c. I wouldn't fancy going any higher as the head, valves, piston crowns and turbo are on borrowed time then.

Very wise words, most people rely on the fact there tuner knows the safe limits. In the past I have had cars tuned that when checked after were running right on the limit of engine knock with very aggressive AFR and Timing, the engine would not have lasted very long if I had not checked things.

 

[SteveX]

So a punter on here wants a remap on a C230k, what can be done. Nothing as the volume of air is fixed.

Your answer has zero to do with widebands.

Change the pulley, up the boost and remap from the other sensors that the Ecu uses (such as map).

 

[HumberMart]

More power = more diesel = higher temperature = reduced longevity. /QUOTE]

If you sincerely believe that equation to be true (in the real world) then there's little point continuing the debate.

How come the W212 E220 and 250 had identical economy figures in 2009?

Marketing is what drives everything these days, not optimum solutions.

Despite what others claim. CO2 banding is by far the biggest sales divider at the moment. Does anyone believe that Lexus just happened to end up at 99 for the new IS300 by chance?