Discussion
Centurion07 said:
4key said:
The reason tuners state that the fuel consumption improves when they map things is so that the thought of halving the mpg doesnt put people off doing it, not because the gains are significant. Its not worth doing it for fuel economy, they just want to advertise that mapping your car wont leave you with 10mpg.
Now THAT is utter b
ks I'm afraid.A lot of people used to be put off the idea of mapping their car because they thought it would ruin their fuel economy, by advertising the fact that you may even gain a couple of mpg by mapping your car its dispelled that myth.
Fuel economy never even used to enter the equation when we used to go stick a car on the rollers, most people who did it had a far from standard engine and expected to be stopping at every other shell station. Times have changed and people are flashing standard cars so the advertising has moved on to stating that you wont be killing your fuel economy.
Its worth throwing a few hundred quid at if you want more power, but its pointless doing it just because you want to gain a couple mpg. How long will it take for you to profit from it, ontop of the fact youve probably got to use £50 worth of juice to drive to the place and back
GroundEffect said:
4key said:
The reason tuners state that the fuel consumption improves when they map things is so that the thought of halving the mpg doesnt put people off doing it, not because the gains are significant. Its not worth doing it for fuel economy, they just want to advertise that mapping your car wont leave you with 10mpg.
Incorrect. You can actually improve the mpg of a modern diesel relatively easily because they are so constricted in their calibration to CO2, CO, HC and NOx therefore if you ignore that target and go for BHP and mpg you can get improvements.4key said:
Centurion07 said:
4key said:
The reason tuners state that the fuel consumption improves when they map things is so that the thought of halving the mpg doesnt put people off doing it, not because the gains are significant. Its not worth doing it for fuel economy, they just want to advertise that mapping your car wont leave you with 10mpg.
Now THAT is utter bks I'm afraid.A lot of people used to be put off the idea of mapping their car because they thought it would ruin their fuel economy, by advertising the fact that you may even gain a couple of mpg by mapping your car its dispelled that myth.
Fuel economy never even used to enter the equation when we used to go stick a car on the rollers, most people who did it had a far from standard engine and expected to be stopping at every other shell station. Times have changed and people are flashing standard cars so the advertising has moved on to stating that you wont be killing your fuel economy.
Its worth throwing a few hundred quid at if you want more power, but its pointless doing it just because you want to gain a couple mpg. How long will it take for you to profit from it, ontop of the fact youve probably got to use £50 worth of juice to drive to the place and back
Reading comprehension fail on my part. Apologies. But I wasn't the only one!
Centurion07 said:
As a taxi driver, not too long at all!
Reading comprehension fail on my part. Apologies. But I wasn't the only one!
Reading comprehension fail on my part. Apologies. But I wasn't the only one!
The main problem with posting from a phone is that you try and get your point across with as little typing as possible, I am crap at that and usually fail causing me to have to type twice as much to explain myself 
It's not just outright power that gets changed, my old td4 freeby was remapped by a well known LR tuner.
Yes there was a clearly noticeable power jump but it was the in gear grunt that changed the car for the better, it smoothed out the delivery do was no longer an "all or nothing" but more progressive. 3rd gear was great for overtakes and 5th would have a good 50-70 time. It made keeping with motorway flow much better.
My mpg rose as well.
Best tank was 598miles and that was mostly motorway, a few around town drives and some higher speed driving.
The disco3 will be getting mapped once I have it properly serviced and any mot work done. Extra 50bhp and nearly 100lbft or torque to be gained.
Yes there was a clearly noticeable power jump but it was the in gear grunt that changed the car for the better, it smoothed out the delivery do was no longer an "all or nothing" but more progressive. 3rd gear was great for overtakes and 5th would have a good 50-70 time. It made keeping with motorway flow much better.
My mpg rose as well.
Best tank was 598miles and that was mostly motorway, a few around town drives and some higher speed driving.
The disco3 will be getting mapped once I have it properly serviced and any mot work done. Extra 50bhp and nearly 100lbft or torque to be gained.
Assume we are talking about remaps only, and not significant hardware changes (DPF deletes etc) then on a modern (say last 5-6 years) CR diesel, there will be no real economy gains to be had. Yes, plenty of people report (and probably get) "better" mog after remapping, but that is because they are driving differently. On a diesel engine, fuel mass = torque, so if you inject less fuel, then you make less torque. (which would result in your car traveling slower).
The only significant area that can improve BSFC is injection timing, where the engine calibration is a compromise between combustion noise and economy (early pre injection reduces rate of rise of cylinder pressure, and hence damps that characteristic "diesel clatter" sounds. However, these days, with the pressure for OEMs to absolutely maximise fuel economy at light loads (over the EUDC test cycle for instance) OEM engine calibrations are typically within 1% of the optimum BSFC operating point.
So this leads me to the question: How many aftermarket tuners have the skills and necessary facilites to actually accurately reprofile the injection timing maps? It certainly can't be done accurately enough in a car to be repeatable, and engine dyno is necessary, and all the OEM's will be doing it with real time in-cylinder combustion analysis equipment (~£100k's worth) and almost certainly a high speed exhaust emissions and particulate analyser (another ~£300k).
So, simple answer, if you are not making hardware changes, just drive the car in a more economical fashion, that gives the best results and is completely free.
The only significant area that can improve BSFC is injection timing, where the engine calibration is a compromise between combustion noise and economy (early pre injection reduces rate of rise of cylinder pressure, and hence damps that characteristic "diesel clatter" sounds. However, these days, with the pressure for OEMs to absolutely maximise fuel economy at light loads (over the EUDC test cycle for instance) OEM engine calibrations are typically within 1% of the optimum BSFC operating point.
So this leads me to the question: How many aftermarket tuners have the skills and necessary facilites to actually accurately reprofile the injection timing maps? It certainly can't be done accurately enough in a car to be repeatable, and engine dyno is necessary, and all the OEM's will be doing it with real time in-cylinder combustion analysis equipment (~£100k's worth) and almost certainly a high speed exhaust emissions and particulate analyser (another ~£300k).
So, simple answer, if you are not making hardware changes, just drive the car in a more economical fashion, that gives the best results and is completely free.
Lee540 said:
nottyash said:
You don't have to have the DPF removed to remap a car, and done properly there is no smoke.
I understand that you don't, some tuning companies make claims of +45bhp increase with a stage 1 map.. however, reading into it a little further, this is with removal of DPF.I would consider a remap tomorrow if I knew it wouldn't chuck out black smoke everytime I went on the throttle.
Could you pelase point me to one where I could get maximum benefit without removal of said parts.
I have also had a REVO remap on a Petrol 1.8T Golf GTI which transformed the car but seemed to put economy down slightly across the board.
Ok - so I can expect some reasonably decent performance gains, better drivability but not any major economy gains.
BUT I can have more grunt without sacrificing cruising mpg (90% of my driving is motorway and DC driving) and I might even see a few more MPG.
As far as I'm concerned more power for the same MPG is the same as better MPG (man maths at its very best)
So - who comes recommended for the Audi 3.0Tdi unit?
.
BUT I can have more grunt without sacrificing cruising mpg (90% of my driving is motorway and DC driving) and I might even see a few more MPG.
As far as I'm concerned more power for the same MPG is the same as better MPG (man maths at its very best
)So - who comes recommended for the Audi 3.0Tdi unit?
.
I got my Fabia 1.9tdi (pre-DPF) remapped a while back (130-172bhp). The difference in MPG to be honest was negligible 1 or 2 at most. The map did make the car drive like a bat out of hell though, it couldnt even put the torque down in 2nd and sometimes 3rd without the wheels slipping. Definetly something I would recommend if you are looking for cheap-ish performance gains from a VAG unit.
Also the 3.0 V6 sounds bonkers when remapped with a decent exhaust system.
Also the 3.0 V6 sounds bonkers when remapped with a decent exhaust system.
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