Engine mapping

haveibeendone

Being an old dinosaur I have no idea how engine mapping/remapping works.

In my days the only way to get more power was to skim the head etc to increase the compression ratio, change form carbs to fuel injection and stick on a sporty exhaust.

Now I am told that for £295 I can increase the BHP on my A3 2.0TDI by a minimum of 50 (from 140 to approx 190) AND get better fuel economy.

Does this sound right? Also the same company is offering an electronic box as a DIY option for £395.

The reason for the DIY option being if you want to change back again. But why would you want to change back with more power and more MPG.

LandyAndy

haveibeendone wrote: »

Being an old dinosaur I have no idea how engine mapping/remapping works.

In my days the only way to get more power was to skim the head etc to increase the compression ratio, change form carbs to fuel injection and stick on a sporty exhaust.

Now I am told that for £295 I can increase the BHP on my A3 2.0TDI by a minimum of 50 (from 140 to approx 190) AND get better fuel economy.

Does this sound right? Also the same company is offering an electronic box as a DIY option for £395.

The reason for the DIY option being if you want to change back again. But why would you want to change back with more power and more MPG.

If you found reliability and/or wear and tear on brakes/tyres/suspension was affected?

davemorton

Or if you had a crash and had not 'got round' to informing your insurance company of the modification.

bigjl

The main reason why you get better MPG is the more flexible power delivery, meaning you don't have to drive the engine as hard to get up to speed and to maintain speed, more torque sometimes mean you don't have to change down as often.

My wifes Clio is a 68bhp model DCi and is woefully underpowered, to keep up with traffic you have to give it some boot, a friend has a more powerful DCi Clio, and get better mpg, I have driven it and the car is transformed, there are no major differences between the two, so the wifes will be getting remapped soon.

As an aside, my Mondeo Tdci is easy to drive, hardly need to touch the throttle, it is a 130bhp model and gives better mpg than any 115bhp I have driven.

Your 140bhp Audi will really benefit from a remap as in standard tune it is abit wet pulling away from stationary, a bloke I know at work had an old shape A4 (PD engine 130 bhp I beleive) and "upgraded" to the new model with the 140 engine, he hated it, sluggish, no pull from stationary, he really hated pulling out into traffic.

After he had it remapped he said the car was transformed, he had thought about selling it initially, but I advised him to get it remapped.

I think he only got a small improvement in fuel consumption, mainly, I think, because most of his miles are done on motorways and dual carraigeways, so on a steady throttle, but he says he can overtake without dropping a gear and feels the car is a lot punchier.

He loves it now.

King_Nothing

I had my car remapped, power delivery is night and day apart, more power, and boosts more on the turbo, fuel consumption is only marginally better, depending on how I dirive it, lol.

Mines a petrol though, not a diesel, I don't know much about diesel remapping, guy at work had his A3 2.0TDI remapped, and said it was excellent afterwards.

harveybobbles

Only problem with getting your self more power is you tend to drive it harder.

I had my A4 1.8T petrol done and there was no difference on MPG, yet it went like a rocket mid range! Weeeeeeeeeeeeeeeeeeeeeee..................

Ebe_Scrooge

Call me an old cynic, but you don't get owt for nowt. If remapping is so wonderful, why isn't the engine mapped that way in the first place ? Common sense would seem to indicate that to get more power you've got to burn more fuel, or else stress the engine to such a degree that it's going to blow up before long ?

I'm not trying to rubbish what others have said, I don't know much about this, but I am genuinely interested to know why cars aren't factory-fitted with the "better" mapping ? The cynical side of me says there must be a downside to having it done ?

johnnyroper

Ebe_Scrooge wrote: »

Call me an old cynic, but you don't get owt for nowt. If remapping is so wonderful, why isn't the engine mapped that way in the first place ? Common sense would seem to indicate that to get more power you've got to burn more fuel, or else stress the engine to such a degree that it's going to blow up before long ?

I'm not trying to rubbish what others have said, I don't know much about this, but I am genuinely interested to know why cars aren't factory-fitted with the "better" mapping ? The cynical side of me says there must be a downside to having it done ?

Because standard ecu map is to suite all countries with a wide range of fuel quality.not to mention keeping emissions down.

I had my scooby mapped after I did some mods the drivability was completely different and mpg were better.I was a bespoke map done on the road over a couple of hours and on tesco99 fuel.it was not just about power but the overall feel of the car.although it did cost 700 I would not be happy with a box type map though these normally just fool ecu to thinking outside air is colder so it fuels more.

Gloomendoom

As has been said, the factory maps are often a compromise, designed to offer good performance in a wide range of different environments and varied fuel quality.

They can also be used to manipulate insurance groups or to enable the manufacture to offer a range of different power outputs from the same engine. Of course, the customer usually pays a hefty premium for the higher powered models when it costs the manufacturer practically nothing.

Ford are masters at this.


Tuning boxes have progressed a bit since the old days of a resistor in the fuel or air temperature sensor circuit. Most now modify the fuel pressure data in a non linear fashion and are an established and well proven method of tuning a modern diesel. However, don't be fooled into thinking more expensive is better.

These people have an excellent reputation and will do you a British made box for a lot less than £395... Linky

financequest

I have remapped my Triumph motorbike using laptop, OBD-USB cable, Tuneboy software and an uprated map profile downloaded from the web.I only tweaked the power and torque slightly. All works OK. I suspect that car manufacturers rate engine quality at manufacture time.You will find the same 1.9 diesel engine in various levels of tune in Volkswagon, Seat, Skoda, Audi etc. Better quality engines are mapped for higher outputs. The other engines can be mapped higher, but may wear out faster or fail if mapped too high, plus insurance and warranty may be invalidated.

Gloomendoom

Be very careful remapping your car's engine ecu with laptop via the car OBD port. If anything goes wrong you can end up with a car that won't run at all.