[Closed] Anyone had their car re-mapped for better eco?

can be done. seeing as it's VAG i'd reccomend [url= http://www.pendleperformance.com/ ]pendle[/url] they have a really good rep for it.

Any info on seatcupra.net?

I had my old Toledo remapped (Custom Code), it went from 180BHP to 200BHP and the economy improved at the same time, but only by about 2mpg. A mate of mine had a BMW 330D remapped, had a much bigger power increase and improved economy - around 3 - 5mpg better iirc.
Plenty of people doing maps for VAG engines, talk to Powertorque, or someone doing Revo or Custom Code maps? If a standard map doesn't suit, someone will do a custom one, albeit at a higher price. seatcupra.net is a good place to start though.

How much does one of these re-maps cost ?

I'm not sure its financially feasable. The only way to get more economy out of a car is to allow you to hold higher gears for longer. for instance, with a 10% increase in power, you may be in 4th for 10% less time compared to 5th, whilst you're accellerating. However, unless you're booting it all the time, this is probably only going to make a difference during approx 5% of your driving, and the difference it will make (engine turning over at say 2,000 rpm instead of 2,200rpm) is minimal

overall, you're probably spending £350 to get a 1% improvement in economy. you'll have to do 180,000 miles to make it work out

Indeed, not really worth it unless you know someone who knows someone who will give you the map for free and lend you the programming hardware.

Not strictly true 5lab, with a diesel it means you can use far less throttle driving it on the peak of the torque curve. My VAG diesel has gone from 130 - 240HP and 228-400LB/FT and the higher the state of tune the better the economy has got.

It will also have a knock on effect on things like gearbox/clutch life expectancy (if it is remapped properly it may put develop more torque) and any increase in economy may be offset by increased insurance premiums. Personally it is not something I would consider on a car which already has 130k on the clock.

Maps are cheaper than they used to be, you can get them done for £200 - £250 for a standard map, plus various owners clubs get two for one offers (that's how I got mine done a few years back).
In my experience (all I've got to go on), if a performance map gives you approx. 7% mpg improvement on a petrol engine, and getting on for 10% on a diesel, an economy map could well be financially viable. I think the key thing is how many more miles are you going to do in that particular car?

overall, you're probably spending £350 to get a 1% improvement in economy. you'll have to do 180,000 miles to make it work out

not sure i quite agree with your assumptions but your not far off.

I make a 1 mpg improvement (39-40) payback after 120000. 3 mpg pays back after 40000 miles.

you might be better off getting a decat pipe. reported gains on VW vans is 1-2mpg. (about £130 for the pipe) pays back after 30k miles.

😀

I'm not sure its financially feasable. The only way to get more economy out of a car is to allow you to hold higher gears for longer. for instance, with a 10% increase in power, you may be in 4th for 10% less time compared to 5th, whilst you're accellerating. However, unless you're booting it all the time, this is probably only going to make a difference during approx 5% of your driving, and the difference it will make (engine turning over at say 2,000 rpm instead of 2,200rpm) is minimal

overall, you're probably spending £350 to get a 1% improvement in economy. you'll have to do 180,000 miles to make it work out

You *do* know how fuel mapping works, don't you?

I had my 320d done. Not specifically for economy, but working on brim to brim calcs it comes about about 5mpg better when cruising at m-way speed, and is substantially pokier the rest of the time.

The decrease in consumption is almost exactly offset by the increase in insurance though. But you get a faster car out of it.

You *do* know how fuel mapping works, don't you?

yes thanks. do you? a chip gives good gains in power by allowing more air to enter the engine (essentially upping the boost). this doesn't do much for fuel economy. in fact, if anything, working the turbo harder should lessen economy, by a miniscule amount.

adding extra air into the engine allows more fuel to be added, increasing performance. lovely. however that extra fuel isn't free. If you don't use the extra performance, no more fuel is used, if you do, more fuel is used.

how do *you* think a chip 'saves fuel'?

Not strictly true 5lab, with a diesel it means you can use far less throttle driving it on the peak of the torque curve. My VAG diesel has gone from 130 - 240HP and 228-400LB/FT and the higher the state of tune the better the economy has got.

I thought your car had had other work done to it, freeing up the breathing on the engine? that will improve economy. You will use less throttle with a more powerful engine, but thats more because each 'inch' of throttle is more power, so using '50bhp' of power is higher up the pedal travel than it'd otherwise be..

😯 😆 😆

My ECU remap controlled the fuel injectors. It altered the amount of fuel injected, not the amount of air.
It had two settings. One for more fuel and therefore more power, one for less fuel and therefore more economy.

My ECU remap controlled the fuel injectors. It altered the amount of fuel injected, not the amount of air.
It had two settings. One for more fuel and therefore more power, one for less fuel and therefore more economy.

right. and how exactly does the economy map use less fuel than the default map? whats the default map doing? throwing fuel out the window? burning it in the wrong cylinders?

Are you being serious? 😕

I'm not sure how to approach explaining the differences between how you think a remap works and how a remap actually works.

Start here,
[url= http://auto.howstuffworks.com/fuel-injection5.htm ]http://auto.howstuffworks.com/fuel-injection5.htm[/url]

then go here,
[url= http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/fuel-mapping-computer2.htm ]http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/fuel-mapping-computer2.htm[/url]

then come back if you have any questions.

i am serious. A map will already be running lean on anything other than close-to-WOT. there's no benefit to not running lean on half throttle, so a car (which is sold on things like fuel economy) will be set up to run as lean as possible on mid-throttle positions, without causing pre ignition. Manufacturers spend a lot of time and money getting these kinda things just right.

So I'll ask again, compared to the default map, how is your map going to save you fuel? why would a tuner put two maps on? surely they'd just program the 'extra power' map to run lean on anything other than open throttle. other than having extra power so being able to use a lower gear, there isn't a way of eeking significant fuel savings out of an engine using a map

Ok.

On the rolling road, tuner identifies points in the stock map that aren't optimal. Could be down to fairly extensive engine and breathing modifications, could be down to the octane rating differences between Japanese fuel and UK fuel, could be down to mass produced car sold in various specs having a standard map that was tweaked slightly between specs - a kind of Jack of all trades, master of none scenario. Anyway, tuner creates one map for 1.2bar of boost on VPower. It's based on the engine being under load quite a lot, so it uses more fuel and gives more power. Tuner then creates a map for 0.7bar boost on 95RON fuel. This is the one that uses less fuel and gives better mpg, because it's tailored for general cruising.

why would a tuner put two maps on? surely they'd just program the 'extra power' map to run lean on anything other than open throttle

Lets take a trip to 5lab's Bizzaro World for 5 minutes. Explain to me how a remap increases the amount of air that gets to the engine, and I quote, "essentially upping the boost*"?

* 😆

Also, before you call me on it, I know that technically a lower octane rating fuel requires the engine to run richer to avoid knock, but when you factor in the added air at 1.2 bar vs 0.7 bar, you still end up with more fuel used on the high boost map.

Anyway, back on topic, go for it OP. You'll not lose.

5lab, I think you are confusing a 'chip' (a resistor that fools the engine into over-fuelling by changing a sensor value) with a remap, where a tuner will prioritise economy and performance. Cars from the manufacturer have to balance economy and performance with strict emission controls and to cater for poorer quality fuels.

This is why manufacturers don't blank off the EGR valve and remove the particulate filter, they have to fit them for emissions even though they have a (minor) detrimental effect on economy and performance. Once the car is sold, the owner can remove these items and still pass the less stringent MOT test.

I've been lucky enough to secure a free remap for my campervan, just haven't got round to arranging it yet 🙂

5lab, I think you are confusing a 'chip' (a resistor that fools the engine into over-fuelling by changing a sensor value) with a remap, where a tuner will prioritise economy and performance. Cars from the manufacturer have to balance economy and performance with strict emission controls and to cater for poorer quality fuels.

Semantics, but "a chip" comes from the old days when a remap was done via removal of the ROM 'chip' (integrated circuit) and re-inserting another. A re-map is simply the replacement of the load/fueling/spark tables in an engine management system - it doesn't matter how it's done. A live remap is done on the rollers at a rolling road, or on an engine dyno. A resistor isn't anything, certainly not chipping or remapping, it's an aborted method of botching poor results and fooling people.
There's an intermediate point which is a piggyback ECU that takes the existing fueling calcs and replaces them with modified ones, but this is technically a remap too, but closer to what you might consider "chipping" these days.
{re-maps engines fairly regularly}

Reading that back, I do sometimes come across as a giant arsehole, eh? No hard feelings 5lab?

I think part of what causes confusion is that remaps can include boost and fuel pressure raises, and TD's require a different tuning method than petrols, all of which confuse people.

As for running two maps - I run two maps on my own car but there's not really any point if I'm honest. One's mapped to much higher boost and slightly higher advance for when I'm feeling fruity and have a tankful of 99 RON, but both maps are essentially identical off-boost, all the second map allows me to do is have slightly more resolution in the off-boost area and run higher RON fuel. If you're assuming you're always running the same fuel and the same boost there's no point in having 2.

Yep, had my fabia remapped by Shark from 130bhp to 165bhp for economy, now im getting it mapped to 204bhp to be a hooligan, mapping can make cars more drivable and more fun too, look out for deals my map cost £150.

Had my wife's Alfa Q2 remapped with a rolling road session.

Extra 5bhp overall but around 60lb/ft torque extra. Also the car is putting out more power at a lower engine speed, up 10bhp at 2000rpm.

Economy has remained the same but it drives so much better which is the main benefit in my opinion.

I used pendle and revo in the past. I'm not 100% sure if economy is increased. However power is and I can still get over 600 miles out of 50 litres in a VAG 2.0TDi kicking out about 190bhp

I had my VW T4 Multivan (150bhp German Model) remapped and it went to 185bhp.
(it's had a decat pipe fitted too, and EGR deleted)
.
The fuel economy (over the last 6000 odd miles) has averaged 42.5mpg.
.
Pre remap I was getting just under 36mpg.
.
If I drive sensibly on a long run, I can easily get it to 50mpg.
.
I do more than 20k miles a year, so as a rough estimation I reckon that's saving me over £400 per year.
.
Worth every penny !

No idea what difference it's made to fuel economy, but I've fitted a DTE Systems tuning box to my Ranger pick-up and it made a big difference to its performance with definitely no drop in fuel economy.

It cost £300, and isn't a re-map, but does have different map settings for nutter performance, although I've never budged from the factory settings. It doesn't just increase fuel pressure as cheap chips do, but does increase the time the injectors are open (in milliseconds). It's supposed to 'learn' your driving style too.

Low - mid-range grunt is impressive and it will beat all but performance cars off the lights and 60mph lane 2 to 80mph lane 3 on motorways is effortless. It's taken quoted figures from 140bhp to 170bhp/400nm

I average 30mpg, get 27 if booting it and 34 if driving sensibly - not bad considering it's a 2.5l 2.2t 4x4.

Ta for the feedback everybody!

🙂

Remember to inform your insurance company that you've had the engine tuned. Add on the cost of the additional premium in order to calculate the break-even point.

Yes, don't worry, I like to keep things all above board!

You are the poster boy for "a little knowledge is a dangerous thing" and I claim my £5.
A tuner might create two (or more) maps because the car owner might use his car for different things. Driving the length and breadth of the country on VPower at 1.2bar will cost quite a bit more than at 0.7bar on bog standard unleaded. Similarly, blasting up and down the drag strip at Crail is going to be more fun in a car mapped to 1.2bar/VPower than it is at 0.7bar/95RON.

Lets take a trip to 5lab's Bizzaro World for 5 minutes. Explain to me how a remap increases the amount of air that gets to the engine, and I quote, "essentially upping the boost*"?

so, running a turbo at 1.2 bar instead of 0.7 bar is precisely what I meant by 'upping the boost'. It is putting more air into the engine, increasing the effictive displacement, and allowing the engine to produce more power. as I aslo stated above, doing this will, in itself, use a smidge more fuel than running it a low pressure as more power is sapped from the exhaust to produce the extra boost in the intake. obviously the fuel map may have to be altered to allow for understanding what to do when the extra air is passing into the engine, but the real benefit is the extra air in the combustion chamber which allows for extra fuel to be added.

For this reason (and probably more so that you can run 95 ron fuel when you're feeling poor), you have 2 maps, however, I'd wager than the 0.7bar map isn't too disimilar (if disimilar at all) from the manufacturers original map.

so, as I eluded to in my first post, the map won't do much for fuel ecomony other than allowing you to hold a higher gear for longer.

OP : on a car like that if you want to save money, look into using veg oil instead of diesel in it. Engine should be appropriately low-tech that it will work (but I don't know the specifics of that engine)

5lab - yes, veggie oil is something I'm looking into too.

Fortunately DieselBob Tuning is on my way to work, so I'll have a chat with them.

It's an old 'farmyard technology' 1.9TDi apparently. Sounds like a tractor too!

You can definitely remap the manufacturers maps for increased fuel economy - combinations of fuelling, boost, rail pressure, timing and pilot strategy will get you there. It isn't to do with holding a higher gear for longer but with optimising the combustion so that you are making use of as much of the energy as possible. You will be surprised how un-optimised the calibrations on 'bog standard' OEM vehicles are. The company I work for essentially does this for a living and I have personally worked on projects taking vehicles from 120g/km CO2 to 99 or even 95g/km CO2 (g/km CO2 being proportional to fuel consumption), all while sticking within Euro 5/6 emissions limits. If you take those out of the equation then you have a lot of room for manoeuvre.

Yep, had my fabia remapped by Shark from 130bhp to 165bhp for economy, now im getting it mapped to 204bhp to be a hooligan, mapping can make cars more drivable and more fun too, look out for deals my map cost £150.

No chance on the standard KKK KP39 turbo, Shark is possibly an appropriate name, they're either bullshitting or your turbo is going to disintegrate rather quickly. You'd be looking at 180bhp at a real push.

have you got a link to their products? the only info google will find suggests the benefits are holding lower gears. If you can knock 20g/km off a car's rating, surely that would be massively popular in london with folks who are forced to pay 4 figures annually for the congestion charge?

so, as I eluded to in my first post, the map won't do much for fuel ecomony other than allowing you to hold a higher gear for longer.

The only thing you've "eluded" is any kind of understanding of how engines work.

I’m wading in with my experiences, if I may.

I’ve ran beemers in the past (don’t now) I’ve had 330D Sport Touring’s and on those I had a remaps done. They chuck out huge torque as standard anyhoo’s but I was towing sportsboats around at the time and was looking for better fuel consumption and a bit more mid range grunt to help tow. The map cost me £250 each time and it vastly improved the cars, both in umph and fuel consumption, going from ave 45mpg to 55mpg and when towing with 4 crew and kit in I still got 43 ave.
I then changed to a 530D Sport Touring and did the same thing, same engine and similar results, just a couple of mpg lower, I just needed a bit more room and I hate(d) X5’s (which are smaller inside) I then ran an M3 which had nothing done to it and got 25mpg, to say I was shocked (expected shock) was an understatement.
I’ve also ran a fleet of SMART ForTwos for work and (one for home) of the 7 I had 4 were remapped to stage 1. I did this as a bit of fun and an experiment, none of the kids who I employed knew which ones were done, but they soon found out. SMARTs in “that” town do an ave of about 45-50mpg stop start all the time, if they’re treated kindly they will do 60mpg but we’re talking kids here. With the remap they would do about 58-60 ave and pick up and gear change better and smoother. Of the cars that had been done the kids got to know which were better to drive and run and nearly all the time the standard cars got left behind, to the point of me getting them done 7mths later. The map I had done on these was a £100.00 each and I think was worth the effort. The lad came around, stuck a PC into the dash and ran a small programme and each car was done in 10mins. With the beemers it took half a days fiddling each car as they had to take the cowling off the engine and pull some wires off etc.
Warranty issues.. As the SMARTS were done by an “authorised” Merc tuner none of the warranties were compromised, in fact I was told that you couldn’t tell if a car had had it done or not. All the SMARTs were serviced by Merc and none ever came back with any advisory notice or anything, I also called our insurance agent and told him what I was doing/done and no extra charge was levied at all.. With the beemers it was different, even though the map was completed by a “beemer tuner” the local garage did know it had been done and each time I got the car serviced by them I’d get an advisory letter explaining that beemer only warranted such work which was completed by an “authorised, ie; dealer” tuner, the guy I used wasn’t but he did warranty the work he carried out. The insurance people were also interested to hear what I’d done and loaded my policy accordingly.

Of the experience I had I’d say seek a reputable tuner, make sure the cars not falling apart before you go, get insurance advice if you need to and check with your dealer to see if there are any warranty issues caused by having the work done. (all my cars were new when done and sold within 3yrs) If you pass on the vehicle I think it’s only courteous that you notify the new owner that the car has a map (unless you take it off/reset it) as the new owner will be under the impression it’s standard.

I still have the SMART and it’s performing as it should, just covered it’s 32k miles and have had no issues at all with it. One thing makes me laugh is acceleration onto motorways down the slip road, I often get a gasp when I accelerate past someone trying to overtake me… I don’t use the car much now maybe once a month (as we have a Prius) but can’t bring myself to sell it. I like it that much.

The only thing you've "eluded" is any kind of understanding of how engines work.

in fact, if anything, working the turbo harder should lessen economy, by a miniscule amount.

i guess from your lack of answer, you don't have any understanding of how a chip\remap can give you extra economy, or the differences between your 'economy' map and the boggo one the car comes with then..

have you got a link to their products? the only info google will find suggests the benefits are holding lower gears. If you can knock 20g/km off a car's rating, surely that would be massively popular in london with folks who are forced to pay 4 figures annually for the congestion charge?

If they want to pay several million pounds for it then they would be more than welcome! We are working directly with OEMs as a consultancy rather than doing private remapping. So yes, what we are doing is at the extreme end of the scale, but was more just to show that it is certainly very possible to do.

[url= http://ricardo.com/News--Media/rq/Ricardo-Quarterly-Q2-2011/RQ-02-2011/ ]It's the article on the Volvo DRIVe models[/url]

There's some real b***sh1t up there^ But this - "You will be surprised how un-optimised the calibrations on 'bog standard' OEM vehicles are." Really takes the biscuit. Mr speed12 could probably earn millions if he knows how to do it better! OEM's need to make sure that a balance of low cost, performance & durability requirements are met. Like the light, cheap, strong options on bike parts - perm any two of the three - the choice is yours...

Can someone explain to me how you re-map a diesel?

When the only thing you controll is the ammount of fuel going into it? You could make the thrrootle sharper as its fly-by-wire, and make it open further (by holding the injectors open longer or upping the fuel presure).

But how does any of that improve economy?

Also boost pressure can be altered, mine is running 2.1bar. I'm not totally up on the true technicalities but what I do know in the real world is that you can drive the car around on the peak of the torque curve using practically no 'throttle' and make good progress.

i guess from your lack of answer, you don't have any understanding of how a chip\remap can give you extra economy, or the differences between your 'economy' map and the boggo one the car comes with then..

If they want to pay several million pounds for it then they would be more than welcome! We are working directly with OEMs as a consultancy rather than doing private remapping. So yes, what we are doing is at the extreme end of the scale, but was more just to show that it is certainly very possible to do.

See - in the case of these DRIVE cars (and the equivilent from other manufacturers) - there's loads going on. Lowered suspension, thinner/harder tyres, stop/start technology at the lights, longer gears on the gearbox, aerodynamic mods and aero wheel covers. All of this is done *and* a different fuel map (the tech behind which will proably be way more than a typical '£300 chip' kinda place), and they can only reduce co2 by ~10-15% (stop/start gets half of that alone, due to the way the tests are done).

I stand by what I say that a 'eco map' would make negligable difference, other than being able to hold higher gears for longer

hold higher gears for longer

The fuel map is a lookup table that tells the ECU how long to open the injectors for under differing engine conditions, and therefore is directly related to how much fuel is used. It doesn't increase boost. It doesn't - it [i]can't[/i] - have any effect on the amount of air present.

re: manufacturer's map vs tuned map, and I'm simplifying massively here.
There's a magic ratio of air to fuel at which every single drop of fuel is combusted. This is close to 14.7:1 for normal fuel. This perfect combustion a bit too much heat for your average engine though. To compensate this, a fuel map will be programmed to run the engine rich. More fuel than is necessary is introduced into the combustion chamber, and this extra fuel provides a cooling effect. If the fuel map is adjusted to provide less fuel than the stock map but still enough to provide some cooling, then you have reduced the amount of fuel used over the stock map.

@rogg (3 poster in) that's pretty impressive for one of these

[img] [/img]

I've got no bloomin idea how these things work and I don't really care, it's like electrics init, don't care how it works just so long as when I flick a switch I gets power, same with an ignition key.

Just to clarify, I've had them done on both diesels and petrols.

It doesn't increase boost

I was under the impression that on a turboed car the map also controlled boost. And, on a diesel, injection timing and EGR. So by adjusting those things you can do an awful lot to increase power AND economy.

More advanced injection timing means more power and economy, but higher NOx emissions and noise so manufacturers retard it a bit in some if not all circumstances.

Damn, just wrote a really long answer and it lost it!

The cliffnotes from it are....

There's some real b***sh1t up there^ But this - "You will be surprised how un-optimised the calibrations on 'bog standard' OEM vehicles are." Really takes the biscuit. Mr speed12 could probably earn millions if he knows how to do it better!

Yes, that is exactly what we (as a consultant to OEMs) do. OEMs only have so much knowledge and skills and so come to companies like ours for the 'harder' stuff like emissions, fuel economy etc.

The holding the higher gears thing is, basically, incorrect as well. An economy calibration will optimise very finely the combustion for certain speed/load points which you mostly drive at, but will NOT actually change the main fuelling quantity at any point - otherwise you would change the torque structure of the engine. This sounds ridiculous but is true.

The ECU calibration has maps for pretty much anything you can imagine. There is not just 1 fuel map and 1 boost map etc. Imagine at least 10-20 maps for each parameter that makes torque in some way and you are getting there. The software guides we are given which details the maps in the ECU and how they interact can be up to 77,000 pages long. They are not simple things! This is exactly why companies such as ours exist. Molgrips has done well in his last post to explain it very simply.

WTF does this even mean in the context of the effects of a remap?

The fuel map is a lookup table that tells the ECU how long to open the injectors for under differing engine conditions, and therefore is directly related to how much fuel is used. It doesn't increase boost. It doesn't - it can't - have any effect on the amount of air present.

There's a magic ratio of air to fuel at which every single drop of fuel is combusted. This is close to 14.7:1 for normal fuel. This perfect combustion a bit too much heat for your average engine though. To compensate this, a fuel map will be programmed to run the engine rich. More fuel than is necessary is introduced into the combustion chamber, and this extra fuel provides a cooling effect. If the fuel map is adjusted to provide less fuel than the stock map but still enough to provide some cooling, then you have reduced the amount of fuel used over the stock map.

that is true on a petrol engine. it is not true on a diesel engine. A diesel engine does not control the amount of air entering an engine. There is no throttle. As a result, under anything other than full accellerator pedal compression, a diesel engine is run very very lean (under no accellerator pedal compression a diesel engine may be running 200:1 air:fuel ratio, or even infinate if it has cut the fuel supply entirely).

So lean burn has nothing to do with diesel technology, as this thread was about. I admit you can use lean-burn on a petrol engine (in fact several engines do at stock, including the mitsubishi GDI engine), however to do this often requires a different catalytic converter, as there's something about lean burn that doesn't work well on stock catalytic converters (I don't know if it damages them, or if they just don't work properly, but either way you may get a nasty surprise around MOT time).

5lab, what you are saying above is absolutely 100% correct true (well...95% maybe...), but is not how you would re-calibrate for fuel economy. The engine is not given more torque in order to run in a higher gear - the areas where the engine does run (1000-1800 rev/min in a diesel typically) are simply optimised so that combustion is as effcicient and complete as possible. Other than for pilot injections, which are a fraction of the main pulse, no fuel is added or taken away (I realise this seems paradoxical).

Ahhh that makes sense, bigger pressures = greater efficiency [b]OR[/b] more power.

Note the [b]OR[/b], you can't (practicaly*) go faster and get better economy.

*tehre might be a very small overlap on the same map where you can get slightly more power and slightly more economy as opposed to lots more economy or lots more power.

Ahhh that makes sense, bigger pressures = greater efficiency OR more power.

Note the OR, you can't (practicaly*) go faster and get better economy.

Correct - think of it as pushing the boost up (which generally will increase torque), but then changing the timing so that the total torque remains the same as before you started fiddling, but now the injection is in a better position that all of the fuel can be consumed. Couple that with various other calibration tweaks and you get your increased fuel economy.

true. however most 'remaps' or 'chips' also affect the boost control valve on the car. Yours is one of these, which is why you talk to the turbo running 0.7 bar vs 1.4 bar. The ECU is controlling this, and the updated software/different ECU you purchased is overriding the default values, pushing more air into the engine, and allowing it to produce more torque.

That being said, I'm completely lost by your comments. I know how my car works. That's enough for me.

speed12 - I understand that's how the maps you guys do work - as you probably aren't allowed (by the manufacturers) to 'overboost' the engines (ie run them at a higher pressure than they're designed for). I was more trying to explain why some people, with a simple 'add more power' chip you can get from superchips or a similar company, may experience better economy as well as more power 🙂

OK, maybe a bit of crossed wires then - yes, if you could produce more torque then theoretically you could chug along at slightly lower revs which could use less fuel. It's definitely not the ideal way to go though!

A diesel engine does not control the amount of air entering an engine

Well it does - most modern engines have variable vane turbos so you can have as little or as much boost as you want up to a maximum dictated by gas flow through the exhaust, I suppose.

More boost would mean more back pressure though (more obsctruction to the exhaust gas so less efficiency) so if you are driving slowly I'd guess it would be more efficient to run no boost, but then you might compromise driveability and response because when you hit the pedal the turbo would have to spin up from standstill...

I've always wondered what the difference is between VAG bluemotion engines and regular ones. The reviewers say there's a lack of low-end torque, which must mean they are mapped significantly differently. All I can think of is that they run less boost at lower speeds.

Perhaps speed12 can shed some light without giving any secrets away?

you see what I mean thou - compared to a traditional petrol engine with a butterfly throttle, there's not much control there.

For the bluemotion things - I wonder if they lack of low-down torque is more a symptom of the higher gearbox ratios? most diesels develop naff-all torque before the turbo is on song - if you raise the final drive by, say, 20%, it will have 80% of the torque it had previously, but in addition the turbo threshold will be at 20% faster road speeds (ie 24mph in 2nd instead of 20..).

Yeah, I would probably say the Bluemotion 'lack of torque' would be down to a final drive change (haven't done any work on them so this is all purely speculation). It's one of the main no-calibration ways you can directly reduce CO2 from the engine so would be a first step for most companies. Unfortunately, everything in the business is tuned for the NEDC cycle (or equivalent for the US, Japan etc), and the aim is to move the engine speed/load into the areas you want. This doesn't always correspond to areas which mean good driveability in the real world. Although I would hope most OEMs/consultants try as hard as we do not to compromise real world driving.

How the system I bought works....

[url] http://www.dte-diesel-tuning.com/how-does-it-work/35-how-diesel-tuning-works.html [/url]

5lab - if you close the throttle a lot on a petrol there will be less air in there but the compression ratio won't be much (compared to atmospheric) so you'll lose out there. Diesels are even more efficient at lower speeds despite compressing extra air.

Actually.. turbo diesels have a lower compression ratio than non-turbo, perhaps to address this very issue when driving off boost...

No chance on the standard KKK KP39 turbo, Shark is possibly an appropriate name, they're either bullshitting or your turbo is going to disintegrate rather quickly. You'd be looking at 180bhp at a real push.

My car's running a Garret GT1746VB Forge intercooler ect so it's right enough for 200bhp.