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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
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 [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.
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.
it is a way in which a remap can generate fuel economy. if an engine has enough power in high gears to make appropriate progress, the user of that car can keep the car in a higher gear. This means lower average revs for the car, which in turn means less compression\friction lossesWTF does this even mean in the context of the effects of a remap?
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.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.
Nope. It's the Blitz Dual SBC that controls the boost. The original ECU is long gone, with an Apexi Power FC in its place which (amongst other things) contains the fuel map, and the Datalogit that connects to the Power FC allows for switching maps.
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.