Why don't manufacturers "Map" their engines

[otolith]

German said:

otolith said:

Max_Torque said:

Funny thing, although load of tuners claim "better fuel economy" not one (as far as i am aware) has had one of their cars tested over the EU std test cycle. Something that costs as little as £1k. Now i wonder why that may be................

But then who would pay to get their car optimised for that cycle, given that they will never actually drive it like that?

I'd argue almost everyone already pays to have their car optimised for the cycle....when they buy it new

Yes, because it affects the number on the registration document, which affects the amount of VED or BIK paid. But performance on the EU test cycle is disconnected from actual economy in use, because nobody drives like that. So there would be no point in an aftermarket tuner trying to remap a car to beat the OEM EU cycle performance, because there would be no BIK or VED benefit and no actual fuel consumption benefit. So even if a tuner can improve on the OEM's in-use fuel economy (by chucking the OEM's efforts to meet emissions standards out of the window) a test against the EU drive cycle wouldn't be a good way of showing the benefits.

[otolith]

Mr2Mike said:

otolith said:

But then who would pay to get their car optimised for that cycle, given that they will never actually drive it like that?

According to their claims the map is already optimised to gain better economy, as well as power. If their claims are true then back to back testing under the exact same conditions would prove (or much more likely disprove) this, no further optimisation should be needed.

The exact same conditions being a scenario which nobody sane will give any effort to mapping, because the car simply won't be driven like that?

[Mr2Mike]

otolith said:

The exact same conditions being a scenario which nobody sane will give any effort to mapping, because the car simply won't be driven like that?

A scenario which is rigidly defined and repeatable, completely unlike driving on a road. Doesn't matter if you don't drive exactly like that, if you can get better economy on a controlled test then it should still translate to better economy on the road, even if the actual numbers are substantially different in either case.

[Lowtimer]

nickfrog said:

laingy said:

I guess the question should be why don't manufacturers map the cars to the country they are selling them to, and not have to worry about one map fits all?

Because new cars often get re-shipped to a different country than its country of destination. Very easy within the "LHD zone".

Never mind "shipped", what about "driven"? People can and frequently do drive their cars across several countries. Once you get the train to France it's land all the way to several markets on the Eastern fringes of Europe where you won't find anything remotely resembling VPower.

[Lowtimer]

Mr2Mike said:

A scenario which is rigidly defined and repeatable, completely unlike driving on a road. Doesn't matter if you don't drive exactly like that, if you can get better economy on a controlled test then it should still translate to better economy on the road, even if the actual numbers are substantially different in either case.

Not necessarily true at all. The EU cycle involves the average car engine developing no more than about 50 hp. If you drive normally almost all your driving is outside the parts of the map which the engine will use for the EU tests..

[otolith]

Exactly. A map determines an arbitrary set of output parameters for a given set of input parameters. You can't infer from how it behaves under one set of conditions how it will behave under another.

[anonymous-user]

Lowtimer said:

Mr2Mike said:

A scenario which is rigidly defined and repeatable, completely unlike driving on a road. Doesn't matter if you don't drive exactly like that, if you can get better economy on a controlled test then it should still translate to better economy on the road, even if the actual numbers are substantially different in either case.

Not necessarily true at all. The EU cycle involves the average car engine developing no more than about 50 hp. If you drive normally almost all your driving is outside the parts of the map which the engine will use for the EU tests..

Not really, If you do a scatter plot of the load/speed points from an EUDC test you'll find the average driver visits those points very very often indeed. For example, a 50mph cruise on a flat dual carraige way, some 1st/2nd gear low speed in traffic, a 75mph cruise, and numerous other conditions. The reason that in general people don't quite "get" the claimed fuel economy in the real world is as follows:

1) People tend to accelerate harder occasionally. This uses more fuel.
2) People don't coast down as much, they tend not to "Look up the road" and as such use their brakes more
3) Choosing the wrong gears. A lot of people simply are not in the most efficient gear for a lot of the time
4) cold starting. The test is at 25degC. That is well above the average uk temp.

If you have a car that has improved fuel economy over the EUDC, it WILL have improved real world fuel economy (because these days, much of that fuel economy comes from road load optimisation and down speeding)


Also, you don't have to only do the EUDC. Hows about the Highway fuel economy cycle, or the US FTP-75. Or the US-06 test. There are any number of mandated test cycles over which you could compare fuel economy under controlled and repeatable conditions. But no, the tuners just say "oh, i just did 3mpg better one day" and that's about it............

[Mr2Mike]

Lowtimer said:

Not necessarily true at all. The EU cycle involves the average car engine developing no more than about 50 hp. If you drive normally almost all your driving is outside the parts of the map which the engine will use for the EU tests..

So the vast majority of your driving has the engine making more than 50bhp? I think not.

[GVK]

Otispunkmeyer said:

On petrol engines.... manufacturers are essentially locked to the 14.7:1 AFR thanks to the catalyst. The 3 way cat works best at this AFR, even a little move either side can kill the effectiveness of one of those catalyst processes. So keeping that in mind, you can't increase air admission without increasing the fuel as well to keep the AFR right.

Generally petrol engines only run 14.7:1 AFR (Lambda 1) on idle and cruise situations (once warmed up enough for closed loop operation), full throttle engine goes back into open loop.

[anonymous-user]

The latest petrol engines are using watercooled exhaust manifolds (usually integral with the head casting) to attempt to maintain stoichiometric operation all the way to WOT.

[CraigyMc]

Kawasicki said:

Pints said:

BMW used the same 2.0l lump in everything from the 116d to the 123d.

You can never be 100% sure that the parts are identical between lower and high powered versions of the "same engine". For example the 116d might have a cast crank, while the 123d might have a forged crank. Car manufacturers aren't daft.

You can, actually, if you're of a mind to. I'm not super-beardy, but I did take a look at this in some detail when I was looking at remapping my 320d/ED.
You can go to http://www.realoem.com/bmw/select.do and have a look at the parts numbers for the various BMW engines (realOEM is specific to BMW).

For the BMW 2.0 i4 diesels (N47D20 family) from x16d to x20d, the short engine is identical, as is the head. I've not checked the other, more powerful versions.

There are changes outside the basic engine, in the turbo and fuel systems for example.
It isn't the case that each model of engine runs a different setup - they tend to go in pairs: the x16d and x18d engines are physically identical to each other, save for a different mapping.
The same goes for the x20d and x20d ED engine: same exact motor parts (but incompatible with the x16d and x18d parts), it's the different tuning that results in the loss of ~20bhp in the ED engine.

By the way the N47D20 range also has the x25d in it: the 125d (for example) is now a 218ps i4 2.0 diesel.

• x16d (116ps)
• x18d (143ps)
• x20d/ED (163ps - ie. 320d EfficientDynamics)
• x20d (184ps)
• x23d (204ps) *deprecated. replaced with x25d engine
• x25d (218ps)

All the current engines run the same bore/stroke and compression ratio (16.5:1), but the injector pressures vary as follows:
116d, 118d :1600bar
120d/ED, 120d :1800bar
123d, 125d :2000bar

BMW have a modular approach to diesel engines: their N57D30 (and N57S) 3.0 i6 diesel engines have the same piston size/shape/compression ratio as the i4 engines do.

If you were able to take the technology from their x50d engine and apply it to the i4 (2200bar injection pressure etc) you may end up with a 254ps 2.0 diesel. I'll be quite surprised if they don't do that someday and call it something like "528d" or something like that.

For completeness, note that the 114d and 116d/ED engines are actually 1.6 turbos from the Mini/PSA and aren't "pure" BMW engines - I only add this in case someone's wondering why there's no 114d above.

C

[Lowtimer]

Mr2Mike said:

Lowtimer said:

Not necessarily true at all. The EU cycle involves the average car engine developing no more than about 50 hp. If you drive normally almost all your driving is outside the parts of the map which the engine will use for the EU tests..

So the vast majority of your driving has the engine making more than 50bhp? I think not.

It doesn't have to. It's not where you spend the greatest amount of time that controls your fuel consumption, it's where you spend the time that accounts for the vast majority of my fuel consumption. In my case that is sustained cruising at, let's say, typical Pistonheads speeds on cleat motorways, or driving at a good clip over open country A and B roads. On the A roads and B roads I am usually either atr full throttle or on the over-run cut-off. Most of the fuel that is being burned, is burned areas of the map outside the EU tests.

I accept someone who burns much of their fuel in stop-start low speed traffic, or at steadyish speeds on busy motorways and duals where the traffic flows at 50 or 60 mph, they might spend a lot more time in the areas of the map that the EU tests also concern themselves with.

However, the vast majority of the EU cycle is spent at outputs of well, well below 50 bhp in something like a 320D - that was just a number I plucked out of the air as a maximum plausible power output it might require (it's enough to do about 80 mph on the level).

[hedges88]

Just wanted to add my fuel mapping experience to this thread, bearing in mind this was with an NA engine which those who are ignorant will tell you there are no significant gains

The car I mapped was a North American Honda, it was designed to use Premium American grade gasoline (91 RON) as opposed to standard American gasoline (87RON) so it wasn't too heavily de-tuned for our market, but I decided to optimise it for Shell V-Power/Tesco Momentum anyway

First thing I had to do was convert the car from an OBDII to an OBDI setup, I know that sounds like going backwards but the map was not tuneable with OBD2, and any gadgets such as SAFC required OBDI.

The car was tested before the changes at 107BHP (Honda Rated at 105BHP). It was already using high octane fuel, but as the stock setup had no knock sensor there was no benefit bar extra detergent helping possibly provide a better injection spray.

I used a Harness to convert to OBD1, ordered a new OBD1 ECU from Ebay and opted to have the optional ZIF socket (lever socket like for a cpu) for the fuel MAP so I could easily test and change the MAP. The Ebay store allowed me to request a basic standard map, advising them what octane I was using (99RON) and Manual/Auto transmission and how aggressive I wanted the MAP to be. I separately also added a knock sensor (The location is already available on the D16Y7)

End result after much tinkering (Ensuring no knocking on 99RON even under very high temp) was a healthy 123BHP, a gain of 16BHP on an NA motor. Torque did drop by nearly 10NM however with the new map, not sure what I did wrong there.

[anonymous-user]

Lowtimer said:

On the A roads and B roads I am usually either at full throttle or on the over-run cut-off.

Of course you are chap, Well done!

[StottyZr]

An idle thought that popped into my head today.

I noticed today whilst sitting in traffic my temp gauge rising, do OEMs allow the maps to change based on engine temp for example. Over fueling would aid cooling which could be very helpful whilst the car is running warm. Similarly they could run as close to a 14.7:1 AFR to aid warming up (even under full throttle for example) and then slowly amend the AFR as the car warms up.

They could also use the gear and a gradient sensor so the ECU has an idea of what load the engine is going to be up against at each throttle input etc...

[Nedzilla]

I have recently had my 2009 Nissan GTR remapped by litchfield and i have to say the results are pretty staggering!
Ive owned the car for about 18 months now and tried my best to keep it standard but the temptation was just too much.
I had a secondary de cat pipe fitted last year which is a popular mod just to make the car sound better and i put the car on a dyno at a dyno day and it produced 502 bhp. The de cat pipe combined with the remap is what comprises litchfields stage 1 upgrade and is claimed to give the car 'at least' 580 bhp.
Boost pressure is raised from 0.8 to 1.1 bar and the increase in performance is substantial to say the least. One owner on the forum has seen 597 bhp with just these mods!

Also the car drives much smoother,less turbo lag and more responsive everywhere. I have also seen an increase (which was claimed) in mpg. £50 usually saw 150 miles give or take a few with a combination of driving wheras i am now seeing around 170 which is significantly better.

The only downside i can see is that i never got it done sooner!

[anonymous-user]

StottyZr said:

An idle thought that popped into my head today.

I noticed today whilst sitting in traffic my temp gauge rising, do OEMs allow the maps to change based on engine temp for example. Over fueling would aid cooling which could be very helpful whilst the car is running warm. Similarly they could run as close to a 14.7:1 AFR to aid warming up (even under full throttle for example) and then slowly amend the AFR as the car warms up.

They could also use the gear and a gradient sensor so the ECU has an idea of what load the engine is going to be up against at each throttle input etc...

Wow, you should sell some of these "ideas" to the manufacturers. I doubt they have thought of such "advanced" ideas themselves. I mean, it's not like that have huge offices and workshops full of hundreds highly qualified and trained engineers, with access to the best data logging, analysis and simulation techniques, carrying out thousands of system and vehicle tests each week, and each car has probably only a couple of million man hrs of development in it, so i think you might be onto a winner there.............


/massive sarcasm


;-)


(BTW, overfuelling, does not provide extra "cooling")

[New POD]

If you go on jobsite and type in Calibration Engineer, you'll probably discover that the going contract rate for a 'mapper' working in an engine test department for one of the big boys is between £25 and £45 an hour. They have so many inputs from so many sensors that getting that "map" right, and achieving the power, torque, drivability, emissions, consumption, reliability etc makes it a major task.

[GVK]

Max_Torque said:

The latest petrol engines are using watercooled exhaust manifolds (usually integral with the head casting) to attempt to maintain stoichiometric operation all the way to WOT.

The little 3 cyl ECOboost Ford motor is like that isn't it?

[New POD]

Max_Torque said:

(BTW, overfuelling, does not provide extra "cooling")

On a diesel, extra air can be used to this effect. (So said Brian Horner, consultant Turbo Engineer Retired ex garrett and VNT expert)