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Do you know what the mechanical differences are? Would be interesting to understand what can be achieved by parameters only and wheren/when mechanical (or other) measures are necessary. Do they all use the same transmission and brakes too?

Jeroen

Taking a guess at what might be the logic behind the single parameter based tuning and larger range of output gains.

Its just a key value pair in the ECU, like a hash map. All (major) components might be querying this table to verify the state of tune and then applying the corresponding matching value for that parameter from a specific metric table. And i expect there must be loads of reference tables for every function.


Try to imagine the other way round. Option 3 might be the normal working/optimum output for that hardware. Option 1 and 2 are just under-powered specs for lower variants/models. In future, they just spike those with next higher parameter and push it back to the market at a higher pricing.

E.g. The 2.2mhawk runs at 120bhp in scorpio and 140bhp in xuv. They increase the parameter after a few years and now make engines run at 140 and 170bhp respectively. In reality, the engine might be actually capable of 170bhp since the beginning or maybe more.

I would guess a jump table index/ vector. If so, calling it a parameter would be misleading.

Regards
Sutripta

Proof 1

Proof 2

I'm not an expert, I happen to work in this field.

The engine I mentioned is Petrol, TC. But the concept is applicable to NA engines as well. However, there is a limit to what can be achieved with a NA engine.


The difference is, dealerships just flash the software to the control unit, they don't manipulate it or alter it, unlike tuning maps where the software is modified / bypassed.


I think he has, that's how it works, and this post pretty much as well.

I don't have one, the company I work for has. But I'm not involved in Dyno testing.


I don't understand where your problem lies? If it is with over/under dimensioning, that's true. It's also the manufacturer's strategy how they look at it. BMW might have different mechanicals for different engine outputs, but looking at the examples shared by other members, this is not something new.

A question to you, what happens when :

a) A car is used in a country where the fuel quality is poor?
b) Engine operates at high altitudes?

How does it work?

Spike

This reminds be about the USA spec Triump V8 and the British spec. The British was 140bhp, and USA was 120bhp. I believe this was for emissions. However, the changes were mechanical too, with 140bhp one having different pistons. So a lot of people who restore Triumphs in USA, try to do the 140bhp one.

A friend is restoring one in his garage, and he says its not worth it. For a typical classic cruiser like the Triumph, that 20bhp is not going to take you anywhere.

3. Toyota 1GD Diesel. Innova 360NM, Fortuner 450NM. 90NM leap, same hardware.

Agreed but these engines have different parts too, and are not exactly the same. Now I know for sure the turbos are different, but I'm not sure what else is.

ECU has thousands of maps. I have got DAMOS for S-Cross 1.6 ECU. I think there are more than 20,000 maps and all these won't be related to engine. A tuner would be dealing only with maps related to engine.

Maps have X and Y axis and the values are mentioned in the table. I have posted the pic of Injection duration opening map in tabular view earlier on this thread. Please see that pic to understand what a map is, what parameters / values are in a map :D

SPIKE ARRESTOR has spoken about variant coding by single parameter change. Don't get it wrong by thinking it's just a single map or single value. Manufacturers have state of the art calibration softwares and it is nothing like the hack methods / tricks used by aftermarket tuners. The way an calibration engineer looks at ECU maps and the way how aftermarket tuner looks at it won't be the same. But as I said before usually many maps are repeated in ECU. I assumed that manufacturers would be code the ECU in such a way that by selecting single parameter / code : couple of maps would be changed and SPIKE ARRESTOR has also confirmed it :)

If i remember correctly 110 upto 150 had the same turbo and associated hardware. 170 and higher had a different turbo and I am not sure about other hardware changes if any.

As I understand variant coding helps in manufacturing efficiency.

An aftermarket tuner getting more power out of the engine by changing "only" variant coding is like activating a cheat code and releasing more factory tuned horses out of the motor. Its not tuning. But sometimes its best to change a code and get some more factory horses out rather than risk being part of tuner's R&D team without even knowing it lol:

Hahaha!!

Don't even dream of aftermarket tuners doing it. 99 percent of the tuners identity few performance related maps and just increase it by certain percentage : Trial & Error method, guess work and what not.. That's the R & D of tuners. Very few tuners were able to crack the ECU at code level, for example switchable maps by APR for few VAG cars and Wolf Moto for Fiat, Renault, old VRS and few Suzuki cars :)

I don't have a problem. I find it remarkable that an engine is manufactured that can produce such a vast range of power output. We had a discussion on a different thread around this although it was more pertaining to manufacturing efficiency. Obviously, overdimensioning is a cost increase per unit, but from producing an overall range of engines, standardisation might still bring the overall cost down. (Actually, if you find that thread (I can't for some reason, you will see that I was very much on the track of standardisation rather then to produce many slightly different parts for different power outputs).

Your proof is just people repeating the same mantra about a certain engine producing so much power and so much power. Still various members are also saying:

I'm just interested to undertand the difference, if any, between the 'same'engines producing a vast range of output. I would think that many of the big component are identical (i.e. crankshaft, cylinderblock, cylinder head, piston (?). But there are likely to be some differences on things perhaps such as turbo's, injectors, gaskets etc. Other members post suggest the same.

So I think the statement that such a vast range of power output comes from one and the same engine is a bit too generic. It could be, but I think in many cases there could be differences in certain parts.

To your other questions; you have to be more specific what poor fuel is. (diesel, petrol, dirt/water ingress, octane incorrect, problems with the dopes etc)

Contrary to popular belief an engine doesn't know at what altitude it operates. So it's performance isn't altitude depended as such. It is however dependent on atmosferic pressure and that varies. Higher altitudes have lower pressure as a rule compared to the ground below, but not necessarily in an absolute sense. (Anorak fact: It's why pilots must adjust their (barometric) altitude meter all the time to the local atmospheric pressure.

Even the very basic Bosch L-tronic system on my 1980s Alfa Romeo has a barometric pressure sensor that feeds into the ECU to adjust for variations in atmosferic pressure. Whether that is due to a high / low pressure zone, or a high altitude doesnt matter.

On carburator cars (or my 1975 RE Bullet) I carry a screw driver so I can adjust the timing on the go. NIether a low pressure zone or a mountain is going to stop me from enjoying my drive

Jeroen

I shouldn't have used the term R&D it gives out the wrong picture. Only a very few number third party aftermarket guys in the world would have access to an R&D facility like Banks, APR and few others. For the rest it best can be called T,D&D*

*Trial, Destruction and Development

I just found the thread I was referring to earlier. We discussed the topic about how much power you can get from a unique engine by altering ECU settings only, and production efficiency in some detail;

Some members did some extensive research trying to figure out which parts are different on seemingly similar engines with different output:

Here some proof that although basically the same engine, there are quite a few parts that are different. So just changing one parameter in the ECU would not get you such a vast range of power output

Have a look at the table on the well known VAG TDI engine. Engine output ranges from 110->170 BHP. From the outside these engines look identical. But to get them to deliver these different outputs, various parts are different. And no doubt a few settings in the ECUas well. In addition if you read the below thread you will also notice that the transmission bolted onto the engine with different outputs differs as well.

http://www.team-bhp.com/forum/techni...ml#post4174346

There is no doubt that through the ECU alone vast differences in power can be obtained. But the question is how much and where do you need to start changing some parts? My gut feeling is that anything up to 30-40% on top of the lowest power output is probably possible. You want to increase more, you are likely to have start changing bits and pieces. But it also depends heavilly on how the engine was designed in the first place and what makes economic sense. I don't see why it can't be done technically, but I haven't seen much real evidence (i.e. identical part list between different variations of the same engine). But as we discussed in the above thread, that is probably more an economic/manufacturing issue then a technical one.

Jeroen

I guess you are confused. BHPian SPIKE ARRESTOR was taking about calibration at manufacturer level. It's not just single value / parameter change in engine maps. Variant coding is something like you can switch a set of maps for different power outputs by single parameter change by coding. No aftermarket tuner would have the expertise to do it and it's a herculean task to reverse engineer the codes.

Same engine can have different power outputs. In some cases the hardware is different. There are few threads related to that in our forum. Let's not go off topic here. Thanks :)

Sure the suggestion in his text:

Is that by variant coding you can get huge power variations out of one and the same engine. Whereas I fully agree you can get different power outputs, I have some doubts as to how much you can get out of the same engine without having to change some hardware bits

Let's leave it at that.

Back on topic; Variant coding has been around in (car) manufacturing for at least 10-15 years. It's essentially a process that enables manufacturers to program a car (ECU et all) with particular variations.

As far as I know it looks at all relevant variations on a model, so not necessarily engine stuff alone. So it's a very efficienct way of dealing with all the different models, variants, keep spare parts to a minimum, ensure interoperatibility etc.

But it doesn't prevent a tuner to remap an ECU. Or otherwise. For instance, I replaced an airbag on a friends Jaguar not too long ago. (First time ever I replaced one). We got a SRSCM variant code error. But on the net we found a procedure and a guy with a little tool and we fixed it. It was a bit cumbersome and hooking it up to the Dealer's electronics suite would have been much quicker, but also much more expensive.

So when we say tuners don't have the capability/tools this is probably true. But for what tuners like to do, does it really matter?

Jeroen