In this entry, I will explain this power/torque increase type max short and straightforward. There will be enough non-flattering nuances, so I’m sure the gentleman whose business will be touched will fix all the tiniest mistakes, including spelling.
What is chip tuning? Chip tuning increases torque/power using either external equipment or the “upgrade” of the DME/DDE software. This time (mainly) is about the second – more advanced solution. The options of the first solution are minimal, so they don’t deserve special attention.
This blog is dedicated to the petrol engines and, unlike other entries of similar articles, I will try to introduce more exact information; for example, I will describe the actual engine of the BMW – B58. But, practically everything written applies to upgrading any other “modern” BMW engine; nuances will be mentioned further in the entry.
So, let’s see the power/torque curve of stock B58 (the actual BM 6-cylinder petrol engine).
Here, B58 curves – continuous line.
I suggest viewing the curve in three areas:
a. in the range of low RPM: idle till 1300 RPM;
b. basic/”work” range: 1300 .. 5000 RPM;
c. range of max power: 5000 .. 7000 RPM.
From the opinion of the chip tuning (and not only), each range also has its own specifics.
Derogation. The main problem of chip tuning (and power limitation/increase as like) – (how) increase air supply in the engine’s cylinders. There are no general problems with fuel supply – its amount can be improved, increasing the Rail pressure and/or opening times of the injector openings and/or installing injectors with a higher flowrate. Instead, the amount of air can be increased, modifying the blade geometry of the turbo unit (typically for the diesel engines) or wastegate work conditions (typically for the petrol engines). I will not describe the chip tuning of the atmospheric engines – its efficiency is close to 0.
*Exception is Power Class change for N43B20 and N53B30 engines (with the inlet manifold for N53; inlet and exhaust for N43 replacements). Note regarding possibly “weaker” pistons and bearing shells is still valid (regarding this – below in the article).
Returning to the three areas of the torque curve:
Range of low RPM
In this range, the kinetic energy of the exhaust gases is low (this kinetic energy is used to “propel” the turbo unit), and not even though the BMW B58 series engine uses TwinPower Turbo technology, the turbo unit is not able to propel “good”. What does it mean “good”? As we see, in this range, the max torque (compared to main work range) is lowered! It is logical to assume that the wastegate of the turbine is closed and the turbine blows “in full power”. In idle RPM, the turbine is not “blowing” at all – the engine works in the mode of the atmospheric engine with the available torque of around 250 .. 300 Nm (typical to the 3-liter atmospheric power aggregate of BMW). No chip tuning can do magic – the turbine is already used “on the full-throttle” in the stock software.
Range of max power
In this range, we see a curve of dropping torque (when the RPM rises); in addition, in this range, the curve is no anymore perfectly flat but slightly “wavy”. In this range, the turbo unit works on max load (its boost pressure has reached the maximum), and the cylinder air supply is limited by the max air flows of the inlet/exhaust tract and the turbine unit itself. In this range, the wastegate is managed so that it almost maximally uses the technical options of the turbo unit. Also, in this range, the possibilities to increase the petrol engine’s torque are close to 0. In this range, torques are basically increased for diesel engines, reducing AFR – increasing the fuel amount in the cylinders. As a result – the “smoke” appears; a considerable amount of soot and MP in the exhaust, which destroys CO and DPF catalytic converters very fast. In the case of petrol engines, the torque benefit is achieved; by increasing the max boost pressure, which, logically, has a most significant impact on the work-life of the turbo unit. In this mode, the turbo unit simultaneously has the most significant rotation; thermal and dynamic load!
Returning to the petrol engines (B58 as an example) – in both previously mentioned working conditions, any significant increase of power/torque without change in the hardware is not possible.
The torque plato range is the only one, in which the chip tuners could “perform” without rebuilding the hardware. In this range, the max torque is limited electronically by managing the turbo aggregate. Exactly in this range, the reserves are hidden, they say!
At this moment, I would like to remark on one crucial nuance: for their engines, BMW makes exactly this – plato-type toque curve in as wide as possible RPM range. Why? Such a curve ensures even acceleration of the car – comfortable driving with (even) a maximally pressed accelerator pedal.
Such plato means – you can drive with this engine both in a lower and higher gear, a good “lift” guaranteed. Instead, when creating a “spike” type torque in the narrow operating range, as if subjectively better “lift” is achieved. Still, in reality, the actual gain is lower because the sense of high torque is created by regular changes in torque (a human’s vestibular system is more “sharply” reacting precisely to the changes in acceleration). To drive such a car in the long term is tiring and unpleasant.
From my experience – a long time ago, I was forced to drive (with a new, according – no, the engine was not damaged) Mitsubishi Outlander 2 with 2.0 liters, 4 cylinders diesel engine, manual gearbox. The torque of this engine till 2000 RPM was so small that, for example, acceleration in the 5-the gear was practically 0. In a range of 2000 .. 3000 RPM, the engine suddenly was “pulling”, but above 3000 RPM, the torque again dropped swiftly. Example of an engine of completely opposite characteristics – it was uncomfortable to drive this car, even would say – unpleasant. The reason is: the largest torque of the engine is available in a very narrow range; you should switch the gears all the time; there is a permanent “shivering”, not even + dynamic acceleration.
And at this moment (probably, I “run ahead”), I will show you two concepts of typical achievements of the “chip tuners” when they “manage” to overdo.
First: two engines in one
As we see, till relatively high RPM (3500 .. 4000), the available torque is low, then rises swiftly and significantly. The current image, I believe, is intended for some drag race car and, as we see, reaches serious numbers, but in the “bottom part” of the RPM, it behaves like a regular atmospheric engine! For the intended use – win the race – such curves are justified, but for a dynamic everyday drive – a nightmare.
Second: chopper style
Here, practically unchanging power in a wide RPM range is ensured by an evenly dropping torque curve. I don’t know; maybe someone enjoys driving such an engine. I would feel like the engine is “dying” when the RPM rises, not that it runs “nice” and smooth.
But now, let’s return to the B58 engine. The manufacturer also offers chip tuning! Here are the torque/power curves of the BMW Performance pack:
What do we see in these curves?
In the range of low RPM – zero gain. It is only logical.
The plato has “risen” by 10% in the operating range.
In the range of maximal power, the increase of the torque – is also 10%.
“And that’s it?” you will ask. No, it is even worse! If the car is equipped with a manual gearbox, the max torque is increased not from 450 Nm to 500 Nm, but only to 480 Nm! The gain of the torque is only 30 Nm or 6%! And, in addition, the exhaust should be changed! Pathetic, isn’t it? Incomparably weaker than any of the chip tuning offices offer!
Here we have to talk about magical reserves, which are hiding in the range of the plate. According to the chip tuners, the manufacturer has left enormous resources (which, as it turns out, he doesn’t know how to use in its own Performance pack). Actually, these primary reserves are:
a. including the use of lower quality fuel (lowest octane number/cetane number);
b. driving in conditions where the oxygen level in the air is reduced (mountainous areas);
c. driving in conditions in which the amount of the oxygen/air density is reduced due to its increased temperatures in the inlet (high temperature of the surrounding environment, low air humidity, the high load of the engine recently);
d. including technological allowances of the hubs (for example, losses in the inlet manifold due to not perfectly even duct walls).
Here in the please is a first critical remark. All previously mentioned graphics picture the worst possible scenario. For my car, I have observed that when using E98 petrol, in a favorable condition (low or average low temperature of the surrounding environment), the maximal torque plato continues even till 5700 .. 5800 RPM. Yes, during summer, when the outside temperature was above 30oC, the torque drop started already by 5500 RPM (which is higher than indicated in the technical materials: around 5000 RPM).
So – BMW, for its engines, performs the adaptations to the obstacles mentioned in points a to c. Yes, this is no surprise because, for example, the knock sensors are installed already for pre-historical engines, and N series engines are detecting the equivalent quality of the fuel (for B series engines, in ISTA, a menu is available, where you can look at the evaluation of the fuel quality).
At this moment, a logical question arises regarding conditions mentioned in a .. c – are there any possibilities of the chip tuning (even though the BMW engine is adapting to the conditions)? My answer is – only in case any of the “hard” conditions mentioned allows “dropping” of DME in the emergency mode due to the inability to manage required/increased torque (or – if the turbo aggregate is not able to maintain the required boost pressure). So – in favorable conditions – everything is as if in order, but DME “drops” in a complete limp mode during the summer heat or fun drive via road serpentines. Excellent!
I don’t think I have to dedicate much time to point D because:
a. the tolerances of technological hubs used in the engines are small;
b. taking into account that in 99% of cases, chip tuners are using copy/paste technology to upload the “upgraded” files, it is clear that nobody does measure the specific of the exact engine. And I wonder, who is ready to measure the difference in the air resistance of the current inlet manifold versus standard, or, for example, the friction coefficient of the rotor of the turbo aggregate? None of the “tuners”. Accordingly, this part (but is very accepted in the chip tuners environment) is complete bullshit and is used only for the conjuration of uneducated “customers”.
For derogation. Almost all chip tuners in their monologues mention – here, the “manufacturer” created the engines of different power classes. We, chip tuners, only are giving access to the hidden reserves, for which the wicked manufacturer charges colossal money. This an also a cheap lie because:
a. in 99% of cases, the range of the engine hubs is different for different power classes. Other injectors, different exhaust, turbo aggregate, intercooler, inlet manifold, etc. If you don’t change the hardware, the real gain is very, very far away from the promised miracles;
b. the material from which the pistons of the engines are made is different for different power classes; the design of the bearing shell is different; there can be more differences (other materials for the connecting rod bearing shells, etc.). Yes, don’t be confused that only one “repair set” is available for all power classes – only the parts intended for the most powerful version are sold. The cause of such manufacturers’ decisions is simple – when manufacturing vast amounts of engines, each cent matters, but when selling the spare/repair parts – the customer (again) pays for everything; it makes no sense to save! Most of the chip tuners community are probably unaware of such nuances, but those who are – again, lying to you regarding “hidden reserves”!
A logical question arises – ”if there are no reserves (as you claim), at what expense then chip tuners increase the power”? Because the increase of power/torques (at least in some cases) is present – it is measured un dyno stand.
On the internet, you will find many stories “I drive like that already for 2 years, and everything is fine!” the answer is simple – the power is increased, exceeding some hubs’ maximum allowed loads. How critical is such exceeding of such loads?
My education in physics and math says – the situation does not looks “nice”. The longevity of the hub, if the max load is overreached, drops very swiftly. Here we don’t talk about “I increased the torque 2 times, the longevity dropped by 30%”. No, here is a theme: I increased the max load by 20% above the max designed; the number of allowed cycles (till the hub collapses) drops many times!
For example, suppose the manufacturer in the technical specification has determined that the gearbox can hold the max torque mode for 10 seconds to hold 20’000 cycles (guaranteed). +20% to max load – in that case, it will typically be able to handle 2000 times, but +40% to max load – only 200 times! Yes, exactly so harsh is the curve of the drop of longevity! The manufacturer has spent years optimizing each hub, reducing its material capacity (because each gram of the metal costs money!). In none of the hubs any huge hidden reserves are left!
Now, we can return to the objection – “I drive for two years; everything is fine!” I understand the situation as follows:
a. let’s be real: in most cases of “upgrade”, the actual increase of the power/torque is tiny or even close to 0 (here I am talking of copy/paste upload of some files). The proportion of such “copy/paste tuning” is depressing because if you pay two hundred + EUR – no specialist will spend uncounted hours on the dyno); accordingly – yes, why should the hubs not serve. Even if after the “tuning” there is some increase of power, for a used car (due to some other damages or wear), typically the actual torque/power was reduced before this “upgrade”. Accordingly – a relative increase of energy as if is present, but in the absolute numbers – the parameters still are around the stock parameters of a new car;
b. even if we consider a dramatic (guaranteed) drop in the resource, nobody says that the piston group or the gearbox will disintegrate when the car drives out of the box. It will serve for some time. Remark “for 2 years” .. sounds funny because the resource is not measured in years, but in motor hours, or – cycles. And here is the place for a question: How many cycles of 0 .. 200 km/h “pedal to metal” has this car handled? Oh, it has driven in the capital city and 3 times “speed up” to reach 100 km/h? Impressive!
c. for example, the maximal load of the secondary shaft of the gearbox (also the gearbox rubber joint, drive shaft, output shafts, and the differential) is precisely in the 1st gear. And here is the question – what kind of tires are we using? If the tires are worn out with a weak grip, in the first gear the wheels will simply spin without giving a max load to the mentioned hubs. Accordingly – the load will be far from the designed maximum, not even talking on overload created by the “chip tuning”. The manufacturer intends that the car will have appropriate tires installed; instead, an average customer of the “chip tuners” is a youth, who wants a supercar dynamic from an old car, be can’t spare enough money for the right tires.
With this, I wanted to say – if you will use the car “by application” after “chipping up”, – its safety is close to zero. Of course, you will be able “spin” in the district, and then – with a towing car to the service – it does not require a lot of skill. But, if you decide to drive this car for 2000 km to the Italian serpentines and “speed up”, with a considerable probability – you can expect “adventures”.
Yes, but ”there are expensive chip tuning companies that offer a warranty”!
Yes, there are, but I perceive it as an insurance case between customers. Well, for example, the company’s experience shows that during the first year (time of warranty), on average each 10th of chipped-up cars “goes down”. Accordingly, the expenses of the repair of this car are covered by the other 9 customers. If restoring one engine costs, for example, EUR 3000, each customer pays +330 EUR for a warranty. Simple and efficient!
Once again, shortly returning to the BMW Performance package vs the performance of other chip tuners. Sounds tempting – not +6 .. 10% of torque for EUR 2500, but at least + 25 .. 30% for EUR 200 .. 1000 EUR, isn’t it?
In case of a BMW upgrade, a guaranteed correct functionality of the car in all its driving conditions remains (including a full guarantee if the vehicle still has it). Huge (comparing to the manufacturer) torque/power increases offered by the alternative “upgraders” mean:
a. there will be conditions in which the turbo aggregate will no be able to “pull” the required boost pressure/airflow, and the error message will be recorded in the DME (which, most probably, will be masked and will not appear in the error message list);
b. there will be driving conditions in which the reaching of required boost pressure will take too much time, and again – error messages in DME (or – they will not appear because they are masked/deleted from the error message map);
c. even without the events described in the a and b, the functionality of the DME is roughly simplified (it does not work anymore in the closed-loop mode), consequences – see at the end of the entry;
d. lifespan of the turbo aggregate and other engine hubs (pistons, bearing shells) is unpredictably abbreviated because the car used this mode of increased torque.
As a result of obstacles previously mentioned in a, b, and c, DME will continue to work in (of course – deliberately disguised by the chip tuner) emergency mode, consequences – mentioned at the end of the entry.
In conclusion – the last argument is why I would not do any “chip tuning” to my car, even if it would be offered for free.
Even more or less modern DME/DDE contains hundreds of management and adaptation maps. Chip tuners have only several available. I will not burden you with a detailed description of the energetical model (which is used by all more or less modern engine management modules). Still, I will only add: the engine management module continuously puts the indications of all sensors in the formulas, which simulate the performance of the actual engine. With the help of these formulas, the engine management module is precisely planning/calculating “initial” parameters (injector openings, wastegate, VANOS, Valvetronic, etc.). It performs continuous adaptation/adjustment and self-diagnostics of all systems.
Unfortunately, limited access to the management and adaptation maps leads to that after such “upgrades” the calculations of the energetical module “don’t correspond”. DME/DDE “sees” that something is not correct and immediately switches to emergency mode. To solve such problems, usually, the error message maps are “cleaned” (display of the specific error messages is stopped to avoid the appearance of “Check engine” and unpleasant questions from the customer).
I have seen countless “upgraded” engines – both petrol and diesel engines. Unfortunately, NONE of them was performed correctly.
Most typical problems for diesel engines in the diagnostics live data:
a. intended and actual Rail pressures don’t match;
b. intended and actual boost pressure don’t match;
c. intended and actual amount or air don’t match;
Typical problems for the petrol engines:
a. intended and actual boost pressure doesn’t match;
b. error messages regarding lean (most popular) or rich (due to inability of the turbo aggregate to “pull” the necessary pressure/air amount; these most often are masked) fuel mixture;
c. live data confirm: incorrect fuel mixture; incorrect mechanical efficiency of cylinders; incorrect prognosed AFR values, as a result – permanent vibration; shivering; misfires; error messages regarding the performance of CO catalytic converters, disbalance of cylinder efficiency; inadequate fuel consumption.
Note. Thanks to the principle of the energetical mode, “from the factory,” the engine works in “closed-loop” mode. Any mismatch of previously mentioned required/actual values means that this management/control system does not work anymore in the closed-loop mode! Accordingly – it is an emergency (limp) mode of DME/DDE. Yes, generally, in such cases, EML (Check Engine) would appear in KOMBI, but – exactly to solve such a “problem”, the “technology” of error map deleting is used.
The funniest results (some of the described in my blog) – after the chip tuning, the result is precisely zero. No, not because the “specialist” has chipped up an atmospheric engine or tried to “upgrade” the advanced N43/N53. The reason is simple – the “chip tuning specialist”, for example, has increased the injector opening times (or Rail pressure) with a thought: more fuel – more torque. But DME, using the individual adaptations of banks and/or injectors, has compensated for this “addition”. The chip tuner added +30% of fuel; DME reduced this amount by 30%. Gain – exact zero! And what is even more interesting is that it is possible that directly after driving out of the ship tuner’s box, it seemed that the car worked better, but – during several hundreds of km, DME put “everything in place”.
All as one, the chip tuners claim – yes, others are tuning incorrectly (destroy the balance of all systems, create incorrect AFR, roughly delete error message maps, etc.), but me… I! I do everything correctly! By the ”feng shui”! I have offered several times to chip tuners known to me – show me the result of your work, and I will evaluate it with the diagnostics tools. Unfortunately, all of them are running from me like Satan from the crucifix. That’s why I don’t have a positive example. Yes, I agree – for pre-historical engines, for example, equipped with MS41/42/43 management units, it was possible to “tune” something (there goes another theme – for the atmospheric engine, it is worth tuning something just in case if the hardware is also upgraded), but for the DDE/DME of newest generations… Sorry, but from my point of view, it is the demolition of the engine management. The reasons are simple:
a. the management of the engine from full functionality is “thrown” into the emergency mode. Accordingly – the essential functions are paralyzed – the creation of the basic adaptations as also many of the self-diagnostics things;
b. the engine is not performing anything of complicated functionality procedures, for example, tests/measurements of individual performance of the cylinders, does not upgrade in injector adaptation maps;
c. thanks to the previously mentioned: both total and cylinder individual fuel mixtures are often/regularly nonoptimal. The engine vibrates and shivers. Both exhaust and engine piston group is damaged;
d. thanks to the disturbing measurements and self-diagnostics, the engine management does not see the leaking of the injectors, detonation, or vibration anymore – in worst cases, the pistons are melted, and CO catalytic converters are burned.
No, thank you, I don’t like to have such an “upgrade”! Even if I would get paid for it!