The owner of a BMW E91 with N53B30U0 approached me. He has decided to take the most straightforward way with increasing the power of the engine: not a full upgrade to the most potent version of the engine but used the service, offered by the chip tuners. Even more – the chip tuners promised the result close to the ideal!
In this entry, you can read how did he succeed.
But in the beginning – concise technical information.
N53B30U0 is a version of reduced power, which ensures 160kW (around 220 hp) and torque of 270 Nm.
N53B30O0 is a full power version, which ensures 200 .. 205 kW (around 270 .. 285 hp) and torque of 310 .. 320 Nm.
Choosing software release from iX car, increasing the thresholds of the crank sensors, using petrol with octane 98, it is possible to get close to the brink of the 100 hp/l or 300 hp.
What is the difference between these engines?
- the mid-range version uses simplified (with the air channels of fixed length) inlet manifold. In the top-range version, the inlet manifold is equipped with 2 pcs of DISA valves, which allows to work it in 3 modes, depending on RPM;
- in the mid-range version in all driving conditions in case of Homogeneous injection method works with a Stoichiometric mixture (with Lambda 1.00: also in kick-down). The powerful versions work with enriched fuel mixture in kick-down mode (even till Lambda 0.80 for iX software version).
- for the mid-range version, the throttle opening is limited with 70%. For the most potent performance, the throttle opens to 100% (relatively).
What do the (correctly performing) chip tuners do to the U0 release?
- change the map of the throttle (remove the limitations), opening it from 70% to 100% – this step ensures the max effect. The most considerable influence it gives in the range of low/medium RPM;
- in the fuel map, enriched fuel mixture in the kick-down mode is intended – this step ensures a slight (till 5%) additional increase of torque/power.
Of course, such an upgrade is far from complete reconstruction (installation of inlet manifold with 2 DISA valves and complete reflash of the software), but – the result can be felt, if everything is done as it should be.
And at this moment, we move to the current case. Here, the print out of the dyno:
The quality of the image is average (in such quality the picture was sent by the service provider), but at the bottom of the sheet you can see the actual data:
- max torque before/after: 269.5/288.7 Nm;
- max power before/after: 213.8/226.2 hp.
RPM points of max torque and power are not changed (they are reached by the same RPM).
The owner of the car asked me what do I think about this result. The chip tuner is said to be confused by the loss of torque by higher RPM. The opinion of the ship tuning “specialist” – there is a problem with an ignition…
I answered that the performer of the chip tuning should get to know the basic principles of DISA. Besides, judging by the curve of the torque, I expressed my suspicions, that the chip tuner did not manage to open the throttle more than it was initially (70%).
The performer of the chip tuning admitted that I am right – the opening of the throttle is only the “next step.” Obviously, at the first step, the use of enriched fuel mixture was allowed. Or – actually, even nothing at all was done!
What is the “gain” of this chip “tuning.” According to the numbers:
- torque: in the max point around 7%, average: around 5%;
- power: in the max point around 6%, average: around 4 .. 5%.
So little gain is not even possible to sense! Such a “gain” is a permissive error of the dyno!
Using Google, everyone can find the articles, in which the chip tuning companies are sharing the results and the accuracy of the results. Here, only two little examples, which show, that such difference of 5% (and even much more) can be reached, “turning” the engine repeatedly or even only changing the settings of the software of the dyno stand:
https://www.hotrod.com/articles/0612phr-dyno-accuracy-testing/
https://www.celtictuning.co.uk/dynos/dynamometers
So, what is y verdict to this chip “tuning”? FAIL. Unfortunately, right so merely.
Wasted time and (customers) money.
What other consequences can be expected after such chip “tuning”?
Desiring to increase the required, but not really reachable torque (it means, setting the higher requested torque) as the engine can perform, in the error message memory of DME (sooner or later), the error messages regarding reduced torque and ”Lambda uberwachung” will appear. Logically, these error messages should be deleted, don’t they?
What are the consequences, if the coefficients of the energetical model of the engine are not modified, but only the fuel and required torque maps are changed? The energetical model does not match, DME detects non-compliance of the energetical model (and also fuel mixture). Yes, the appropriate error messages are deleted from the memory, but the problem stays. As a result of the problem, DME switches to the limp mode. The chemical efficiency of cylinders no longer measured; the adaptation maps of the injectors or bank adaptations are no longer upgraded. Without illusions – when this problem will be detected, even the use of enriched fuel mixture will be prohibited. And there will be precisely zero gain of such a chip tuning.
Or, more precisely – as the creation of the adaptations will be paralyzed, very soon, the fuel mixture will become incorrect, and the CO catalytic converters will get damaged. The customer wanted to increase the power, but instead – paid EUR 500 (!!!) to get additional expenses of at least EUR 1500 in the quite near future. Or even – would start to replace the injectors without any reason (it means, the vibration will appear, unavoidable misfires, in which as if the injectors would be to blame). In my opinion, – rough.
P.S. The chip “tuner” instructed the over of the car to replace the elements of the ignition system (spark plugs and ignition coils) to reach more considerable power. Isn’t it an excellent continuation of the story?
And here, after less than 24 hours first serious problems appeared:
- the engine strongly vibrates in idle;
- in the error message of the DME, the error message recorded: 3070 – cylinder balancing on uneven running cylinder 2.
A very predictable outcome. The software of the DME is damaged, the upgrade of the injector adaptation maps – paralyzed. The mechanical efficiency of cylinder No.2 is incorrect, but DME was not able to solve this problem. Here, the issues with the fuel mixture, which I mentioned before, have started! An excellent “tuning”!
