Grundsätzliche Fragen zum "Tuning" von CR-Motoren | Posts 16+

Good luck.

Thank you, that's something the Punto could use! The box will eventually go to ____...

Don't worry!

"This type of CR tuning isn't really disruptive. However, if the vehicle has a DPF, I would remove the tuning box. By the way, if you push the JTD engines too hard, they simply shut down. I'm now on my third JTD, and two of them were chipped, but with a "good" engine control unit from the company Novitec." They even optimize the engine to meet customer requests if the vehicle produces excessive smoke.

So far, I have only read good things about Novitec. Some Fiat dealerships also offer Novitec parts as accessories, but mostly these are body styling components.

The engine does not have a DPF (Diesel Particulate Filter); there are only a few retrofit solutions available. However, these solutions offer virtually no advantages because, despite any subsidies, the costs outweigh the savings that would be achieved with the smaller engine in terms of reduced taxes. It would therefore be an investment solely aimed at increasing the sales value.

Just out of curiosity: What do you mean by "shutting down" if someone is overdoing it? Do they go into emergency mode, or do they simply shut down?

Hutfahrer wrote:

Just out of curiosity: What do you mean by "shutting down" if someone is overdoing it? Do they go into emergency mode, or do they simply shut down?

It enters emergency mode when parameters are far outside the permissible tolerances (e.g., rail pressure). There is no shutdown in relation to excessively high combustion pressures and exhaust gas temperatures.

"The 20% increase in performance achievable through rail pressure (the high-pressure regulator is designed to limit the pressure even at 100% PWM) results in significant premature wear with just a rail pressure increase, as evidenced by the burning noise." A healthy alternative is to extend the injection duration (only the main injection) and increase the fuel rail pressure to a reasonable extent, which is safest via a chip.

And to call such a device a "chip tuning" box...

Let's see! Thank you everyone...

Hello hat enthusiasts,

I would initially approach the whole thing with a positive attitude. Firstly, you've already bought the car, and secondly, Opel sells this engine with 90 horsepower.
I strongly doubt that the 90 horsepower version uses mechanically different components.
For a 90 horsepower output, not only the injection duration will be increased, but also the fuel rail pressure and the turbocharger boost pressure.
Therefore, with a 20% increase in power, the pump would not have been driven to levels that could damage the material.

(..)the high-pressure regulator is designed such that it limits the pressure even at 100% PWM.

Is your pressure regulator broken?
Typically, the regulations are designed so that when the control signal is 0%, the controller closes, and when it's 100%, the controller opens completely (or vice versa). The entire system is limited by an additional pressure relief valve that restricts the rail pressure if the control system demands more pressure than is mechanically permissible.
This pressure relief valve is a failsafe solution for all incorrectly configured boxes and faulty characteristic curves. Since that's in place, the high-pressure fuel line won't fly off and hit you; only the high-pressure pump will likely fail catastrophically.

With 'only' increasing rail pressure, there is massive increased wear, and the sound of combustion speaks for itself .
That's not entirely correct either, as explained in detail above.
This only applies if the rail pressure is permanently limited by the overpressure valve.

Best regards, Jochen.

Jochen_145 wrote:

Hello hat riders, I would initially approach the whole thing with a positive attitude. Firstly, you've already bought the car, and secondly, Opel sells this engine with 90 horsepower. I strongly doubt that the 90 horsepower version uses mechanically different components. For a 90 horsepower output, not only the injection duration will be increased, but also the fuel rail pressure and the turbocharger boost pressure. Therefore, with a 20% increase in power, the pump would not have been driven to levels that could damage the material. Is your pressure regulator broken? Typically, the regulations are designed so that when the control signal is 0%, the controller closes, and when it's 100%, the controller opens completely (or vice versa). The entire system is limited by an additional pressure relief valve that restricts the rail pressure if the control system demands more pressure than is mechanically permissible. This pressure relief valve is a failsafe solution for all incorrectly configured boxes and faulty characteristic curves. Since that's in place, the high-pressure fuel line won't fly off and hit you; only the high-pressure pump will likely fail catastrophically.

The issue with the engines isn't quite like that. The high-pressure pumps in each system always operate at the target pressure. In the various configurations, larger nozzles are installed in the injector, sometimes with up to 7 holes in passenger cars. The injection time is also adjusted differently. The CP1 always operates at 1350 bar in all systems, and the CP3 operates at 1600 bar. In the different configurations, the injection systems are calibrated so that the pre-injection is regulated depending on the air mass, temperature, and coolant temperature. The pre-injection is intended to "only" raise the temperature slightly so that the main injection can occur after top dead center. We know that at low engine speeds, premature main injection can reduce efficiency (the combustion knocks against the connecting rod, which is at a shallow angle to the crankshaft, and by the time the crankshaft reaches 90 degrees after top dead center, most of the heat is already in the piston and cylinder, and the combustion pressure has already subsided).
Naturally, the different performance classes require different high-pressure pump plungers to provide sufficient flow during injection.

"100% control is not achieved by the high-pressure regulator in the rail; this is a coil, and like the solenoid valves, it would burn out if subjected to continuous voltage. Therefore, the current flow is briefly interrupted, and the back EMF is discharged as before using a diode."
A CP1 with an integrated regulator does not have a safety valve (neither does the HDC16, by the way). Here, the diesel fuel from all three ports is collected and directly fed into the high-pressure outlet! The flow is only limited by the high-pressure regulator, and this is where the aspect of the magnetic field comes into play. The system utilizes electricity, voltage, and frequency, and is designed such that the magnetic field, the resulting pressure on the armature, and the size of the sphere collectively limit the pressure from a constructional perspective to a maximum value.

There was only one injection system operating at 1600 bar, but it was running at 1350 bar. This was the Siemens HDC16 from 2001, which used piezo injectors and was used as a beta test on many customers with two turbochargers and a lion emblem on the hood (fortunately, it was less problematic than the older "CP1 Superspritze" from Bosch).

Naturally, the different performance classes require different high-pressure pump plungers to provide sufficient flow during injection.

Aron, technically speaking, I would agree with you, but in the automotive industry, cost-cutting measures are the driving force!
Identical parts are the most cost-effective way to build vehicles and engines.
Nowadays, it is standard practice to create performance levels solely based on the software.

If you have a 1.3 liter engine that has 70 horsepower in one case and 90 horsepower in another, what is the probability that it is the same engine?
Wouldn't that mean two assembly lines, twice the parts logistics, two warehouses, etc.?
You can achieve the same effect by reducing the power of the 90 horsepower engine to 70 horsepower.
And using parts from other engines makes this unnecessarily complicated and expensive.


'100% control is not achieved by the high-pressure regulator in the rail; this is a coil, and like the solenoid valves, it would burn out if subjected to continuous voltage. Therefore, the current flow is briefly interrupted, and the back EMF is discharged as before using a diode.'

Why not? I've applied 100% PWM more than once.
The coil does not burn out because the ohmic resistance of the coil limits the current.
'Fully on' for a PWM-controlled valve means 100% PWM, which in a vehicle translates to 12V, as long as the valve is not considered in the diagnostic system.
Or do you believe that the stress is significantly lower when using PWM at 99% duty cycle and a carrier frequency of, for example, 500 Hz, compared to a constant 12 V?

A CP1 with an integrated regulator does not have a safety valve (neither does the HDC16, by the way). Here, the diesel fuel supplied from all three ports is collected and directly fed into the high-pressure outlet! The pressure is limited only by the high-pressure regulator.

According to the Bosch manual, however, these pressure relief valves are standard.
Denso also uses them as well. And I'm quite certain that they are also integrated in your system. Otherwise, you'll have a big problem if you get a short circuit against 12V on your pump control line.


A CP1 operates at 1350 bar in all systems, while a CP3 operates at 1600 bar.

Please tell me what kind of system is installed in a 2001 Ford Focus?
I'm not entirely sure, but I believe these vehicles were equipped with HDI engines. According to my data recordings, we have not measured a rail pressure exceeding 800 bar.

You can find similar values in the early JTD engines from Alfa/Fiat.
We both know that the rail pressure is regulated, and this has already been described above.

Why should the maximum rail pressure of an engine have nothing to do with a reduction in performance?
reduce?

Best regards, Jochen.

Jochen_145 wrote:

If you have a 1.3 liter engine that has 70 horsepower in one case and 90 horsepower in another, what is the probability that it is the same engine? Wouldn't that mean two assembly lines, twice the parts logistics, two warehouses, etc.? You can achieve the same effect by reducing the power of the 90 horsepower engine to 70 horsepower. And using parts from other engines makes this unnecessarily complicated and expensive. Why not? I've applied 100% PWM more than once. The coil does not burn out because the ohmic resistance of the coil limits the current. "Fully on" for a PWM-controlled valve means 100% PWM, which in a vehicle translates to 12V, as long as the valve is not considered in the diagnostic system. Or do you believe that the stress is significantly lower when using PWM at 99% duty cycle and a carrier frequency of, for example, 500 Hz, compared to a constant 12 V? According to the Bosch manual, however, these pressure relief valves are standard. Denso also uses them as well. And I'm quite certain that they are also integrated in your system. Otherwise, you'll have a big problem if you get a short circuit against 12V on your pump control line. Please tell me what kind of system is installed in a 2001 Ford Focus? I'm not entirely sure, but I believe these vehicles were equipped with HDI engines. According to my data recordings, we have not measured a rail pressure exceeding 800 bar. You can find similar values in the early JTD engines from Alfa/Fiat. We both know that the rail pressure is regulated, and this has already been described above. Why should the maximum rail pressure of an engine have nothing to do with a reduction in performance? reduce? Hi Jochen

Okay, so I couldn't find anything about pressure regulation in the PSA documentation. I recently disassembled my pump because of a leak, and there's nothing there; it was surprising to me at first.

"Fortunately, if there's a short circuit in the throttle body, the engine control unit (ECU) will shut everything down." The 90% maximum duty cycle makes a significant difference, especially for coils, which only reach saturation with extremely long PWM cycles. In my opinion, whether the coil dissipates 24 or 15 watts as heat makes a considerable difference.

I don't know what Ford used in 2001. Only the newer 1.4, 1.6, 2.0 16v, 2.2 16v biturbo, and 2.7 24v engines, etc., were jointly developed. The CR (Common Rail) systems I'm familiar with (like the HDi 2.0 8v 66.70kw, 2.2 16v, CDI 200, 220, etc.) all reach their 1350 bar pressure at 3000 rpm. The French limited the performance of the 2.0 8v engines solely through the injectors and injection duration.

I can imagine that they might not reduce the rail pressure in the P-max range because a) the hardware is already designed for it, and b) the technology involved would make exhaust gas treatment more cost-effective.

@ Jochen_145, Aron:

Here's the translation:

"Why was the Punto a closer contender? Well, I have the same engine in a 2004 Suzuki Ignis. And frankly, we don't really care whether the metal box around it says Fiat, Opel, or Suzuki! The fact is that this small 1.25-liter "big" 16-valve diesel engine is quite lively, consumes little fuel, and in the long run, we won't be hit as hard because of its relatively small taxable engine displacement, especially if car taxes are raised again, or if there are even higher penalties for diesel engines without particulate filters."

The Z13DT engine, which was initially developed for the Corsa and Astra with 90 horsepower, is mechanically identical to the ones we've driven twice with 70 horsepower each. At first glance, even the turbocharger appears to be the same. It's important to remember that the same engine is also used in the Panda, but with reduced torque (145 instead of 170 Nm). The reason for this is supposedly the gearboxes, which may not be able to handle more torque. Based on our own test drives with the Panda 1.3 JTD, it was definitely eliminated from our closer consideration. The engine feels weak and uninspiring. At the same time, this "detuning" results in an additional 0.2 liters of fuel consumption. That's unbelievable! Even my partner agrees after a test drive, although the Panda was her favorite car overall.

With this engine, the Puntos are by far the most affordable option. A Corsa with the same mileage, age, and comparable equipment would cost at least 2500 EUR more. Based on your explanations, I no longer believe that the previous owner's "brute force" modifications caused significant damage.

Here's the translation:

"What are the differences compared to the 90 horsepower version? The intercooler piping on the 90 horsepower version isn't quite as convoluted, and the intercooler itself is larger. On the Corsa, the airflow to the intercooler is quite limited, and even on the Astra, it's still quite obstructed. In contrast, the intercooler on my Suzuki is relatively exposed, even though it's smaller in volume than the ones on the Opel models. By the way, the airflow to the intercooler on the Punto is also quite poor. You could improve it by removing the front bumper, but who would want to do that?" The intercooler is seriously obscured by the bumper for almost two-thirds of its length!

The modifications to the 90 PS engine will likely involve the injectors, the intercooler system, the turbocharger pressure, and the engine mapping. Whether the turbo still has enough reserve power for factory-standard tuning will be determined by the buyers, who will act as beta testers.

Okay, so what am I supposed to do with this thing now? On the one hand, I'm against continuing to use it because it's illegal! I don't want my girlfriend driving a car where she risks getting pulled over during a check. On the other hand, a young woman in her mid-twenties driving a standard Punto is unlikely to be stopped unless there's a suspicion she's driving under the influence. Most girls probably believe that they don't know how to open the hood of a car.

On the other hand, while it accelerates quickly, it's not particularly fast. It moves at a good pace, but without constant high speed and without aggressively tailgating the car in front. In terms of fuel consumption, it was 0.5 to 1 liter higher than my usual consumption when I lent her my car for almost 4 months due to a work assignment abroad. However, it's important to note that my commute is 2/3 country road and only 1/3 city driving. Their commute is longer and consists of 90% city traffic.

Hmmm... The reservations still outweigh the positives! I could still leave it alone! The important thing was that you got rid of that Kia Pride. It used 7-8 liters of regular gasoline in city driving, and those brakes were terrible! On the other hand, the Punto is a real leap forward...

Conclusion after 2 weeks and approximately 1240 km: A successful small car! Comfortable, zippy, and economical. I particularly appreciate the pleasantly bright and far-reaching headlights when driving in the dark. However, in rain or fog, you can feel that a large amount of light is reflected upwards. This creates the dreaded "white wall," which can be tiring, especially on long journeys. We had exchanged cars because of my work commitments near Braunschweig. My partner drove daily to work with my Suzuki as part of a carpool. Having two more doors makes it more comfortable for three passengers.

The air intake ducting in front of the air filter on the Punto is a design flaw. At highway speeds, it forces so much splash water into the air filter housing that the air filter gradually becomes saturated. This initially results in a gradual loss of power, and eventually, a complete failure. Thanks to my membership in a car club, I received quick assistance just before Braunschweig. Since the correct air filter was not available new, the water-soaked air filter was blown out with compressed air and then dried with a hot air gun. A temporarily attached aluminum hose ensured that the air filter didn't get wet again immediately. Now, it draws air directly from under the hood, above the engine. Certainly an acceptable solution for the current cool and rainy weather, but something better should replace it by spring at the latest.

Otherwise, not much happened. Despite initial skepticism, the Punto proves to be stable and well-built. The poorly designed interiors of previous generations seem to be a thing of the past. There are also no more rattling noises than, for example, in my Suzuki or a more expensive Opel Corsa. After successfully installing a decent Blaupunkt car radio last week, my partner can take over the fully fueled Punto starting Monday morning.


Regarding the story about the tuning box: Could it be that the engine control unit is capable of learning in some way? The engine ran for a week without it, mainly because I wanted to drive a few kilometers on the highway. Afterwards, I experimented with it again. Initially, there was a noticeable increase in torque, but somehow that seemed to disappear a few days later. Have I gotten used to it, or have I noticed that the serial tax control unit is compensating for the manipulation and adjusting the "faulty" CR pressure sensor value?