Sch.....rott Elektronik im Auto | Posts 48+

Well, I wasn't just referring to your Ibiza trip.

You immediately believe the distribution, how about you get on a scale sometime? My Golf4 had 800kg in the front and 650kg in the back, which is a similar distribution, especially considering that during the test, the tank in the back was still empty and was missing about 50kg.
Brake bias is 60/40% front/rear.

Well, what the fuel tank compensates for at the rear, the driver compensates for at the front with their weight

Bubu.

Well, what the tank adds to the rear , the driver adds more weight to the front .

Bubu;)

The driver is almost in the middle, between the two axles... I need to go check the measurements...

Gremlin wrote:

@bertil We were driving the rear-wheel drive cars through the curves at idle, just like the Passat. Okay, it probably wasn't that.

I suspect that rear-wheel drive vehicles are more sensitive in that regard, because an oversteer situation can be relatively easily triggered due to the drive type.

Julian wrote:

Hi Gremlin, It's possible that the rear-wheel drive version is more finely tuned, given that it already has a more pronounced tendency to oversteer. @Julian

Unfortunately, the very soft suspension tuning of the VW Group vehicles also plays a significant role in this. The rear drum brakes, which are still partially used in some vehicles, provide less braking force, and the front brakes have to work harder.

"So, mine has really aggressive rear fins."
Did any G4 TDIs come with rear drum brakes?

Hmmm, so, the Golf IV with the 75 gasoline engine, owned by our street-smartest kid, has disc brakes in the rear, which is very noticeable through the 19-inch Mille Miglia rims, although a drum brake might have been a better size match!

I recently saw a Skoda Octavia Combi that had drums on the rear wheels. I can't say anything about the engine!

According to Autobild, even the diesel Polo with a 75 hp engine has rear disc brakes. By the way, my sister's 75 hp TDI A2 has drum brakes, but it doesn't matter; it brakes incredibly well.

Recently, I saw a Skoda Octavia Combi that had drums in the back. I can't say anything about the engine!


66kW TDI

'Drum brakes or disc brakes are more of an academic topic. When you apply a lot of force to the pedal, both types lock up immediately. Disc brakes are primarily more resistant to thermal stress, and they are inherently less prone to fading. The amount of torque that can be applied (especially in relation to the rear axle) is not really an issue in this context.'

CU Gremlin.

The Octavia Combi TDI with 66kW has drum brakes at the rear. However, if Electronic Stability Program (ESP) is ordered, disc brakes are included instead, as they are better suited for controlled intervention.
Stay cheerful.
OlBe.

Hi Julian,

The guy in the Ibi Forum who wrote that was, as far as I know, weighing the box on a scale. I'm planning to do that too, when the opportunity arises.

For the Golf 4, I can also easily imagine a 60/40 weight distribution, but it's also quite a bit longer than the Ibiza.

The Ibi also has the added disadvantage that its front overhang is at least as long as the Golf 4's, and the front overhang itself is also significant, meaning there's still a considerable amount of mass located in front of the front axle.

@Bubu: I don't think my 60 kilograms will make much of a difference, especially since the driver's seat is located almost exactly between the axles.

Best regards,

Jan.

How does the ASR system work in the Golf?
How is this achieved, similar to how it's done with BMW engines?

Hi,

At least, that's what she does with the Ibiza. Brake intervention is only available with the "differential lock" system; the ASR (Anti-Slip Regulation) electronically reduces power.

It's also important to remember, as mentioned above, that if you're driving on snow, you shouldn't floor the accelerator. The engine then settles at a low RPM and doesn't go any higher.

Best regards,

Jan.

Jan6K wrote:

@Ulf: You're probably going to lose those +35 kilograms

through diet , right?
Hi Jan,

It probably won't be possible: with a (slightly) larger Golf, I managed to remove about 10 kg.
By the way, it didn't get noticeably louder – the engine just sounds a bit "meatier," and I'm enjoying it.

I suppose I'll probably end up doing that with Polo eventually too. But that would, at best, reduce the distance to the golf course back to a normal level...

Now, I feel I need to add my two cents to this discussion.
Okay, ESP, with all its integrated systems, is very useful. There are only a few suppliers of such systems, including Delphi, ITT Industries (Automotive), and Bosch. The latter, together with Mercedes-Benz engineers, developed ESP and were the first to use it in a production vehicle (the MB CL600, an older model). Other companies followed suit.
ESP includes the following well-known systems:

ABS (Anti-lock Braking System): with active wheel sensors (which also detect speeds).
< 7 km/h)
ASR - Antriebs-Schlupf-Regelung: A system that controls wheel slip of the driving wheels in relation to the...
on the other axis, through boost pressure control, adjusting the ignition timing to be later, limiting the fuel supply, or temporarily deactivating individual cylinders.
EDS - Electronic Differential Lock: compensates for speed differences greater than 100 rpm.
The drive shaft equalizes the speed of the wheels by braking the faster wheel; a pressure accumulator is required.
EBV - Electronic Brakeforce Distribution: dynamic brake force distribution between the.
The axles, depending on the driving conditions, engage the rear axle more strongly.
Initiate the delay process. (replaces the mechanical...) Rear axle brake pressure limiter.
ABS+: Advanced Anti-lock Braking System with additional software and sensors (e.g., yaw rate sensor).
The lateral acceleration sensor, also known as Corner Brake Control, stabilizes the...
Vehicle braking, pre-ESP stage.
MSR - Motor Slip Control: prevents the drive axle from locking up during...
Sudden clutch engagement and abrupt throttle release.

ESP, in addition to the above-mentioned features, has... The system consists of the following components:

· Longitudinal, transverse acceleration, and yaw rate sensor.
· Steering angle sensor
· E-Gas
· Electronic throttle valve (or similar system)
· Advanced software and faster computers.
· Vehicle-specific setpoint storage.
· Additional valves in the control block.
· Connectivity with all drive components.

The device compares the measured actual values with the target values multiple times per second (approximately 500 times). If there is a significant deviation, the control unit initiates appropriate measures.
This includes:
· Suppressing control commands (automatic).
· Suppressing or amplifying gas commands.
· Targeted braking of individual or multiple wheels.
· Regulation of engine power.
· Dynamic brake pressure regulation for each individual wheel.


Ideally, each system should be individually adjusted for each vehicle (specifically, for each engine type or model). The extent of this adjustment will vary depending on the vehicle class, ranging from intensive to less intensive. This also explains the different impressions people have of such systems.

If any modifications are made to the vehicle after delivery, such as changes to tire dimensions, suspension lowering, or maximum permissible weight, this will naturally affect the regulations. If these changes shift the handling characteristics beyond the system's tolerances, it can lead to incorrect adjustments.

The described malfunctions by other users are definitely not normal and cannot be explained by a "simplified" electronic system. The intervention thresholds can be adjusted from a very early point (certainly without driving pleasure) to a very late point (last resort). An intervention threshold set too early often masks cheap or poorly tuned suspensions. In a sporty system configuration, the system can also be put into standby mode. It only activates when braking is applied at the limit defined by the rule.

From my own experience, I can say that the early systems sometimes showed excessive eagerness in their interventions. Our 1998 A6 was almost impossible to stop on snow. In contrast, the Allroad Quattro that I'm driving now performs excellently. The ESP system in the A3 (8L) with sport suspension, in the A4 (8E), in the A6 (B5) from the facelift onwards, in the TT, and in the Lupo works very well. However, I have experienced poorly tuned systems in the Golf and the Bora. It was absolutely necessary for our T4, but unfortunately, it can't be retrofitted . It drives very safely, but if you push it too hard, the rear end starts sliding uncontrollably, and you have to use all your hands (and feet) to prevent it from spinning out.
Generally speaking, regarding the driving characteristics of some VAG models:

· T4 TDI (150KW) manual transmission, 225/60 R16 tires on 7(7.5)Jx16 alloy wheels, manufactured in 1999, EDS (engine management system), no ESP (electronic stability program):
Understeers significantly, with a strong tendency to roll around the longitudinal axis. Exhibits strong pitching movements around the transverse axis during braking and acceleration. Indirect steering to maintain stability. Steering feels slightly stiff during acceleration. Powerful braking system with a somewhat inconsistent pedal feel under extreme conditions. Improvements planned for the spring include new Bilstein shock absorbers, 17- or 18-inch wheels, and a lowering of up to 20mm.
· A3 1.8 Ambition with 205/55R16 tires on 6.5x16 inch alloy wheels, manufactured in 1997; Bilstein B6 shock absorbers with original sport springs, EDS (Electronic Differential Lock), no ESP (Electronic Stability Program).
Neutral to slightly understeering handling, direct steering, powerful braking system, very good ABS, no improvements needed.
· A4 1.9 TDI with 205/60R15 tires on 6.5(7)Jx15 alloy wheels, manufactured in 1998, with EDS (Electronic Differential Lock), but without ESP (Electronic Stability Program):
Understeer handling, the comfort suspension results in noticeable body roll around the longitudinal axis and pitching movements around the transverse axis, brake system prone to fading, good ABS. Safe driving.
· A6 2.8 Quattro TT5, tires size 215/55R16 on 7(7.5)Jx16 alloy wheels, manufactured in 1999, air suspension with active damping at the rear, ESP (Electronic Stability Program):
Understeer, comfortable but not "floaty," overly sensitive ESP, undersized braking system, safe handling (except for the brakes).
· *** Allroad quattro 2.5 TDI TT5, with 245/45R18 tires on 8.6Jx18 alloy wheels (215/60R16 on 7Jx16 alloy wheels), air suspension front and rear, active damping, 4 height levels, Servotronic, ESP, manufactured in 2002:
Sporty handling, comfortable, neutral to slightly understeering, very well-regulating ESP, powerful braking system, excellent ABS, no improvements needed.
· A4 1.8T Multitronic, 205/55R16 tires on 7Jx16 alloy wheels (steel), manufactured in May 2003, equipped with ESP (Electronic Stability Program).
Neutral to slightly understeering, stable braking system, safe handling, very good ABS, direct steering, sporty, no improvements needed.


Okay, I hope I haven't bored you, and that I was helpful to some of you with the explanation or my personal experience.

Best regards,

davidshoes wrote:

ESP, in addition to the above-mentioned. The system consists of the following components: · Longitudinal, transverse acceleration, and yaw rate sensor. · Steering angle sensor · E-Gas · Electronic throttle valve (or similar system) · Advanced software and faster computers. · Vehicle-specific setpoint storage. · Additional valves in the control block. · Connectivity with all drive components. The device compares the measured actual values with the target values multiple times per second (approximately 500 times). If there is a significant deviation, the control unit initiates appropriate measures. This includes: · Suppressing control commands (automatic). · Suppressing or amplifying gas commands. · Targeted braking of individual or multiple wheels. · Regulation of engine power. · Dynamic brake pressure regulation for each individual wheel

Hi,

First of all, thank you for the comprehensive and precise description .

As a purist and a potential skeptic of high technology, I naturally view the lists mentioned from the perspective of potential malfunctions and their consequences.

Specifically, the ability to intervene.
"Targeted braking of individual or multiple wheels."
It is, of course, a very powerful tool for determining the future course of the vehicle, including the part (rear, side, front, etc.) that will potentially collide with an obstacle.

If I now imagine that the ESP CPU develops digital migraines or depressions (as we all probably know from our PCs ), or that one of the sensors simply starts to malfunction, and then the ESP could start braking individual wheels at a high speed, then I get a very uneasy feeling just from the mere thought.

Therefore, I took the opportunity to cancel my ESP subscription.
If my Polo breaks down, at least I'll know it's my own fault, but I'll be driving with the relatively reassuring feeling that no CPU will ever actually take absolute control of my car.

(Please don't start any fundamental discussions here - I only wrote that as my opinion , which no one else has to adopt ).

Could you please describe the measures that were taken to keep the ESP under control, so that the horror scenario I described does not occur?

Despite my driving experience, I'm also a bit skeptical about this (like Ulf).

Best regards, WarLord.

Quote:

MSR - Motor Slip Control: prevents the drive axle from locking up during... sudden clutch disengagements

hm?! Isn't that more likely intended to prevent the drive wheels from slipping or locking up when the engine is suddenly decelerated and motor braking is initiated, especially when the vehicle is in a "trapped" or enclosed state?

Best regards,
Sure, here is the translation of the text from German to English:

"Dirk"

Regarding MSR: I've updated my contribution. I had forgotten to include it. Thank you.

For error correction: The driving condition is determined by the interaction of multiple sensors. If any of the sensors provide a signal that doesn't match the signals from the others, the system switches to error mode and ignores that value.
For example, three wheel sensors report "100 RPM," while one sensor reports only five. The longitudinal and lateral acceleration sensors are reporting no values, the steering angle is straight, and the yaw rate sensor is also showing no activity. In this case, the wheel speed sensor on the rear axle is likely defective, which will be ignored and logged as an error, along with an error message displayed on the instrument cluster.
Critical errors will lead to system shutdown (similar to ABS).