RPM Limiter: Explained & How to Adjust

Hi!

Short question: Is the speed actually limited by the chip, or is that a separate feature?


Cu: Marko

Marko wrote:

Is the chip's clock speed actually limited

Hi.

In short: mostly yes. Although the injection cross-section of the nozzles, in combination with the pump's delivery time, etc., probably still plays a significant role...

Okay, here's the translation:

'Hmm... I think that before these components start to limit performance, either the engine is damaged or the pump has failed. The system has a tendency towards self-destruction, after all...'
You can really notice how small the required fuel injection amounts are when you increase the engine speed to 3000 RPM and then turn on the air conditioning compressor (or rear window heater). The fuel injection amount remains the same, but pay attention to the engine speed...


The old mechanical regulators didn't have those harsh cut-off points for no reason.

In an EDC system, this is (of course) done electronically, and the pump no longer has any components related to that. That's why it still has the electric shut-off valve, which is normally not used. But what if the control valve jams or the ball valve breaks? Oh dear...

CU Gremlin.

Hi!

Could this not also be manipulated?
I mean, that would allow for a higher top speed if the speed limit didn't come into play...
Of course, the question arises whether ESP and Lader have already reached the limits of their performance in the speed range?

...but I think that...
Otherwise, it's just a self-destruct mechanism.

cu: Marko

Hi Marko,

It might seem possible, but physics doesn't cooperate. A diesel engine simply burns too slowly; the pistons would run ahead of the combustion process and wouldn't be pushed down by it anymore. Therefore, it achieves absolutely nothing except the risk of destroying the head gaskets.

Best regards,

Jan.

...who finally has a few minutes to write a post.

Hi!

I'm only concerned about a few RPM, that he can reach his claimed 230 "according to the speedometer."
Currently 227 km/h.


cu: Marko

Marko wrote:

Hi! I'm only concerned about a few RPM, that he can reach his claimed 230 "according to the speedometer." Currently 227 km/h. cu: Marko

"However, this isn't due to the rev limiter, but rather the engine power. At 230 [units - likely referring to a measurement on a gauge], the AAT should be running at around 4600 RPM, which is significantly below the maximum RPM of 4700-4800 during the emissions test."
My car has never exceeded 230 km/h (approximately 143 mph), even on the steepest downhill sections of the A7 highway between Kassel and Bad Hersfeld.