Rpm limit explain

[Hussain-vtec]

 

Hello everyone

I will talk about rpm limit and I will keep it as simple as it gets,

1-Rpm limit mode either ignition or fuel cut this is the main aim you want the limit mode.

2-Turn advanced mode on.

3-hard limit you can turn it on if you want bang fire and action, or less action turn it of and keep hard limit activation on 50rpm only, if on hard limit 200rpm or even 300rpm for large bang and fire action.

4-(end cut) I put a green line in image where my end limit shows 95% off cut.

5-(start cut tp100) I put a pink line in image when it staring a cut where I kept it in 40%

So between pink and green is how fast your cut or how slow it is example (tp low 100) if I rais it to 80% A very fast cut I will end up with if I keep lower number like 30% It will bee slower cut. 

6-If you want to do this just put your
(start cut tp low) above
(start cut tp 100) I put mine to(100%) in image
Tp low to( 0.0%) tp to ignore the lower cut tp then re adjust it where you want the lower to be.

7-exis decay rate the period of of cut after full throttle is depresd I mark it in orange from 50 to 80 is the good spot if hard limit on and above 200rpm cut range its different from engine to another engines. 

for examplee

Exis decay rate is at (5%) and let's say your engine rives 8000 rpm it will drop between shifts to 3000rpm or lower because the period is very long for the cut, but if exis decay rate (80%) rpm between shifting will drop to 7200rpm for example.

8- ignition limit trim is the amount of timing pulling during the limit cut. 

 

Here is the image below to explain more

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Data log

 

[Hussain-vtec]

If you try it please share your results along with engine and set up let see how many of you have benif of this thread explaining l. 

[Adamw]

Im sorry, but you have most of this wrong, there is a good explanation of how it works in the help file, you should study that and try to understand how it works before offering advice. 

 

18 hours ago, Hussain-vtec said:

3-hard limit you can turn it on if you want bang fire and action, or less action turn it of and keep hard limit activation on 50rpm only, if on hard limit 200rpm or even 300rpm for large bang and fire action.

No, the hard limit is designed to be used as an extra safety step, it should only ever be initiated if you have the normal progressive limit set wrong and the RPM overshoots the set limit.  Under normal limiting conditions you should not even get close to this limit.

 

18 hours ago, Hussain-vtec said:

5-(start cut tp100) I put a pink line in image when it staring a cut where I kept it in 40%

Start cut is the amount of cut that first gets applied when the RPM reaches the control range.  The general idea is to use the smallest number possible.  You want just enough to prevent RPM over shoot during very high acceleration events (free rev) such as when the wheels come off the ground in a rally car or a jetski leaving the water.  Typically 20 or 30% is normal for a road car engine, whereas 50 or 60% may be needed on a low inertia motorcross bike or jetski engine.

 

18 hours ago, Hussain-vtec said:

6-If you want to do this just put your
(start cut tp low) above
(start cut tp 100) I put mine to(100%) in image
Tp low to( 0.0%) tp to ignore the lower cut tp then re adjust it where you want the lower to be.

The reason for 2 different start cuts is most engines will need more limiting if the throttle is wide open than it does if it is at say only 30% open.  If you set start cut to 100% then you have effectively turned off the progressive limiting altogether and only have a hard cut.  

 

18 hours ago, Hussain-vtec said:

7-exis decay rate the period of of cut after full throttle is depresd I mark it in orange from 50 to 80 is the good spot if hard limit on and above 200rpm cut range its different from engine to another engines. 

for examplee

Kind of right, but poorly explained.  Exit decay rate is how quickly the limiter is reduced to zero after the RPM has fallen below the limit control range.  It effects how quickly the torque is re-introduced.  It is typically used to prevent the sudden increase in torque causing a loss of traction - especially important for launch control limiting and on circuit cars where you may hit the limiter during exit from corners.