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Hard Cut Limiter?


XR655
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2 hours ago, XR655 said:

I’m trying to achieve something like this, 

is it also pulling throttle back to hold it at the set rpm limit? 

It should already do this from the factory. However consistently holding the engine here will destroy oil pumps due to the horrible harmonics that are caused by a limiter like this.

Have a read of this thread to see what you should look at changing.

 

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  • 1 year later...
5 minutes ago, misk said:

Can confirm...

Currently there is no ability to cut spark from the factory PCM. We have played with a few methods however we found a fuel dump/spark retard coupled with a injector cut out to be the safest and most effective way to limit engine speed.

Likely this video is using an aftermarket 2-step or it is just a very aggressive spark retard coupled with fuel dump (will make huge pops and bangs).

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2 hours ago, Roland@pcmtec said:

"it is just a very aggressive spark retard coupled with fuel dump (will make huge pops and bangs)."

Is there a guide for this? Could only get the car to bounce a few times then hold constant rpm with spark retard. 

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20 minutes ago, XR655 said:

Is there a guide for this? Could only get the car to bounce a few times then hold constant rpm with spark retard. 

Set up everything required for flat shifting then you can set your limiter where ever you want. Using the multi tune with launch control is MUCH more flexible though as you can simply set the main spark map to -30 etc. It is super easy to do if you follow the guide.

 

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  • 1 year later...

i just played with settings on a bf mk2 zf config, got it to spark only rev limit. but as it has a straight thro exhaust, its sounds really bad.

 

non esential changes =

AUF1415 engine speed limiting. change to 3/4 so it does not use ETC. i left it at 2 accidently and had to disable ETC as it kept using throttle limiting, however throttle limiting may be good to leave on as it will potentially save you.

AUF0265 - Engine speed limiting - i set to 999 as its only NA wont get that high. But thinking back on it now, you could leave this and just set AUF0265.

 

esential changes = 

AUF0265 - engine speed limiting - i had this set to 6k. but i would say set it to just over whatever you set fuel cut to.

AUF0262 - Engine speed limiting - 0 - so max spark retard can be pulled.

Auf0261 - Engine speed limiting - 1 - so it does not use this feature.

 

Now this is where you have to play, the following is just what i tried today and it worked. but you might get better experimenting. (also i experimented at 2500ish rpm to make sure changes were working)

auF1479 - enleanment - i had this at 0.75.

AUF0144 Rpm Limit - set this to where you want your spark cut to occur. 

AUF11698 - amount of rpm it can exceed limit - 0

AUF12796 - time it can exceed rpm limit - 0

AUF0133 - RPM limit fuel cut - this is your actual fuel cutoff / end of the line wont go any higher.

 

i set rpm limit to 5250 and it sat there around 5350 on spark cut. so if you have an auto making rpm limit to low might break your gearchanges. you will need to experiment.

 

also you will prob break your engine doing this, i take no responsibility for how you take this information.

 

 

 

 

 

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