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Author Topic: Hard Cut Rev limiter on Med9.1  (Read 43979 times)
Garfimp
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« Reply #45 on: April 12, 2019, 01:37:00 AM »

Noise, flames, impress your mates.

So true.. Grin

Can anyone answer my question above ? Smiley

Thanks
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adam-
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« Reply #46 on: April 12, 2019, 07:00:35 AM »

Just to confirm my understanding, the last column of KFTSRL has to be set to exactly the rev limiter ?
Or let’s say can be < or = to nmax ? But not > right ?

For instance, on my car with stock software, the rev limiter is set to 6800 rpm in every “nmax related” singles. So if I want to add hard cut on my stock rev limiter, in KFTSRL I need to set the last column to exactly 6800 rpm and column before that to something like 6760 ? Or should I add a few 30-40 rpm more and set last column to 6840rpm and column before to something like 6800rpm ?

Think about what you're trying to accomplish.  What will the rev limiter do if you set it to 5000?  Do you think you will reach a 0 dwell time if you set the dwell axis at 6800 with engine speed limit of 5000?  Will the engine speed ever get to 6800 if you set a limiter at 5000?
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Garfimp
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« Reply #47 on: April 15, 2019, 05:38:21 AM »

Think about what you're trying to accomplish.  What will the rev limiter do if you set it to 5000?  Do you think you will reach a 0 dwell time if you set the dwell axis at 6800 with engine speed limit of 5000?  Will the engine speed ever get to 6800 if you set a limiter at 5000?

Hey adam,

Thanks for the insight, I agree, of course if I set a hard cut rev at 6800 and have set my rev limiter in other singles at 5000 there is no use, I won't reach it. But the question was more the other way around and for small gap.

But maybe first as you point out I should be sure I understood what physically means a hard rev cut... Smiley
So what I think is intended to do in a hard cut rev limiter is to cut the fuel at a certain rpm, so then rpm will a little drop beacause engine is cut, but if you keep pushing on throttle then it will go back up to the rpm where fuel is cut, and then go a little back dropping and then back up etc etc so it will make "rotototo"  Grin

But my question is more for let's say a very short "gap" between the rev limiter defined in Nmax singles and the one we should put here in last column of KFTSRL, 50 rpm above or below for instance...

So if I have set my rev limiter to 6800 in the other singles of the tune (stock value), in KFTSRL if I put 6840rpm in last column and 6800 in column before maybe the car can still reach this 6840 rpm even if it is slightly above the rev limiter of 6800 ? Or it really will never reach any value above the rev limiter set to 6800 in stock software ? meaning it is really reactive then ?

My instinct would be that the best way is to set last column of KFTSRL to exactly the rev limiter of 6800 and column before to a value really close and below like 6760 rpm in my case to be sure to reach that and have the "cut" happen
« Last Edit: April 15, 2019, 05:50:55 AM by Garfimp » Logged
adam-
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« Reply #48 on: April 15, 2019, 06:09:06 AM »

If you have a limiter set at an RPM < a dwell time of 0 RPM, you will never cut ignition.

Set dwell to 0 where you want your RPM actually cut, and set your fuel cut limiter 100/150/200 RPM above.  Fuck this 50rpm shit. 
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Garfimp
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« Reply #49 on: April 15, 2019, 06:44:03 AM »

If you have a limiter set at an RPM < a dwell time of 0 RPM, you will never cut ignition.

Set dwell to 0 where you want your RPM actually cut, and set your fuel cut limiter 100/150/200 RPM above.  Fuck this 50rpm shit.  

Ok thanks adam, so just to be sure we are aligned, what I want is to cut spark before I cut fuel right ?
So in KFTSRL I can cut spark at 7100 for instance (2 last rows would be 7060 and 7100 for instance) and then I can set fuel cut in Nmax singles at 7200 rpm?

Or another example, if i take this image which was posted before :


I should have Nmax (fuel cut) set to a value >7080rpm ? let's say something around 7200 rpm in the singles Nmax?

Because you said in an old message on this thread :
That's basically where I was going with that.  It's not a big change anyway.

Dwell time to zero at nmax, shift column before to -50rpm nmax.

So I thought fuel cut set by nmax should be = rpm spark cut set in KFTSRL ?
« Last Edit: April 15, 2019, 07:20:33 AM by Garfimp » Logged
Garfimp
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« Reply #50 on: May 09, 2019, 06:24:21 AM »

Ok thanks adam, so just to be sure we are aligned, what I want is to cut spark before I cut fuel right ?
So in KFTSRL I can cut spark at 7100 for instance (2 last rows would be 7060 and 7100 for instance) and then I can set fuel cut in Nmax singles at 7200 rpm?

Or another example, if i take this image which was posted before :


I should have Nmax (fuel cut) set to a value >7080rpm ? let's say something around 7200 rpm in the singles Nmax?

Because you said in an old message on this thread :
So I thought fuel cut set by nmax should be = rpm spark cut set in KFTSRL ?

Up guys ?  Smiley
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gman86
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« Reply #51 on: May 11, 2019, 04:57:48 AM »

NMAX isn't straight fuel cut. There's a torque reduction process that is employed just prior to the hard limit which softens the effect of hard cut. That needs to be numbed to have proper fuel cut, otherwise just set all the NMAX limiters to a value above your greatest dwell RPM column. Be advised, spark cut is brutal on the engine and transmission.
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Roader55
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« Reply #52 on: April 07, 2020, 02:39:23 PM »

That's basically where I was going with that.  It's not a big change anyway.

Dwell time to zero at nmax, shift column before to -50rpm nmax.
what is the map name?
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bamofo
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« Reply #53 on: April 09, 2020, 06:05:40 AM »

what is the map name?

Its two tables

Offenzeit fur funkenbandzundung

&

Schliebzeitkennfeld

Its in post 6...

FUBAOF set to 0
KFTSRL set like image if you want Revlimit @7200rpm
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Albertoak
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Well done is better than well said....


« Reply #54 on: April 09, 2020, 01:44:38 PM »

Its two tables

Offenzeit fur funkenbandzundung

&

Schliebzeitkennfeld

Its in post 6...

FUBAOF set to 0
KFTSRL set like image if you want Revlimit @7200rpm

I still do not understand why put FUBAOF at 0 .... It is not necessary ...

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Albertoak
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Well done is better than well said....


« Reply #55 on: April 14, 2020, 05:06:16 AM »

FR:

"Basically, spark band ignition shows the desired effect when the secondary ignition is within
of the smallest possible angular range. The optimal distance would be about 1 degree.
For this purpose, the open time FUBAOF must be chosen correspondingly small for the common coil ignition systems. This
can, however, lead to deterioration as some engines require the full spark duration.
Usual values ​​for a spark burning duration in which no significant HC increase is noticed are included
about 0.5ms. However, this value cannot be regarded as binding.
The open time is in various projects in which spark band ignition is already used
an order of magnitude in which the spark has long since swung out (2ms). The afterglow is only after
completely reloaded the coil. In this case the ignition would normally be caused by the first
Sparks are already too advanced to be supported by a second spark.
Nevertheless, an improvement of the cold start at extremely low temperatures is noticed in these projects
been. However, there is only an improvement if the first spark has not led to combustion
and the mixture ratios on the candle at the time of the first sparking are such that this one
Inflammation triggers."

after reading FUBAOF in FR. I keep thinking that it is not a good idea ... if someone has a coherent explanation of why set to 0, let them say it. Because in this post everyone is setting it to 0. It is not necessary for the hardcut and it is not good.
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nyet
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« Reply #56 on: April 16, 2020, 09:49:44 AM »

Guys stop giving me unnecessary work.

Be constructive, work together, or don't post.

I know I'm not the best role model here but you can all be better than me.
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Albertoak
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Well done is better than well said....


« Reply #57 on: April 16, 2020, 12:17:44 PM »

Guys stop giving me unnecessary work.

Be constructive, work together, or don't post.

I know I'm not the best role model here but you can all be better than me.

thanks for intervening.  and I think like you.  We are here to contribute and learn together.  not to disrespect us .... greetings
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cedre
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« Reply #58 on: April 25, 2020, 01:43:55 AM »

Good morning all
very interesting topic
I'm looking to confirm the maps
KFTSRL: 1D97BC
FUBAOF: 1C83FC
could you confirm the addresses
best regards
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gman86
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« Reply #59 on: April 25, 2020, 06:14:51 AM »

Good morning all
very interesting topic
I'm looking to confirm the maps
KFTSRL: 1D97BC
FUBAOF: 1C83FC
could you confirm the addresses
best regards

Of course you are. And with only 1 post, I bet you'll be back and contributing to the forum within minutes.
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