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Author Topic: Ignition cut rev limiter me7  (Read 121770 times)
adam-
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« Reply #60 on: July 24, 2017, 03:58:01 AM »

You want to cut spark before you cut fuel.

Lift your NMAX.

Read the maps you're editing and don't just throw numbers in because someone else did the same thing.  Try and understand what you're attempting to do.

You've lifted error detection to 7500 for no reason.
« Last Edit: July 24, 2017, 04:00:31 AM by adam- » Logged
cpp
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« Reply #61 on: July 25, 2017, 09:17:26 AM »

I raised nmaxf 400 rpm to more than nmax. It was the difference between nmax 6800 and nmaxf 7100. I did it because in the original bin it was at 7100 which would be my new nmax. So I added another 400 rpm to nmaxf.
I have 7100 rpm in the soft limiter. I wanted to have that same 7100 rpm with hard limiter.
I did a nmax test at 7300 rpm. More so cut at 5800 rpm.

Thank you for the tip
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nyet
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« Reply #62 on: August 08, 2017, 08:35:13 PM »


Why do I need to change a map which contains the battery voltage? Isn't this unnecessary for a rev limiter?  Huh


Read the FR.
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ME7.1 tuning guide (READ FIRST)
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nyet
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« Reply #63 on: August 09, 2017, 10:49:48 AM »

NMAX is the soft limiter (fuel cut).
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ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
adam-
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« Reply #64 on: August 10, 2017, 04:17:03 AM »

The concept is entirely based around that.  Cut spark before fuel. 
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nyet
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« Reply #65 on: August 10, 2017, 12:15:23 PM »

That means, that KFTSRL and KFSZT are involved in ignition cut?

No, it depends on the ECU.

Not sure how you got this far without reading this:

http://nefariousmotorsports.com/forum/index.php?topic=11664.msg97574#msg97574

and this:

http://nefariousmotorsports.com/forum/index.php?topic=445.45
« Last Edit: August 10, 2017, 12:18:39 PM by nyet » Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
RBPE
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« Reply #66 on: August 11, 2017, 07:27:30 AM »

ZUESZ in the Function Sheet ME7.3 as an idea;

1. Introduction:
Sufficient ignition energy must be made available in order that the sparking plug can ignite the mixture. This is realized by
closing the primary circuit of the ignition coil in good time so that the coil can charge up sufficiently.
On the other hand, the closing time shall not be too long as this can otherwise lead to the ignition output stage overheating
(particularly critical for internal output stages).
After closing, the primary current i increases exponentially with time. The period of time from the primary circuit closing to
opening again (sparking) is referred to as the dwell time.
The energy stored in the magnetic field is given by :
W = 1/2 * L * iˆ2 (L: inductance, i: current flowing at the point in time that the primary circuit opens)
2. Calculation of the dwell time:
The dwell time szout is calculated from a map that depends on the speed and battery voltage, corrected by a factor depending on the
engine temperature (from characteristic FSZTM).
3. Dependency of the dwell time:
ub: The primary current i flows through the primary winding of the ignition coil. This is determined by the battery voltage ub
and the resistance of the coil.
nmot: Above an engine-speed threshold, the dwell time is computed as a dwell angle and output at an angle level.
Thus a speed-dependent lead by the dynamics is required here so that a sufficiently long dwell time is still given even
in the event of maximum speed dynamics. The dynamics lead is taken into account in the map KFSZT.
The dynamics lead required is lower at higher engine speeds.
No dynamics lead is necessary in the lower engine-speed range (dwell time output).
It can also be meaningful to have a shorter dwell time at higher speeds for thermal reasons.
tmot: The ignition coil temperature changes with the engine temperature.
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RBPE
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« Reply #67 on: August 11, 2017, 07:32:25 AM »

I like the visual side too! Good for timing/fuel understanding etc;

https://www.youtube.com/watch?v=jdW1t8r8qYc
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4ringpieces
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« Reply #68 on: August 11, 2017, 07:59:42 AM »

In kfszt.

Make rpm axis 7000, 7050(change depending on your limiters etc)

Put 0 dwell in 7050rpm row

Works in older me
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adam-
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« Reply #69 on: August 12, 2017, 10:44:47 AM »

Mhmmmmm.
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RBPE
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« Reply #70 on: September 05, 2017, 12:54:58 PM »

Thanks RBPE! This makes sense. Smiley

=> But why is the closing time not 0 by default? I thought a good spark is good for the engine?
=> Why would a long closing time overheat the ignition coil? Longer time => Coil doesn't need to hold that much power => colder coil and a lighter spark??
=> Editing the "closing time"-maps lead to a faster ignition cut, am I right? If not editing them, the ignition cut would be a "long/slow bounce", am I right?
=> What map/value defines the ignition cut?

Thanks for the recommendation, but I know how it works.
I repaired oldtimer motorcycles (mostly 2 strokes) for a few years. Smiley

It's all just relative - if Bosch have a known quantity, for example the bit at the beginning here that states 2ms, then you have a set known quantity, you can then work from that with various offsets and variables based on this known figure and elaborate on the variables to your hearts content and that's all Bosch do, continue to break it down and as such evolve the systems as a further breakdown of known/set figures. It's just maths and logic, that's all an ecu can do, I've highlighted some bits in the download file to give you an idea in red; the "offset", "function off", "gradient" type of bits;

http://nefariousmotorsports.com/forum/index.php?topic=10419.0title=
« Last Edit: September 05, 2017, 12:59:14 PM by RBPE » Logged
4ringpieces
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« Reply #71 on: September 05, 2017, 02:04:35 PM »

No charge time No spark. Works amazing on old z20lets Roll Eyes
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HelperD
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« Reply #72 on: September 06, 2017, 07:06:51 AM »

I have had good luck with just using KFTSRL.  Never had to touch KFSZT but I suppose I will give it a try now after reading up on it.

D
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KasperH
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« Reply #73 on: September 16, 2017, 05:11:07 AM »

This is my 1.8T now, still with original DP and Cat. Grin

https://www.youtube.com/watch?v=cND_j_2ihNQ

Changes:
KFSZT
=> 0'ed the last row (6000 rpm, I think it's enought)
=> Set next-to-last row to 5960

KFTSRL
=> 0'ed the last row (6000 rpm
=> Set next-to-last row to 5960

NMAX + NMAXOG
=> 6200 rpm

FTOMN
=> 0



Exactly what I did, and it's fun as hell  Grin
But with cat in place it'll take some serious damage.
Decat and you'll be spitting flames all day and won't have to worry
about the cat melting and plugging up the exhaust Smiley
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RBPE
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« Reply #74 on: September 18, 2017, 01:25:04 PM »

I've been digging out and rebuilding some files lately and uploaded some ignition patent info if it helps on this, various years I think; makes it easier for me to find!  Wink

https://app.box.com/s/7uqaix0y9c9z59g7722dr7z54q8f5k4u

https://app.box.com/s/4wt0gxgvyu3bklxa1g0fxopummwnogc3

https://app.box.com/s/08g950lz8gg9o1w01hlt7rj01wo0zhj9

https://app.box.com/s/kjw5zi30k4bbbm2yawpcdigl9p8rwbtv

https://app.box.com/s/lgvp59z16vrr90l2qbbfodm91mep6h9s

https://app.box.com/s/7j1jcahdo4yvxoz5e5n52begxhejz16z

https://app.box.com/s/hxj7kqpfiwqp7q8n7delntx7nlcxn97n

https://app.box.com/s/xgs2vl4bun9ldvl3gscfsijgig4gpjgk

https://app.box.com/s/lr5yx98l0j8az3xb1d94mgik2t7s2p6t

https://app.box.com/s/mgalngtwdggjwj9ciy08yachlvtz4zvw
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