Pages: 1 2 3 [4]
Author Topic: Hard Cut Rev limiter on Med9.1  (Read 9492 times)
Garfimp
Full Member
***

Karma: +0/-1
Offline Offline

Posts: 50


« 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
Logged
adam-
Hero Member
*****

Karma: +83/-23
Offline Offline

Posts: 1761


« 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?
Logged
Garfimp
Full Member
***

Karma: +0/-1
Offline Offline

Posts: 50


« 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-
Hero Member
*****

Karma: +83/-23
Offline Offline

Posts: 1761


« 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. 
Logged
Garfimp
Full Member
***

Karma: +0/-1
Offline Offline

Posts: 50


« 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
Full Member
***

Karma: +0/-1
Offline Offline

Posts: 50


« 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
Logged
gman86
Hero Member
*****

Karma: +31/-55
Offline Offline

Posts: 639


« 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.
Logged
Pages: 1 2 3 [4]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.018 seconds with 18 queries. (Pretty URLs adds 0s, 0q)