launch control, knock tuning, and ecu disassembly

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supasixfo
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launch control, knock tuning, and ecu disassembly

Post by supasixfo » Fri Mar 29, 2013 11:00 am

so, over the past few weeks, i've made some headway on realizations playing with launch control. context: i had a -10 block around 4500rpm that was good for making 10-14psi on the line. OM NOM NOM NOM NOMZZZ...

problem was ecu was registering knock like crazy. after some effort and logs ,and getting 22-30+ counts of knock on launch, i tried something new. i put in a stationary limiter of 4000, and -5 block around there, interlopololaping vertically from 3500. now, only building 5-7psi, but engine no longer freaking out.

not sure how it works on the subie ecus, but i have a few tables to play with in the evo. either increase the load where knock control starts through 4000-4500rpm. or increase the knock multiplier tables by 20% in the phantom knock range. by doing this, i'm pretty much saying ignore knock in the 4000-4500 range. from what i've read, knock is more of a concern near redline, but it seems disingenuous to filter knock out when the car is rolling, when what i really want to do is have a knock filter apply only at launch... so what i really want to do is say if (speed<xmph or clutch engaged), use this temporary knock filter map...

i saw that a friend called idapro was sometimes referenced for this kind of work...hmm... that kind of sounds familiar...wondering if anyone on here has played around with ida for modifying ecu roms... or can point me in the right direction of what is needed to disassemble ecu roms, or how to add new functions, etc. or that this is overkill for what i'm trying to do and that i'm crazy :P
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Sabre
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Re: launch control, knock tuning, and ecu disassembly

Post by Sabre » Sat Mar 30, 2013 8:10 pm

Honestly, you want knock control to be good anywhere above 15PSI. At peak torque it's important because you're making a hell of a lot of pressure, at redline it's important because things happen so fast it's harder for the ECU to compensate.

Thought: Boost sensing relay that will physically turn off/on the knock sensor.

romraider.com will have some info, but if you really want to get in to the nittygritty, check out NefMoto.

A couple of us have IDAPro experience, so feel free to ask :)
Sabre (Julian)
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zaxrex
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Re: launch control, knock tuning, and ecu disassembly

Post by zaxrex » Mon Apr 01, 2013 6:49 pm

Ohh ohh, an arduino band pass filter based on RPM that is only active in launch mode...
Brilliant!
Patience is the ability to idle your motor when you feel like stripping your gears

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ElZorro
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Re: launch control, knock tuning, and ecu disassembly

Post by ElZorro » Mon Apr 01, 2013 7:34 pm

zaxrex wrote:Ohh ohh, an arduino band pass filter based on RPM that is only active in launch mode...
Brilliant!
Easy, I wouldn't even use a 'duino, 8-pin PIC with an internal oscillator.
Jason "El Zorro" Fox
'17 Subaru Forester 2.0XT
DCAWD - old coots in fast scoots.

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