Notices
Series I Engine Tuning Forum EMS (Flash Tuning, Interceptor, Piggy Back, Stand Alone)

Factory PCM knock control discussion

Thread Tools
 
Rate Thread
 
Old Dec 19, 2011 | 02:05 PM
  #26  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
So, it must be there for a reason, should I leave it or have it pull less timing?
Reply
Old Dec 19, 2011 | 03:15 PM
  #27  
oltmann's Avatar
Registered
 
Joined: Sep 2010
Posts: 531
Likes: 1
For the positive RPM delta values, I think it is there to reduce detonation during transition from cruise to acceleration.

At light loads - as are used in normal everyday cruise conditions - an ignition advance of 40 degrees or more will improve responsiveness and economy. This advance can be used successfully on many engines - even those with an 11:1 compression ratio, if they are being run on high octane fuel. One factor limiting the cruise ignition advance that can be used is the maximum ignition timing attack rate provided by the ECU - that is, how fast the timing can change. If very advanced timing is being used with light loads and the attack rate is not high, there may be slight detonation when the engine load suddenly increases. link
OTOH, I think the Yamamoto books says that this type of detonation isn't problematic for rotaries.

For negative RPM deltas, more advance increases engine braking.

I have run with these tables zeroed, and I didn't have major problems. Still, caveat emptor.

Last edited by oltmann; Dec 19, 2011 at 03:20 PM. Reason: also
Reply
Old Dec 20, 2011 | 01:21 AM
  #28  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
maybe you should explain why in your mind that it even needs to be messed with?
Reply
Old Dec 20, 2011 | 01:39 AM
  #29  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Originally Posted by TeamRX8
maybe you should explain why in your mind that it even needs to be messed with?
to whom are you referring to?
Reply
Old Dec 20, 2011 | 08:29 AM
  #30  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
You, why would I be asking anyone else?
Reply
Old Dec 20, 2011 | 12:26 PM
  #31  
oltmann's Avatar
Registered
 
Joined: Sep 2010
Posts: 531
Likes: 1
Originally Posted by TeamRX8
You, why would I be asking anyone else?
Because your question makes no sense -- Fazda never asserted that it does need to be messed with. He merely asked a question.

So, it must be there for a reason, should I leave it or have it pull less timing?
It seems that in turbo applications it might actually be useful to retard the timing somewhat during deceleration, which seems to be the opposite of how things are set up in the OE calibration.

This feature is useful for engine braking under ecology limitations.

In order to avoid rich spices under throttle off it is useful to provide some additional air that is counterproductive for engine braking. Retarded ignition fills the bill.

Secondary, ignition retarded provides inti-lag feature for turbo application if you wish to accelerate sharply after breaking or gear switching. link
Reply
Old Dec 20, 2011 | 12:27 PM
  #32  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Well it all started looking at 3gear wot logs, right around 5950rpm the car decides its not going any higher, standing on the throttle. Afrs look good, but timming is 5. So I am thinking that having this timming to small that it stalls the cycle, and it cant recover. To early a spark and you loss all power. All my other logs I have seen like to have 9 - 10 on the leading, through that boosted range with out timing pulled. So thats what I am shooting for. I have already adjusted my timing for boost, do I really need another? Maybe this is a rear occurance.
Reply
Old Dec 20, 2011 | 02:01 PM
  #33  
oltmann's Avatar
Registered
 
Joined: Sep 2010
Posts: 531
Likes: 1
This is what those tables ought to look like:


So, if you are seeing timing that is 3-8 degrees retarded on the leading and 8 degrees retarded trailing, I think there is a good chance these tables are the cause.

Whether or not it should be "fixed" is really a judgement call.
Attached Thumbnails Factory PCM knock control discussion-delta.png  
Reply
Old Dec 20, 2011 | 04:04 PM
  #34  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Ah thanks, On the previous page I posted my rpm and timing portion of the log. have you had positive result in adjusting this table for boost?
Reply
Old Dec 20, 2011 | 04:41 PM
  #35  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Originally Posted by TeamRX8
Ok, I will sit back and watch you run him in useless circles then
Please, if you have something to add, please do, if you dont want to share it openly I have an empty pm box
Reply
Old Dec 20, 2011 | 10:13 PM
  #36  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
You don't adjust anything for boost in the RX8 AP. You adjust for load. The difference is subtle, but you need to understand it.

If the engine is stalling at 6k then the problem is elsewhere. The timing would have to be mega-fubar to be the cause of this.
Reply
Old Dec 21, 2011 | 02:25 PM
  #37  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Ok, ill keep looking.
as a side note wont the power suffer with that kind of timming pull to 5 degrees?
Reply
Old Dec 21, 2011 | 10:01 PM
  #38  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Originally Posted by TeamRX8
in reference to what? You haven't provided much info. We would need to know the parameters that were occurring then, such as a log, etc.
log.....
Attached Files
File Type: txt
Fazda4_0_6_gg.txt (13.1 KB, 237 views)
Reply
Old Dec 22, 2011 | 07:32 AM
  #39  
dannobre's Avatar
Modulated Moderator
iTrader: (3)
 
Joined: Feb 2004
Posts: 13,720
Likes: 345
From: Smallville
Is that log when it's doing it? Would expect higher TP if you were "standing on it" ?
Reply
Old Dec 22, 2011 | 07:33 AM
  #40  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
I'm starting to think the problem is obvious, lol
Reply
Old Dec 22, 2011 | 07:37 AM
  #41  
dannobre's Avatar
Modulated Moderator
iTrader: (3)
 
Joined: Feb 2004
Posts: 13,720
Likes: 345
From: Smallville
The brain attached to the foot that runs the computer taking the logs?
Reply
Old Dec 22, 2011 | 08:16 AM
  #42  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
I was only kidding, but nobody can be of any help without the proper information
Reply
Old Dec 22, 2011 | 12:55 PM
  #43  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
Open excel, click file, open. select all files open text file. Text import wizard opens. Click next. Under delimiters checkbox comma, click next, then finish.

Rx8club does not let .csv or .exel files to be attached
Reply
Old Dec 28, 2011 | 01:51 AM
  #44  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
bump
Reply
Old Dec 28, 2011 | 08:51 PM
  #45  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
thinking out type

I am hoping its obvious,
the problem is me
you don't have enough info to help me

dannobre looked at my logs and noticed

Throttle Position = 67 (did a search this is the normal max)
Accel. Pedal Pos. =100

Last edited by FazdaRX_8; Dec 29, 2011 at 12:26 PM.
Reply
Old Dec 30, 2011 | 02:58 PM
  #46  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
I am beginning to think I got it backwards, perhaps the hesitation is causing the timing pull.....
Reply
Old Dec 31, 2011 | 03:54 PM
  #47  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
2nd gear


3rd gear

Last edited by FazdaRX_8; Jan 1, 2012 at 01:02 PM.
Reply
Old Dec 31, 2011 | 08:53 PM
  #48  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
much better, thank you

now can you provide us with a detailed description on what is occurring and when relative to the log?
Reply
Old Jan 1, 2012 | 12:50 AM
  #49  
FazdaRX_8's Avatar
Registered
iTrader: (1)
 
Joined: Jun 2009
Posts: 2,019
Likes: 5
This is a third gear pull, car accelerates fine, then around 5800 the cars tone changes and it stops accelerating, no jerks, no jolts. Just stops accellerating
Reply
Old Jan 1, 2012 | 01:46 AM
  #50  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,936
Likes: 2,141
Please send me your email address
Reply


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -5. The time now is 06:48 AM.