Major New Product Announcements: Pre-release info
01-21-2008, 05:54 AM
#77
rev it up
Well done Hymee
I look forward to more information on your system. I am at the crossroad as well with my car so, this kit may be enough to keep me interested.
I hope you give Brisbanites some preference
Good luck
skc
I look forward to more information on your system. I am at the crossroad as well with my car so, this kit may be enough to keep me interested.
I hope you give Brisbanites some preference
Good luck
skc
01-21-2008, 02:42 PM
#79
Shootin' from the hip
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Congratulations Hymee. Best wishes for a successful launch in March. 
Now, get a Sydney tuning shop on board!!!
Those of us who are mechanical
will need support with this if my inability to follow most of this thread is anything to go by 
.
Now, get a Sydney tuning shop on board!!!
Those of us who are mechanical
will need support with this if my inability to follow most of this thread is anything to go by .
01-21-2008, 06:27 PM
#80
Go Texas Longhorns!
Congrats Hymee, your S/C kit was one of the nicest pieces of after-market equipment I have ever seen and I have no doubt that this product will be just as good.
Are you going to create some base line flashes for N/A cars and say the Greddy Turbo, it would be great to have a starting point that is somewhat conservative and could be dialed in at an individual level.
Awesome work man!
Are you going to create some base line flashes for N/A cars and say the Greddy Turbo, it would be great to have a starting point that is somewhat conservative and could be dialed in at an individual level.
Awesome work man!
01-22-2008, 12:03 PM
#82
Administrator
I would expect the PCM has a defined Lamba reading at each load/rpm point...and in closed loop will try and adjust to that...hence the LT and ST fuel trims.
In open loop...there is no adjustment...so the trims are not changed. You get what your tables say for that Mass air flow
What I'm not sure about...is whether or not the trims are carried forward into the open loop areas or not ....
In open loop...there is no adjustment...so the trims are not changed. You get what your tables say for that Mass air flow
What I'm not sure about...is whether or not the trims are carried forward into the open loop areas or not ....
01-22-2008, 12:16 PM
#83
Momentum Keeps Me Going
Yes and for example, if you use the RB flash, RB's web site (if you read carefully) instructs you to pull the 'room' fuse just before you start a track session to erase any learned trims so they won't affect you track maps they have set into your ECU. Then the only trims the ECU can start to 'learn' from are those produced from your on-track driving, and likely that is much more tuned towards 'very agressive' and a majority of 'open loop' driving lol. Bottom line, I do the 'room' fuse pull each session.
01-22-2008, 12:23 PM
#84
Administrator
ok woah guys . where did we all lose our memory. od you're running a flash in your car now. is the pcm trying to impose stock values?
NO! Because the values have been changed. period end of story the pcm has been given a new set of instructions. where it used to do A it now does 3
Flash tuning for FI is done all over the auto industry. will it work? YEAH of course see above.
RB has done a flash tune for FI- remember the white SC'd car? Damon did that tune while at RB before he moved to Mazda.
Trim- Short term fuel trim is used to adjust the long term fuel trim. LTFT adjusts the actual fuel delivery. Lets use some real easy numbers. During CLOSED LOOP the PCM gets info on the amount of air the engine is ingesting. It looks at a table and says i need to inject 5 parts of fuel so i need to fire the injectors for that much fuel.
Then the wide band mesures the result and says " you know what it looks like you only injected 4.5 fuel so keep the injector open a little longer, m'kay?"
rinse and repeat. thats stft. those increments are added to the LTFT so that from then on the computer fires teh injectors for what the table says AND LTFT. it keeps checking it over and over and adjusting to hit the target.
with tuning YOU CHANGE THE TARGET. so it does all of its adjusting to the new target. during OPEN LOOP the PCM fires what the table says +/- LTFT but without the checking and adjusting you get in closed loop.
in reality what would be best is not forcing open loop but having a system that was able to operate in closed loop no matter what rpm /load etc was going on- it would be more accurate
we just arent there yet.
NO! Because the values have been changed. period end of story the pcm has been given a new set of instructions. where it used to do A it now does 3
Flash tuning for FI is done all over the auto industry. will it work? YEAH of course see above.
RB has done a flash tune for FI- remember the white SC'd car? Damon did that tune while at RB before he moved to Mazda.
Trim- Short term fuel trim is used to adjust the long term fuel trim. LTFT adjusts the actual fuel delivery. Lets use some real easy numbers. During CLOSED LOOP the PCM gets info on the amount of air the engine is ingesting. It looks at a table and says i need to inject 5 parts of fuel so i need to fire the injectors for that much fuel.
Then the wide band mesures the result and says " you know what it looks like you only injected 4.5 fuel so keep the injector open a little longer, m'kay?"
rinse and repeat. thats stft. those increments are added to the LTFT so that from then on the computer fires teh injectors for what the table says AND LTFT. it keeps checking it over and over and adjusting to hit the target.
with tuning YOU CHANGE THE TARGET. so it does all of its adjusting to the new target. during OPEN LOOP the PCM fires what the table says +/- LTFT but without the checking and adjusting you get in closed loop.
in reality what would be best is not forcing open loop but having a system that was able to operate in closed loop no matter what rpm /load etc was going on- it would be more accurate
we just arent there yet.
01-22-2008, 12:51 PM
#85
Momentum Keeps Me Going
Well, I didn't lose my memory, and the fact is that unfortunately the trims the RX-8 creates are not created to a 'perfect tune' goal apparently, but a 'rich tune' goal. So there are still tricks that need to be played on it even when the 'perfect tune' ala RB race flash (perfect tune) has been implanted in it's little brain.
So unless and until (perhaps Hymee's flash is able to do this) the algorithms or constants that determine these offset trim numbers are redone, I'll continue to pull the fuse.
So unless and until (perhaps Hymee's flash is able to do this) the algorithms or constants that determine these offset trim numbers are redone, I'll continue to pull the fuse.
Originally Posted by RB web site
In developing this flash, we disconnected the Front Oxygen Sensor so that we had a stable, unchanging platform. Otherwise, the system would continually develop new trims that we would have to chase. Of course, it is not appropriate for you to do this (except in racing) because the system NEEDS the oxygen feedback information to correct the engine’s operation at light to moderate throttle settings. The fact is, in our experience, the PCM will usually build a 2% to 3.5% top level trim, which means the engine is running that much richer than best power mixture. In general, this is a small amount, and will only cause a fraction of 1% loss of power. On the other hand, if you don't want to run with this factor (i.e. racing applications), you have two choices:
1. Disconnect the Front Oxygen Sensor (at the top of the bell housing), pull and reinstall the "ROOM" fuse (in the left kick panel) to eliminate the 3 trim levels, and the PCM will NEVER build a fuel trim (it will turn on the "Check Engine" light, but that's all).
2. As an alternative, you can simply warm the engine prior to a competition run, shut off the engine, pull and reinstall the "ROOM" fuse, and begin your competition shortly after starting the engine. In this way, the engine never sees the "cruise" operation it needs to build the trim level.
1. Disconnect the Front Oxygen Sensor (at the top of the bell housing), pull and reinstall the "ROOM" fuse (in the left kick panel) to eliminate the 3 trim levels, and the PCM will NEVER build a fuel trim (it will turn on the "Check Engine" light, but that's all).
2. As an alternative, you can simply warm the engine prior to a competition run, shut off the engine, pull and reinstall the "ROOM" fuse, and begin your competition shortly after starting the engine. In this way, the engine never sees the "cruise" operation it needs to build the trim level.
01-22-2008, 01:05 PM
#86
Administrator
not you spin- that was mainly directed to the previous page. and 2% rich with a 1% difference in power on an FI rotary using normal at the pump fuel sounds like a good plan to me
01-22-2008, 01:12 PM
#87
Momentum Keeps Me Going
wondered but didn't know what (who) 'od' meant. But anyway, even 1% (2.32HP) power being so easy to obtain (and use) at the track, why not? That's equal to/more than many exhausts or pulleys or intakes or ...... a lot of things 
01-22-2008, 06:02 PM
#89
Administrator
iTrader: (7)
01-22-2008, 06:08 PM
#91
Administrator
iTrader: (7)
01-22-2008, 06:39 PM
#92
Administrator
im sure trim algorithms are in the firmware and not in the flashable software
01-22-2008, 06:55 PM
#93
Momentum Keeps Me Going
I guess there will still be the bugabo of 'fighting the trim' and by that I mean 'fighting FOR the lean tune WE want vs what the car wants, i.e., with the car wanting a bit too rich a tune, even when we can flash. Oh well maybe it's not enough to worry about in the end.
01-22-2008, 07:06 PM
#94
If the lookup tables can't be changed with a flash tune...we are wasting our time trying to flash the PCM for FI uses.....so The lookup tables must be accessible to the flash tune.
I just hope all the knock and throttle values can be tweeked as well
I just hope all the knock and throttle values can be tweeked as well
01-22-2008, 07:33 PM
#95
Zoom--I understand what you are saying about target values being replaced. i cant talk about details but it seems "it ain't that easy". It seems one secret to getting this pcm NOT to trim toward undesirable a/f's is to get the maf to not trim to much. After a number of study cars it is FAIRLY standard that the MAF is trimming 3-5%. One car was actually adding fuel but it was because it had a small vacuum leak.
so a target of 12.5 could be trimmed 5% richer or leaner. resulting in a range from 13.1 to 11.9 basically. Now do you sacrifice the 12.5 to go with a target 11.9 because you DO NOT want a 13.1 on a boosted engine?
That is what i talking about concerning the trims.
oldscdragger
so a target of 12.5 could be trimmed 5% richer or leaner. resulting in a range from 13.1 to 11.9 basically. Now do you sacrifice the 12.5 to go with a target 11.9 because you DO NOT want a 13.1 on a boosted engine?
That is what i talking about concerning the trims.
oldscdragger
01-22-2008, 07:39 PM
#96
DGAF
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Easy, fellas. A wishlist won't do us any good at this stage. I'm just looking forward to being able to view and adjust what my car is doing without paying $1200 for the privilege.
01-22-2008, 07:53 PM
#97
Not questioning this product at all now please understand. I was just wondering how they were handling this trim problem. I never meant to insinuate that it wasnt possible, just meant i dont have a clue as to how they handled it. I prefer to have some idea of how things work before i get them. I have learned that lesson.
rotor on
oldscdragger
rotor on
oldscdragger
01-22-2008, 08:36 PM
#98
I think there is a forest and trees issue here.
You don't need to "deal" with the LTFT in a flash program - the way it works is you change the values in the look-up tables. That is what flash programming is.
Once you change the target, the LTFT will adjust to that - not the old, unwanted, original values.
If you are having an issue where tuning an external device is changing the trims (I don't understand why you would need that, but it seems to be what is being discussed here), you just change the lambda look-up for that load cell to reflect the desired value and it will trim to that.
You don't need to "deal" with the LTFT in a flash program - the way it works is you change the values in the look-up tables. That is what flash programming is.
Once you change the target, the LTFT will adjust to that - not the old, unwanted, original values.
If you are having an issue where tuning an external device is changing the trims (I don't understand why you would need that, but it seems to be what is being discussed here), you just change the lambda look-up for that load cell to reflect the desired value and it will trim to that.
01-22-2008, 08:43 PM
#99
Momentum Keeps Me Going
MM then please explain RB's comments about using their flash. They've modified the tables through a 'flash', but are still saying the internal ECU goal will lead to a overly rich mixture anyway by developing trims over time from using 'light to moderate load' developed numbers... then using these during WOT to change the 'perfect tune' they flashed in?
It's either one way or the other. Either you can flash the ECU to do what you want completely or you can't and have to account for its action otherwise.
edit: maybe there's a way to turn off the effect the ECU has developed (its trims) so it doesn't play into WOT fuel maps any longer?
It's either one way or the other. Either you can flash the ECU to do what you want completely or you can't and have to account for its action otherwise.
edit: maybe there's a way to turn off the effect the ECU has developed (its trims) so it doesn't play into WOT fuel maps any longer?
Last edited by Spin9k; 01-22-2008 at 08:47 PM.
01-22-2008, 08:49 PM
#100
I don't believe RB ever successfully modified the lambda tables.
I think they only played with the load targets.
I think their whole "pull the O2 sensor" reasoning was borne out of this.
As far as I can tell, the RB flash is pretty worthless for an FI application because they didn't really get control of anything.
They simply made a virtual Canzoomer box.
I think they only played with the load targets.
I think their whole "pull the O2 sensor" reasoning was borne out of this.
As far as I can tell, the RB flash is pretty worthless for an FI application because they didn't really get control of anything.
They simply made a virtual Canzoomer box.