Tuning tips

[pzero]

Hello,

I have a m800 on a subaru sti. It has been tuned by professionals before. The problem is that I would like for the car to be streetable and not just run WOT. I would appreciate any tips on adjusting for drivability, idle (this is the toughest one - I've been told that you can't get motec to idle correctly) and accel enrichment. Tips for logging these and later making adjustments using I2 would be great.

Again, thanks in advance and for having this site.

[figgie]

Wow

MoTeC can not get the idle correct?

Who told you that? Who ever did, never ever listen to them ever again.

The issue is idling and street tuning are one of the hardest things to do as you need compensation maps for all type of weather, engine condition etc to get it right. Idling is like any other part of the map, requires a know-how of what to do.

So my first question to you would be. What do you have for idle control? Does the Subaru have a Idle Air Control Valve? If so is it a PWM based valve or a stepper motor based valve? Perhaps the car is DBW?

We will need alot more information

[pzero]

Hello Figgie,

Thanks for the information. I did figure that the motec CAN idle. Just need to get it right. The car has DBW

Thanks

[pzero]

Just let me know what information would be helpful. I am basically looking for tips on how you would go and perform the process.

Thanks

[RossB]

Idle, starting and drivability can take quite a bit of time to tune but the M800 is certainly capable in these areas. If you are wanting to learn more about this and using i2 you can now download the MoTeC Seminar notes from our website. There's quite a bit of reading but it is a good place to start.
http://www.motec.com.au/downloads/downloadseminars/

[pzero]

thanks RossB,

I started working on the idle this weekend. Its a 2.5L with 1600cc injectors . I turned off accel enrich and made sure that there weren't any other compensations (other than map comp) working on the fuel main map. I was able to get the car idling great at 1300rpm with a constant pw of 1.9ms. This is very rich (.7 lambda). I set the DBW integration limit to over -20 to get the motor to close against the spring. (the tps wouldn't go below 1.5%). The car ran great.

The next day, the car was not idle right (more erratic). I noticed, like I have noticed before, that the lambda was around .75. this seems to be the case all the time. Don't know if it is due to the injector size.

What I did next is made the idle a bit richer .66-.67 and adjusted the tps low and got the tps to 1% and had the car idle at 1100. Seems like the car likes 1300 better since 1100 runs a little more rough. My question is; Does the fact that the car likes .67 lambda (idle wise- the idle always returns to aim rpm (approx) due to the large injectors or am I missing something here. I was looking at a battery compensation graph for my injectors and it seems like they should handle 1ms. Any thoughts. Also, I will look at the seminar. Before I forget, the injector scaling is set at 3.

[RossB]

Injectors that big are going to cause you a problem with idle. What ECU do you have? Is it a Plug-in M800 or a standard M800? What channel are you reading your 1.3 ms from? Are you able to post a log file?

[Pascal]

Dear pZero, is it EJ25 WRX year 2006-2007 Subaru? If it is then trust me, those cars idle very nice and it is pritty easy to do. Let me know if you wanna have settings from 2 of mine if that can help you out.

Regards Pascal

P.S. change tuner
P.P.S. just kidding, guy maybe did not check it properly, i am sure that u'r tuner have best intentiones

[pzero]

Hello Pascal,

it is a 2007 DBW sti. any help would be appreciated.

I am reading the actual pulse width

[pzero]

Here is a list of questions problems I am currently facing.

1. I was able to get the car to idle through careful adjustments to the dbw and idle values. The problem that I am noticing is that the car will idle perfectly all day long while the ecu manager is connected to the ecu. When I close the manager and laptop, the idle stops wanting to idle and begins hunting. This is very apparent went I reopen my laptop to make adjustment to only be faced with the idle correcting itself when I open ecu manager. One thing that I do notice is that the throttle position doesn't pull back to the same value each time (not a issue with tps). you blip the throttle, and you sometimes get 0.5% and sometimes you get 0%. never consistent.

2. I am trying to get accel enrichment going. at the moment, I have the throttle with decent response with I stab the throttle. went I log lambda, I get a dip on the rich side and a return to norm. I tried using decel and sensitivity (with clamp) to get rid of it. It doesn't want to work. if I remove clamp completely, the spike goes lean so I know that something is working. How do I address this? i.e. when the car is idling and you stab the throttle, what values are used in the calculation. Is this a moving target (as rpms increase, does the ecu adjust calculations as the cell sites move?) on decel, is it the initial cell site which makes the calculatoin once throttle is stabbed.

3. I have the lambda table with values of 0 at the idle region. I am noticing in my logs that closed loop isn't working sometimes (or has a poor delay of over many seconds). How do I speed this up. I am using short term trim and not long term.


Thanks