TD_D mod journey. From stock to the 'bastardmobile'

[Td_d]

Really? Are you yanking my chain?

Pleas tell me you are not cause I have such a huge smile on my face right now!

Nope, really did sneak out and take a drive! Very smooth - but short drive, I'll get the chance today to really test it out.

 

[Td_d]

Sigh... ok, been driving around on the tune most of the day - definately smoother - but there's still lumpiness, albeit in more specific load situations - in particular lower RPMs and higher load (up hills). I also noticed that if you punch the throttle i.e. shift rapidly to open loop, around 3000 there's a significant stumble. Definite improvement, but still a ways to go.

This is so frustrating!

 

[Td_d]

Hey George - so what next? More load comp drive and logs? What's so annoying, is I've loaded the original base map for the mean time for driveability sake - and it's quite smooth, and yet when I look at the logs on this map, the MAF scaling is horrendous, totally off...

By the way - congrats on the STI of the month win - well deserved!

 

[Td_d]

Let me run a theory past you - I've decided that getting frustrated is counterproductive

I know that the stock AVCS intake advance and exhaust retardation tables have very large overlaps in the low load, low RPMs, for emissions reasons. I've read a number of threads talking about the reduction of this overlap making engine driveablilty much smoother in the closed loop areas. So with the theory in mind, I compared the 'basemap' without stumbles to the original crappy map that tuner gave me and the one that we've been working on - and I may be on to something? The key difference between the 'stumble-less' map and the other is that AVCS is zeroed in those areas - which from what I've read takes the 'EGR effect' out of the loop, making fueling more predictable.

This stuff really is over my head at the moment - what do you think?

 

[HolyCrapItsFast]

Let me run a theory past you - I've decided that getting frustrated is counterproductive

I know that the stock AVCS intake advance and exhaust retardation tables have very large overlaps in the low load, low RPMs, for emissions reasons. I've read a number of threads talking about the reduction of this overlap making engine driveablilty much smoother in the closed loop areas. So with the theory in mind, I compared the 'basemap' without stumbles to the original crappy map that tuner gave me and the one that we've been working on - and I may be on to something? The key difference between the 'stumble-less' map and the other is that AVCS is zeroed in those areas - which from what I've read takes the 'EGR effect' out of the loop, making fueling more predictable.

This stuff really is over my head at the moment - what do you think?

I believe you may be on to something. Can you send me a copy of that base ROM that runs smooth? I need to see what is going on there. I'm almost wondering why we didn't start with that one if it is running smoothly. What you suggest makes sense but I just need to see it to get a good picture.

 

[Td_d]

Sure - let me PM you the link. I think the reason why we didn't start there is that other than the bottom end, the rest of the tune is pretty horrible - MAF scaling is a mess, and the primary fueling tables are completely lacking in resolution - big bands of single numbers...

I'm curious to test this theory - but I'm much to afraid to mess with the AVCS tables given the impact it has on timing over all, EGTs etc. - my gut feel tells me that not knowing what you're doing here could land up as a very expensive exercise...

 

[HolyCrapItsFast]

http://www.drift-ready.com/Files/TD_D/750RC_4-4-2011_Rev-A.zip

I think you were right about the AVCS settings. In this version I used a very slightly modified version of your base map AVCS values. But in this one I also set the closed loop targets to be the same as open loop targets by simply zeroing out the table. This will make closed loop to open loop transitions smoother. I also modified load comps to address the low RPM higher load.

Lets give this a try and keep your fingers crossed.

Of course you do realize that we will have to go back and do some more MAF scaling. :tard:

 

[Td_d]

Great! Looking forward to it. I have to admit, I experimented a little

I took our latest MAF scaling, injector scale and latencies, and applied it to the map that the tuner (i.e. the original 750RC map) made. I then trimmed the AVCS overlap down some in the lower end, tweaked the throttle map a little to get rid of the problematic idle (oddly, by altering requested throttle at 0% angle to 0 as opposed to 2% solved it...)

Then went out, plugged in Romraider dashboard and flew up and down the road, carefully monitoring knock - none. Drove much smoother (and like a bat out of hell) but the stumble at 3000 remained (not as bad) - felt like it could be cleaned up by compensation map.

Very keen to test drive this map and compare!

 

[HolyCrapItsFast]

Great! Looking forward to it. I have to admit, I experimented a little

I took our latest MAF scaling, injector scale and latencies, and applied it to the map that the tuner (i.e. the original 750RC map) made. I then trimmed the AVCS overlap down some in the lower end, tweaked the throttle map a little to get rid of the problematic idle (oddly, by altering requested throttle at 0% angle to 0 as opposed to 2% solved it...)

Then went out, plugged in Romraider dashboard and flew up and down the road, carefully monitoring knock - none. Drove much smoother (and like a bat out of hell) but the stumble at 3000 remained (not as bad) - felt like it could be cleaned up by compensation map.

Very keen to test drive this map and compare!

This is excellent. I definitely encourage you to experiment. It's how we learn! Just keep me in the loop so I don't get lost.:tup:

 

[Td_d]

Ok - test drove the map you uploaded - it went further south. The only way I can describe it is that the stumbles (at around 2400 and 2800 or so) now moved higher up the RPMs, but have 'merged' for lack of a better explanation - there's a 'band' of severe hesitation now between 2800 and 3200, at a a slight load - it's so severe that the car bucks quite strongly, and you have to punch it out of closed loop to have it 'release'. Also very sluggish in closed loop - I wonder if the AVCS tweaks would require significant base timing changes? Any ideas?

On the experimentation side (I'll PM you the link for the ROM) it went a little better - I got the chance to do a pretty long drive today, so I thought I'd try to use the opportunity to see whether I could do a load comp drive (although in hindsight, should probably make should the MAF is still relatively aligned). Got a fair number of data points - and a very interesting result - here's the calculated compensation.


It's shifted to the left quite significantly, i.e. very low relative manifold pressure. So if I were to test drive these calcs - would it just be a case of inserting the areas with sufficient data points into the load 'cruise' table? Or both cruise and non-cruise? These were the logs - going to check the MAF scale now as well. http://dl.dropbox.com/u/3099895/TD D 4 apr 2011 Log.rar

EDIT - only use log 49 - forgot, I combined logs 49 and 50 into log49 to do the comp calcs. And you'll notice that the manifold relative pressure has been converted to PSI (spreadsheet bombs otherwise!).

 

[Td_d]

This is the log from the ROM you uploaded - have not had a chance to look at it - but I suspect the trims will be pretty wild!

http://dl.dropbox.com/u/3099895/log0052.rar

EDIT: Looking at it, the learnt parameters are actually pretty tight (between -2 and +2) and that's not averaged, so it looks like the MAF scaling is still relatively accurate.

 

[Td_d]

Well, running the MAF on the 'hybrid' map, and the good thing is that it's still dead straight - however it's consistently between +4% and +5% - I guess I should adjust the injector flow down by a factor of 4% to 5%?

 

[HolyCrapItsFast]

From the description I would say don't bother with that MAP. You can try what ever you think would help but I'm going back to the drawing board and back to that last map we made. I think it was iteration 3-28-2011 B

Stay tuned... This is really taxing my brain. What the hell are we missing here. :tard:

 

[Td_d]

^ yeah - I think the 4-4-2011 map will only have us running around in circles. The Hybrid map is the one with the 4/5% positive corrections, other than the stumble which is not too severe (which looking at the comps would make sense since it's a very low manifold pressures) is feeling relatively decent, need to scale down the injector though - a little worried about going into open loop with postive trims. Actually, the other way I should be worried about, right? If it was pulling fuel just before going open, it would likely lean out, right? So it's likely going in rich - might explain the spectacular exhaust pop changing gears 2nd to 3rd WOT. I'm sure there's fireball, too bad I'm not at the back to watch it :tard:

 

[HolyCrapItsFast]

I'm not sure I follow. I thought 4-4-2011 was the hybrid map.

I think we should continue on from post #347. I still think it is load comp related. I was hoping I could convince you to take a nice long log with 3-28-2011 B :tup:

 

[Td_d]

Ah - ok - crossed wires! Will do - let me load dig up the 28 Feb B map, and see if I can get a nice long drive in today.

 

[Td_d]

This is so weird - second time today I've written a post, it's registered, and then I see its gone later. Odd.

What I posted earlier was that the map I was referring to was the one that I was tinkering with (not 4-4-11) - which was the original map, with our MAF scaling, and some tinkering with the throttle maps and a little AVCS. I subsequently also did a load comp adjustment. Well, I'm pleasantly surprised - drove it with the load comps today - no stumble anywhere! Slight 'murmer' where the stumble was, but I guess some further refinement might sort it out completely. Car feels awesome, great power delivery, and smooth. I'll PM you the map.

Will only get a chance to do a serious long drive on 28-2-11B tomorrow probably - will keep you posted.

 

[HolyCrapItsFast]

Wow! this sound promising. I think I would like to just sit back and see how you make out with this. I would definitely like to see what you came up with. :tup:

There's not really much more input I can offer anyway until we are ready to do open loop.

 

[Td_d]

I can't thank you enough for all the help - I've also learnt so much!

I need to crunch the logs from this morning, it was a little lean in closed loop (adding 4-5% fuel), but still straight, so I tweaked the injector flow down by 4%, will see.

There's a little knock, but low down - 2000-3000 RPMs range, and it disappears very quickly (so very few data points) so I might need to tone down the ignition timing a little - incrementally how much should I drop at a time - 1 degree? How would I be able to discern whether it's tip-in knock - throttle angle delta between the two data points where the knock starts?

What I do know is that I'm getting no knock at the really critical areas of high load and high RPMs, phew.

Wow, what an awesome process this has been!

On the open loop - just my luck, the LC1 controller unit was a dud (sensor works perfectly, also tested with an LM1) - went on the blink within 2/3 days, dammit. Waiting for a replacement, should be here this week, then we can roll on the open loop?

Another quick question - you know me, inquisitive - if I go WOT, and take it up rapidly to around 6000 RPMs, and shift quickly, I'm getting the most delicious sounding backfire (I'm certain there is flame :evil. I assume this is indicating a rich mixture, nothing to worry about like high EGTs? I gather that would show up in knock?

 

[HolyCrapItsFast]

Just to save myself some time here I'm gonna quote myself from the PM I sent you and for the benefit of others that might read this...

Remember that if your total trims are with in +/- 6% your are considered ideal. Albeit I am an anal perfectionist and am always looking to get better than perfect. Perhaps that is my mistake when trying to teach others. It tends to get in the way and my students lose focus. But my point is don't kill yourself trying to get MAF scaling perfect because you will be at it for ever. Just get it ideal and move on. The later when you have ironed out everything else you can go back and revisit that. I think the load comps require this level of perfection though. I would focus on that.

How little knock are we talking? If it is less than -2 then I wouldn't even consider it if it is in the low rpm/load region. The key to looking at knock is to look at the whole picture and take all of the knock and timing monitors into consideration.

For instance you might see some learned knock and nothing else. This just means that the ecu is retarding timing in that area because it saw some knock there and is now applying the retard based on past events. Chances are that now that the ECU is retarding timing in the learned knock column, it is not actually knocking because it has retarded timing in the event of knock.

The Knock Feedback column is really the one you want to focus your attention on. When you see activity in this column that means that the ECU is hearing what it perceives to be knock in real time. However, this still does not mean it is bad. You also need to look at your dynamic advance (I forget what they call this in RomRaider). If your total timing is greater than your base ignition timing then chances are you are in a good situation even though feedback knock has removed some. This is because the ECU is adding dynamic advance up to the threshold of knock and once it hears some it back off a little.

It can get more complicated than that but I would be more concerned about knock during open loop. Any feedback knock during high load and or WOT is not desired.


To answer your question though. I have always found 2* increments to work. 1* increments never seem to do enough for me.

That sucks about the wide band man. You definitely need that to do WOT monitoring and tuning. And yes all that means is you are runnning rather rich up top. It's probably of no consequence as long as you don't do it to often and as soon as we have a chance to do some open loop tuning. Mine has been back firing for years now because I have a BOV. I won't get rid of the thing because I am such a god damn child I love the noises and back fires to much. So i just learned how to tune for it.