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First time tuner


Andrew
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Hey everyone.  First time tuner here, trying to learn on my 2004 BA - so be prepared for some dumb questions!  Hopefully my early learning will be useful for someone doing the same. 

Car is completely stock tune-wise (as far as I know) and hardware wise just some supporting stuff - high-flow cat, twin 2.5" cat-back, wideband, boost gauge, oil pressure gauge, fuel pump.  About to put in a trans cooler for the BTR and a bigger intercooler.

More detail of the mechanical stuff will be here http://www.fordxr6turbo.com/forum/topic/93864-ba-turbo-build-thread-sort-of/

So far I have just done a fair bit of reading on forums and books to try and get a feel for how all of this works, particularly Greg Banish's Engine Management book.

My first round tune will aim to up the boost pressure to maybe a max of 9 PSI, plus richen up the AFRs accordingly.  Later on I'm planning to give it more boost and a set of new injectors.

My first problem is my desired boost table (auF0306).  It looks like this:

image.png.b5f767aa3c4898ee9f26805f8a7a1828.png

If I look at the stock files for my strategy (HAANFHZ), the table looks much more like what I would have expected.

image.png.25cde154b777f971bb74aa5f3f56e7fa.png

Similarly the wastegate duty cycle table is a flat 0.45 across the board.  

My boost gauge only ever reads about 6 PSI, so it is obviously not even trying to reach the sort of boost that is in the map.  So I'm thinking that maybe the car has been tuned before, but in a very unusual way?

Now that I write that, about 2 and a half years ago I had a new turbo core put in.  I had previously fitted a new boost gauge teed off the BOV and removed the hose from the old gauge to a contraption I assumed was a boost pressure sensor specifically for the gauge. The turbo place that did the CHRA replacement said there was some sort of weird boost control device hooked up to the turbo, which he removed but couldn't work out how it functioned.  I said nah, its just the sensor for the old gauge.

Maybe the car had some sort of boost controller hooked up (I'll see if I still have it floating around the shed for a pic) and the tune boost tables were just zeroed out so that this device did the boost control?  And now that the device is out, the boost I'm getting is just a function of load/WG spring pressure and the WG duty cycle table?

Any thoughts or suggestions would be great!  I'm thinking I probably need to reset my boost control tables to match the stock strategy, flash that and see how it behaves?  Or any thoughts on why else my boost tables would be so whacky?

Base fuel table is untouched compared to stock strategy. AFRs are bang-on what I would expect too, so I don't think the tune has been beaten-up too much otherwise. 

 

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Hi Andrew and welcome to the Forums.

Your car has definitely been tuned by someone. I suspect the car has been put in "Open Loop Boost Control" which means the Desired Boost table will be ignored and the Wastegate Duty cycle table will be used exclusively for boost control. Do a compare against factory and check what parameters have been altered in the Turbo area.

You can also post up your tec file here or send it to support@pcmtec.com.

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Thanks Darryl!  Yes, I think you are correct.  I ran a file compare against the stock strategy (excellent feature by the way!) and it showed me a few other tables that have been modified too (a bit of timing, some transmission tables, etc.).

Given I've got no idea of the source of the original tune I'm not inclined to trust it, so I think I'll use the file compare feature to set my tune back to factory.  Then I'm starting my tuning from a known base.  I'll drive it for a bit on the stock tune to make sure everything is working as expected and boost control is fine.

Actually, if you are interested in the file I sent it to support on Tuesday as Roland was troubleshooting a licensing issue for me.

Keep up the great work guys!

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Edited the original tune last night to match the stock HAANFHZ strategy and flashed it in.  The compare feature and apply feature are both excellent!  Main things to revert were the boost control, some base fuelling (At WOT and high RPM, was set leaner than the factory tune!) and turned cat overtemp protection back on.

End result is attached.  There were also some differences between HAANFHZ and my file in relation to some torque management and transmission tables.  The changes seemed a bit more extensive than the rough approach taken to boost, etc. so I'm a bit suspicious that these could be an official strategy update or something at some stage.  I haven't put these tables back to match HAANFHZ yet.

If anyone is familiar with these tables and has a view on whether they look modified, that would be great (ie comparing my file to HAANFHZ).

The other interesting thing is that my file refers to HAANFHZ/A3HD.  Whereas the tag on my ECU refers to 3R23-12AB50-AHA and A3YA.  Not sure if that is relevant, but made me a bit reluctant to change things other than those that I was 100% sure were different to stock.

I'll drive it for a couple of days on the current strategy to make sure everything is behaving itself and then start on my boost control and fueling tables.  

 

 

BA XR6T A4 2004 return to stock except trans and torque mgmt.tec

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  • 3 weeks later...

After running the near stock tune for a few days, everything was behaving itself nicely, if a little slow :)  

Then built a tune with as much boost as I was happy to chuck at the stock injectors - about 9 pounds but tapered it off at higher RPM.  Made some lambda changes too, especially at high load.  Car feels good again and wideband is reading all good.  Interestingly, my fuel economy has improved by about 10% compared to my original tune.  I'm thinking that if the previous boost maps were targeting a set boost level across the whole map, or were open loop with the same wastegate behaviour across the whole map, then I probably had the waste gate either shut or at at least 50% DC based on what was in the tune.  I'm guessing that would have been bad for economy due to the extra exhaust restriction at light cruise and idle?  Anyway, is a nice bonus.

I also flashed the transmission torque strategies back to stock for safety.  I'd always thought the BTR in my old EL XR6 was a lot smoother than the BA, and the tune explains why.  Happy with the stock tune in it because having the transmission last is ultimately more important to me than having thumping, ultra quick gear changes.

So I feel like I'm pretty happy with where the tune is at for the minute, save for a couple of minor tweaks..  Time to get around to installing the trans cooler, bigger intercooler, 0.8mm spark plugs before I grab some injectors and go again.

 

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If you are running stock injectors with trims under 5% try turning closed loop O2 off entirely. You can then put 1.07 or higher (experiment) in the requested lambda at cruise to get even better economy. Your nitrous oxide emissions will go out the window though. 

If you are running more boost I would richen up the part throttle as well as reducing the a/d count for CL to OL transition (assuming you leave O2 enabled). 

Also ensure you aren't hitting the max load on the spark tables, if you are make sure to reduce spark, or rescale the axis to allow it to hit a higher load with appropriate spark values. 

Have fun. 

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Thanks - could be an interesting experiment!

Which table drives idle speed when in gear?  My car's combination of exhaust and probably slightly tired engine mounts causes a bit of annoying vibration at idle stopped in drive.  This is especially so if lights, demister, etc. are loading up the alternator.  If I feather the throttle it is much nicer, so I figure if I up the RPM slightly at idle, I should be good. (Although I should check out the engine mounts properly too.)

I assumed table auF0022 (Idle RPM AC on in gear) and set that to 620 for IATs of 0-90.  Was 580 I think.  Doesn't seem to have made any difference.  Maybe there is a scalar coming into play or maybe I should try adding like 400 RPM or something to the table so that there's no mistaking whether the change has worked or not.

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Just edited my post above.

Regarding the idle it depends on airflow and also spark. They normally run as low as 6 (8 maybe?) degrees at idle and will add up to 25 or so degrees timing if needed to increase the idle. Higher spark values mean less air for the same idle rpm, hence it will be rougher. You want your idle spark to be fairly low so you have reserve for when you get fluctuations. 

So to increase idle you could technically raise the min spark, however the proper way is to increase airflow. There are a few rpm setpoints, in gear, coasting and in neutral I believe. If you raise these providing you don't go past the max airflow set point the rpm will raise.

So first check your idle spark, if it's normal eg below 10 degrees simply raise the set point. If it is quite high already it suggests a mechanical issue which you should resolve first.

Edit: no harm in setting idle to 2000 rpm just to see what happens either. 

Edited by Roland@pcmtec
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Thanks - that's useful!  I think I'm basically at the point where I've got a decent but safe performance boost compared to stock, and now I can spend quite a bit of time learning and fiddling around the details more.

Actually, the other thing I should mention from a safety perspective is that after a wrote the boost map, I compared both the boost maps and timing maps with a BA F6 to give me a rough indication of what I should work within that will give me a decent safety margin to avoid knock.  As it is being road tuned I doubt I will ever try and tune it within an inch of its life.  I'd rather keep a decent margin for changes in conditions.

 

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  • 1 year later...

Hey Roland in regards to the above ( You can then put 1.07 or higher (experiment) in the requested lambda at cruise to get even better economy) what area of the Fuel MAP would you be adjusting would it be in the 100 - 200 range between 1500 rpm and 2500 rpm ?

IMG_6394.png.4c461dfaf7cfc6a9e44acc0100169641.png

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It ignores the base fuel map when in closed loop and targets 1.0 lambda at all times (as that is all a narrow band can accurately target). If you want to disable closed loop you can have a look at the various methods in the closed loop thread here. The TPS threshold vs rpm is probably your best bet.

You can run up to 1.1 lambda usually without a misfire, beyond that you lose too much torque. Remember this will damage your catalytic converter over time and make your NOx emissions sky high (like 10-20x more than the legal limit) which is why no OEM does this anymore.

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Hi, i might be off topic here but i have a newbie question about boost.

I have been reading what i can about na engines, but the word boost seems to come up a lot, is it still relating to na?

If so, what or where is this boost they are referring to?

Thanks in advance

Steve

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5 hours ago, Roland@pcmtec said:

Can you give us some context?

Hi, well typically I can't find the post/s at the moment but if I come across something I'll get back to you.

But apart from that is it fair to say that the word "boost" wouldn't be used if talking about an n/a?

Cheers Roland

 

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