Dano's Boost Tuning 101 + Cool Stuff

[Ziggo]

Originally Posted by 3speedy You prematurely quoted me. I saw the error in my ways and edited the post. Is my statement right now???

There is no set pattern for WGDC, it depends on the turbo and even timing settings. If the turbo is getting more efficient (turbine side) with higher flow (like a BT will) it will require a lower percentage of the exhaust energy to maintain the boost.

The K04 WGDC goes up drastically with RPM because it is so undersized that both the compressor and turbine wheels move well past their peak efficiency points, so it needs all the energy it can get, and then turns alot of that energy into heat on the compressor side. The tiny shaft between the wheels then bends because of the high temps and super high rpms. K04 fail summarized in a single paragraph.

[Dano]

^^^^**

Word


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[Dano]

Originally Posted by 3speedy As I understand it, a 0% WGDC the solenoid is closed therefore not allowing any of the boost pressure to bleed off (lower boost). The waistegate would open at whatever spring rating it has internal to it. A WGDC of 100% would mean the solenoid is bleeding as much as it can (raising boost). Maybe the reason WGDC decreases at a higher RPM is that more air is being forced through the turbo. To compensate for this the solenoid reduces the cycle to reduce the exhaust energy being sent to the turbo (lowering the boost). If I didn't take this precaution the car could go into overboost potentially. Does that sound feasible to anyone else?

Keep in mind there is a big difference in an OEM [bleed] BC system and a 3port [interrupt] system. If you look at the diagrams on the perrin site you will see the difference clearly.

The below material taken from : http://www.perrinperformance.com/pages/show/113

OEM BC



EBC BC

[amoosenamedhank]

Sorry for turning this into my personal "I don't know what the fuck I'm doing" thread... but quick question for you guys.

You can see in logs 13 and 14, the row right before I let off the throttle, the car immediately goes lean. I let off the throttle at different RPMs in the logs, so it's not that. I was thinking it has something to do with a transition back into CL but the lean happens before I let off the throttle according to the log.

Log 12, the only difference was a change OL/WOT command where I changed my command to 11.8:1 to RL... so something changed... not sure what.

Any thoughts would be appreciated.

[jracer]

i am a dumb ass at tuning.. but how much better or power if felt by boost tuning compared to load tuning ?? Christian did my etune and i guess he did load tuning i guess..
would getting boost tuned be better ?

[amoosenamedhank]

I don't think there is necessarily more power to be had between them. If your car is correctly tune using either method, I wouldn't expect much difference. I think it more comes down to your preference in how you would like to obtain your results.

For me, it's easier to grasp the concept of targeting a psi number opposed to trying to obtain a numeric value based of some formula in the ECU. So that's why I choose to go after boost based targeting. I'm sure your load based tune from Xtian is just fine.

[SRTie4k]

I understand about 80% of this stuff, the one question I have is...if you plan on tuning by boost, are you supposed to zero out the gear-based load tables?

[Dano]

Nope. The boost toggle defeats the load tbls

A boost tune appears to yield a smoother throttle response than a load tune. Making no other changes, ie APP, DBW etc a boost based tune allows for smoother more controlled application of power for me.

With load tuning power is controlled by RPM only and not directly by throttle input. One could argue this point but I am simplifying it for this discussion. You can hold the throttle in one position and get a tremendous surge of power as RPMs rise. This translates to a hard to control torque curve at times and will blast the front tires off on a FWD car. Also, since it is load based and the ECU is responsible for calculating load, it can be unpredictable and you get very different power applied at times.

Boost tuning on the other hand, is controlled by TPS and RPM so you can more easily control when the power gets laid down by throttle position. Some have described this as a "softer pedal feel", meaning it takes more pedal to make the same power. to me you get more pedal "resolution" this way. We all know how you get 100% power at just over 50% pedal position right? well not with boost tuning along with a little APP tweaking.

For me, I prefer this side effect of boost tuning and now the either on or off feeling of throttle is gone.

I have further refined this effect by tuning my APP per gear to limit power in the lower gears without neutering power like in the TRL xgear tables.

Of course you could spend hours perfecting a load based tune [ or just be smarter than me which wouldn't take much] and perhaps get the same results but for me, boost tuning is a faster way to get those same results.

[m4tic]

also with boost tuning you remove variables like.. which load table A-E is going to be used at any given moment

the only concern is ol/cl transitions

[Dano]

post 89 updated with more "impressions" of boost vs load tuning.

[Dano]

Originally Posted by amoosenamedhank Sorry for turning this into my personal "I don't know what the fuck I'm doing" thread... but quick question for you guys. You can see in logs 13 and 14, the row right before I let off the throttle, the car immediately goes lean. I let off the throttle at different RPMs in the logs, so it's not that. I was thinking it has something to do with a transition back into CL but the lean happens before I let off the throttle according to the log. Log 12, the only difference was a change OL/WOT command where I changed my command to 11.8:1 to RL... so something changed... not sure what. Any thoughts would be appreciated.

so are you saying that before you made your OL/WOT AF change this wasn't logged?

to me it just looks like resolution in the logging. In relaity the rows that are logged don't meet up in realtime. if you do enough logging you can see these patterns occur. you might log Acel Pos so you can see exactly when you let off.

I don't know if it is the processing within the ECU that gives us the low resolution or the AP processing itself but either way it would be nice to have higher res.

[amoosenamedhank]

Originally Posted by Dano2010 so are you saying that before you made your OL/WOT AF change this wasn't logged? to me it just looks like resolution in the logging. In relaity the rows that are logged don't meet up in realtime. if you do enough logging you can see these patterns occur. you might log Acel Pos so you can see exactly when you let off. I don't know if it is the processing within the ECU that gives us the low resolution or the AP processing itself but either way it would be nice to have higher res.

This had crossed my mind... that the refresh rate between the values might not always line up perfectly. Good point about the acceleration pedal... I suppose this could be explained in part by the delay between the time I lift my foot and the time the throttle plate actually closes.

But to answer your first question, no this was not logged this way until I leaned out my OL/WOT to 11.8 to RL, coincidence?

[FreeFlyFreak]

Originally Posted by amoosenamedhank coincidence?

Yes.

If you had a DashDaq which logs very fast you would see clearly that nothing lines up exactly, on the AP stuff can be 1 line off, on the DD stuff can be 10 lines off.

[Dano]

yes purely coincidence

[super_pablo_]

trying out this boost tuning deal (thanks to socks) and, although i havent pushed the car hard enough yet (learning fuel trims), i can DEFINITELY see the difference in pedal feel. not only smoother, but the power is actually delivered gradually, not in an on/off manner.
Ill post more impressions later.

[triple_threat]

I love the boost based tuning! its way easier, and the car just feels way smoother all around. Not to mention i can actually hold boost now

[amoosenamedhank]

The overall driving experience has really improved for me since switching. As others have mentioned everything is a lot smoother and a lot more linear. And the ability to actually be able to control boost n00b style, is amazing.

I'm giving the previous owner (JohnnyT) shit because the car feels 10x better than he's ever had it.

[SRTie4k]

I just made a 17psi map real quick and boost tuning is definitely way easier and more predictable.

[Dano]

Originally Posted by bmorrisj also with boost tuning you remove variables like.. which load table A-E is going to be used at any given moment the only concern is ol/cl transitions

you can remove that variable by setting your CL Max Throttle tbls to 100 and set your CL Max Load D tbl to like 1.1 and you will always transition to OL at 1.1 load. oh for an MS6 I think the table to change is E. I don't think it hurts anything to change all of them to the same. Just set them to 1.1 from 500 to 4.5K. You can leave the lower values there to RL as you will always be above those load points. FYI, you can see that in OEM trim, the ECU tries to stay in CL until 4.5K.

Once you make that change ensure that your fuel tables are changed to match. Meaning start at the 1.1 row in the 3D fuel tables and enter your desired AFR. Make them all match and your are good to go and will have very stable fueling.

[amoosenamedhank]

Originally Posted by Dano2010 you can remove that variable by setting your CL Max Throttle tbls to 100 and set your CL Max Load D tbl to like 1.1 and you will always transition to OL at 1.1 load. oh for an MS6 I think the table to change is E. I don't think it hurts anything to change all of them to the same. Just set them to 1.1 from 500 to 4.5K. You can leave the lower values there to RL as you will always be above those load points. FYI, you can see that in OEM trim, the ECU tries to stay in CL until 4.5K. Once you make that change ensure that your fuel tables are changed to match. Meaning start at the 1.1 row in the 3D fuel tables and enter your desired AFR. Make them all match and your are good to go and will have very stable fueling.

I changed my CL Max load/CL max throttle tables the same time I enabled 'boost based tuning'. Because of this, I unfortunately didn't get the chance to feel what each brought to the table independent of each other.... but man, between the two of them, this thing is as smooth as butter.

It has made me completely fall back in love with driving the car.

[Dano]

hahah

well I made my CL changes way back when....almost a year ago while working around the load cap...so I can tell you that both offer great control over what the motor does but the pressure based boost tuning is what really makes the control over power smoother.

keep the comments/ideas coming.

[SRTie4k]

From reading earlier posts, it looks like you state the the Boost Dynamics table makes modifications to the WGDC if boost is off. Are you sure BD doesn't actually modify boost targetting? If you look at the subtitles, it says "Boost Compensation" as opposed to something like the Boost Comp IAT in which the subtitle says "WGDC Compensation".

[Dano]

It is accepted knowledge the Boost Dynamics and Load Dynamics tables alter the values in the WGDC table to achieve either target boost or target load respectively. In reality the BD table IS performing "boost compensation" as it determines boost is either too low or too high and the only way for it to adjust boost is through WGDC.

Also, Cobb labels the tables and notes so you can take that with a grain of salt. Keep in mind when Trey de-codes the tables there are not labeled like we see them in ATR.

[SRTie4k]

Yeah I figured that out after zeroing out the negative BD values. So far I've got my boost exactly where I want it past 4000RPM, and boost doesn't spike at all between shifts. Now I'm just trying to adjust the initial spoolup WGDC to hit 17psi.

Whatever the case, this method of tuning with the AP is 10x easier than load based tuning, and a lot easier to prevent spiking.

[Dano]

tuning spoolup, my friend, is where the fun begins...LOL

I should have some updated WGDC and BT values in a day or so that are very different than what I have posted now. I just need to verify they are stable.

[manelscout4life]

Originally Posted by Dano2010 Once you make that change ensure that your fuel tables are changed to match. Meaning start at the 1.1 row in the 3D fuel tables and enter your desired AFR. Make them all match and your are good to go and will have very stable fueling.

Dano would you mind posting your fuel tables I'm curious to see how yours looks compared to mine

Are you talking about changing the CL Commanded EQ or OL/Part Throttle Commanded EQ

[Dano]

my entire map is in post #1 and the only map changes have been with regard to boost tuning so the fuel tables in the map are what I am running now.

now I am exiting CL at 1.25 load so a bit higher than in my 1.1 example...just don't want to confuse anyone. I started out at 1.1 but moved it up to 1.25 which removed some of the touchy throttle response. I think most guys that are forcing CL exit are doing it at 1.1. It probably doesn't really matter as long is you are in that general area. when going WOT you fly through those load points very fast anyway.

[m4tic]

i cant read your ATR map... can you post up your 3d fuel tables... i want to make sure i understand what you're saying about making them match

[Dano]

Well this guide is for MS3s we don't like MS6 guys...move along, nothing to see here...LOL


Fuel tables I have changed the "unused" and throttle closed are OTS

after making the changes at the load point you choose, you will want to IP, interpolate from your new AFR value up about 6 rowes to smooth the transition out.

And I think it goes witout saying but I'll say it anyway, when you make fueling changes please log log log and make sure things are responding correctly.

[m4tic]

ahh i see.. guess i caught the gist of it, thats what i laid out.
we dont have a fuel OL commanded base table

[Dano]

do you know which table on a 6 is for CL Max Load? IIRC it is E but I don't know for sure.

[cld12pk2go]

I got my Grimspeed installed in intercept mode.

I capped off the turbo boost source line with the pill in it. I also capped off the top (smaller) wastegate actuator port.

Configuration:

Port 3 to boost source (I tapped into my silicone hose coupler on the discharge of my turbo).

Port 2 to wastegate actuator (using lower, larger port).

Port 1 is vent to atmosphere (will probably eventually connect to the turbo inlet pipe).


The way it works in this configuration is that with 0% WGDC (solenoid not energized), the path is always open from boost source to wastegate actuator (will run spring pressure).

As WGDC is increased it restricts the boost source to the wastegate actuator (increases boost).



This is flipped from the recommended setup for bleed, which is:

Port 1 = Top port on wastegate actuator
Port 2 = Turbo Inlet Pipe

In this configuration 0% WGDC means no flow (bleed), which will result in just running spring pressure.

Increased WGDC will increase the amount of pressure bled from the wastegate actuator, which will increase boost.

Hope this clarifies things...

[Dano]

That's how my Grimm EBC is routed. intetested to see how you setup your DC tables and are you going to use the OTS BD table? it seemed way to reactive for EBC 3 port.

[m4tic]

we have CL max load a-d .. C i the prime table we believe

@cld12pk2go
it doesnt matter what port on the wga you use since its straight through... just capping the bottom is harder to reach if the cap splits and starts bleeding boost away from the wastegate

[cld12pk2go]

I started with my WGDC table at 10 from 2000-7000 RPMs and aiming for 17 PSI in boost targeting mode.

I know that I experience boost creep with my stock K04 when it is cold out. Typically, I creep to ~18-19 PSI when it is 20°F around 4000 RPMs when just running spring pressure. As the compressor efficiency falls off up top my pressure falls to ~15 PSI (again on spring pressure).

My current BD table is as follows:

0.08 0.05 0.03 0.02 0.00 0.00 -0.01 -0.06 -0.12 -0.30 -0.70

Originally Posted by bmorrisj @cld12pk2go it doesnt matter what port on the wga you use since its straight through... just capping the bottom is harder to reach if the cap splits and starts bleeding boost away from the wastegate

Correct. I used the bottom b/c I was running 1/4'' hose.

[Dano]

I have now worked my way back up to Christain's BD table from the neutered version I was running.

0.04	0.02	0.01	0.01	0.00	0.00	-0.00	-0.01	-0.02	-0.04	-0.09

I see you are allowing the BD table quite a bit of authority to reduce WGDC but keeping things tight in the under run area. I did find that if I allowed BD any compensation for 1PSI over or under the EBC was way too reactive so I'll be interested to see how yours turns out with the -0.01 in your 1psi over run cell.

with not allowing any compensation in the 1PSI area I have found that having your WGDC table spot on actually is a bad thing as BD will let you "Hang" out in a 1PSI error state until the next RPM range. Does that seem possible to you 12pk?

[Frequentflyer]

Originally Posted by Dano2010 Well this guide is for MS3s we don't like MS6 guys...move along, nothing to see here...LOL Fuel tables I have changed the "unused" and throttle closed are OTS after making the changes at the load point you choose, you will want to IP, interpolate from your new AFR value up about 6 rowes to smooth the transition out. And I think it goes witout saying but I'll say it anyway, when you make fueling changes please log log log and make sure things are responding correctly.

Confirm you're running a meth system? My fuel tables mirror yours except I'm targeting 11.6 at WOT without meth. It keeps me a little more warm and fuzzy.

[Dano]

yes I typically spray 100% meth on a 7 nozzle but my local shop is out for the season so I am running 5050 water/heet for now. 7 nozzle isn't big enough to change my AFR so I need to step up to a 10 and tweak my trigger points to end up with gph flow of something like an 8 or 9 nozzle size.

FF you could go up to 11.8 and just fatten up the 5.5k and up range where the K04 starts to heat up. may give you a bit more kick IDK probably have to have it on a dyno to see any difference LOL.

[Cataphract_40]

dano, thanks very much for all the great info in this thread. I've been quietly following along and am now successfully running an 18psi tune using boost based tuning.

My AFRs are the most stable they've ever been...11.76 all day long, solid as a rock. You kick ass man!!

[manelscout4life]

Originally Posted by Cataphract_40 dano, thanks very much for all the great info in this thread. I've been quietly following along and am now successfully running an 18psi tune using boost based tuning. My AFRs are the most stable they've ever been...11.76 all day long, solid as a rock. You kick ass man!!

Can you post up your map so I can compare to mine