My Unassuming RBP LGT Journal/Tuning Thread

[Scooby2.5]

You order the FMIC new from AVO?

[joeleodee]

You order the FMIC new from AVO?

 

No, Fred Beans.

 

Had some issues in my learning view. In the mid ranges, I was seeing -10s to -11s. Dropped my scaling in those ranges by 5% and yielded pretty good results. One thing is questionable. That low load/low RPM FLKC. Haven't ever seen that drastic of a number and don't know if that's something to worry about in that range.

[chimera]

Out of curiosity update your version of LV to the latest see if you get different results, I'm sure when I did this a few weeks ago my LV values were slightly different (before you ask, i did no driving in between upgrading!)

[joeleodee]

The reason I don't upgrade is I can use either my tactrix or Cobb v1 cable to run my LV. I don't know that the new version will be compatible with my old v1 cable.

[chimera]

I think LV will be fine, just ecuflash that's the problem. LV is obviously just one executable file. I'll test this tonight, as I'm sure I saw different results... but it may have just been one beer too many

[fahr_side]

Had some issues in my learning view. In the mid ranges, I was seeing -10s to -11s. Dropped my scaling in those ranges by 5% and yielded pretty good results. One thing is questionable. That low load/low RPM FLKC. Haven't ever seen that drastic of a number and don't know if that's something to worry about in that range.

Remember that timing is calculated from load, which is calculated from the MAF scale. If you adjust MAF scaling lower, meaning you have a lower load number for a given MAFv, you reduce the load value the ECU will calculate and in a timing table set up in the normal way that will further advance timing for that combination of MAFv and rpm.

 

Another thing to watch out for is pre-emptive knock correction due to overboost. Not all year models have this logic, but it's something to look at especially if you make changes that for example improve spool or hold boost better at high revs. The ECU will pull timing via knock correction when boost error values go negative, sometimes with a small time delay. Do some logs and check if you have overboost in the areas you see the FLKC values set.

[joeleodee]

^ Thanks for the suggestion. I'll look into that. I'm by no means a proficient tuner. I'm just learning as I go so help is appreciated.

[fahr_side]

^ Thanks for the suggestion. I'll look into that. I'm by no means a proficient tuner. I'm just learning as I go so help is appreciated.

 

We're all learning as we go. I feel very sorry for those without the humility to accept that.

[joeleodee]

Took the car out after doing some more fueling adjustments and I got my AFR curve right where I wanted it. It comes in a tad on the rich side to help spool and flattens all the way through redline. You can see it below. At first, I thought the WBO2 froze up on me again, but it was just that flat according to the data. 11.2-11.3ish throughout.

 

Now it's time to turn up the boost and advance a little timing for mo' powah! . Here's my question. Will adding a few degrees of timing in the higher load and RPM ranges have a significant effect in the observed AFR? Or is this something I shouldn't worry about?

[joeleodee]

BTW, the reason I didn't turn up the boost last night; After sweeping the area for other cars/cops, I made my initial run. I pulled into a nearby parking lot to observe the datalog and a cop car pulls in behind me. I'm thinking 'Oh shit!'. They're lights are on my cabin, but no cherries. As they approach and I roll the windows down, they ask, "Did you call 911?" Apparently, a call came in from someone in that area reporting a person shooting BB guns at cars. They politely informed me to leave that parking lot to avoid getting my car shot by BBs. I decided not to push my luck and brought the car back in for the night.

[fahr_side]

It comes in a tad on the rich side to help spool...

Richer AFR usually means lower EGT, which is less heat and less energy to spin the turbine.

There are two schools of thought for how how to handle this.

One says run less timing, leaner fueling and less AVCS advance to spin the turbine quicker and lower VE to quicken spool. The other says run as much timing as possible and raise VE with optimum cam advance to get best torque in this area, even if it costs spool.

 

I

Now it's time to turn up the boost and advance a little timing for mo' powah! . Here's my question. Will adding a few degrees of timing in the higher load and RPM ranges have a significant effect in the observed AFR? Or is this something I shouldn't worry about?

 

I'd suggest nudging timing up a degree at a time. Note that with stock heads and cams, volumetric efficiency drops off quickly after 6k0rpm so you can usually ramp timing up quickly after this point. This is because as VE falls, so does cylinder pressure.

 

Adding a small amount of timing will not affect measured AFR but you may find you have to add some WGDC to maintain your boost target. More timing should lower EGT a little which may reduce boost slightly.

[joeleodee]

Richer AFR usually means lower EGT, which is less heat and less energy to spin the turbine.

There are two schools of thought for how how to handle this.

One says run less timing, leaner fueling and less AVCS advance to spin the turbine quicker and lower VE to quicken spool. The other says run as much timing as possible and raise VE with optimum cam advance to get best torque in this area, even if it costs spool.

 

See, I've heard that a richer mixture with less timing on spool helps for quicker spool, but I've also heard this side of it. Perhaps I will experiment with both methods and see which best suits my setup. I'll keep researching and run my own trials.

 

 

I'd suggest nudging timing up a degree at a time. Note that with stock heads and cams, volumetric efficiency drops off quickly after 6k0rpm so you can usually ramp timing up quickly after this point. This is because as VE falls, so does cylinder pressure.

 

Adding a small amount of timing will not affect measured AFR but you may find you have to add some WGDC to maintain your boost target. More timing should lower EGT a little which may reduce boost slightly.

 

I was definitely going add only a degree at a time. What I'm trying to determine is at what load/rpm range do I add it to especially considering the above exchange. As well, I still have a couple degrees I can add in the knock advance table.

 

As far as boost goes, being that I'm running hybrid BC, wgdc is maxed at 100% wot and it's kept very consistent. It tapers by about 4 psi or so from peak to redline every single time. I'll be interested to see how/if timing affects that.

[fahr_side]

See, I've heard that a richer mixture with less timing on spool helps for quicker spool, but I've also heard this side of it. Perhaps I will experiment with both methods and see which best suits my setup. I'll keep researching and run my own trials.

It's a question of degree. If you're running so little timing that combustion hasn't finished when the exhaust valves open, you run a high risk of melting the valves. I'm a fan of tuning for torque. Torque accelerates the car, not boost. In your case you are running massively rich in the spool area. I'm impressed you're not getting misfires or even rich knock in that area. Try coming back to the low 10's in the dip there and see what happens.

 

 

I was definitely going add only a degree at a time. What I'm trying to determine is at what load/rpm range do I add it to especially considering the above exchange. As well, I still have a couple degrees I can add in the knock advance table.

I prefer to leave the Max KCA table pretty flat and increment timing up and down via the primary table, but everyone has their own style. What tools are you using to edit timing, Airboy's spreadsheet?

As far as boost goes, being that I'm running hybrid BC, wgdc is maxed at 100% wot and it's kept very consistent. It tapers by about 4 psi or so from peak to redline every single time. I'll be interested to see how/if timing affects that.

You really want to be tapering less than that. If you have an MBC in parallel with a 3-port then I don't see why you're peaking to 20psi if the MBC is set to vent at 16psi. If you're at 100% WGDC the whole way to redline then I don't see why boost is dropping off like that at higher revs. Something odd about this setup.

 

Would you post a log of that last pull?

[joeleodee]

Thanks for wanting to take a look. I'm at work now so I'll respond and post that log when I get home this evening.

[joeleodee]

It's a question of degree. If you're running so little timing that combustion hasn't finished when the exhaust valves open, you run a high risk of melting the valves. I'm a fan of tuning for torque. Torque accelerates the car, not boost. In your case you are running massively rich in the spool area. I'm impressed you're not getting misfires or even rich knock in that area. Try coming back to the low 10's in the dip there and see what happens.

 

My AFRs already dip into the low 10s upon spool. You'll see that in the log below. I like the idea of better torque.. I'll also post a shot of my base timing table for you to look at. Maybe you can steer me in the right direction to yield better torque by adjusting my table.

 

I prefer to leave the Max KCA table pretty flat and increment timing up and down via the primary table, but everyone has their own style. What tools are you using to edit timing, Airboy's spreadsheet?

 

Actually, to build a timing map, I tweaked a table that Edmundu used. Basically, I used it as a starting point and made some changes based on how my car was reacting. the reason is that my setup is so similar to how Edmund had his. His was on meth, though. However, I'm not familiar with how the Airboy's spreadsheet is used to edit timing so I'll have to look into that.

 

You really want to be tapering less than that. If you have an MBC in parallel with a 3-port then I don't see why you're peaking to 20psi if the MBC is set to vent at 16psi. If you're at 100% WGDC the whole way to redline then I don't see why boost is dropping off like that at higher revs. Something odd about this setup.

 

Would you post a log of that last pull?

 

There's another dyno plot of an AVO 450 on this sight that does the same thing. It's shown to peak at 26 or so and tapers to 21-22. The difference is that one hits peak at like 5k whereas mine will hit peak around 43-4400 rpm (4k in the colder weather). Maybe it is something I need to look at, though.

romraiderlog_20130629_235354.csv

timing.csv

[fahr_side]

I wouldn't try to replicate that boost curve of 26psi tapering to 22psi unless you're running E85 or water/meth injection. From what I've seen of this turbo it should be able to hold at least 18psi until redline, so I would be shooting for holding 20psi until say 5,500rpm and then steadily tapering off to 18psi at redline. Looking at your log, this is roughly what your targets are set to, so tweak boost control until you hit those targets. It looks to me like you have the MBC set too low and it's venting pressure to the wastegate actuator, even though WGDC is pegged at 99%. Remember that in a parallel setup like this, air pressure will pass through either the EBCS or MBC, whichever one offers the path of least resistance. Use the EBCS as your primary boost control device and the MBC to simply cap boost at 20psi to avoid spikes.

 

Your sampling rate in that log is pretty low, so resolution isn't great. If you're logging via Romraider turn on fast polling and make sure the ROM is patched for fast polling via CAN.

The raw timing values look okay and the curve is as it should be, basically a mirror image of the load curve. 12.5* is quite acceptable in the saddle there, at peak load. 19* up at 6k4rpm is likewise not overly aggressive IME. What you will find is that as you raise boost at higher revs you'll probably lose some timing, so once you have boost control sorted you may need to adjust that area to get that timing back. I couldn't open your timing table, but base timing by itself is only half the story. Total timing in the log tells me what I need to know however.

 

I was looking at the scale for boost pressure in that VD plot, not AFR. My bad. AFR looks quite okay for the most part but you could try edging up to the 10.8 range in the saddle to see if that improves spool. It should improve torque, if you can keep the same timing values.

[joeleodee]

I actually am currently running E85. Basically, the tune that I'm on right now is a conservative pump 93 tune with changes in the injector scaling and maf scaling so the car can run happy. That being said, I'm comfortable with adding some boost and timing to take advantage of E85. I could probably safely run a little more lean as well, but it's a work in progress and this has been a fun project for me to learn this stuff with.

 

Now, it's my understanding that in hybrid boost control, there's a couple different school's of thought. As you describe, my setup is not plumbed, nor tuned that way. If I'm understanding this correctly, the hybrid setup you're talking about keeps port #1 on the EBCS plumbed through to the turbo inlet. Conversely, my port #1 is capped. Mine is tuned so the MBC handles WOT boost, while the EBCS handles partial throttle boost. Hybrid setup eliminates one of the common gripes seen with MBCs which is PTFB, but keeps the positive aspects of tuning with an MBC such as quicker spool, no boost spikes, or what have you?

 

If what I have said is not sound, or I'm misunderstanding, tell me. I'm a novice at this as I've stated before so I always like to hear from others more experienced. One of the members in THIS thread is local to me and he walked me through this when I first started tuning for HBC. However, I am surprised that this turbo tapers by 4psi to redline with this particular setup. Perhaps HBC is not the ideal way to control the boost on this turbo.

[fahr_side]

Okay, but would've been nice to have that info from the beginning...

 

IMO you're missing the benefits of running on high octane fuel if you're running such low boost on that turbo. All the data on those turbos seem to indicate they only really come alive at higher boost pressures. Ask your tuner why he set it up that low.

 

As to boost control, an MBC in the loop usually does help with earlier spool. OTOH, I've never tuned a car with one plumbed the way you have it, either IWG or EWG, just as below:

 

http://i126.photobucket.com/albums/p99/drxt78/ewgdiagram2.jpg

[joeleodee]

Okay, but would've been nice to have that info from the beginning...

 

I'm sorry. That information is all in previous posts in the thread so I thought you were aware. But that reminds me that I need to update the OP. Thanks

IMO you're missing the benefits of running on high octane fuel if you're running such low boost on that turbo. All the data on those turbos seem to indicate they only really come alive at higher boost pressures. Ask your tuner why he set it up that low.

 

I am the tuner. I fired my previous tuner and started studying and tuning on my own with the help of a friend and the folks online like yourself. I loaded my previous healthy stg2 tune and went from there. As for the low setting, I'm slowly building up to higher pressures little-by-little. I started at 15psi and yes, all the research I've done has this turbo coming to life north of 20psi.

 

 

As to boost control, an MBC in the loop usually does help with earlier spool. OTOH, I've never tuned a car with one plumbed the way you have it, either IWG or EWG, just as below:

 

http://i126.photobucket.com/albums/p99/drxt78/ewgdiagram2.jpg

 

Perhaps I'll take the 1 minute and plumb port 1 to the inlet just to see if it makes any noticeable difference or a change in the recorded data.

[fahr_side]

I think there's something wrong with your boost control in that almost 80% WGDC across the board only got you that low boost level. Either the plumbing is off or your MBC is set too low. IIRC, the Avo actuators are pretty stout, at least 1bar, so you should be able to hold your boost targets easily.

[Strizzy]

What MBC are you using?

[joeleodee]

Grimmspeed MBC and Ebcs with 44mm EWG.

[fahr_side]

I wouldn't object if you just short-circuited the whole boost control system and logged what boost pressure you got simply off the EWG spring.

[Strizzy]

When I was tuning my HBC with my Hallman MBC, I couldn't boost past 20ish psi with the spring it came with, and had to swap out for the stiffer one.

How much more do you have on the MBC before it's maxed out?

[joeleodee]

I wouldn't object if you just short-circuited the whole boost control system and logged what boost pressure you got simply off the EWG spring.

 

Not a bad idea. Should be around 11-12 psi based off the springs stacked in there.

 

When I was tuning my HBC with my Hallman MBC, I couldn't boost past 20ish psi with the spring it came with, and had to swap out for the stiffer one.

How much more do you have on the MBC before it's maxed out?

 

The notches go up to 8 and I'm only at about 3. There's plenty left in the MBC and I've been holding this back to make sure everything else is in line before turning it up.