Changes to the DAL table ???

[Super Sky]

If I make changes to the DAL table it seems like it takes a couple of ignition cycles to take effect.

Example, I'm running say 20lbs of boost. Bump the DAL from 195 to 200. 1st run boost goes to 30lbs of boost. A couple of ignition cycles later boost steady at 22lbs. This is with a BW 6758 turbo. I believe this symptom had me chasing my rear for a while.

What is your experience with this ???


This is on a 2007 Sky Redline.

Thank you, Larry.

[cobaltssoverbooster]

can you post a tune file? i believe something is interfering with your results possibly causing a learn down.
There is a learn in which can be more drastic if other tables aren't calibrated close enough to the learned in factors but its usually not that aggressive once the learn down mode features are disabled.

[Super Sky]

can you post a tune file? i believe something is interfering with your results possibly causing a learn down.
There is a learn in which can be more drastic if other tables aren't calibrated close enough to the learned in factors but its usually not that aggressive once the learn down mode features are disabled.

Cobalt, I will see if I can post a tune file tomorrow eve. I'm going to test it a little more tomorrow morning. I have the WGDC at 90% and the DAL table max set at 200. I ran a couple of highway dyno runs tonight and max boost was around 25lbs. My gut feel is if I reflash the same program back in tomorrow it wll boost 30lbs for a few ignition cycles. We shall see.

Thank you, Larry

[Super Sky]

can you post a tune file? i believe something is interfering with your results possibly causing a learn down.
There is a learn in which can be more drastic if other tables aren't calibrated close enough to the learned in factors but its usually not that aggressive once the learn down mode features are disabled.

Cobalt, I reflashed a couple of small changes to the DAL table today and it did not act as previously described. I have attached a copy of my latest tune.

It is running 19lbs of boost at 4,000
21lbs 4,500
22.6lbs 5,000
25lbs 5,500
24.6lbs 6,000

I believe I'm happy with those numbers. I race it on road courses (HPDE) and don't want to stress it too much. It pulls pretty strong.

Cobalt, and all others me know what tweaks the tune needs.

Thank you for your help.

Larry

[TurboCobalt]

I haven't looked at your tune but if you have WGDC of 90 i think that's too high for a BW 6758 turbo.
What you are experiencing is the vehicle "learns" or adapts to your hardware and reduces the WGDC. I think you would benefit from turning down WGDC, probably a lot.

EDIT: this may not help much with WGDC, but might be fun to play with Borg Warner match-bot, since they actually have the tables for the 6758.
http://www.turbos.borgwarner.com/aft.../matchbot.aspx

[cobaltssoverbooster]

your pe table is all fucked up.. never run a di ecotec engine under 12:1 under boost. it causes all sorts of cylinder wash, oil quality, and missing issues. Generally speaking they tend to enjoy the .86 lambda range. fix it and your performance will increase by a fair amount.
turn your etc, iat , afr spark modifiers off. use the main spark to set a base and then come in and make adjustments to the others as needed. the factory settings are not setup for aftermarket setups and cause people to wonder why things arent as commanded all the time.

if i were you i would target a lower wgdc count than 90%. to do this bump your dals up and lower the wgdc to a range that is controllable. anything around 90% gets a dal adjustment to keep it closer to the mid 80's. this prevents circuit overheat on the solenoid and maintains a stable control range on the wg control mechanical circuit. the rest looks fairly well setup. One reason you cant exceed 25 psi consistently is because your max boost limit is set to 247 kpa which is under 23 psi. one run from another it trims itself back to meet the boost max requirement.

overall good start

[Super Sky]

Cobalt, than you for your input. Looks like I got a little work to do. I knew I was running it on the rich side. When I had the Trifecta tune with the stock turbo they were around 11.0 WOT. I guess I figured the richer the better. I will fix it. Going to bring the WGDC down and adjust DAL as needed. I'm starting to understand a little of this if I don't blow it up first. I'll make some changes before my road course event this weekend. I also have a water meth injector installed. It runs cool on the street (187 to 189) coolant temp. with no injection. If I give it 3 or 4 boosted runs back to back the coolant temp will come down to 183 to 184. Who would have thought.

I'll let you know how she does this weekend.

Larry

[cobaltssoverbooster]

after running that rich you may need to change plugs before calling the tune finalized. Run standard NGK 7 range plugs and pinch them to .028" throw them in and call it done after a quick test log to verify running conditions havent changed.

almost forgot.....when leaning out to the proper setting dont forget to re-visit the spark advance and dont exceed 15* ignition until you know the rest of the system is good.

[Super Sky]

after running that rich you may need to change plugs before calling the tune finalized. Run standard NGK 7 range plugs and pinch them to .028" throw them in and call it done after a quick test log to verify running conditions havent changed.

almost forgot.....when leaning out to the proper setting dont forget to re-visit the spark advance and dont exceed 15* ignition until you know the rest of the system is good.

I have it leaned out now. Runs about 11.9 or so at WOT at 6,000 rpms. After 75 miles plugs looked good. I dropped the WGDC from 90% down to 70%. This dropped the boost to 20 psi. I raised the DAL from 200 to 245 in 5 steps. This raised the boost to about 23 psi. I'm taking it to the road course this weekend. I will probably run a few sessions at this setting and then may bump the WGDC from 70% up to 75% to see if it raises the boost a little. I think I would like to see around 24 or 25 psi. It is running very strong at it's present setting. It is running a steady boost pressure now and is not so erratic. No knock retard at all.

Thanks for the help, Larry.

[ECaulk]

I have it leaned out now. Runs about 11.9 or so at WOT at 6,000 rpms. After 75 miles plugs looked good. I dropped the WGDC from 90% down to 70%. This dropped the boost to 20 psi. I raised the DAL from 200 to 245 in 5 steps. This raised the boost to about 23 psi. I'm taking it to the road course this weekend. I will probably run a few sessions at this setting and then may bump the WGDC from 70% up to 75% to see if it raises the boost a little. I think I would like to see around 24 or 25 psi. It is running very strong at it's present setting. It is running a steady boost pressure now and is not so erratic. No knock retard at all.

Thanks for the help, Larry.

Running 11.9 is still to rich for a DI ecotec, try getting closer to 12.6

[Super Sky]

Running 11.9 is still to rich for a DI ecotec, try getting closer to 12.6

Now you guys are really making me nervous. Hell I was afraid going to 11.9. So just to be clear, you feel 12.6 at WOT on 24lbs of boost at 6K rpms would be safe??

Thank you, Larry.

[ECaulk]

I've been running at 12.9 for over 60k miles on a KO4+ boosting to 23-24psi. If you keep running at 11.9 you'll likely loose a cylinder due to the issues CSSOB mentioned above. Don't let your port injection experience taint how the DI engines work, the LNF/LDK like things leaner than a port injection ecotec.

[cobaltssoverbooster]

stock gmpp pe is set to 13:1 under boost of roughly 18psi and 13.3 at roughly 13 psi.

[Super Sky]

stock gmpp pe is set to 13:1 under boost of roughly 18psi and 13.3 at roughly 13 psi.

I was wondering today what the GMPP tune was set at. That is very interesting. I may lean her out a little more this weekend. Let me get a little more data. My plan is to run a30 min. session as it is now. If all goes well I'm plan to raise the WGDC from 70% to 75% to see if I get another lb. or 2 of boost. I will be watching the A/F and the knock retard closely. Then if all looks good for a couple of 30 min. sessions I may lean her out a little.

Thanks for all the help guys.

Larry

[Super Sky]

stock gmpp pe is set to 13:1 under boost of roughly 18psi and 13.3 at roughly 13 psi.

OK , went to the track today. Car ran strong. So strong the clutch is starting to slip in 3rd and 4th gear pulls.

But a new issue showed up. It went into limp mode with an error code of P0234. Overboost condition. Never seen that in my street dyno runs. I had my Boost limits pressure limit set pretty close to my max boost. Is this the variable it looks at to trigger that P0234 code ???? If so I'll set it around 60psi and be done with it.

Thank you, Larry

[cobaltssoverbooster]

disable overboost test

[Super Sky]

disable overboost test

I disabled the overboost test and it kept it from posting an error code but it still went into limp mode with no pending DTCs. I took the car of track and did 16 runs to 6,800 with 22 lbs of boost in 2nd and 3rd gear. No problems, car ran great. At the track I only run 3rd and 4th. I finally determined it was only getting this overboost error when I was in 4th gear and that was because the clutch was slipping. I guess it was running 22lbs and the clutch started to slip which decreased the load on the engine and it triggered an overboost condition. I will do a little more testing tonight but it looks like it was the clutch slipping that was causing the error.

Larry

[Pmj-07]

I had the same 0234-issue on my 2010 Opel Insignia 2.0 Turbo with the A20NHT engine ( also called LDK) , similar as in 2011 Buick Regal cxl. I solved it by increasing the Allowed Overboost Error somewhat.

See also thread

https://www.hptuners.com/forum/showt...-A20NHT-26-psi

[Super Sky]

I had the same 0234-issue on my 2010 Opel Insignia 2.0 Turbo with the A20NHT engine ( also called LDK) , similar as in 2011 Buick Regal cxl. I solved it by increasing the Allowed Overboost Error somewhat.

See also thread:

https://www.hptuners.com/forum/showt...-A20NHT-26-psi

PMJ, thank you for the info. So I guess we are saying that the "overboost enable RPM" does not work as I have it set @ 10,200. I will be raising the " Allowed overboost error" value.

Thank you, Larry.

[cobaltssoverbooster]

overboost enable is a test parameter. this prevents the code from being thrown. you still have to go in and raise any limits that prevent you from going higher. if one of those limits includes allowed overboost then you may need to raise that to keep going higher.
my tuning style modifies everything, even if it isnt necessary because it falls under a coding table such as overboost enable.