Stroked LS2 SDOL tune T56 car E40 pcm - bog on hard shift at redline log attached

[schpenxel]

They told me they couldn't add it.. let me know if you get a different answer!

[dankmac]

I will keep you posted.

Sounds like my best option is to slow the opening rate of the throttle - which in my opinion is kinda sucky.

When I'm running MAF only shouldn't dynamic air and MAF be reporting identical values? On the shift it still was not. I don't have a log handy right at this moment. The MAF peaked with an overshoot immediately and settled. It mirrored the MAP sensor in response time whereas the dynamic air seemed to truncate and take time to reach the max value almost as if it was over damped with a filter or something...

[schpenxel]

"MAF only" isn't actually "MAF only". VE table is still used during quick changes, transients, etc.

There is no true 100% MAF only mode on these ECM's, despite what a lot of tuners say and do

[Lakegoat]

I don't know why you don't just run that thing in SD Closed loop, no MAF. A lot easier tuning and you fueling will be correct when you get the VE table dialed in. Did you know that you had 30-31 degrees of timing at WOT? That car must be light.

[dankmac]

The car weighs 2850 with a half tank. It likes the timing with the 4" arm it really surprised me.

I want to be running SD closed loop in the long run. Probably STFT only to prevent the long terms from influencing WOT fueling. This bog issue has kept me from working to finalize the VE table and re-enable closed loop.

[GHuggins]

You can't dial in the VE table with any sort of hard throttle transition any way... You should never dial in the VE table that way... You need to dial in the VE table with constant slow throttle movement... Everything else is transients I assume you have Lakegoats tune saved as he removed it - yes? Copy over his injection timing tables and transient settings, dial in your VE or use cylinder math calc to do so - it will be overly rich and actually help a little with your issue... If you use the math calc - make sure your MAF is dialed in correctly... Do all of this with steady slow throttle movement except for the higher engine speed wot tuning If you do this - it should get things extremely close...

[dankmac]

Shoot I didn't save it yet.

I definitely agree with what you wrote though. I am lucky to have good stretches of road by me I can go from idle to redline in the bottom 4 gears without getting arrested. I'm happy enough with the part throttle drivability and AFR's are safe enough to be driving on until I can get it on a dyno. Hard to motivate myself to drive around in circles for hours again when I have access to a dyno if it ever stops raining (rollers are outside). I've done a good number of road tunes using that strategy despite how crappy my logs look here. Trying to fix the bog has left things looking kind of mangled.

I was actually happy enough driving on my open loop tune and have a good few thousand miles doing so. It was on my todo list to go back to closed loop but my only real gripe was the bog running speed density which I assumed would happen either in open or closed loop speed density.

[dankmac]

Support@hptuners asked me for a table ID for manifold volume. Where would I find that?

[GHuggins]

It's ECM 12003, but it's not available on the E40's... I'm sure if you ask Lakegoat nicely he might email you his tune... His tune had good transient and injection tables

[Lakegoat]

Here it is again, thought you got a copy. When you get rid of the MAF, be sure and find a place in the intake stream for the IAT sensor.
And, Thanks to several guys on here otherwise my tables would be all screwed up.

[dankmac]

One thing I've been thinking about - I have an LS3 top end.

Things like intake manifold volume, throttle body diameter... The LS3 plenum and port volume certainly are larger than the LS2. How any variables like this are going to be hard coded into the LS2 cal.

Should I be using a lot more LS3 based tables? Transient fuel, timing table

Here it is again, thought you got a copy. When you get rid of the MAF, be sure and find a place in the intake stream for the IAT sensor.
And, Thanks to several guys on here otherwise my tables would be all screwed up.

Thanks for re-uploading it. I had planned on coming back to it. I did change some of those Engine Diag values you suggested and didn't get anywhere with it. I checked for codes first and didn't see them.

Jealous of your low RPM airflow with that blower haha.

I noticed that your EVAP transient are still stock compared the stock GTO tune. You did fine with just the impact transient?

Based on the other thread I think I will slow down the throttle opening rate and hopefully that will overcome the issue...I just don't know how lame that will be. I also just need to turn the MAF back off I can't drive it much with how bad it is misfiring.

I think I will go back to SD and try a couple more tweaks. Then focus on carving out some time to swap my intake and put the headers on and start fresh.

[Lakegoat]

I have made so many tweaks to this tune that I don't remember what I changed in the impact. I can tell you that I have had 3 different cams in the last 10 months and one was a 244/256 and I didn't make any changes other than the VE tables and base running airflow. No bucking, surging or any of that. I had a lean blip from idle (in gear) when I tried to ease down on the gas. In the ve table I just increased the few blocks that it was occurring in, and it is gone. You can see the little hump in the ve table at low rpm in 3d mode. I tried several other changes to get rid of this, but the changes just caused other problems.
My GTO had a 6 speed before I swapped in the '80e and I never had the issue that you are having. You might check your ve table against your log where the bog happens and see if it happens in the same spot in your ve table. You may be running lean/rich in that spot. You said that to consistently get the bog, you had to completely let off the pedal. Hope you find the problem.

[dankmac]

Do you have an old log when you had a 6 speed and ran speed density? I'm really curious to see if your dynamic air calc is lagging behind the MAP sensor like mine does.

[Lakegoat]

I looked at your timing table and there is a big change from the 30-31 degrees to maybe 8 degrees when you let off the gas, and then back to 26-28 when you get back on the gas. Sort of like on my '13 pickup when it shifts and the torque table pulls timing and it feels like it slows down. Maybe you could smooth that out and have a better transition? Just guessing here

[Lakegoat]

No, not any more. It has been a few years

[Lakegoat]

Did you check the part number on the MAP sensor and identify what it is?

[dankmac]

I looked at your timing table and there is a big change from the 30-31 degrees to maybe 8 degrees when you let off the gas, and then back to 26-28 when you get back on the gas. Sort of like on my '13 pickup when it shifts and the torque table pulls timing and it feels like it slows down. Maybe you could smooth that out and have a better transition? Just guessing here

In my log it shows the timing actually spikes upward between shifts. I think it takes a moment before the coastdown spark starts.

My MAP sensor came off a 2006 GTO I took my engine or of.

[Lakegoat]

Cure= get a 2 step so you can no lift shift.

[10_SS]

my E38 spikes lean to 29.4:1 at WOT shift above 4000rpm, and this is with a delayed Throttle Opening rate. This may be the same problem. Did you try it below 4000rpm, like 3500rpm than nail throttle? Again, only way i made mine "ok" was to reduce throttle opening rate. Below 4000rpm I get plenty of Transient fuel, no problems. Just above 4000rpm the problem.

[dankmac]

my E38 spikes lean to 29.4:1 at WOT shift above 4000rpm, and this is with a delayed Throttle Opening rate. This may be the same problem. Did you try it below 4000rpm, like 3500rpm than nail throttle? Again, only way i made mine "ok" was to reduce throttle opening rate. Below 4000rpm I get plenty of Transient fuel, no problems. Just above 4000rpm the problem.

Mine rarely bogs when I punch it from part throttle. I have done both above and below 4k but haven't done it back to back to log it. The shifts are consistently bad. I should do the below 4000/above 4000 thing and see what the transient is like.