Throttle Cracker Tuning Question {B4309}

[voda1]

What version of the tuning software are you using here?

[pinstripebob]

What version of the tuning software are you using here?

I'm using v7.5. I have v8 mostly setup for scanning, but v7.5 seems a little easier since I've been using it longer.

[pinstripebob]

My thoughts on this are that for some reason the TR55's appear to be more suited to your engine than the TR6's for normal street driving. Keep the TR6 plugs... if you ever decide to go racing, you'll definitely need to use them when the engine is working hard all day.

This last log was a little bit shorter than I need... try to get me around 10,000 frames at full operating temperature. Also try to take a long way home which involves a good variety of driving. A log of mostly steady cruising isn't as useful to me as a log which has a good mix of accelerations and decelerations as well as some cruising.

Your return to idle is looking mostly decent, but transient fueling is messing with it in some situations... so we're going to try to eliminate as much of that transient issue as we can.

Not a problem! I've stashed the TR6s in my garage, I'll swap them the next time I go to a track.

I got a log, everything seemed to go pretty well. There were only a couple places where bucking was fairly noticeable. Frames 4837-4857 are probably the worst of the log. I altered my route and got a pretty good mix of cruising and accelerating, hopefully enough decelerating to help out.

I did some throttle blips at the end of the log as well. The first two blips are without headlights, the second two blips are with headlights and the heater on max. Let me know what your thoughts are, or if you need me to make any other changes. Thanks again for the help!

Log:
GTO March 25 2019 IBC to home.efi

[pinstripebob]

I remembered something I wanted to point out in case this helps troubleshoot the transient fueling that didn't want to cooperate. After I installed the cam and did some RAFIG logs/tunes, I did some logs and modified my B3702 EOIT table. I ended up lowering it about 0.13 reference pulses. I was having trouble understanding the spreadsheets people made, mainly because I couldn't find the boundary values anywhere.

I've done some re-reading and it makes sense to me now. I ended up changing my timing by 0.10 reference pulses, flashing the tune, and doing a log at operating temp idleing in my garage. I had about 10 different logs for different EOIT values. I plotted my MAP values versus my EOIT value and chose EOIT based on what gave me the lowest MAP reading at idle.

I wanted to point this out in case you wanted to look into changing B3702 at all, or if you thought this might be contributing to some frustration we've had.

[statesman]

I wanted to point this out in case you wanted to look into changing B3702 at all, or if you thought this might be contributing to some frustration we've had.

That was one of the first changes I made, and I told you about it. Back in page 2 of this thread...

I'm making some changes to your fueling... most notably, your injection timing. You were spraying really late... this is unwarranted with your cam.

[statesman]

Not a problem! I've stashed the TR6s in my garage, I'll swap them the next time I go to a track.

I got a log, everything seemed to go pretty well. There were only a couple places where bucking was fairly noticeable. Frames 4837-4857 are probably the worst of the log. I altered my route and got a pretty good mix of cruising and accelerating, hopefully enough decelerating to help out.

I did some throttle blips at the end of the log as well. The first two blips are without headlights, the second two blips are with headlights and the heater on max. Let me know what your thoughts are, or if you need me to make any other changes. Thanks again for the help!

Log:
GTO March 25 2019 IBC to home.efi

I think with a couple of more adjustments we should be able to cure most of the bucking. I'll try to get to your log in the next day or two.

[pinstripebob]

Yep I was way late, I had B3702 at 6.32 before you corrected it, sorry about that! Poking around a little more, do we need to lower B3703 a bit based on its description?

[statesman]

Poking around a little more, do we need to lower B3703 a bit based on its description?

No, I don't think so.

[statesman]

I altered my route and got a pretty good mix of cruising and accelerating, hopefully enough decelerating to help out.

Yeah, that was a good log for me to work with. Log the same route again this time if you can.

[pinstripebob]

Got it, same route logged! There weren't any horrible bucking situations, the worst was probably frames 5723-5813 while cruising at low speed/low TPS.

I got a few throttle blips as follows:
No headlights:
Frames 14487-14517
Frames 14516-14578

Headlights/heater:
Frames 14585-14634
Frames 14637-14687
Frames 14690-14742
Frames 14744-14782

With the headlights on, it seems like RPM comes back down nicely, hangs for a moment above idle speed, dips, then comes back up to idle speed. I had a few extra blips with the headlights on trying to get a couple blips that matched headlights off.

I am kind of curious about the times when my commanded AFR is 15.46:1. It looks like when I'm stopped and idling, after a moment the engine commands 15.46:1 for about 4 seconds then goes back to 14.68:1. FUELSYS-A is in OL-Drive. Out of curiosity, what part of the tune is making this happen? CL mode is 8 the whole time I'm stopped, so that isn't changing.

Anyway, attached below is the log. Like I mentioned above, overall it seems to behave pretty darn well under normal driving conditions. Let me know what you think, or if there are any changes/tests you want me to perform. Thank you!

Log:
GTO April 1 2019 IBC to home.efi