2003 C5 M6 Big cam Idle dips/dies

[TrackDriver]

My recently modified LS1 was built with a Fast92, 90mm LS2 TB, Comp Cam (231/242 .617/.593 112 LSA (14 deg. overlap). It made 450 rwhp on a loaded Mustang Dyno (92 degree ambient temp day). It runs like a beast on the track. It drove like ass in a parking lot. By reading every related post by mowton and Chris@HPTuners (Thank you Gentlemen), I was able to eliminate the return to Idle hang by reducing the low RPM Cracker air. I was able to slow the return to Idle with the Follower. Rolling Idle RPM set to 950. Rolling Airflow adder is .2 g/S across the board.

All is good until I depress the clutch. Then the RPM dips to ~600, or it just dies. I understand the TC and TF are disabled when clutch is engaged.

I noticed the the RAF table was zeroed in the P/N row. As a "shot in the dark" I populated that row with the airflow numbers that were in the In-Gear row.
and... VIOLA! Now when I depress the clutch, the RPM's drop to my Rolling Idle RPM and does not dip!!!

This leads me to a few questions...

Chris@HPTuners stated that the Rolling Idle "was a mode of the TC". Is the Rolling Idle and it's associated airflow adder also disabled with clutch in?
Is the RAF (P/N) used when the clutch is depressed until the RPM's drop to a point that Adaptive Idle takes over?
Does this tuning S/W consider P/N (Automatic) values the same as Clutch-in (Manual)?

Looking forward to any wisdom you gurus can share. Thanks for reading.


See my last post for fix.

[TrackDriver]

Bump

[anniversaryss]

I was under the impression the P/N is used on just autos. But then again im still new to this.

[TrackDriver]

That's what I thought too. I was hoping to get my questions above answered but, no resident tuning gurus have replied to my thread.

[TrackDriver]

124 views, and 1 response.

I do have to update my original post. Filling in the P/N BRAF did not stop my throttle dipping.

Help?

Here is my tune

[outoftune]

TrackDriver, I'm in a comparable situation. C5 Vette, N/A Ls2 bottom, ls3 top with higher compression pistons, large Comp Cam over 600 lift with a high 240 duration, ls3 intake with ls2 throttle body. Larger injectors with all injector data downloaded LS3 mass airflow with scaling copied from an LS3 Camaro stock. Have good amount of trouble starting engine unless I go above 20% throttle. After about 30 seconds idle settles in to about 1000rpm. It will idle all day long with long-term fuel trims within 4% and even better once you throttle up to about 3-4 thousand RPM .Once U let it come back to idle almost always stumbles below idle then stalls unless you keep the revs below 2500 it seems . Probably going to post my tune and some logs for some help. I work nights and usually pull the rest of my hair out during the day trying to figure this out. Done a fair amount of reading on forum tried a whole bunch of things to no avail. Definitely on a steep slope with learning curve of hptuners ! Have an appointment with a tuner in about a month but I'm trying to get it as close as possible so they don't waste too much time! I'm in New York about 50 miles out of the city. I'll try to keep you posted on what I find works if anything over the next week. Please do the same good luck!

[DougO]

https://www.youtube.com/watch?v=o_2gtlGy_UU
Try this tutorial.

[TrackDriver]

Thank you, but this tutorial is for an Automatic. My car is a manual, and has Clutch-in Idle issues

[TrackDriver]

Thank you outoftune for the reply.
I have done a ton of reading too. LOL It seems that the consensus is for Idle dip/droop is to adjust Throttle Follower Airflow/Decay tables.

(FWIW, I am by no means an expert but, you should not have to give your car 20% throttle to get the car started)

[DougO]

http://www.masterenginetuner.com/
I bought this book writtten by Dan Maslic for $20.00 there is a lot of great info in it.

[TrackDriver]

Well, I was finally able to tame the drooping/dying Idle on Clutch-in. As Chris@HPTuners and mowton have said... It's all in the rolling Idle. They said to start populating it with .2 g/S across the board and adjust from there. What I found worked the best for me was to copy the vertical RPM row in the Throttle Cracker table that aligns with your desired Idle RPM.

Now, "Clutch-in" idles down at the same rate and stops at my desired RPM as "Clutch-out" does.

Thank you Chris@HPTuners and mowton (Ed) for your insight.

[anniversaryss]

Well, I was finally able to tame the drooping/dying Idle on Clutch-in. As Chris@HPTuners and mowton have said... It's all in the rolling Idle. They said to start populating it with .2 g/S across the board and adjust from there. What I found worked the best for me was to copy the vertical RPM row in the Throttle Cracker table that aligns with your desired Idle RPM.

Now, "Clutch-in" idles down at the same rate and stops at my desired RPM as "Clutch-out" does.

Thank you Chris@HPTuners and mowton (Ed) for your insight.

That's good to know. I assume rolling idle only is used for manual cars and clutch engagement?

[cobaltssoverbooster]

I was told that when the os is set to manual transmission populating both braf sections is not necessary because the switching function for toggling the tables is disabled.
this is why conversions from manual to auto require a segment swap instead of just toggling the trans type.

I have not verified this by toggling the signal for p/n to see if it switches over so i can not say with 100% confidence that this is true. I was told years ago by another user that this was the way it was. Maybe Chris can drop a reply to tell us how it is.

[TrackDriver]

I was told that when the os is set to manual transmission populating both braf sections is not necessary because the switching function for toggling the tables is disabled.
this is why conversions from manual to auto require a segment swap instead of just toggling the trans type.

I have not verified this by toggling the signal for p/n to see if it switches over so i can not say with 100% confidence that this is true. I was told years ago by another user that this was the way it was. Maybe Chris can drop a reply to tell us how it is.

I have validated that if you populate the BRAF P/N (for a manual) doesn't do anything for clutch-in Idle. Clutch-in operation is all about the Rolling Idle table.

[cobaltssoverbooster]

Thanks for sharing that.

[ryan_axberg]

I would put some stock values back in your PID settings and go from there. Also not related to idle but the power enrichment eq ratio should be around 1.18 for a na engine

[garrettg]

Well, I was finally able to tame the drooping/dying Idle on Clutch-in. As Chris@HPTuners and mowton have said... It's all in the rolling Idle. They said to start populating it with .2 g/S across the board and adjust from there. What I found worked the best for me was to copy the vertical RPM row in the Throttle Cracker table that aligns with your desired Idle RPM.

Now, "Clutch-in" idles down at the same rate and stops at my desired RPM as "Clutch-out" does.

Thank you Chris@HPTuners and mowton (Ed) for your insight.

Any Chance you could post your tune or values for all the rolling idle settings. I am struggling with this as well after installing a sloppy stage 2 cam, it wants to choke itself anytime I push in the clutch below 5mph.