Hanging Idle, Base Airflow, and Throttle Follower help. - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

WVracer · 03-12-2022, 10:50 PM

I just finished having the car tuned by a reputable shop through email and HP tuners. It took over 20 datalogs and tune revisions but the tuner finally said he thought it looked good. I told him I'm still having some drivability issues but he said he the tune still looks good. I understand that it makes it hard to fix through email and I don't want to put a bad name on the shop so I'm just trying to sort my issue

My main issue is a hanging idle. My idle falls very, very slowly from 2000 to around 1100 then it remains there for about 10 seconds before returning to 825 target idle. Occasionally, it will hang at 2000 for a couple seconds, then hang at around 1600 for another couple seconds, and then fall to 1100 again and repeat. It seems to do it even more when cold. I tried lowering the Throttle follower values but it didn't seem to help much. I did try pulling some air from the base airflow tables but it worries me because based off other tunes I've seen from people with the same mods I'm already a bit lower in value on my airflow tables then them.

The car also does not buck at all, even at 1000rpms. Its my understanding that this cam should buck harder than a PBR champion.That makes me think the airflow is jacked somewhere either in the follower tables or the base airflow.

I also posted this over on the HP tuners forum. Since it wont let me post my tune file here I'll just post some pictures of some of the tables.

Its temping to just swap over to the GPI SS4 and have them tune it but I'm going to save money to flycut the pistons, a solid roller cam, adjustable rockers, Johnson lifters, Holley Hi-ram and heads. Goal is to get 600RWHP N/A on stock bottom end

Mods are: CAI, TSP 2" Longtube Headers w/ offroad extensions, TSP F-35 cam 235/248 .649"/615" 111 LSA, 109.5 ICL

First photo is Base Airflow, second photo is Throttle Follower Torque values. These are exactly as they came from the tuner. No adjustments made by me on these photos

Name: tune2.jpg
Views: 1384
Size: 135.9 KB

Name: tune2.jpg
Views: 1384
Size: 135.9 KB

Name: tune1.jpg
Views: 1393
Size: 130.3 KB

dreksnot · 03-13-2022, 11:15 AM

Leave the Throttle Follower alone (stock) for now. Reduce your min IAF (idle airflow) by 3% from 2000rpm and down. Drive. Repeat until no longer hanging.

1JEWLDSSRS · 03-13-2022, 01:47 PM

Quote:

Originally Posted by dreksnot

Leave the Throttle Follower alone (stock) for now. Reduce your min IAF (idle airflow) by 3% from 2000rpm and down. Drive. Repeat until no longer hanging.

Good stuff there dreksnot!!

HOJO · 03-13-2022, 03:20 PM

I am no tuner but had the same issue with my M6 after turbos and a cam install. Tuner was lost for some reason, even after tuning a number of LS engines. After some lengthy digging I found there to be a table, sorry don’t remember the name but it’s in HP tuners. It has to do with Park, neutral and I want to say coast down idle. It is this table that corrected my idle hang. My idle would hang when coasting with clutch in, even on a slow coast. Once completely stopped it would finally come back down. Sorry I can’t be more specific. Tuner may have over looked this table some how. I would run it by him. I found my answer over on HP Tuners website after a lot of searches.

dreksnot · 03-13-2022, 04:25 PM

Quote:

Originally Posted by HOJO

I am no tuner but had the same issue with my M6 after turbos and a cam install. Tuner was lost for some reason, even after tuning a number of LS engines. After some lengthy digging I found there to be a table, sorry don’t remember the name but it’s in HP tuners. It has to do with Park, neutral and I want to say coast down idle. It is this table that corrected my idle hang. My idle would hang when coasting with clutch in, even on a slow coast. Once completely stopped it would finally come back down. Sorry I can’t be more specific. Tuner may have over looked this table some how. I would run it by him. I found my answer over on HP Tuners website after a lot of searches.

What you're describing is Adaptive Idle Spark. Generally, can keep those somewhat close to stock, removing spark to smooth the idle and get more of a "natural" cam lope, or adding spark to get the cammy chop. There are also Adaptive Idle aifrflow tables that can be massaged a little. I don't think either are your problem. Minimum Idle Airflow is the subject. However, without seeing the tune, there could be other gremlins in the works that I'm not aware of.

FasNuf · 03-13-2022, 05:07 PM

Simple but accurate explanation

WVracer · 03-13-2022, 05:19 PM

Quote:

Originally Posted by dreksnot

What you're describing is Adaptive Idle Spark. Generally, can keep those somewhat close to stock, removing spark to smooth the idle and get more of a "natural" cam lope, or adding spark to get the cammy chop. There are also Adaptive Idle aifrflow tables that can be massaged a little. I don't think either are your problem. Minimum Idle Airflow is the subject. However, without seeing the tune, there could be other gremlins in the works that I'm not aware of.

So I pulled some base air out and got the hanging idle to go away yesterday. I put the follower tables back to stock tonight. Drek, would you mind taking a look at my file and a log tomorrow morning after I get a log with the new tune? It worries me that after 20 tune revisions and logs that the pro tuner didn’t manage to figure out that the base airflow was too high. It worries me that there are other things that probably aren’t right in the tune. I can cash app you some money for your time.

03-12-2022, 10:50 PM	#1
WVracer Drives: '11 2SS/RS LS3 M6 (Sold) Join Date: Dec 2015 Location: VA Posts: 200	Hanging Idle, Base Airflow, and Throttle Follower help. I just finished having the car tuned by a reputable shop through email and HP tuners. It took over 20 datalogs and tune revisions but the tuner finally said he thought it looked good. I told him I'm still having some drivability issues but he said he the tune still looks good. I understand that it makes it hard to fix through email and I don't want to put a bad name on the shop so I'm just trying to sort my issue My main issue is a hanging idle. My idle falls very, very slowly from 2000 to around 1100 then it remains there for about 10 seconds before returning to 825 target idle. Occasionally, it will hang at 2000 for a couple seconds, then hang at around 1600 for another couple seconds, and then fall to 1100 again and repeat. It seems to do it even more when cold. I tried lowering the Throttle follower values but it didn't seem to help much. I did try pulling some air from the base airflow tables but it worries me because based off other tunes I've seen from people with the same mods I'm already a bit lower in value on my airflow tables then them. The car also does not buck at all, even at 1000rpms. Its my understanding that this cam should buck harder than a PBR champion.That makes me think the airflow is jacked somewhere either in the follower tables or the base airflow. I also posted this over on the HP tuners forum. Since it wont let me post my tune file here I'll just post some pictures of some of the tables. Its temping to just swap over to the GPI SS4 and have them tune it but I'm going to save money to flycut the pistons, a solid roller cam, adjustable rockers, Johnson lifters, Holley Hi-ram and heads. Goal is to get 600RWHP N/A on stock bottom end Mods are: CAI, TSP 2" Longtube Headers w/ offroad extensions, TSP F-35 cam 235/248 .649"/615" 111 LSA, 109.5 ICL First photo is Base Airflow, second photo is Throttle Follower Torque values. These are exactly as they came from the tuner. No adjustments made by me on these photos __________________ 2011 IOM 2SS/RS LS3 M6- Injen CAI, TSP 1 7/8” headers, PTB, Hurst short throw, Corsa catback exhaust, 20" TSW Nurburgrings, BMR lower control arms, BMR tunnel brace, Hotchkis lowering springs. 3660lbs. Tuned by me (sold) 2010 RJT 1SS/RS LS3 M6- CAI, TSP 2” headers, TSP F-35 cam, PTB, Hurst short throw, Dronemaster catback, BMR lowering springs, Kirkey seats, 20”/18” Weld Belmonts, 3550lbs. Last edited by WVracer; 03-12-2022 at 11:48 PM.

03-13-2022, 11:15 AM	#2
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,642 View My Garage	Leave the Throttle Follower alone (stock) for now. Reduce your min IAF (idle airflow) by 3% from 2000rpm and down. Drive. Repeat until no longer hanging. __________________ > > 2021 Camaro ZL1 1LE A10* - power upgrades in the initial design phase* > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily Last edited by dreksnot; 03-13-2022 at 04:27 PM.

03-13-2022, 05:07 PM	#6
FasNuf Drives: 2014 Camaro ZL1 Join Date: Jul 2019 Location: Oregon Posts: 1,659 View My Garage	Simple but accurate explanation __________________ . . . . https://www.youtube.com/channel/UCgN...etl17hA/videos

03-13-2022, 03:20 PM	#4
HOJO Drives: 2014 Camaro SS/RS 1LE 1967 Camaro Join Date: Oct 2013 Location: Fort Wayne, IN Posts: 873	I am no tuner but had the same issue with my M6 after turbos and a cam install. Tuner was lost for some reason, even after tuning a number of LS engines. After some lengthy digging I found there to be a table, sorry don’t remember the name but it’s in HP tuners. It has to do with Park, neutral and I want to say coast down idle. It is this table that corrected my idle hang. My idle would hang when coasting with clutch in, even on a slow coast. Once completely stopped it would finally come back down. Sorry I can’t be more specific. Tuner may have over looked this table some how. I would run it by him. I found my answer over on HP Tuners website after a lot of searches.