what table controls how fast it drops to idle when slowing down?

[mvvette97]

I think I need a little bit of tweaking. When I push the clutch to slow down for a stop it will hang at 13-1400 while slowing down. It will finally drop to idle after making pretty much a complete stop. I'm just not sure what table to be messing with. Anybody know off hand? thanks Here is what my tune look like

[WeathermanShawn]

Table B4309, Throttle Cracker Airflow in Gear.

Your year has up to 3 g/s of air around those rpm's. Take air out (less air). Sometimes I will use a 2002 Z06 M6 Throttle Cracker Table for Starters. As an experiment you can also make that entire TC table Zero's. Your idle will never hang. Just depends on your preference. Rpm's will drop rapidly. You may not like that much engine braking.

You can also adjust the Throttle Follower Tables. If you lower the TF Decay Delay, B4318 from the stock 3 seconds to 1 second to get rid of the annoying length of time for the idle to settle.

Most likely adjusting Table B4309 will solve your problem.

[mvvette97]

Best bet is Table B4309, Throttle Cracker Airflow in Gear. Your year has up to 3 g/s of air around those rpm's.

Take air out (less air). Sometimes I will use a 2002 Z06 M6 Throttle Cracker Table for Starters.

Occasionally you have to mess with the Throttle Follower Tables. I'll drastically lower the TF Decay Delay, B4318 from the stock 3 seconds to 1 second to get rid of the annoying length of time for the idle to settle.

Again most likely Table B4309 will solve your problem. As an experiment you can also make that entire TC table Zero's. Your idle will never hang. Just depends on your preference. Rpm's will drop rapidly. You may not like that much engine braking.

Give it a shot. Good luck.

..WeathermanShawn..

ok I dropped the B4309 in the problem range from 3.00 to 1.5 so I'll have to try it. It snowed 4 inches today so it will be a few days before I can get it out and try it.

[swingtan]

If you want the idle to drop to the normal commanded speed pretty much as soon as you press in the clutch, use B4310. Set all the cells to "0" for the road speeds where you want the idle to drop, then blend up above those speeds. For example, drop all cells below say 15MPH to "0" and then blend up above that. This will result in no additional air being added when the clutch is pressed in and the car is at any speed below 15MPH. You could set all cells to "0" but this may effect the feel of gear changes.

B4309 will have no effect on the airflow once the clutch is pressed, as this put the PCM into "P/N" mode.

Simon.

[TAQuickness]

You may find some air in the TC and TF tables necessary to support the transition to idle depending on your mods. The other options are to adjust the respective decay rates to bring the engine back to idle sooner.

[SSpdDmon]

Personally, a slightly higher RPM while coming to a stop might not be a bad thing. If the accessory demand on the motor increases suddenly, you don't want it to stall out. IE sudden lane change = extra power steering pump demnad....electrical load increases....etc.

[wadesns]

I had the same issue with my vehicle I had to change my timing to fix the issues. I had too much of a change in timing for the drive to idle transition. something you might try doing is smoothing this area out. What is your map value when this occurs?

I have noticed that in this post it states that if the clutch is depressed then the pcm goes into P/n mode how is this affected if the car has no clutch switch? Also how would the pcm read if or how would it perform if the switch was bypassed? Not trying to change subjects just curious. Seeing as I dont have a clutch switch :)

[swingtan]

if you disconnect the clutch switch, then the PCM will always think the clutch is out. So it will never transition into the "P/N" tables. Another thing to remember here is that if your are running DFCO, then the car may stall when you press the clutch as the PCM will still think it's in deceleration mode and not transition to the idle tables.

Simon

[SSpdDmon]

if you disconnect the clutch switch, then the PCM will always think the clutch is out. So it will never transition into the "P/N" tables. Another thing to remember here is that if your are running DFCO, then the car may stall when you press the clutch as the PCM will still think it's in deceleration mode and not transition to the idle tables.

Simon
Be careful not to start the car in gear with this solution...

[Sid447]

Apologies for steering away from floating idles.

Simon, my interpretation of your post #8 is in that case a car would never use the Base Spark In Park/Neutral table? (specific to LS1-B here).
It would always stay on the Base Spark In Gear table? (assuming the speed parameter was set at say 410kph and the TPS parameter was left @ 1.19).

I converted my car from A4 to M6 (LHD) back in 2003 and we never wired in any kind of clutch switch.

As for rev float, I have also found happiness with the 2002 ZO6 tables with a mix of the 2004 HSV GTS tables too for TC and TF values.

[swingtan]

Post #8 was meant to be specifically for B4310 / B4309, though it may also hold true for other tables. If you check the description for B4310, you get the following...



Airflow values added to idle airflow when the throttle cracker function is active and the transmission is in neutral or the clutch is pressed.


I've found that if a driver of a manual car feels the motor is hanging too much for their liking, when slowing to a stop with the clutch in, that B4310 gives the quickest and simplest fix. I've only dropped the values to "0" on cells below 30KMH and use the cells above 30KMH to help with the gear changes. If the normal idle settings are correctly set, then it shouldn't matter if there is an ancillary load change.

I've just had a look at B5933 and it wouldn't surprise me if you never see this table in a manual converted car with no clutch switch. You may be only using B5932 in that case.

Simon

[mvvette97]

ok if the throttle cracker tables are more for the air flow in gear would the follower table B4319 be the one to change to make the idle not hang so much when the clutch is pressed? If I push the clutch at 50mph it will stay hanging at 1700 till I get down to about 8-10 mph then will go to normal. I would like to have it hang in the 1200 range when slowing down if I could. Oh and I don't seem to have table B4310 like said above..

[Sid447]

ok if the throttle cracker tables are more for the air flow in gear would the follower table B4319 be the one to change to make the idle not hang so much when the clutch is pressed? If I push the clutch at 50mph it will stay hanging at 1700 till I get down to about 8-10 mph then will go to normal. I would like to have it hang in the 1200 range when slowing down if I could. Oh and I don't seem to have table B4310 like said above..

As a suggestion,

try the TC and TF tables from a 2004 HSV GTS tune file, or the tables from a ZO6.
I removed all delay from my TC table {B4314} & TF {B4318 & 4320}
:)

[ls1vt209]

Sid what is the chance of the tables you mention above working on a cammed car, or are they just suited to stock cams?

[mvvette97]

Sid what is the chance of the tables you mention above working on a cammed car, or are they just suited to stock cams?
Mine is cammed so I'll find out what happens

[Sid447]

Sid what is the chance of the tables you mention above working on a cammed car, or are they just suited to stock cams?

I'm "modified" too. Though it took more than two years to get the idle and low rpm stuff how I wanted it (Zero float, non hesitant return to idle and a nice robust idle).
I've got a blend of GTS and ZO6 in these two tables with some small self-tweaks.

A good thing to remember before you start to adjust for any idle/low rpm stuff is to ensure the PCV valve and CCV system are working as they should. :)