Stall Saver

[jlutz]

I've been messing w/ some of the basics of HP tuners and made some simple mods already. It's a pretty user friendly yet powerful program.

My rpms drop pretty low when turning on the AC and I'm not sure how to use the stall saver function. All the values are 0. Do I just put a 1 at the lowest rpm I want to activate stall saver ?

Thanks,

Jeff
'99 Formula M6 WS6
ASA cam, Pacesetter LT's, TSP cat Y

[WS6snake-eater]

I'm not too sure about this either. I went in an reduced all points in the reference table by 75 rpm:

So at 400 rpm I have the stall saver set to 325 rpm
at 1200 rpm I have the stall saver set to 1125 rpm

Like I said I'm not too sure if I'm doing it right, or if it is even working

[MNR-0]

Thats the way I did it too. I tuned a 224/227 idle the other day and it seemed to work. Stopped the stalling when coming to a stop.

[Chris@HPTuners]

the stall saver function basically calls into action the derivative idle control (fast) at a RPM Fast/SLow ratio of 1.0 and disables the AC.

If your car is stalling or dipping then more likley you idle airflows are out and the adaptive idle is going out of its limits.

try logging the new idle MPIDS:
- Idle Adapt (STIT) (lb/min,g/sec)
- LTIT Gear/ACoff (lb/min,g/sec)
- LTIT PN/ACoff (lb/min,g/sec)
- there are also many others

The STIT should be around 0 and the LTITs should be within the limits shown in the editor. Important to note that the STIT is set to 0 every time you go off-idle.

If they aren't then you need to adjust either the airflows to get them within the limits, or the limits themselves.

The limits represnt the "remembered" IAC airflow for that idle condition (PN/Gear/ACon etc.) if you have idle transition issues then chances are your STIT is having to make a quick catchup everytime you return to idle because the LTIT is at the limit.

[WS6snake-eater]

the stall saver function basically calls into action the derivative idle control (fast) at a RPM Fast/SLow ratio of 1.0 and disables the AC.

If your car is stalling or dipping then more likley you idle airflows are out and the adaptive idle is going out of its limits.

try logging the new idle MPIDS:
- Idle Adapt (STIT) (lb/min,g/sec)
- LTIT Gear/ACoff (lb/min,g/sec)
- LTIT PN/ACoff (lb/min,g/sec)
- there are also many others

The STIT should be around 0 and the LTITs should be within the limits shown in the editor. Important to note that the STIT is set to 0 every time you go off-idle.

If they aren't then you need to adjust either the airflows to get them within the limits, or the limits themselves.

The limits represnt the "remembered" IAC airflow for that idle condition (PN/Gear/ACon etc.) if you have idle transition issues then chances are your STIT is having to make a quick catchup everytime you return to idle because the LTIT is at the limit.

Thanks Chris,

I see the STIT making drastic movements when at idle, and it corresponds with the surging/searching idle. my LTIT is showing -.40 at idle with the a/c off in park, and -.14 in drive.....which direction should I adjust the Idle Air tables to get things back in line?

Matt

[SideStep]

Thanks Chris,

I see the STIT making drastic movements when at idle, and it corresponds with the surging/searching idle. my LTIT is showing -.40 at idle with the a/c off in park, and -.14 in drive.....which direction should I adjust the Idle Air tables to get things back in line?

Matt

I am interested also....

[God_Forgives_IDont]

I am interested also....

Me Too!

[MNR-0]

Add more air, ie., increase Idle Ariflow vs ECT.

[ozorowsky]

how do you know when exactly you have TOO MUCH air??

[MNR-0]

Log your MAF g/sec at idle and set it to that as a baseline. Too much air will result in rich conditions at idle which you can monitor both using your LTRIMS and Idle TRIMS. Idle can also be coarse as the VCM hunts to maintain stoich.

[Chris@HPTuners]

how do you know when exactly you have TOO MUCH air??

too much air will result in very negative LTITs & STIT , likely you will have RPM hanging up when you go off idle or come to a stop.

Aim to get your LTITs within limits (~0) for all driving conditions

[TXCAMSS]

I have reduced my Base Idle airflow to get my STIT @ "0", but both of my LTITs are still at -3.30/-3.55 . What would cause them to stay so low? I did expand the limits to see how far off I was, but I can't get my LTITs up without way over shooting the STIT. When I turn the fans off it raises the STIT slightly

My VE is in line as well as my desired vs dynamic air. I am still getting a slight dip when coming to a stop. ???

[chrisj6]

You need to log your idle trims with both fans off. Thats probably why they vary between the two that much. They will be much closer when you correct it this way.

Chris

[WS6snake-eater]

I have reduced my Base Idle airflow to get my STIT @ "0", but both of my LTITs are still at -3.30/-3.55 . What would cause them to stay so low? I did expand the limits to see how far off I was, but I can't get my LTITs up without way over shooting the STIT. When I turn the fans off it raises the STIT slightly

My VE is in line as well as my desired vs dynamic air. I am still getting a slight dip when coming to a stop. ???

Hey man I may be able to meet up with you and get you lined out either Thurs, or Friday...Let me know if you need help. You can always PM me on Tech, as I'm over there a little more often.