High CR ls1 - Idle advice and IAT timing retard

[shitfaced]

Hey guys,

Doing some tuning on a new motor and have noticed off idle quality and off idle response are very poor. I've gone through a couple idle threads here and checked things out but am not noticing anything obviously out of place. It doesn't like to idle below 1200rpm (currently using the throttle stop to keep it running) and it's very difficult to get the car moving from a stop. Can anyone tell me if I'm missing something?

The other issue I've noticed is that the tune is pulling timing due to high IAT's. Are my settings conservative on the IAT retard table or should I investigate piping in colder air?

Tune and log are attached and the build is as follows:

347ci ls1, 11.3:1
Lingenfelter ported 317 castings (cathedral port)
2.02" and 1.57" valves
LSXR 102 intake manifold, 102mm throttle body
Cam - .634/.637" lift, 233/[email protected] duration, 113 lsa

Many thanks for any help you guys can give.

7.16.16_6.hpl7.16.16_6.hpt

[5FDP]

Do you have a wideband o2 sensor at all??

It can help you with tuning in idle and off idle tuning. Can help you dial in the VE table too.

[Asylumwarp]

Did you watch his log? Notice the o2 reads during WOT. wow... This motor maybe running LEAN. I suggest a wideband as well. Maybe out of injector I don't see injector duty plotted. STFT disabled? LOTS of timing at idle for some reason, it doesn't need that much. That can push a car.. With base running airflow so high, and in gear zero'd out? This car with such a big cam may benefit from a 5/32 drill thru the TB hole to bring down IAC counts.. Theres lots going on. Tune looks familiar, almost like we went over this in another post from another user.....

[5FDP]

His o2's like never changed the whole log and only when he let off after WOT, I did notice that. The tune looks to be open loop with no STFT, LTFT, closed loop.

[Asylumwarp]

I don't think they swing when you disable the fuel trims completely. They're stuck. I haven't verified but I think I remember seeing that when I shut down stft to test my wideband stuff... I don't usually shut off stft anymore..

[07GTS]

your injector "flow v kpa" is flat but then the "offset v volts" is tapered should be set up for your fuel reg if its vac ref or not..?

[shitfaced]

Guys, thanks for all these replies! I'll respond in order.

5FDP - The car does have a wideband. This data should be in the log and it is indeed what I have been using to modify the VE table. Let me know if there's something I'm doing on my end that's preventing it from being visible.

Asylumwarp - The motor was rich more or less everywhere going by the wideband. It has 80lb injectors from the previous blower build, so I don't think it's out of injector, but I'll certainly give this a look. With regard to STFT's, my understanding was that they are to be turned off while tuning VE table as they will change the data (they would be trimming fuel..). Please let me know if i'm off here. Incidentally, I tried turning STFT's back on after my last tuning session (posted here) and oddly they caused the car to run poorly, oscillating between 13:1 and 16:1 air fuel ratio's and causing the car to surge. Not sure what's up here, maybe bad O2 sensors? Please advise if there are any ideas.

What would you recommend idle timing be set to?

07GTS - The fuel pressure regulator is vaccuum referenced.

I tuned yesterday and smoothed out the fueling near idle, this seemed to help a lot but still doesn't feel quite right. It did allow me to back the throttle stop all the way out, but the car still idled around 1350RPM and wouldn't come down. Please advise if you guys have any ideas, I'm thinking it may be a vaccuum leak.

Also, from before: can anyone advise on the IAT retard settings? If these are set conservatively, I'd like to change them once I get the car on a dyno. If they are where they should be, my assumption is I need to get the motor some cooler air.

Lastly, I did notice some knock retard on this last run. I'm not sure whether to interpret this as false knock or real.

Many thanks for all the help here.

[07GTS]

in your "offset v volts v vac" copy the 0 column 4.5v to 18v and paste it into all other columns 5-80kpa so each column is the same

[shitfaced]

in your "offset v volts v vac" copy the 0 column 4.5v to 18v and paste it into all other columns 5-80kpa so each column is the same

I'm actually not able to find this table. Where is it located and what will your recommended change do?

_Untitled.jpg

[schpenxel]

Edit-->view-->advanced

Close/reopen tune

You're not able to see almost everything right now in beginners view.

[07GTS]

whole new world in Advanced view, where bouts is the IAT sensor..? the table looks ok but the reading seems high for n/a if your loosing timing, i see around those temps but i have a blower with IAT in the manifold, is your ambient a hot day..? u should be around ambient when driving then idling might climb up a little, should also log cyl/air for timing to suit the main table to use for adjustments u have it with map at the moment and it wont translate to main table as easy, and injector PW helps too

[schpenxel]

If you're using the ancient version then it's under engine diag, airflow

If you're using V3 or newer it's under airflow-->general

That's the sensor settings

For pulling spark based on IAT, that's under spark, advance, IAT spark, "base", and then there should be a multiplier table or two near there as well