I played with a lot of different things to try and smooth it out, was better but not silky! I had previously tuned the LT1 pcm and had no issues but something in the LS1 pcm doesn't like aluminum flywheels. Do some searches on that and you will find reputable tuners that took them out of their own cars because they are a royal pita.
Isn't that usually an issue with idle? I've not heard of a light weight fw being an issue with surging while driving. The super light 110 tooth fw and 7.25" clutch in the racecar I was talking about took a lot of work, and still occasionally stalls. BUT we have no surging at part / light throttle while driving.
Jason
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So I did some more logging today. Changed dynamic airflow zone rpm and map boundaries to stock LT1 values (thanks Jason). Changed closed loop integrator delays and multipliers to account for the headers by adding about 25% to the values. Then went logging. The jerkiness was still there, maybe a little softer than before. The VE table looked richer than before after changing those settings, probably why it felt smoother. I haven't adjusted my VE or MAF tables based on these logs yet but I will tonight. For the drive home I made changes to the LTFT boundaries then re-enabled LTFT's. Still has that softer jerky feeling.
I should point out that those are not the stock LT1 zones. Those are the zones I used once I installed the cam since like the stock LS1 zones, I didn't get to half of them once the cam went in.
Jason
what zones are you talking about that have to be changed???
Oooohhh gotcha. I'll probably change them to my driving style then.Quote:
Originally Posted by JasonS5555
Under Engine > Airflow > Dynamic > Zone RPM Boundaries and Zone MAP BoundariesQuote:
Originally Posted by capss9c1
This what I was taught a long time ago, assume it still holds true.....
Map -- Low = approximately 5 kpa higher than kpa at idle, High = 80-85 kpa (s/b around your PE enable) and mid is 1/2 way between
RPM -- Low = 100 rpm above idle, high = 2400 and mid is 1/2 between
Ed M
Thanks for the info Ed. I had always been told that the low should be below the idle MAP to account for the zones where you're at part throttle but decelerating. Is this less important than I had thought? My idle MAP is ~ 50 so I had set my low zone to 40....
Thanks for all your help,
Jason
Just to clarify, the low zone starts at zero and stops at the number you set correct? Just like the high zone starts at the number you set and ends at 105? (or 7000 if we're talking rpm) I figure there's 4 main conditions I drive this car in: idle/coasting, low speed cruising, high speed cruising, accelerating. My RPM zones are 1250, 2250, 3000. Pretty much all my driving happens between 1250 and 2250, most of my accelerating happens between 2250 and 3000. Looking through my logs, the MAP behavior is very different in these RPM zones so I gave each RPM zone different MAP values based on how I drive. The zone where the bucking happens (1250-2250 or Zone 1) has 37, 49, 79 as the MAP boundaries. When I'm coasting, MAP is always below 37. When I'm low speed cruising, MAP is always between 37 and 49. When I'm high speed cruising, MAP is always between 49 and 79. I changed the LTFT MAP and RPM boundaries to match. I haven't driven the car with these changes yet, probably won't notice anything but we'll see.
If nothing else, it gives the PCM more cells to store LTFT since you're getting to more than just a few zones with the stock boundaries.
Jason