Hello All
I have been messing with the idle settings for a little bit on my 09 LS3 E38 PCM with a stage 2 TSP cam and long tube headers.
For now I am using the narrow bands to dial things in and will be adding a wideband in the spring to do some PE tuning and dial everything else in a bit nicer.
The cam specs are as follows TSP Stage 2 Cam 229/244 .629"/615? 112 LSA, 109 ICL
I have dialed in EOIT and SOIT to match the Cam. EVC = 394^ and SOIT at idle is 389^ with the Injection boundary set to 470^
I have the car starting up cold with some rpm oscillating until 80 degrees Celsius then it smooths out considerably.
I have a few things I feel I can or need to change but want to run it by you guys first for clarification.
I will include the tune and my latest log with a cold start until warm up.
I have changed the following from stock.
1) Spark advance/idle adaptive spark over and under speed tables. > cut them all in half or multiplied by (.5)
2) base spark has been set to 16 degrees throughout the entire table
3) I have used the method in this guide to figure out a base idle air flow of 10 g/s and 16^ base timing and idling at 800rpm for a very smooth idle
https://forum.hptuners.com/showthrea...e-tuning-guide
4) idle/rpm - adaptive idle overspeed error correction table was cut in half or multiplied by (.5)
The one thing I noticed is my 2009 vette idle adaptive over speed correction table values were lower at 20 and 32 degrees were cut in half as compared to the rest of the
values. However I have seen recommendations to use integral and proportional tables from a 2010 CTS, 2014 Camaro SS or a 2013 A6 Vette. all of these vehicles have a
much more even error correction table for the over correction table.
So after extensive reading I think I have a handle on things. There are many guys who just disable Proportional Air flow and just stick to integral air flow with more aggressive cams or just raise the error correction on the Proportional Air table. I would like to do things correctly and properly so I'm guessing sticking to the proportional air flow table is a better way to go, but I am not sure?
I did notice the proportional table does not do a whole lot in my case except for cold start and if I rev the engine up a bit. If it is only idling and warmed up it seems like its using the integral air flow table. I have attached my log and this will show both these tables.
I am planning on dropping the base air flow table to 10 g/s at operating temp to see if that will improve things but I also noticed my start up airflow table is messed up around 10-20 degrees ECT so I really need to clean that up as I believe its affecting the idle on a cold start.
My idle oscillates a fair bit until the engine warms up to 80 degrees then smooths out. I can see the overspeed/under speed correction tables are causing an unstable idle and wondering if I should reduce/relax them a bit more.
One thing I read is with the camshaft to let it idle the way it wants to, as in ,it will hunt up and down slightly and to just let it do that and loosen the error correction a bit.
Just looking for some pointers here, hopefully someone can chyme in.
It would be greatly appreciated.
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