Not happy with idle

This is a 5.3 with a Whipple. Cam is CM 230/248, .631/.629 115.5 lsa, overlap 8.6. PCM is a 2012 Silverado and is stand alone. The engine is in a 2000 Camaro.
It runs good so far as the few short trips down a short road. I have been working on the idle and got to the point of changing things just as a what if? Not a good plan. It likes to idle around 950 to 1000 rpm. I can't seem to get it to idle where I need it to be. My alternator is computer controlled and kicks on after about 2 minutes after start and pulls down the idle about 150 rpm---at least. And then when I put it in gear (auto) it puts another load on it. Is there some table that I can use to offset the load, or what's the best solution. This is my car and I don't do any other tuning, so I know you guys run into this often. Log is just startup and idle so you can see what it is doing. Thanks

So if I understand you correctly - as reading your signature - it's a gen V L83 being run by a gen 4 ECM, cammed and whippled all in an older car? OK "normally" it's transmission shift airflow, min air, ac airflow and things like that, but your engine dynamics are completely different from the base cal chosen vs the engine in it, which means torque and everything including your tb airflow model is going to be different. You can treat it like a higher compression with better flowing heads 5.3, which I assume is what you're doing. You just need to make sure to use the right tables for the right components.

What TB did you use? Is it still the higher compression L83? I don't see a whole lot idle timing change or anything as far as adaptives goes - You capped your adaptive timing via the main spark table. Main spark is your cap for idle timing - need to raise that back up so adaptives can do something.

The TB is an 85mm GM that has been cleaned up a little. The heads were worked by Katech---they just do a clean up on the L83 heads because they flow pretty good as is. Pistons are forged L83 with larger valve reliefs. I get you on the main spark table. Thats one of the "I think I will try that" guesses.
You lost me on the trans airflow/tb airflow model suggestion.
And the direct injection is gone. I converted the Whipple to port injection.

Changed the spark table.
Looked up a 2013 Corvette Auto tune and used the trans airflow, ac airflow. I will load it up tomorrow and see how it acts..
Thanks

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Originally Posted by Lakegoat

The TB is an 85mm GM that has been cleaned up a little. The heads were worked by Katech---they just do a clean up on the L83 heads because they flow pretty good as is. Pistons are forged L83 with larger valve reliefs. I get you on the main spark table. Thats one of the "I think I will try that" guesses.
You lost me on the trans airflow/tb airflow model suggestion.
And the direct injection is gone. I converted the Whipple to port injection.

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You mean 87mm? So the stock LC9 TB then? And not the stock L83's 80mm? Well throttle body should work with the background etc area and baro tables then. You just have to correct torque output and airflow for correct throttle control.

I will get on it. Thanks

The L83 throttle body has a different plug and wiring then Gen4, so I switched to the Gen 4 TB. Acc pedal is a Corvette item and has the same plug as the truck pedal. I used a stock 2012 GMC harness and a BPauto fuse box. The GM fuse box is TOOOO big to fit anywhere.
I changed the airflow and torque tables and now it idles where I ask it to. I need to get it back to idle sooner when I let off the gas. No biggie. When the alternator kicks on, I can't even tell. Shifting into gear barely makes any difference. I can go in now and reduce my min airflow back to some reasonable numbers. THANKS FOR THE POINTERS !!!

Quote:

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Originally Posted by Lakegoat

This is a 5.3 with a Whipple. Cam is CM 230/248, .631/.629 115.5 lsa, overlap 8.6. PCM is a 2012 Silverado and is stand alone. The engine is in a 2000 Camaro.
It runs good so far as the few short trips down a short road. I have been working on the idle and got to the point of changing things just as a what if? Not a good plan. It likes to idle around 950 to 1000 rpm. I can't seem to get it to idle where I need it to be. My alternator is computer controlled and kicks on after about 2 minutes after start and pulls down the idle about 150 rpm---at least. And then when I put it in gear (auto) it puts another load on it. Is there some table that I can use to offset the load, or what's the best solution. This is my car and I don't do any other tuning, so I know you guys run into this often. Log is just startup and idle so you can see what it is doing. Thanks

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There are no spark adaptive really happening on this. This is the problem. Looking at your tune file you've neutered them quite a bit. I'd go back to stock

Thanks Alvin, I put under and overspeed back to stock. My car is a rockin'. How do I smooth out the idle?

Idle spark over/under speed. But you have to be careful so you don't end up losing control of the idle speed.

You have lots of work to do. The trims are pulling a bunch of fuel. You shouldn't need to idle at 900+ RPM. Although any lower and it'll probably feel rougher.


Attachment 143290

Does that mean that I need to reduce the numbers in the over/under? I just put them back to stock.
The trims should look better than that. That was a startup in the garage to see what my timing looked like after the change. The O2 sensors don't start switching until the alternator kicks on.
I would be happier with 850 idle. Thanks