DIY LTCC or similar system for LT1s

**spfautsch** · 11-05-2018

Sorry for the excessive posting but I parsed the 0.9.13 source with cppcheck and it found an out of bounds error in the est_isr() and a missing address of operator in getDwell(). Fixes are on github as 0.9.14. Also cleaned up some preprocessor warnings about narrowing casts. This build is untested but I will try to test base functionality (starts, runs, etc.) tonight. EDIT: basic functionality tests were good.

By the way, one added feature in this build that I overlooked in my previous post is the theoretical ability to handle ATDC (aka negative advance) spark timing. I'm not sure how to test this in-vehicle - possibly wait for the next ice storm and go out for a short drive to trip the ABS.

**Terminal_Crazy** · 11-05-2018

Originally Posted by spfautsch

By the way, one added feature in this build that I overlooked in my previous post is the theoretical ability to handle ATDC (aka negative advance) spark timing. I'm not sure how to test this in-vehicle - possibly wait for the next ice storm and go out for a short drive to trip the ABS.

Serious question: What does that achieve?
Mitch

**spfautsch** · 11-06-2018

If you're referring to tripping the ABS, it's because kur4o has speculated that might be the only time ATDC timing is commanded by the PCM.

If your question is more broadly asking what does retarded spark achieve that would be for torque management - i.e. traction control, abs, between gears on a slushbox (auto trans), etc.

**Terminal_Crazy** · 11-06-2018

Originally Posted by spfautsch

If you're referring to tripping the ABS, it's because kur4o has speculated that might be the only time ATDC timing is commanded by the PCM.

If your question is more broadly asking what does retarded spark achieve that would be for torque management - i.e. traction control, abs, between gears on a slushbox (auto trans), etc.

Sorry, must have missed that bit!
Thanks
Mitch

**kur4o** · 11-06-2018

Here is a source code that has retard limit removed. Now you can command up to 60 degrees of retard and test all kind of scenarios.
Beware of possible engine stall if you go too far with the retard.

**spfautsch** · 11-06-2018

Thanks! Does this require patches to the bin / a reflash of PCM?

With as much overlap as my cam has I suspect even 1 degree ATDC spark would cause an almost immediate stall. But I can log the controller and tell if it's firing the coils correctly - if it doesn't it will probably blow the coil fuse after four coils are energized simultaneously.

You have a PM from me BTW.