Quote:
Originally Posted by jsveb
Very interesting article. Thanks
I am nothing but a rookies that wonders, but here goes...
On the turbo side of the pelican forum, there has recently been a thread about auto tune features in modern efi systems, and wether this is possible or not.
My questions is regarding ignition timing and tuning.
Wouldn't it be possible to use a combustion pressure sensor, I.e. one of these:
https://www.avl.com/pressure-sensors-for-combustion-analysis
Based on the peak pressure and cam/crank position sensors, have the efi adjust ignitin timing so peak pressure occurs at 14 degrees after tdc, optimum? |
In theory you could use autotune but it's not that simple. The very best way is to use a load dyno to determine Peak Torque for a given condition. It simply turn out that peak torque occurs around that 14deg peak pressure range.
The other much more dangerous issue is that peak torque can't always be done because detonation prohibits it.
In the past I've also mentioned how important it is to understand the effects IntakeAirTemp has on peak torque. A common mistake is to tune on a cold 30F day, dial in WOT ignition and call it a day. Huge mistake! The ignition values that can be used with cold IATs won't work once IATs get hot like 90+F! Good ECU systems have IAT and CHT Ignition comp tables, the stock DME has these built in. Knowing howto properly setup these tables can really help get some extra torque at cold temps. But you must dial back ignition as IATs and/or CHTs rise.