hmhaga

The guy I use to map my STI V3/4 engine and the Power FC, is having serious trouble eliminating engine knock.

I almost expected there to be problems after the first mapping session, as he only did a series of "pull throttle" runs and tuned the cells showing up in the map trace. Sure enough, back on the road it would knock (92 ) as soon as I applied abrupt throttle or accelerated from a high gear from low rpms.

Went back and did a series of runs where he locked the dynapack to 2800, 3200 and 4000 rpm (max torque) and applied max throttle. Could hear the engine loading up and ZAPP! Engine knock. Terrible sound! He corrected all the cells causing high knock vaules and when finished it was not possible to provoke engine knock at the dynapack.

But again, it had engine knock on the road. Even worse on the following track day, ended up reducing the boost from 1.3 to 1.1 bar and removed 3 degrees of ignition advance (entire map) - that eliminated most of the engine knock.

Is it supposed to be this difficult reproducing road conditions on a dynapack? Or is my mapper taking short cuts, not changing all relevant cells?

Tempted to do it myself, as it is the ignition timing which is causing the problems. Run a map trace for the conditions causing knock and decrease ignition advance in those areas?

hmhaga

Thanks for nothing

Found the problem, right after the torque peak at ~4000 rpm the ignition timing was too advanced. Probably to widen the torque curve (?). Removed some ignition advance at these points , knock levels back to normal.