Casually reading through my 1996 Helms Integra Service Manual, I run across the following:

Ignition Timing control
-The ECM contains memories for basic igntion timing at vaarious engine speeds and manifold pressure. Ignition timiing is also adjusted for engine coolant temperature.
-A knock control system is adopted which sets the ideal ignition timing for the octane number of gasoline used (B18C1 engine).

This is written on Page 11-44 in the manual. Does anyone

1) have a sense of how engine output is affected by adjusting the timing based on coolant temp. changes;
2) know if such an adjustment feature, allowing to alter ignition timing based on coolant temperature, is built into an engine management solution (Uberdata, Hondata, Haltech, etc...);
3) know if a knock control system which takes gasoline octane as an input is available and effective?

I searched H-T, but it would be better to look at pgmfi.org for the info. Just thought that one of the ECU gurus would have something to say about this.


Modified by mdpalmer at 8:41 PM 8/27/2004

 

I beleive the coolant temp input is simply cold start or not. so once the car is running for a bit it uses the regular adjustments. not 100% on that on though.

Uberdata and the like have timing maps with rpm on one axis and vac/boost on the other, so yes they are fully adjustable for any timing you may need.

The knock sensor does not take fuel octane as an input. It is basicly just a microphone with, what I understand is some pretty crappy signal processing to 'listen' for engine knock. If it hears knock at a certin rpm under 5000 it will retard timing. Say you normally run 93 and the ecu has maps that work well for that octane, then you put some 87 in, the sensor is supposed to pick up the noise from detonation and pull timing. i'll let some of the ecu nerds handle the rest of that...

J&S safegaurd is a knock system you might want to read about

 

i am with bailhatch

i beleive they refer to the coolant temp as far as the ecu will look at it just to determine if the engine is hot or cold

for example, cold rev limiter,... under 180 deg, the cold and hot rev limits are different
they prob mean, due to cold engine the timing might be affected and kept mininum perhaps