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View Full Version : How much can the ECU compensate for ign. timing?



janders211
06-09-2005, 10:15 PM
I just installed a camshaft about a week ago and apparently managed to FUBAR my distributor installation (of course I found Enthalpy's clarification of the substellar manual only after I installed everything). So I ran around with 23 degrees base timing and it actually ran quite well. The idle was a little lopey, but acceleration seemed normal, and even excellent on chilly morinings (70*F). I also heard no audible knock, which is suprising, but maybe my loud exhaust just covered it up.

This is on the stock ECU, t25, 3inch piping, FMIC, Walbro 255, no cat, 12.5psi max.

How conservative is the stock ECU timing at WOT, 4500-6000 RPM?
How much timing can the ECU pull when it detects knock?

Vapor
06-09-2005, 10:50 PM
stock ecu is pretty conservative timing wise, and is very lean a/f in the low rpm with typical bolt ons. I ran 17 deg timing and had knock in the low rpm before tuning, none after, but i was using a safc, which takes away timing when adding fuel

DeatschWerks_Dave
06-10-2005, 09:33 AM
How conservative is the stock ECU timing at WOT, 4500-6000 RPM?
How much timing can the ECU pull when it detects knock?



The ecu doesn't just pull timing when it detects knock above threshold, it switches to a completely different map. When I get home I'll get you some numbers if someone doesn't get them before then. I don't know off the top of my head, but like John said, it is pretty conservative.