Question about KR, AFR and Spark
Thread Starter
Staging Lane
Joined: Dec 2002
Posts: 99
Likes: 0
From: Elkridge, MD
Question about KR, AFR and Spark Sorry if this is a stupid question...still a lot to learn. I have the Predator and loaded the base tune on the dyno...1 HP Gain. Adjusted Fuel to -2 and picked up 5hp. No knock at all. I only had two runs so that was all I could see. The guy running the dyno said to go ahead and lean it all the way out to the predator's 5%. Did several WOT street runs to about 115 in 4th tonight. Registered between .9 and 1.7 KR. Advanced spark 10%(about 2 degree's) not to try to correct KR, but to see what would happen. KR now between 2.8 and 3.9. My question is since KR was 0 on the dyno and 1.7 on the street with the same tune except for 3% leaner on the street runs, which works out to about .5 cleaning of the AFR, is it possible that any of the knock was picked up from road noise/conditions? I have backed the spark back to stock, but I am wondering if KR varies between dyno conditions and road conditions. Sorry for the novel length post, and any help would be greatly appreciated.
Thanks!
Thanks!
On The Tree
Joined: Jan 2003
Posts: 172
Likes: 0
From: Central MD
Re: Question about KR, AFR and Spark ummm, set your WOT fuel back to zero. Advance your spark all the way to +10. This is about 2-4 degrees advance. Do some WOT runs and check for KR. If you have under 1.0 KR, lean out your WOT fuel again point by point. When you start getting KR on your runs set the fuel back a notch to where there was no/little KR. You should have the max spark advance and a slightly leaner (negative) WOT fuel. The right combo should score you 8 hp or so.
