Burst Knock Retard - How important?

[BJM]

I was looking through a couple of chips of mine and noticed that the BKR had been disabled on one of them. My other chips all have the stock values in place and my Thrasher actually increases the time to 0.2 seconds from 0.1 and increases the retard to 14 degrees to 18. Obviously opinions vary from not needed to very important. What are people's experience here?

[Eric Marshall]

I believe the idea is to help prevent any instantaneous knock that might occur from the rapid opening of the throttle and the resulting in-rush of air, etc. Having to wait for the proper airflow to be measured, then LV8 calc'ed, then the timing lookup, may take too long, so burst knock retard is applied the instant the set delta tps is met.

I have tried it at zero and "perceived" no difference, and have never recorded any knock under those conditions, although I don't think setting it to zero will gain anything since the time it is applied is so short.

In the Thrasher, the time may have been increased because the BKR timer is used to activate another small subroutine.

[BJM]

I will have to take a look, Thanks.

[Bruce]

With the BK enabled, you don't have to worry as much about the AE being right, and you can run less AE. Less AE the easier to pass the EPA testing, and better MPG.

I spend alot of time on the AE, and PE stuff so I don't need to use it.

If you have any doubts about tip-in preignition then by all means use it.

If you don't have a WB you're shooting in the dark as far as AE goes. You need a bargraphy display with a fairly fast refresh rate, but once you see the normal lean spots at tip-in, and what the car feels like once you cure them, you'll probably wonder why you didn't get a WB sooner.

[BJM]

Bruce

I had a chip that had tip in problems that I adjusted until there was no bog at first and then finally no hesitation at all. Are you saying that feeling isn't necessarily believing?

I have noticed that you are a proponent of wide bands. Never mind the display refresh rate, does the sensor itself have an adequately fast response time? I wouldn't want to be looking at a display with a lag w.r.t the actual signal. What brand would you recommend and how much am I in for to get such a thing?