Tuning without knock sensor

[Tom]

I don't understand how people are tuning without a knock sensor. If knock is bad enough to cause you to feel it or see it on a dyno, then you are already pitting the combustion chamber. So my question is, how on earth are people tuning motors without a knock sensor? Tuning an AFR reaches diminishing returns quickly, as you quickly reach the point of tuning the fuel ratio for the ignition timing. How can we push past the barriers of stock timing, with no means of detecting knock?

 

[Tom]

No one wants to share the secret?

 

[John390]

I fully agree, especially seeing as how hard it is to pull the plug. Old school tuning, make a dyno run in a taller gear or on the street, then pull the plug and read it. Not gonna be practical on this bike.

I am not tuning timing as the RapidBike Evo doesn't have it. I didn't want to spring for the Race version as its a cheap bike to start with.

AFR with a dyno and wideband would be as far as I'd go I think.

The Rapidbike stuff auto tunes right out of the box, so thats one of the reasons I went with it.

I run the highest street fuel octane that I have around here. Been proven on dynos on turbocharged cars beyond a shadow of a doubt. Done so on 3 of my turbo cars myself. Zero alcohol fuels too.

I'd be curious what others are doing as well.

 

[Tom]

So it turns you can get systems like the PLEX v2, that allow you to connect an auxillary knock sensor to the bike while on the dyno. I'm going to start calling around to see if any of the tuners in my area use something similar, before settling on where to get my final tune performed. It seems like the Wide Band Commander with closed loop tuning capabilities from HardRacing has been doing an amazing job so far on the fuel trims. I installed the Grey Area KTM intake with larger injector, and the Wide Band Commander corrected all of the cells to the AFR values I entered within 100-200 miles of riding.

I purchased the kit that comes with the AFR gauge, and the gauge tucks nicely against the upper corner of the dash against the wind screen. Very slick looking, and super helpful in monitoring the progress of the auto-tune.

 

[CDN Duke]

Tom, you're running PCV? I'd be interested in seeing your map if you're willing to share.

I'm headed to dyno soon with Grey Area airbox and injector for before and after analysis.

I've currently got Chad Wells tune for Akra ECU, open lid and exhaust but it's not ideally suited to the short Competition Werkes pipe I have, hence the plan to dyno and tune.

 

[Tom]

The map is for Rev extend to 11,250RPM, and 93 octane. I put 1 degree of timing advance in the WOT column but thats as far as I was willing to go. The bike is on a stock filter with open lid and a stock exhaust. I'll be more than happy to share it with you. I know there is definitely some more power to be made on it, and it could use some optimization in the mid-range cells, but I've been using it to commute to work on the warmer days with no issue.

One thing I did notice was that for the 0% throttle column, everything outside of the idle cells should be placed with added fuel. It seems like the larger injector needs this to compensate for a longer dwell time, otherwise the bike will want to stall with quick blips of the throttle in neutral or with the clutch in.

Again, the map is for the HardRacing version of the Wideband commander, so the cells in closed loop will probably have no effect for you if you are not running their unit.