Anyone running a BD Adjustable kit W/O timing key?

Advancing the timing can make the sled leaner as well so make sure you account for that. IMO there there is performance lost when lowering the timing. I think BD tries to offset that by retarding the timing later in the RPMs.

I have tested a similar fuel blend in the pro with and without the three degree progressive timing key and I concluded the key cost between 1-2psi of boost in wot performance. I did this at the recommendation of a Canadian turbo builder that was targeting lower charge temps and wanted most HP per boost possible for long chute climbs. My findings matched his. More timing made more power per boost level and a lower charge temp could be reached with similar power.

Applying the timing retard on a modern EFI two stroke with multiple fuel and timing map inputs is not as straight forward as declaring what the result will be. The Polaris ECU is making adjustments to fuel delivery, spark advance, and exhaust valve mode for throttle position, intake air temp, rpm, baro/MAP, exhaust temp, coolant temp, and deto if present. When retarding timing you exchange out cylinder pressure and heat (less) for exhaust pressure and heat (more). As a standalone adjustment this decreases the chance for detonation and it can actually make the throttle response between wot and half back to wot feel more "rippy" because the exhaust heat/pressure drive the turbo quickly. Advancing the timing increases heat and pressure in the cylinder while decreasing it on the exhaust pipe. The safe limit of that heat and pressure is the point at which detonation occurs. If you remove the key, your exhaust temp will drop and your ecu could remove fuel without you knowing it.

My advice is to test it across a hard pack field (low load condition) and run WOT with and without the key to measure your resulting rpm on the same pass. If you have an air fuel ratio guage watch it close both ways to avoid unexpected lean down of fuel. After doing all this I leave my timing retard key in on most rides and pull it hillside when I know I have good fuel and I want peak performance. Lacking good fuel the three degree retard is awesome at limiting detonation and is worth any penalty that comes with it.

Im not on a polaris so im not sure how different this might be but i have a 3 dagree advance key on the crankshaft and had the bd retarder on as well . i decided to pull the retarder out and try it works great i never did put the retarder back on. Throttle responce is noticably crisper.