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BEC Ignition advancers
aka Keith - 12/5/08 at 03:16 PM

Another noobie questions. For all the BEC's out there - is the purchase of an ignition advancer for the zx9r worth it? pros and cons


marco - 12/5/08 at 04:38 PM

I've been looking for one for a while and everyone is out of stock. Apparently they should improve the burn though and if you've rejetted the carbs and now have a better flowing exhaust system then it can only improve things.


froggy - 12/5/08 at 07:07 PM

the tre for the tl1000 engine i use is worth a few hp only because the ignition is timed to soften the delivery in the first three gears not sure about other engines


smart51 - 12/5/08 at 08:03 PM

R1 engines are tuned to run on 91 RON fuel. It seams reasonable to expect to be able to advance the ignition a little for the 95 RON fuel we have here, or perhaps even a little more for 97 RON.

Advancing the ignition generally means that the pressure made from burning the fuel comes sooner and so pushes on the piston for longer before the exhaust valve opens. Too much advance causes knocking (which can be cured with higher octane fuel). More advance still means the pressure start to build up too soon, slowing the engine down at the end of the compression stroke. A few degrees ought to be advantageous. A 2% improvement would be another 3 BHP on top of 150.


hobbsy - 12/5/08 at 08:41 PM

Are you sure its 91 RON and not 91 MON/PON? 91 RON is pretty poor fuel.

I'd rather use an ECU / piggyback (like the PC3R) that can do ignition across the rev / load range rather than just a static advance across the range.

Costs more admittedly to get set up but will yield the best results. But even then you're only taking about a few more peak hp but maybe better torque and driveability lower down.


aka Keith - 14/5/08 at 04:08 PM

I do not think there is a piggy back (PC3R type) version available for the ZX9r C series, but if any knows any better, can you please let me know.

Cheers
Craig


smart51 - 14/5/08 at 09:39 PM

quote:
Originally posted by hobbsy
Are you sure its 91 RON and not 91 MON/PON? 91 RON is pretty poor fuel.


Yeah, RON. It surprised me too. So much that I went back and checked it a couple of times. What beats me is how they got an engine to run at 12:1 compression on such watery stuff without knocking.