Next Year's Engine Arrives

Today my nice shiny new CBR1000 RR engine turned up from Malc at Yorkshire engines. Very new looking it is too. It looks like an American spec engine as it seems to be fitted with the standard American emissions control systems.

Along with it also arrived the CBR 10000 clocks which contain a very nice sweep tacho, and I’l be finding a way to incorporate this into the racer instead of the Digidash.

The CBR engine has a couple of other interesting quirks, firstly it does not have a gear position switch. Now the Kwaka zx12r has a gear position switch to tell the ECU which gear the system is in, so that the fuel and ignition mapping can adjusted accordingly. Usually the ECUs do things like limit the pickup in first so that the rider doesn’t fall of the back of the bike, provide max torque in the mid gears and them apply a top speed limit in 6th. Some racers have benefited from telling the system that it is always in 5th so that max power is always available without an ECU imposed limiter.

The lack of gear position switch must mean that the Honda ECU calculates gear ratio based on engine RPM vs output shaft speed using the gear ratios of the standard bike to modify the fuelling. The second issue is that I’ll be without a gear indicator in the racer as my current indicator is driven from the KWakas gearbox switch. Still it’ll save the weight of the wiring but will be a new challenge to have additional awareness of how many change downs are needed for each corner.

It also has a secondary set of external injector (injectors that are positioned above the inlet trumpets on the outside of the butterflies) which are housed and mounted in the airbox. Now this probably means that I’m going to have to retain the original airbox, which has a nifty little vacuum driven sealing flap on the air intake which is vacuum driven and closes when the engine is on overrun to ensure any fuel floating around inside the airbox gets sucked into the engine. I’m understandably nervous about fuel vapour in the engine bay. This will cause me some initial packaging issues as the air intake on the bike points forward in front of the engine. In the racer this will be facing the bulkhead so not to much air flowing there then!


On the subject of the digidash, I’m really only using this for oil and water pressure\temp alarms now, and for sporadic Laptiming. But I’ve never been very successful at getting the timing to work reliably and it’s a pretty heavy unit to just feed me Alarm data. Although in fairness I am also using the output from the sensors to feed into the DL1 Data logger.

SO my Plan is to lose the Digidash and replace it either with Tim Hoverd’s palm pilot based dash\laptimer which he wrote the code for. It does lap timing and sensor monitoring based on the serial stream out put from the DL1 and also does useful things like providing a count down timer which help as all our races are now measured as X minutes + 1 lap. Hmm I wonder if Tim’s DL1 software can display the current gear?

Or if I win the lottery use the Specific dash available for the DL1 from Race technologies, and maybe if I got amy arse in gear I could develop a little minidash of my own.