V4moto, 4/6/2018 at 12:52 PM
I don't see any reason to ditch the stock O2 sensors just because of age. With less than 20k miles they should have plenty of life left. If the Rapid Bike can produce a good tune with them then that's what I'm interested in. For me part of the attraction of Rapid Bike is the ability to use the stock sensors. I realize that the wide band sensors are better at tuning for large throttle openings but I'm more interested in overall driveability and smaller throttle openings (closed loop fueling).
While the 20 year old o2 sensors could be okay or on their way out, they still will not be anywhere close to as accurate as a new Bosch wide band. Though the difference in tuning a lightly modded vfr could be negligible, so its your call (but it seems like you have already made your decision). A wide band o2 sensor will tune faster and more accurately than the factory narrow bands, at all throttle and rpm positions (Not just large throttle openings). I guess you go this idea from how the Honda ECU only uses the factory narrow band o2 sensors at light/steady throttle, but this is irrelevant, as the narrow bands are disabled to the honda ecu when the Rapid bike is added (Rapid bike will take information from narrow bands at all ranges for tuning its own mapping, but send a steady signal to the honda ecu, so the honda ecu stays in open loop while the rapid bike stays in closed loop. This happens whether using factory narrow the band o2 sensors or the my tuning wide band kit.)
I do understand the gain per dollar argument and just installing a Rapid Bike Evo with no other options or dyno tuning required is attractive and definitely doable on +2000 VFR800's, I am just giving you my opinion on what I would do....
Stray, 4/6/2018 at 7:31 PM
Description of my tuning bike module says their wide band sensor should be used IN ADDITION to the stock narrow band sensors.
It may say this on their website, but this is false. I threw away my factory narrow band o2 sensors almost 9 years ago and I am using the Rapid Bike Racing module plus My tuning bike wide band o2 sensors with great success.
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Their wide band should only be used alone on bikes that were not equipped with o2 sensors in the first place.
This is also false, for reasons that I listed above. (my 2007 vfr800 is running great with no narrow bands and the rapid bike wide bands).
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My ‘98 has no sensors. I’ve been wondering if I should stick one in after the collector for the Rapid Bike Racing module or not.
Yes this is a good idea. A single wide band o2 sensor in the collector with the My Tuning kit.
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A single sensor is not ideal, however, as the rear cylinders run richer than the front. You’d need a different sensor for front and back.
You definitely do not NEED separate front and back wide band o2 sensors (literally every single VFR800 that has been dyno tuned, has been tuned with a single wide band down the collector), though you are certainly right, 2 wide bands would be more ideal than one wide band and furthermore, 4 wide band o2 sensors will be more ideal than 2 (I am actually currently using 4 my tuning kits for individual cylinder mapping and it is phenomenal).
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In the perfect world I’d install 2 wide bands with 2 my tuning bike modules but the cost would be insane. Cheaper option is just to install 2 narrow bands plugged straight into the RBR.
Stray
Definitely debatable, as everyone's idea of bang for the buck is different, though if you do go the narrow band route, please buy new oem from Honda and not mystery used ebay o2 sensors.
Stray, 4/7/2018 at 6:55 AM
Thanks Mohawk, I am riding on your coat tails here. Your results with this module are the reason I got interested. Huge debt owed to you, both on this and other mods.
Like you, I was hoping to mess with ignition advance but it is disappointing to hear your findings that only 3 degrees are available. Is that throughout the entire rev range or does it vary?
The ignition advance varies. On the Rapid Bike supplied 5th gen ignition map you will see 3 degrees at low throttle/rpms, 2 degrees at medium throttle/rpms and 1 degree at higher throttle and rpms. Honda just did not leave as much on the table on the 5th gens as they did with the 6th gens (which will take 5 degrees advance through the entire low-midrange).
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If memory serves you got the my tuning bike kit with wide band sensors too, yes?
As mine is a pre-sensor model I was wondering if I could weld two wide band sensors into the downpipe collectors and plug them straight into the Rapid Bike Racing unit WITHOUT the My Tuning Bike module. Will the RBR accept these directly? Hoping to save money here.
No. The Rapid bike will only accept the factory narrow bands directly or the Bosch wide bands with a my tuning bike module.
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As for saving money, the RBR unit is a poor choice even if moving it from bike-to-bike. The harness alone costs £130 (including tax and shipping). A new PC3 would be about the same!
Rapid Bike Racing and Power Commander are in totally different classes. Not much of a comparison, but for you 5th gen users, yes the RB Evo and PC are a better bang for the buck and if the buyer is not interested in traction control, launch control, engine braking adjust-ability, closed loop fuel tuning, on the fly fuel trim adjustments etc, the PC would be more cost efficient.
This is a totally different story on the 6th gens (maybe 8th gen as well), where the race module's added ignition advance totally transforms the bike, with much stronger 2500-8000 rpm torque and throttle response.
V4moto, 4/9/2018 at 11:14 PM
Thanks for the great information Cimaj. When you say you used the narrow band sensors in pair mode, does this mean that the two sensors work together to generate one map, or one map per cylinder pair? Also curious if you have tried adjusting the engine braking setting. Lastly, does the Rapid Bike harness plug into each injector individually or does it tap into fuel system harness with a single connector?
Cimaj was talking about blocking off the pair valves that inject air into the exhaust ports, as they dilute the exhaust gas and can give an inaccurate AFR reading.
I have used the Engine Brake feature and it works phenomenally, it really smooths out the on/off throttle transition, where Honda was actually shutting off the fueling for emissions compliance (most prominent in the top three gears above 5000 rpms).