Quick question, I have a customers bike in today that has had some problems in the past in regards to fueling.. I have in the past demonstrated to people how the upper injectors shower fuel into the engine in the upper rev range, by chance I wanted to observe the uppers injecting fuel today with a college as a matter of interest with said bike. However at no point from 0 to redline do the upper injectors on this bike shower any fuel. With RR8+ they should be active from 5,000rpm and 10deg throttle. You can use a stethoscope to listen to the injectors clicking (or just view them with the airbox open like I have today) and you can check you have 12v feed like I have and you can check they are in range of 13Ohms and all connections seem to check out too, they do not click on the scope or as I say do they shower any fuel. The only way to view the injectors trigger is with an oscilloscope and I only have an old snotter so thats a no go for me for now.. I guess my question to you all is has anyone with an RR8+ seen the upper injectors running consistently on there bike, with my RR7 the uppers shower a large amount of fuel progressively from around 5k rpm onwards so much fuel its hardly surprising it makes so much power. The shower style injectors in the CBR are one of its impressive features and they were revised a number of times over the years to get where they are now with a tight 12 hole pattern that fires perfectly atomized fuel into the velocity stacks to improve top end power. I have good fuel presure and oddly the bike seems to perform and run well even with the slight popping thats been a problem in the past I now thing I have found the reason why this bike has had some funny goings on in the past with PCV etc however two dyno centres have not picked up on any major problems. Maybe its just me....lol
lol Well you would think someone would have questioned it "if" they happened to have there head in the air box when reving to +5K....lol Or am I the first? :S
I think your right! Or more to the point the better more "fuel happy" RR7 Seems that Mr Honda changed the mapping of the uppers with the 08+ blades, they no longer shower fuel at 5K+ RPM like they say in the service data, my guess is they just printed that to do my head in....lol However it does seem that wheel speed and or gear position is a factor in the uppers and it seems that Bazzaz does seem to have an algorithm to add fuel from the uppers also (as the second bike tested visually is fitted with ZFi), I say an algorithm as there is no way of independently mapping the uppers with the Bazzaz software unlike DynoJets SFM so you can only assume thats why this one showers a little more fuel over the other (fitted with PCV) that never seems to shower any (next test is on the Dyno), Why all the fuss you ask? Well simple from RR4 onwards the uppers play a massive roll in top end power and the operation of them is clear as enough fuel is sprayed to sink a boat, Honda made changes to the number of nozzles and the spray pattern back in 06 (now 12) to improve mid to upper range power so when you see NO fuel being injected you have to question is this normal? And more so when you suspect a bike of not running quiet right, however NO one seems to have observed the uppers on the RR8+ and Honda (most dealers tbh did not bother asking) do not know, tuners would have a full understanding of the requirements of a motor and take into account flow rates, timings and other factors of the primary and secondary injectors to perfect top end power and feed the high spec motors they build or do they just rely on the likes of Bazzaz and DJ (take into account there are many other ECUs like MoTech etc etc etc etc etc that cost huge amounts of money and a team to setup) to obtain good fueling....thats the kind of question you will find it hard to get answers and they do NOT like to talk about how they get good power from the bikes we all see racing. Anyway I will look at others in time to put my mind at rest and learn more of the later injection systems that are now fitted to superbikes, its a shame I can not read the raw code from the ECU to see when and where the timings are sent to control the upper injectors thats something that Bazzaz and DJ will have done moons ago to develope the software and hardware you add to remap your bikes sounds simple but not so when you do not have a key to unlock such info..
Well Chris my mate Mark with his fancy scope may have time to pop in this week and we can look at the timings from both bikes, it will show in real time the pulse from the ECU and even record them so they can be replayed back with the Bazzaz timings overlaid from the other bike, he is a master with electronics and modern ECUs and will be able to comment more about the wheres and whys... IF he has time.... All in the name of curiosity you understand...
hey just watch what you are doing with that HRC mate lol hopefully your bike will be sorted soon Chris
