Spencer Posted March 8, 2022 Share Posted March 8, 2022 Yes forgive me I am a troll. But hard to beat a Q-jet on big donk for economy without reinventing the wheel. Has real small primaries and as said vacuum feedback on needles that drop down into the jets. You can dial up a real nice lean mix for cruise and when you crack the throttle up a small hill the needles pull out a tad and it give a safer mixture for the load. All that is fully adjustable with the needle spring pressure, taper and jet size so you could put a mean cruise tune on any donk. Secondaries are giant and easy to tune just change jets, usually stock dumps in super rich 12:1. The hard part is the idle system is kinda fixed so if you have a cam then you need to drill holes and/or change tubes to give a good idle. That is where everyone gives up and puts on a Holley because you have to lean and figure some shit out on the idle side. There is a book for that though from the guru guy. 4 Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted March 8, 2022 Share Posted March 8, 2022 56 minutes ago, Roman said: Got 4.02l per 100km on way to Auckland today. Man I feel a 'great oldschool economy challenge' coming on... 6 Quote Link to comment Share on other sites More sharing options...
shrike Posted March 8, 2022 Share Posted March 8, 2022 1 hour ago, Roman said: Got 4.02l per 100km on way to Auckland today. Better economy then my CBR500RA I get 4.5L per 100km with mixed driving Quote Link to comment Share on other sites More sharing options...
Mop Head Posted March 8, 2022 Share Posted March 8, 2022 2 hours ago, Roman said: Cletus I want you to know that this thread is a safe space for fuel economy chat without bullying from Spencer. Got 4.02l per 100km on way to Auckland today. Might set an all new gas tank distance PB. Mean. End of the month will have some $$ for exhaust bits. In the meantime I will setup knock sensing properly. You slamming this thing down the strip at Meremere? Would be keen to come watch the next time (whenever that may be) and take a few videos of this vehicular perfection if you're not averse to such things. 2 1 Quote Link to comment Share on other sites More sharing options...
Popular Post GARDRB Posted March 8, 2022 Popular Post Share Posted March 8, 2022 4 hours ago, Roman said: Got 4.02l per 100km on way to Auckland today. Might set an all new gas tank distance PB. Mean. End of the month will have some $$ for exhaust bits. Notice how the price of gas is increasing at the same rate that your economy is improving? Illuminati confirmed 5 3 5 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 8, 2022 Author Share Posted March 8, 2022 4 hours ago, MopedNZ said: You slamming this thing down the strip at Meremere? Would be keen to come watch the next time (whenever that may be) and take a few videos of this vehicular perfection if you're not averse to such things. That would be excellent! Not sure when next event will be but i will let you know. In other news I dont think I will manage 800km on this tank. Got about 360-370 by the half way mark. But still a few tricks left to try. This is still on semi slicks and only thing ive changed is the fuel map. Will get cruise control working, optimize the ignition, and some skinny tyres again (not these monstrous 185s) 5 1 Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted March 8, 2022 Share Posted March 8, 2022 How big are the tanks on these? I wonder how much a difference a set of 4 biscuit (spare) wheels would make to resistance? I realise they have a speed limit but hey... Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 8, 2022 Author Popular Post Share Posted March 8, 2022 Internet says 45 litre tank. But I usually get around 35 litres in from a bit below empty. If theres still another 10 left after thst point then 800 will be doable. Also looking at itb options. Bmw s1000rr has 48mm throttles, built in e-throttle motor and super compact. Also extra injector bosses if needed/wanted. Looks like a sweet setup! Will keep looking for options but will keep these in mind for other projects. 19 Quote Link to comment Share on other sites More sharing options...
Snoozin Posted March 8, 2022 Share Posted March 8, 2022 Those throttles are so cool! 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 9, 2022 Author Share Posted March 9, 2022 Got back home on a below empty gas tank. 732km and 37.25 litres. So 5.08l per 100km I guess the cold starts and slow parts of trips ate away my highway results a bit. Maybe if I overtook one less truck it would be in the 4s haha. But still pretty sweet. And yeah those throttles are cool. I was thinking since the s1000rr motor is only 1 litre it would have the throttle centres closer together. But it turns out that its actually got a 5mm larger bore diameter than a 1nz! And a super short stroke so it can rev to a zillion rpm. So i might need to look for a motor in the 700ish cc range to try find a nice center spacing and a little smaller diameter. 1nz ports have the area equivilent to a 37mm circle. So 40ish mm throttle should be good. 5 Quote Link to comment Share on other sites More sharing options...
shrike Posted March 9, 2022 Share Posted March 9, 2022 Yamaha R6 from 2006 forward have 41mm ride by wire ITB Few mentions of issues with the 06-07 ones so maybe look at the 08-16 models Believe the 08 up also have dual injectors as well 1 Quote Link to comment Share on other sites More sharing options...
kpr Posted March 9, 2022 Share Posted March 9, 2022 40mm runner seems to choke out at 130kw. have tired it on couple different setups. throttles that size mounted close to port and runner tapering bigger, probably good for a little more. Maybe nz engine would actually benefit from opening the whole port up a little. assuming they would be designed for high air speed at lower rpm to get that economy 2 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted March 9, 2022 Share Posted March 9, 2022 Lol my bike is around 5.5l per 100 when I'm driving pretty darn nice. Have heard bikes have a shit coefficient of drag but no idea how that compares with an eco. 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 9, 2022 Author Share Posted March 9, 2022 Coefficient of drag can be a bit misleading. Because its a value of drag in relation to the frontal area. But total drag can be completely different. Echo has a CD of 0.30, and your bike has a CD of 0.55 to 0.6 But because the frontal area of your bike is comparatively tiny, the actual horsepower needed to overcome drag might be something like 10hp for your bike, and 35hp for the car (or whatever) 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 9, 2022 Author Share Posted March 9, 2022 2 hours ago, kpr said: 40mm runner seems to choke out at 130kw. have tired it on couple different setups. throttles that size mounted close to port and runner tapering bigger, probably good for a little more. Maybe nz engine would actually benefit from opening the whole port up a little. assuming they would be designed for high air speed at lower rpm to get that economy Hmmm okay. You know what, I was thinking that a less aggressive taper in the manifold from port to the throttles would help fill in the low end a bit. As it's quite aggressive currently: But actually looking at the full throttle fuel values from my ITB vs Aqua manifold, the Aqua manifold isnt any better, anywhere: Apart from that tiny smidge at 4k-ish. Despite having a consistent runner profile all the way. Admittedly I havent adjusted cam timing or done much else to the Aqua setup yet. Maybe ITB is richer everywhere just because its uneven or leaks perhaps. But it's not what I was expecting.I found a page of common bike throttles and their dimensions. Having 80mm throttle spacing sounds close/good, and 42mm throttle size. But then when I model it up, the narrower spacing is a worse situation than the slightly-too-wide of the silvertop throttles. Some of the Yamaha options are cool, in that there are two sets of butterflies. One is completely cable operated, then the other completely e-throttle. So in theory you could probably have best of both worlds somehow. At trackdays, leave the e-throttle ones completely open and have the response of cable. Then on the way home, lock the cable ones open and rely on e-throttle so you can have cruise control etc. However I might just look for one of the S1000RR setups. They arent tooo expensive, (likely 3-400 landed) especially if factoring in that I could sell the silvertop and blacktop throttles that I've got here already for nearly that much. And it's an incredibly neat and tidy setup! 4 Quote Link to comment Share on other sites More sharing options...
kpr Posted March 9, 2022 Share Posted March 9, 2022 Seems basically same as what ive found, you have to go real small on the runners to get any significant low end benefit. Will start to loose top end before see any real change down low. (tvis again) some people swear by small intake runner, but its usually on a crappy setup that has reversion issues. basically adding more pressure on the intake side to combat the exhaust flowing back. but not the way to fix it. going too big is a thing. but worse going too small 4 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 9, 2022 Author Share Posted March 9, 2022 Well one of the S1000RR manifolds was on Australia Ebay for stupidly cheap, so bought it. We shall see if 48mm is a bad thing... I'll just have to try make the manifold as long as possible from head to throttles to absorb the shape change a bit. EDIT: I've just realized that at the outlet, silvertop throttles are 45mm anyway. So 48mm wont be as much of a drastic change as expected. Apart from less of an hourglass sort of shape inside the throttle itself down to 43mm at the plate. Fingers crossed that the actual spacing between throttles is reasonable. 4 1 Quote Link to comment Share on other sites More sharing options...
shrike Posted March 9, 2022 Share Posted March 9, 2022 The ones for 149? Out of a wrecker in NSW Was looking at them before, do they include the plug for the dbw motor? (Tps had one) buy no injectors etc I'm also curious how they mount do they use a vband setup or? (Guessing could always weld onto them as needed) Quote Link to comment Share on other sites More sharing options...
ThePog Posted March 9, 2022 Share Posted March 9, 2022 Well this is just fucking excellent. 5 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Truenotch Posted March 10, 2022 Popular Post Share Posted March 10, 2022 We've come a long way eh. It used to be push rod engines with bike carbs, now it's Prius engines with drive-by-wire bike throttles. 10 3 Quote Link to comment Share on other sites More sharing options...
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