Haybusa Parts and Service Member Support

Author Topic: LOW power, given my jetting ?  (Read 15374 times)

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
LOW power, given my jetting ?
« on: October 31, 2007, 08:16:10 PM »
hey all,

well, right up front, i don't have a hay bus.  i'll wait for the chuckling to subside...thanks.

2003 Honda 919...cbr900-based motor, though with f.i., detuned like most nakeds, and  "old school" horizontal intake runners.  in other words, there was no "belly" to the intake port for me to tap and install nozzles.  so i had to install my nozzles (wet) in the throttle bodies with a fitting, just under the throttle plates.  ie, it's a little bit more of a trip for the juice to get into the firehouse...combustion chamber.  if that matters...

as far as i can tell, i may have the only wet nitrous honda 919 in the world, so there's no experience within my "peeps" for this.  that's why i am here now, hat in hand, on a busa forum.

before nitrous, my bike ran a 10.73 @ 123.  my best with nitrous is 10.46 @ 134.  11 mph tells me i'm making SOME power, but not the 68 shot i'm jetted for:  .021 nitrous, .024 fuel as i recall.

i have not yet dynoed, or run my bike with air/fuel measurement.  but i HAVE made dozens and dozens of passes with no damage ( i reckon i'm not lean) and i've not fouled or soaked plugs (i'm not WAY rich).   i have played with auxiliary fuel pressures from 3 psi to 7 psi with surprisingly little difference so i've been running higher pressures/richer to be safe.  the bike seems to "carburet" well on the juice...smooth power,  a nice kick compared to running off the bottle.  last year i ran .020 nos and .021 fuel with very little difference in performance/trap speed compared to .021nos/.024 fuel.

i am eager to hear ideas from anyone who has had consistant performance on the bottle, but consistantly disappointing.  i'm sure i'm forgetting to mention some things, so please: let me have it.  where's my 140-145 mph trap speed?  my best 60' times have unfortunately been about 1.63, and for me to get a 10.73 @ 123 from a 105 rwhp bike OFF the juice, i reckon the fault's not NECESSARILY the rider. 

is it POSSIBLE that i can only cram so much nos into my (factory) restrictively ported motor? 

ideas?  criticisms?  hell, even if you just want to say something negative about my mother, that's fine too.  this bike needs to drag me into the nines next year, or die tryin'.  i'm comin' humble here: let me have it.

Offline E-RACER

  • Universal Post Whore
  • *******
  • Posts: 9408
Re: LOW power, given my jetting ?
« Reply #1 on: October 31, 2007, 10:28:53 PM »
bottle psi?

make sure the bottle is postioned right??

sounds like the path of the nitrous and fuel may be the problem..

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #2 on: November 01, 2007, 10:23:45 AM »
No help here at all.

But damn!  10.7's at only 123?  I'm jealous :)

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #3 on: November 01, 2007, 12:44:16 PM »
i've got a bottle heater (in Alaska...good thing) and i've tried pressure all over.  settled on 900-1,000 most days.  the bottle is in a trac dynamics swingarm (8" ) in their bracket.  fairly vertical, valve facing up.  presumably, if i didn't have a siphon tube i wouldn't get 11 mph even after a couple of passes on a 2# bottle.

eracer: path how?  distance too great?  in contemplating that, i think that most car systems have the nos and the fuel travelling much greater distances, don't they?

fjman:  jealous of what part of that?  quick for the apparent power i'm making off the bottle?  we've got good dense air here, and The Tinman launches pretty well for what he is.

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #4 on: November 01, 2007, 02:48:30 PM »
and just so you know, i'm not arguing with anyone's questions or ideas.  i'm very grateful of ALL input. it's just that i've had most of the arguments in my own head, and so i want to clarify and ask follow up questions to see how you respond.  to see if you shed some light, even if accidentally.

more system info:  using a schnitz throttle position/rpm window switch, NX pump and solenoids, NOS nozzles.

i've tried several different plugs. due to a ground electrode of an NGK falling off into a 5 hour old $3,500 jetski motor a few years ago, i'm sortof reluctant to use their products.  especially because they wouldn't even contemplate doing anything for me over it.
so i've mostly run ND, 3 heat ranges colder but have also tried a champion equivalent (i know, i know...but i'm DESPERATE !) (my nitrous supplier asked, "what are you drag racing,  a lawn mower?") .  i've not retarded timing, other than loosening the ignition rotor bolt and "indexing" the rotor to as retarded a position as manufacturing tolerances allow, and retightening.  MAYBE i've pulled a degree or two out?  maybe none.  i'm trying to have dynojet build me a custom ignition box so i can control my timing with my pcIII.  i've used vp racefuel, blended VP with pump gas at various octane blends, and now Torco Accelerator at different octane blends as well.  slight differences in performance with the different spark plugs and fuel blends, but within about a .1 second and 1 mph difference is all.

thanks for any and all input/dialog

Offline firemanjim

  • Post Whore
  • ****
  • Posts: 914
  • Gender: Male
    • Black Art Racing
Re: LOW power, given my jetting ?
« Reply #5 on: November 02, 2007, 12:03:19 PM »
A couple of things-- are you gapping your plugs down? And I have had good luck with Champion racing plugs with recessed tips--look here for chart
http://www.championsparkplugs.com/search_char.asp?seenWarning=1&manufacturerID=2
Definitely get it on a dyno to see what your air/fuel is doing, best bet for safety and HP.
Do you have a fuel pressure safety switch on your system,bad things can happen if you loose fuel pressure--ask me how I know?
Sounds like you are on the right track.
Official Site Tuner

Home of one of the fastest 750cc bikes in the world
239MPH faired, 217MPH naked!
Bonneville 200 Club
El Mirage 200 Club
Mojave Mile 200 Club
Mojave Magnum 200 Club
NEDRA 100 MPH Club
Gairdner 200MPH Achiever 2013
2014 1st place Mojave Mile N/A bike
2015 top speed trophy at WOS
Colorado mile 200 MPH club
2017 DLRA 200 MPH club
2018 Shift Sector 200 MPH Club

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #6 on: November 02, 2007, 02:25:51 PM »
i do have a safety switch installed.  thoughts of lubricating my rear tire @ 140mph formed the initial planning in my work.  thanks for the champ plug chart.  i have a set in right now, though i haven't put the fire to them on the track.  our "last chance" day was rained out.  yes, i gap down to somewhere in the .025 range. 

my other thought was that a) i'm not spraying in first and b) the lag time through the window switch on each shift is probably costing me a half second or more in e.t.  i think when i rig a quickshift for it next year and spray through the shifts i may get my 9.99.

i guess i will dyno it, but again, i've tried what i fully believe should be lean and rich and everything in between and i still can't get the trap speed that my jet sizes tell me i should.  i was hoping that 1 out of 50 nitrous installs worked WELL, but not STRONG and that there was a common "oh, that?  yeah, you gotta..." for my predicament. 

i've read everything on this site that i can find, and because it has more activity and more members than most sites, i was hoping that someone might provide me an "ah-HAH!" moment.  like i said, i think i may be the only wet nitrous Honda 919/Hornet in the world, so there's no body of information out there for me.  i think there's ONE turbo in Denmark also.  as far as i know, and i've asked around a LOT, i have the world's quickest 919.  which is really like saying i have the world's quickest motorhome.  when you modify something that nobody else modifies, it's easy to be quickest.

thanks all, and i'm going to continue checking back here, remaining cautiously optimistic.  a guy i race with has a pretty nice turbo 'busa (license plate, "BOOSTA") he may sell me, but i'm kindof fond of my current bike.  nostalgia regarding my late dad and such factor in to it.

Offline WAR MACHINE 1300

  • Post Whore
  • ****
  • Posts: 952
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #7 on: November 07, 2007, 07:19:34 AM »
DO YOU HAVE PICS OF YOUR NOZZLE PLACEMENT  THAT  MIGHT  BE AN ISSUE

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #8 on: November 07, 2007, 03:24:36 PM »



hopefully, one of these will work. i'm a noob at pic hosting sites

http://picasaweb.google.com/buckakke/BikeStuff

« Last Edit: November 07, 2007, 03:26:12 PM by buckyworld »

Offline WAR MACHINE 1300

  • Post Whore
  • ****
  • Posts: 952
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #9 on: November 08, 2007, 06:31:41 AM »
PLACEMENT LOOKS RIGHT  TAKE THE NOZZLES  OUT OF  THE TBSAND  CHECK SPRAY PATTERN ON A  PEICE OF CARDBOARD  THATLL TELL YOU IF  ALL 4 NOZZLES ARE SPRAYING  CLOSE TO THE SAME PATTERN IF IT ISNT  CHECK FOR BAD  NOZZLES AND OR TRASH IN THE NITROUS FILTER ON THE SOLENOID ALSO DOUBLE CHECK THE  NUMBERS ON THE  JETS   YEAH  I  KNOW  BUT SOMETIMES YOU DONT SEE THE  NUMBER  YOU THINK YOU SEE  LOL HOPE  THAT  HELPS
« Last Edit: November 08, 2007, 06:33:50 AM by WAR MACHINE 1300 »

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #10 on: November 08, 2007, 01:26:21 PM »
thanks war machine.  i'm POSITIVE about the jets: checked them SEVERAL times: 21nos 24 fuel across the board.  i'll check the rest.  was just hoping that someone would have had a similar problem in the past, even given my choice of a different bike than most of you all.  i sure hope Dusty at Dynojet can find an ignition module that'll work on my bike so i can rig a quickshift and spray through my shifts, if nothing else.

Offline BATTMAN

  • Mad Post Whore
  • ******
  • Posts: 4032
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #11 on: November 15, 2007, 08:36:41 PM »
Where are you at in Alaska?  Are you in Wasilla? The only dyno in Alaska is in Anchorage at the House of Harley's.  Most of them dont know anything about sport bikes, but there's a guy there named Greg.  He knows his stuff.  He dynoed my bike and mapped it before.

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #12 on: November 16, 2007, 04:06:40 PM »
i would likely borrow a portable wide band exhaust sniffer before i'd dyno.  i tried to arrange that with my nitrous supplier to no avail this year.  this is a one of a kind nitrous system, and as many good things as i've heard about greg at h.o.h. , i'm pretty controlling and protective and i don't want someone grenading my bike on the dyno or playing too far off my baselines.   unlike a 'busa, no one has experience tuning a setup like mine (as far as i can find on the net or anywhere else) so they're no better off than i am in some regards.

also, any jetting changes to the nitrous system require removing the throttle bodies, airbox, etc.  it ain't quick and it ain't easy.  so no dyno operator is going to take the time to try different jets in my nozzles during a typical dyno session.

i'm in anchorage, and why didn't we see your bus at the strip this year?  i would have loved to take your money !


Offline Nosgsx1300

  • Mad Post Whore
  • ******
  • Posts: 2508
  • Gender: Male
  • RCC GT4088R WHOOOT
Re: LOW power, given my jetting ?
« Reply #13 on: November 17, 2007, 03:47:59 AM »
stock wheelbase?
when are you hitting the button?
RCC GT4088R
2011 Loring 204.88mph "naked"
2015 Loring 220.01743 MPH Faired in fifth gear

Offline BATTMAN

  • Mad Post Whore
  • ******
  • Posts: 4032
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #14 on: November 17, 2007, 05:44:11 PM »
I was in Fairbanks.  Me and a friend of mine would go there all the time.  He had a green ZX-9 with alot of nitrous.  I was in Iraq for the last 2 track seasons and then this year I moved to PA.

Offline Chuck Wilburn

  • Post Whore
  • ****
  • Posts: 726
    • http://www.tupeloperformancecycles.com
Re: LOW power, given my jetting ?
« Reply #15 on: November 17, 2007, 05:55:39 PM »
Sounds like he's getting on the button late.  If you're not on it at the bottom of 2nd gear at the latest you're not going to pick up much et.

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #16 on: November 23, 2007, 11:52:31 AM »
fjman:  jealous of what part of that?  quick for the apparent power i'm making off the bottle?  we've got good dense air here, and The Tinman launches pretty well for what he is.

10.7's at only 123 mean you're making poor power (110hp tops, I'd expect) but you're REALLY lighting the first half of the track on fire.  I'm trapping similar numbers and lucky to be .2 slower!

I think you're right, you're really down on power for the jetting you're at.  What are you seeing on motor?  I think you can kinda guess at the power gains if you look at the back half gains between motor and bottle.  I pick up 21-22mph with similar numbers as you, with perhaps 110hp at the wheel, if that gives you a starting point (101ish at half track, 122 at the line).

I almost wonder if you're not rich on spray, but it'll take the plugs to tell the tale there.  Once you look at bottle pressure, if you're going by recommended settings, I think you're going to find yourself fat.  It might very well be worth putting out $250 for some dyno time, just to find out for certain.

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #17 on: November 27, 2007, 03:18:01 PM »
to address several questions at once, and to clarify earlier statements of mine:

10.73 @ 123 MOTOR
11.43 @ 134 SPRAYING

i spray in the bottom of 2nd gear, but it is WELL into the meat of 2nd by the time it fully hits

8"-over TRAC custom arm

with my tps/rpm window switch, the system shuts off during shifts.  there's a slight lag in activation after each shift.  i BELIEVE at least a half a second's worth cumulatively.   i think i REALLY need to find a way to make a dynojet quickshift work so i can spray in 1st and continuously through the quarter mile.

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #18 on: November 27, 2007, 09:35:31 PM »
You're going 11mph faster and seven tenth's SLOWER on spray?  Eh?!

Edit, sorry, looked up and saw you said 10.4's in your original post.  Makes more sense, surely.

If you were getting the full boost from a 60ish shot on a 100hp bike, it should feel like getting rear ended by a semi when it comes in.  Part of the problem, you're right, is that you're not using it for the duration of the run.

Have you tried smaller jetting?  Say a .016 or so?  I'd guess that it'd provide the same benefit as your .021's, assuming it's working.  I know that on at least some bikes, they misfire if the load is too high, and good coils/close gaps are required to light the mixture at all.

« Last Edit: November 28, 2007, 07:59:50 AM by FJman »

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #19 on: November 28, 2007, 02:03:51 PM »
i had contemplated smaller jets.  it's a shame that my system requires SO much work to change jets, and frankly, i don't feel my system is rugged enough to allow too many jet changes before something gets broken...too much fiddly plastic crap gets r&r'ed in the process for me to feel comfy round-tripping it all several times per year.  so i jetted it on the fat side this year, and play with fuel pressure to trim.

this year will entail SEVERAL different types of spark plugs, and i am looking into hotter coils as well. 

i think the quickshift will get me into the high nines, and that perhaps igniition issues may get me around mid-nines.  the nitrous delay during each shift feels like an eternity.  the new cbr1000 has a factory quick shift, so i may take a peek at how they do it too.  naturally, with a bike as unpopular as the Honda 919 (AND discontinued for 2008), there isn't a whole lot of "plug and play" out there.  i've had to fight for nearly everything i've got.  i'm jealous of you 'Busers, not that some of you haven't been through the school of hard knocks.

rather than "rear ended by a semi" i would say i currently get what feels like a two-stroker coming on the pipe.  close, but not quite a semi-truck hit.

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #20 on: November 28, 2007, 02:07:05 PM »
oh yeah, and DUH !  10.43 spraying.

this damn state job is distracting me from the important stuff in life !

Offline Nosgsx1300

  • Mad Post Whore
  • ******
  • Posts: 2508
  • Gender: Male
  • RCC GT4088R WHOOOT
Re: LOW power, given my jetting ?
« Reply #21 on: November 28, 2007, 02:44:49 PM »
I had my best ET reduction with the .018/.022 jets
I would hit the button in the top of first knowiing that when I did the front would start to climb and when it hit a certain point I would let go of the nitrous button and the front would float back down touching right as I punched the 1-2 shift then I would get back into it in second

bigger jets even with a 2 dial progressive was harder to ride
RCC GT4088R
2011 Loring 204.88mph "naked"
2015 Loring 220.01743 MPH Faired in fifth gear

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #22 on: November 28, 2007, 04:22:43 PM »
just keep in mind that IF my nos was PERFECT, i'd be making about the same power as a stock 'bus with a pcIII, or just a few ponies short of an '08 stocker.  i ran .020/.021 last year.  there are other variables, but i did run a TAD quicker this year with .021/.024. 

with my 8-over TRAC arm, airing out the front wheel is NOT an issue.  a slight wiggle at MOST.

i intend to spray in 1st with a quickshift next year, and stay on the button through at least 5th gear.

and again, maybe different coils and spark plugs.

what kind of times did you have with the 18/22's, Nosgsx? 

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #23 on: November 28, 2007, 07:16:15 PM »
I don't think smaller jets are going to make you quicker (they might, though), just that they sound about right vs how much gain you're getting.  Sounds like the bike isn't actually using all of the nitrous, not burning well or something.

Of course if you go to a smaller set and notice a significant reduction in MPH, that would tell you that the bigger ones ARE making more power, just that they aren't being used enough (too much time off bottle during shifts, etc).


Offline Nosgsx1300

  • Mad Post Whore
  • ******
  • Posts: 2508
  • Gender: Male
  • RCC GT4088R WHOOOT
Re: LOW power, given my jetting ?
« Reply #24 on: November 28, 2007, 08:14:59 PM »
I suck bad launching
I was running 9.4's on motor at 151-154mph
I was going 8.9's  with that jetting at 162-164mph

Are you running a progressive?
What is the bike/rider weigh?
there is a formula to give you roughly a good idea of how much gain you are getting
234/weight*&%&^%&5  I forget it
there is also a vaugly similar formule for e/t

my bikes from dynoed nukmbers
the et/weight=hp formula comes out way low it is effected by rider a lot
MPH,weight=hp formula comes out closer but still low

and no I don't think it is possible to cram too much nitrous into a motor
Something would break well before that
are you SURE you are getting LIQUID nitrous to the foggers?


RCC GT4088R
2011 Loring 204.88mph "naked"
2015 Loring 220.01743 MPH Faired in fifth gear

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #25 on: November 29, 2007, 01:32:01 PM »
nosgsx: 
not a progressive controller.   all or nothing.

i've not scaled it, but i'm confident that the bike/rider/gear weigh 660 pounds, give or take 10.

i know i'm not cramming too much juice in the motor, but i sometimes wonder if i'm trying to cram too much , too far from the intake port to assimilate with the airflow properly.  yeah, you're right.  that sounds like a crap theory, doesn't it?

i'm NOT POSITIVE i'm getting liquid nitrous at the nozzles.  i'm sure some of my hoses could be a little shorter, but nothing runs past hot surfaces, and the summer temperatures here are pretty cool compared to...anywhere that ISN'T alaska. 

last year, when there were other variables fighting me simultaneously, i tried running with the bottle upside down.  results inconclusive due to those other variables.   i am going to take apart my bottles this winter and double check for a siphon.  everything i read says that a NX 2-pounder comes with siphon tube, but at this stage i can't take anything for granted. 

i get a serious "kick" when the juice hits, but i am thinking i SHOULD have a 9.5 bike/rider combo here and am still looking for nearly a second of elapsed time.  right? if i can run a 1.64 60-foot time and shift the damn thing, i SHOULD be tapping mid nines with a 105 rwhp bike adding a 60-shot???   i've pulled a fair amount of weight out of a bike that was pretty light to start with too.

 the possibility of getting gaseous nos and not liquid, and/or maybe incomplete combustion due to plugs/gaps appear to be my most likely impediments.

fjman:  "not burning well or something" seems EXACTLY it.  and so far, i've heard VERY LITTLE about people's nitrous giving a hit, but not as much of a hit as it should.  it generally seems to either work or it doesn't for most bikes/people.

at least i'm learning new lessons in patience ~

Offline WAR MACHINE 1300

  • Post Whore
  • ****
  • Posts: 952
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #26 on: November 30, 2007, 04:24:02 AM »
IM THINKING BOTTLE PRESSURE  IS  DROPPING IN MID RUN  AND OR MAYBE  BAD  BOTTLE FILL TRY A BOTTLE  HEATER?   IF YOU  CAN RUN THE BOTTLE  UPSIDE DOWN TAKE  THE SIPHONE TUBE OUT  .

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #27 on: November 30, 2007, 12:18:11 PM »
i've got a heater.  pressure is at least 800psi AFTER a run...some dropoff but not abnormal.  i've tried different bottle pressures with little change in performance.  and i've made dozens of runs and several different fills over the summer.

unfortunately, both of my bottles are completely full so if i want to check for siphon tubes, i will have to either see if my nos guy will pump it back and forth for me or i will lose it all.  OR, i could just make the first few runs next year trying different spark plugs and setting up my (hopefully) new quickshifter.  i am relatively sure that my (bought new by me) NX 2# bottles have tubes.  but before i refill them, i WILL remove the valves and be 100% certain.

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #28 on: November 30, 2007, 12:21:20 PM »
You're not on the juice for a BUNCH of your run.  Between shifts and all of first gear (probably 3s or so in first alone, maybe 3.7s total!)


Airshifter (or get the quickshifter rockin).  I still say you should drop down in jet size a bunch, if you lose much mph that's a sure sign that your motor isn't actually firing the bigger mixture.  Two dyno runs would also reveal this (with rejetting between, know how much of a nightmare it is to swap jets).


Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #29 on: November 30, 2007, 02:04:47 PM »
fjman, i hear you.  dropping jet size a bunch WOULD tell me that, but frankly, i think 134 mph trap speed tells me too.  that there's missing horsepower, that is.  my inclination is to try to make up for lost time with the quickshift, and play with plugs/possibly coils mainly because it's so tough to change jets in my application.


this is the level of teardown needed to rejet.  the horizontal intake runners/ports of the 919 crowd it up under the backbone of the frame.


HOWEVER:  for all i know, the cumulative time spent off the bottle due to shifting lag time and not spraying in first MAY be all of my trouble.  this dang thing COULD run a 9.2 once i keep the system spraying for 2 or 3 more seconds of each of my runs.

so if i don't hear any "AHA !" responses here, i'm going to TRY a quickshift with ignition module.  which as i've mentioned, dynojet DOESN'T  actually make for my application.  so even this step is a $600 guess, and electronics aren't generally returnable.  if i can't get a Honda 919 owner in SoCal to allow a try-sie at dynojet, i reckon i'll check connector configurations and try one for a cbr929 or 954.

but if anyone has any other thoughts on low power for a given jetting, i'd sure love to continue the conversation.

my original point with this bike was to drag it kicking and screaming into the nines, in homage to my late father.  i gotta honor him as i set out to do 3 years ago.
« Last Edit: November 30, 2007, 02:19:34 PM by buckyworld »

Offline Nosgsx1300

  • Mad Post Whore
  • ******
  • Posts: 2508
  • Gender: Male
  • RCC GT4088R WHOOOT
Re: LOW power, given my jetting ?
« Reply #30 on: November 30, 2007, 02:32:53 PM »
okay using the formula
(((mph/234)cubed)xweight)
I get 123mph 660lbs works out to 95HP
        134mph 660lbs works out to 123hp
you are agining ~28hp
deff low with those jets
I would put the .018 nitrous jets in it with whatever fuel go with them for your system(fuel pressure dependant)
aslo possible is is detinating if you put the smaller jest in and your MPH doesn't change that much then I would be worried that that is what is going on

Now the more you are out of the throttle to shift or in the first 60' the lower these numbers will be
when bored at work I compare that formula with the et one
I like to see what percentage I can get with the ET formula
cause the closer they are the "better the run is"
RCC GT4088R
2011 Loring 204.88mph "naked"
2015 Loring 220.01743 MPH Faired in fifth gear

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #31 on: November 30, 2007, 04:08:49 PM »
the problem in trying to use those formulas is that i KNOW (due to not spraying in first gear, and cumulative shift lags) that i'm making 105 rwhp for approx. half of my run.  i KNOW that i'm making an OPTIMISTIC maximum of 140-or-so rwhp for approx. 5 or 6 seconds of the run. 

so you'd have to modify the equation to deal with those variables.  it'd be like calculating for a standing start 1/8 mile at 105 hp, then a flying 1/8 (110 mph to 134 mph) at 140-ish hp.  more or less.  too much math, and it would still be somewhat guess-based.

here's my thinking now:  the engine hasn't pinged...so i'm NOT too lean on fuel.  my all-motor runs have not dropped off et or mph...so i haven't done internal damage in my experimenting.  i KNOW that my system has to shut off and start up several times per run right now...losing me hp, et, and mph.

so it seems that my first point of focus now should be making sure that my system is on and juicing for a greater percentage of my run.  more important to me than getting more performance when it IS on, make sure that it's on longer.   and as i said, peformance wasn't much different with slightly smaller jets last year.

this looks more and more like i'll have to buy a dynojet quickshift and ignition module on a guess (along with a new pcIII - i bought existing one used and it has cold start issues) ... spending a total of around $1,000.  or seeing as i had Trac build an air tank into my swingarm, i COULD use an MPS air ram w/ ignition interrupt for less money, but the quickshift would be a tidier install and easier operation (no worries about air pressure before my runs, fewer moving parts/ variables). 

it's tough being the guinea pig !  it's tough taking the $ leap of faith !

Offline craigster

  • Rider
  • ***
  • Posts: 139
  • Gender: Male
    • Hell Fire Performance
Re: LOW power, given my jetting ?
« Reply #32 on: November 30, 2007, 10:52:01 PM »
With NOS systems on carb bikes I've run 22n - 26f in order to get 70 hp.  Not that it will get you to your expected 144 mph, but it should help raise mph slightly.

Offline FJman

  • Rider
  • ***
  • Posts: 345
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #33 on: December 01, 2007, 07:36:26 AM »
okay using the formula
(((mph/234)cubed)xweight)
I get 123mph 660lbs works out to 95HP
        134mph 660lbs works out to 123hp
you are agining ~28hp
deff low with those jets
I would put the .018 nitrous jets in it with whatever fuel go with them for your system(fuel pressure dependant)
aslo possible is is detinating if you put the smaller jest in and your MPH doesn't change that much then I would be worried that that is what is going on



Remember that that 28hp estimate is an average of the total run.  It could be closer to 40hp, say... but it's being used for only 2/3 of the total time (or whatever ratio works out to, it won't be linear, either).

I'm thinking that using a smaller set of jets for the same mph is an indication that the motor is experiencing partial burn, detonation, or whatever, and not getting the expected gains.

Offline Rocketgeezer

  • OFF TOPIC
  • Universal Post Whore
  • **********
  • Posts: 7835
Re: LOW power, given my jetting ?
« Reply #34 on: December 01, 2007, 07:41:59 AM »
Hi guys;  I don't do much with nitrous any more,but a few years ago did a bunch had mike thermous # on speed dial  anyways as to why low power on the juice?  as I have found there are a few things that can cause low HP when on the nitrous, first is your bottle being filled correctly? I questioned this cause they seemed to runout a little to fast, the guy filling them got pissed, started filling my own. if you try to refill the bottles and they are not empty they may not fill completely with notrous it might have the pressure up but it will be filled with air [small scale may verify this]  then the bottle be positioned correctly so it flows liquid not gas bottle position on the bike and sipion tube must be in right place. your nitrous line must be short as posable and with no kinks or blockage. also if you run a large volume of nitrous it must be big enough, also your nitrous selonoid may not be flowing correctly if all this cks out and sill low hp you may have to much fuel going in for that amount of nitrous and I think I would try to rig someting up so your system comes on at the top of first and stays untill you back off,   hope this helps  
The older you get do you notice you start chickening out way before the bike does

Offline WAR MACHINE 1300

  • Post Whore
  • ****
  • Posts: 952
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #35 on: December 01, 2007, 08:00:38 PM »
GET ONE  OF  MATTS KILL BOXES AND  WIRE  IT  TO  THE STARTER BUTTON OR HORN WHITCHEVER ONE ISNT  BEING  USED  FOR THE NITROUS AND  LOAD THE SHIFTER  AND  HIT  THE BUTTON   IT  SHOULD  SHIFT AS FAST  AS  ANY QUICKSHIFTER  AND  PROBABLY  BETTER  THAN  THE DJ SETUP

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #36 on: December 05, 2007, 05:43:12 PM »
thanks again all.
DaveC., i have checked those basics, short of replacing a solenoid.  and warmachine, i also want to retard my timing slightly, and the mechanical ignition advancers/retarders out there won't work on my bike.  i wasted $75 trying a difft. honda's retarder to no avail. 

Good news !  i just got an email from Dynojet saying that my persistance has paid off, and they will be marketing an ignition module for the Honda 919.  So that allows me to pull a degree or two out while spraying, use a quickshift (spraying all the way down the track), and select from different maps when i spray/don't spray.  all the things i wanted.  well, i WANT a 9.99 or better too, but i'll just have to wait and see.

of course, i'll only have the small matter of ponying up $600 for the quickshift and ignition modules...

Offline WAR MACHINE 1300

  • Post Whore
  • ****
  • Posts: 952
  • Gender: Male
Re: LOW power, given my jetting ?
« Reply #37 on: December 06, 2007, 07:00:00 AM »
ID GET  A  KILL BOX FROM MATT  ON HERE  OR  MPS AND HOOK IT  UP  SO  YOU  CAN FOOT SHIFT IT  WITH  THE BUTTON  IT  WILL BE  A  LOT  CHEAPER  THAN 600 BUCKS    BUT   DO  WHAT  YA GOTTA DO

GOOD  LUCK

Offline GSXRTURBO1

  • OFF TOPIC
  • Post Master
  • **********
  • Posts: 1830
Re: LOW power, given my jetting ?
« Reply #38 on: December 06, 2007, 09:27:10 AM »
I seem to recall Honda's generally having a weak spark, which may be your problem.... I recall someone turboed a Honda bike and had to run very low boost when using the stock ingnition and coils.

I'd try to close the plug gap up to .018", and use smaller jetting. You may get a better ET with a lower MPH, but it's the ET you want, not the MPH.

Give it a shot, I know it's a lot of work given what you've told us, but I think it would be worth the effort. Good luck!  :thumb:
Thomas

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #39 on: December 06, 2007, 05:12:33 PM »
war machine, between my somewhat emotional preference to go with the quickshift and my desire to pull a little timing out of it, i'll probably go with the dynojet stuff.  plus they said they'd give me the prototype ignition module that i pushed them into making !  i wanna show a little loyalty to them for their generosity. 

gsxrturbo1, i am stronly contemplating high energy coils too.  i was getting smooth power (if not exactly thunderous) , which at least loosely implies that ignition events were successful.  i may drop my gaps way down first, to see if that produces any change.  BEFORE i attempt another rejet.

my first project bike, approx. 25 years ago, was my brother's 1976 Honda CJ360T.  way back then, i'd read of the weakness of many stock motorcycle ignition coils.  i found a magazine article about switching automotive ignition coils onto bikes, and did this to my brother's bike.  i think it cost somewhere around $20 complete back then.  maybe it's time for me to scour the archives ?

Offline buckyworld

  • Apprentice Post Whore
  • **
  • Posts: 19
  • Gender: Male
  • Where am I?
Re: LOW power, given my jetting ?
« Reply #40 on: January 08, 2008, 12:36:33 PM »
Ignition Module received, Quickshift and MultiFunction Hub have shipped and should arrive late this week.

And I've got about 3.5 months to get it sorted out.
The ONE good thing about Alaska motorcycling:  plenty of wrench time during a long winter.