SuzukiHayabusa.org
TECHNICAL => NITROUS => Topic started by: TrackRat on October 04, 2009, 09:50:42 PM
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:evil: Man I was at MIR today and ran my best time ever on my bike (8.81@ 156mph). A problem has come up but i can figure out what it is. On some passes the bike acts like it's on the rev limiter and wont rev past about 6 or 7 grand. I can watch the fuel pressure and it starts bouncing between 50 and 60 psi. It's hard to pin point the problem because it does not happen every pass. I looked at the wideband log on a good run and i was 13.0- 13.8 afr. here is a list of what I have and what I have tried. Let me know if I am missing something.
1397 12.5:1
stock head two intake cams degreed 105/106
45 shot of NOS
PCIII
Dyno Jet ignition module
s2000 injectors
walbro fuel pump (the one Hahn puts in their stage 1 kits)
I have replaced the following
PCIII ( on my third one ---just making sure because I get the 32-35 injector codes)
s2000's (two Sets-- all cleand and flow tested)
Played with fuel pressure and no change. Running 55 psi right now ( seems a bit high for s2000's)
I dont think it is cam timing because it does not do it all the time.
Any help would be greatly appreciated and thank in advance:thumb:
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Congrate on the 8.81 Kevin!
What is your injector duty cycle on teh S2000's at 55 psi?
There whould be no need to run more than 43 psi on those injectors with the power you have.
We only run standard pressure on Calvin's big motor bike with S2000's and he has gone 8.48@168 with his body weight.
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(8.81@ 156mph :thumb:
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Congrate on the 8.81 Kevin!
What is your injector duty cycle on teh S2000's at 55 psi?
There whould be no need to run more than 43 psi on those injectors with the power you have.
We only run standard pressure on Calvin's big motor bike with S2000's and he has gone 8.48@168 with his body weight.
From what I remember kind of high 80's. That's why I bumped up the fuel pressure. the more I think about it the more I think I have a bad pump. There is no way with s2000's and 55psi fuel pressure I should need 40 in the 100% row of the PCIII. I'm only spraying a 45 shot. What do you think?
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You didn't indicate what you are running for fuel or timing, but for that size shot, its possible that 13.8 to 1 is too lean and the motor is breaking up due to lean condition. Once the motor starts to break up, you can't measure the A/F, so you don't know if its even leaner on those bad runs. I generally try to keep it between 12.3 and 12.7. Does it feel like its on a limiter, or is it just breaking up?
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You didn't indicate what you are running for fuel or timing, but for that size shot, its possible that 13.8 to 1 is too lean and the motor is breaking up due to lean condition. Once the motor starts to break up, you can't measure the A/F, so you don't know if its even leaner on those bad runs. I generally try to keep it between 12.3 and 12.7. Does it feel like its on a limiter, or is it just breaking up?
It breaks up before I go to the nitrous. Like i said it does not do it every pass. It may go 5 passes without doing it then bam wont pull past 6000 or seven grand and I get all the injector codes. I pull 2 degrees at WOT just to be safe and only one time on the log it showed 13.8 for less than a second. It showed the 13.8 just as the nitrous came in at 6000 rpms. fuel is pump gas and cam 2 (50/50 mix)
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We are pretty much at high 80's on Calvins 1535 while spraying a 65 shot on top of it with S2000's at stock pressure, Walbro intank pump.
Like I said, he ran 168 with that.
Get that PC off of there fool and get your ECU tuning on... I know, you're scared... :hys:
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We are pretty much at high 80's on Calvins 1535 while spraying a 65 shot on top of it with S2000's at stock pressure, Walbro intank pump.
Like I said, he ran 168 with that.
Get that PC off of there fool and get your ECU tuning on... I know, you're scared... :hys:
for some reason when I try and map it with ecu editor it wont change maybe next time you come down to MIR I can watch you tune yours. No one around here really uses it. I have the service connector on my turbo bike but I can get another one from greg. I was able to extend the ecu but not map it. I need to do a little more learning :oops:
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Check your kickstand switch- seen it happen many times.
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Yup. Good call. Forgot about that one.
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Ok --I replaced the cam sensor just for the hell of it. This is the one thing that stands: I put a new fuel pump in and the pressure went from 58 to 64 psi with no adjustment to the regulator. i had to beck down the pressure to get it to idle. I am going to take it to get tuned on thursday and test at the track on Friday. Maybe one of these fixed it. On the kick stand switch can I just jump it to test the theory or does it read resistance?
thanks for all the replies!
Kev
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The switch could be bad but I've never seen one go bad. The ones that have the problem just aren't being pushed in all the way from the kickstand. Then when you make a pass, vibration or a bump in the track causes the kickstand to move back and forth and cause a rev-limiter type situation.
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The switch could be bad but I've never seen one go bad. The ones that have the problem just aren't being pushed in all the way from the kickstand. Then when you make a pass, vibration or a bump in the track causes the kickstand to move back and forth and cause a rev-limiter type situation.
So what do you use to get the switch to close all the way? :oops:
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bypass it. just cut the 2 wires and solder them together
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The switch could be bad but I've never seen one go bad. The ones that have the problem just aren't being pushed in all the way from the kickstand. Then when you make a pass, vibration or a bump in the track causes the kickstand to move back and forth and cause a rev-limiter type situation.
i see what your talking about. The kick stand could get stuck just about all the way up and not push the plunger all the way in. My kick stand had a bunch of road grime in it. i took it off and cleaned it then lubed it with white litium grease. I hope one of these things fixed my problem :thnks:
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Check charge rate at the battery & connectors at the voltage reg. Mine did a similar thing, it was charging at 13 not 13.5 volts, fixed the regulator plug & no more problems. Leigh
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Problem solved----- six passes and no problem. Just incase anyone else has this problem I changed the following:
Cam sensor
fuel pump
cleaned and lubed the kickstand bracket so it wont get hung half way up
Bike ran pretty good with my heavy azz on it and the A/F ratio was much better. 12.9 was as high as it got :thumb:
1.41 60ft
3.87 330ft
5.79 1/8th
Thanks for the help guys! :thumb: