phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
Would anyone know the camshaft duration of lift/camshaft profile for the FJR??
Last edited by a moderator:
What duration of lift for intake/exhaust??
- Thread starter phoneman91
- Start date
Help Support Yamaha FJR Motorcycle Forum:
Toecutter
What would DoG do?
Why?
vectervp1
Well-known member
phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
Why not?? I am just interested in how Yamaha tuned the bike to get this extremely wide torque band---aside from the 1300CCs and relatively low weight.
radman
R.I.P. Our Motorcycling Friend
Wide torque bands are typically produced by short duration,low overlap profiles. With a lift of .450, a cam with 230 degrees @.050 will produce more horsies than a cam with a duration of 220, but the 220 will have a better torque band, and better low rpm response. Lobe centers can also affect this, with a 220 at 110-114 degrees or so, the 230 at 108-110. Cam profiling is some of the most fascinating motor shit there is, and is the stuff of mystery. Tomorrow-dual pattern discussion. 
Lift is, I believe, .317 on the Feej,no duration spec given, but given the performance envelope and relatively smooth idle characteristics,I would suspect it's in the 220-230 degree area.
Lift is, I believe, .317 on the Feej,no duration spec given, but given the performance envelope and relatively smooth idle characteristics,I would suspect it's in the 220-230 degree area.
Last edited by a moderator:
:glare:
[karnac impersonation]......I see you purchasing a service manual in your future.....[/karnac]
phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
The FMS doesnt list duration and lobe separation--just lift. I would agree that short duration and high lift would be the likely configuration.
The WIDE torque band of this bike is unbelieveable!! Finally a ST with weather protection,luggage,and power and torque--with relative light weight!! Just what I wanted back in 1986 when I bought my Connie.(Sorry guys--still not over the new bike high--I love my 07!!)
I was just wondering if anyone knew the cam profile.After all--the cam on this bike is the "mechanical brain"--as on all four strokes.And I kind of miss the technical write-up that old "Cycle" magazine(RIP -DIED 1991) would do on bikes during their road test/technical evaluation.
Last edited by a moderator:
Kaelaria
Well-known member
Get me a cam and I'll run it through my profiler for ya
ionbeam
2 FUN
I have a copy of a publication called “FJR1300 Technical Orientation Guide” published in Canada but has no publishing date, I suspect that it is for a 2003. FWIW, this is what it has to say about valve timing:
radman
R.I.P. Our Motorcycling Friend
Well well well. Dual pattern, 255 gross in, 260 gross out, bout a [email protected] in, 235@050 out. Roughly. And I mean roughly. 110 degree center. Check my math someone, but I thinks I damn near nailed it. Thanks Ion.
I agree with all the above.....but there is more to it than just the cam timing.
Not that the cam isn't important, but the cam is dictated by the physics of mass and acceleration of the valve train and Yamaha doesn't have any specific insight on the physics that others don't have. That is why most cam profiles, regardless of who designs them or the OEM, tend toward very similar dimensions and orientations.
I suspect that the majority of what you are "feeling" on an FJR as a wide torque band...i.e...good low end torque and an engine that doesn't wheeze out of breath at 9000....is the effect of the displacement.
There are really only two ways to "create" torque all other things being equal. A higher compression ratio and more displacement. Oh....and....a blower is another way to create torque.... but that is another discussion.
You can move the torque band around with cam timing changes but you are not really creating torque, just moving the torque peak and compromising power for torque....or vice versa.
The FJR can run a reasonably high CR due to the central plug location and smallish combustion chamber (typical four valve design) so it is probably pretty well maxed out in that area while still being capable of running on regular fuel without undue risk of detonation.
The displacement is the big thing. That "makes" torque simply be moving more air (and burning more fuel) regardless of the cam timing. Within reason, there is an almost linear relationship between torque and displacement. Increase the displacement by 20% and you will get a 20% torque increase. Like I said....within practical reason...assuming the engines in comparison were both reasonably optimized by the OEM. You are not going to get that sort of torque increase by compression and certainly not by changing the cam timing if the cam timing was already optimized for that range of RPM operation.
The cam is not much more aggressive than on a similar 4 valve 600 cc engine. But the 600 seems somewhat gutless on the low end but it will rev beyond 10,000. Put that cam timing and larger valves (bigger bore) on top of the 1300 cc and you inherently get much more low end torque and still have reasonable extension in terms of RPM capabiliyt without running out of breath.
The OEM production engines MUST idle reasonably smooth and stable at a relatively low RPM so most OEM cam timings are going to look similar for lift, duration and over lap/lobe spread and then you "get what you get" in terms of low end torque and extension of the power band. It really is heavily restricted by the idle quality requirements. Which is why the first thing to go with aftermarket cams is the idle quality. Without the idle quality restriction the aftermarket cams can run more lift/duration and allow more overlap which is inherent when you start increasing the lift/duration of the lobe event. Lobe CENTERS are going to remain somewhat fixed as dictated by the RPM range the cam is designed for so adding life and duration will inherently increase the overlap to allow the valve train to still function.
Not that the cam isn't important, but the cam is dictated by the physics of mass and acceleration of the valve train and Yamaha doesn't have any specific insight on the physics that others don't have. That is why most cam profiles, regardless of who designs them or the OEM, tend toward very similar dimensions and orientations.
I suspect that the majority of what you are "feeling" on an FJR as a wide torque band...i.e...good low end torque and an engine that doesn't wheeze out of breath at 9000....is the effect of the displacement.
There are really only two ways to "create" torque all other things being equal. A higher compression ratio and more displacement. Oh....and....a blower is another way to create torque.... but that is another discussion.
You can move the torque band around with cam timing changes but you are not really creating torque, just moving the torque peak and compromising power for torque....or vice versa.
The FJR can run a reasonably high CR due to the central plug location and smallish combustion chamber (typical four valve design) so it is probably pretty well maxed out in that area while still being capable of running on regular fuel without undue risk of detonation.
The displacement is the big thing. That "makes" torque simply be moving more air (and burning more fuel) regardless of the cam timing. Within reason, there is an almost linear relationship between torque and displacement. Increase the displacement by 20% and you will get a 20% torque increase. Like I said....within practical reason...assuming the engines in comparison were both reasonably optimized by the OEM. You are not going to get that sort of torque increase by compression and certainly not by changing the cam timing if the cam timing was already optimized for that range of RPM operation.
The cam is not much more aggressive than on a similar 4 valve 600 cc engine. But the 600 seems somewhat gutless on the low end but it will rev beyond 10,000. Put that cam timing and larger valves (bigger bore) on top of the 1300 cc and you inherently get much more low end torque and still have reasonable extension in terms of RPM capabiliyt without running out of breath.
The OEM production engines MUST idle reasonably smooth and stable at a relatively low RPM so most OEM cam timings are going to look similar for lift, duration and over lap/lobe spread and then you "get what you get" in terms of low end torque and extension of the power band. It really is heavily restricted by the idle quality requirements. Which is why the first thing to go with aftermarket cams is the idle quality. Without the idle quality restriction the aftermarket cams can run more lift/duration and allow more overlap which is inherent when you start increasing the lift/duration of the lobe event. Lobe CENTERS are going to remain somewhat fixed as dictated by the RPM range the cam is designed for so adding life and duration will inherently increase the overlap to allow the valve train to still function.
phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
Aren't some of the liter/liter+ sport bikes running 300 degree duration advertised on stock cams?? I wouldn't think that idle concerns would be a big issue for the go-fast guys on the sport bikes. And large displacement allows more duration/lift while maintaining idle/low speed quality--compared to lesser displacements.
(I had a 1985 ZX1000 ' Saki that had 300 intake and 290 exhaust advertised stock cams and it was the most unusually cammed stock bike I ever rode--no torque at all below 4K in any gear above second--but amazing top end rush above 6k. And uneven idle.It was a fast bike back in '85. First factory stock bike to be magazine tested with a top speed of 161 MPH.And first sport liter bike to have a full factory fairing)
And aren't poor idle concerns on high overlap factory cams ,usually handled by higher set factory idle speeds and lower gearing??
I agree that displacement plays a large factor in FJR torque spread. But it's relative low weight for a ST--is a factor also. And apparently this factory cam profile.
Yamaha could have geared this bike lower or/and given it a more agressive cam profile and made it quicker and faster--but at the expense of low speed speed torque and wide torque band and gas mileage.
I think that Yamaha made the correct decision--the bike is perfect now for it's intended use.
But --who will bet that the first thing that gets changed on the 08/09 FJR--when the Concours 14 comes out--will be the cam profile??Or the addition of variable value timing?? There is additional power in the FJR just waiting to be released.
(I had a 1985 ZX1000 ' Saki that had 300 intake and 290 exhaust advertised stock cams and it was the most unusually cammed stock bike I ever rode--no torque at all below 4K in any gear above second--but amazing top end rush above 6k. And uneven idle.It was a fast bike back in '85. First factory stock bike to be magazine tested with a top speed of 161 MPH.And first sport liter bike to have a full factory fairing)
And aren't poor idle concerns on high overlap factory cams ,usually handled by higher set factory idle speeds and lower gearing??
I agree that displacement plays a large factor in FJR torque spread. But it's relative low weight for a ST--is a factor also. And apparently this factory cam profile.
Yamaha could have geared this bike lower or/and given it a more agressive cam profile and made it quicker and faster--but at the expense of low speed speed torque and wide torque band and gas mileage.
I think that Yamaha made the correct decision--the bike is perfect now for it's intended use.
But --who will bet that the first thing that gets changed on the 08/09 FJR--when the Concours 14 comes out--will be the cam profile??Or the addition of variable value timing?? There is additional power in the FJR just waiting to be released.
Last edited by a moderator:
I feel another point that has been left out is exhaust emmisions. While more aggressive cam profiles and other changes will allow the engine to create more power, the bike must still meet Federally mandated emmission levels before it can be sold.
Hence the catalytic converters and lean mixture settings from the factory. 145 HP is really not that great when compared to what engines are making with even less displacement in other bikes. You can rest assured that there is significantly more power available and Yamaha will extract it if necessary to maintain its sales base should another manufacturer (Kawasaki ?) bring in a competitive model that trumps the FJR in power and torque output.
Good luck and ride safely.
Hence the catalytic converters and lean mixture settings from the factory. 145 HP is really not that great when compared to what engines are making with even less displacement in other bikes. You can rest assured that there is significantly more power available and Yamaha will extract it if necessary to maintain its sales base should another manufacturer (Kawasaki ?) bring in a competitive model that trumps the FJR in power and torque output.
Good luck and ride safely.
phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
Wait when the Concours 14 comes out--it too will be low emission/Euro 3 spec with cats and it will have very high horsepower--probably 170 or more horsepower. But one thing it wont have is-- sexy good looks!!
Last edited by a moderator:
I doubt that the horsepower of the Kawasaki will be anywhere near that high. On the Kaw website the max torque is listed as 100.3 lb-ft @ 6200 rpm. Compression ratio is 10.7 : 1.
https://www.kawasaki.com/Products/Detail.as...=specifications
The FJR's max torque is 99 lb-ft @ 7000 rpm.
I think the redline on the Kaw is 10500 rpm, a bit higher than the FJR's 9000 rpm.
Since the max torques on the engines are about the same the max hp's will be a function of how rapidly the torques roll off from their peaks as the rpm increases.
I expect the Kaw's hp to be just a bit higher than the FJR's but not much higher. They can then claim they have the most powerful supersport tourer.
https://www.kawasaki.com/Products/Detail.as...=specifications
The FJR's max torque is 99 lb-ft @ 7000 rpm.
I think the redline on the Kaw is 10500 rpm, a bit higher than the FJR's 9000 rpm.
Since the max torques on the engines are about the same the max hp's will be a function of how rapidly the torques roll off from their peaks as the rpm increases.
I expect the Kaw's hp to be just a bit higher than the FJR's but not much higher. They can then claim they have the most powerful supersport tourer.
phoneman91
Active member
- Joined
- May 2, 2007
- Messages
- 28
- Reaction score
- 0
d
If you consider that the Concours will have the same engine as their ZX14 sport bike--and it has an advertised horsepower rating of + 190 horsepower @ crank(167 HP @ rear wheel dyno )--it isn't unlikely that the Connie will have ~ 170. And don't forget the variable timing camshaft--that should give the Connie a top end rush!!
Peak Torque is mainly determined by displacement--not tuning.
But you may be right--the Connie may have disappointing power output--and may be the cause of it's delayed release. I can picture a poor Kawasaki technician being told that they wont let him go home until he gets the Connie in a state of tune that out runs and pulls the FJR on a dyno!!!
Last edited by a moderator:
The ZX-14 engine is set up quite a bit differently from the Concours engine.
ZX-14
Max torque = 113.5 lb-ft @ 7,500 rpm
CR = 12.0 : 1
Redline = 11,000 rpm
Concours
Max torque = 100.3 lb-ft @ 6,200 rpm
CR = 10.7 : 1
Redline = 10,500 rpm
The ZX-14 likely gets its higher torque from its higher CR.
I'd guess the Concours max HP will be approximately 155.
I think the VVT will primarily affect engine operation at lower rpm's -- boosting the torque at cruising engine speeds.
ZX-14
Max torque = 113.5 lb-ft @ 7,500 rpm
CR = 12.0 : 1
Redline = 11,000 rpm
Concours
Max torque = 100.3 lb-ft @ 6,200 rpm
CR = 10.7 : 1
Redline = 10,500 rpm
The ZX-14 likely gets its higher torque from its higher CR.
I'd guess the Concours max HP will be approximately 155.
I think the VVT will primarily affect engine operation at lower rpm's -- boosting the torque at cruising engine speeds.
