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[fj1289]

Well, I'll  try to finish that last post now...not sure what happened.

Tried mounting GoPro on the tank for the last three runs.  Forgot to turn it on for the first run!  The last two the camera didn't record (operator error - thought it was in one-touch mode - oops).  I really like the perspective in a video Randy forwarded to me - cool view of what the chain is doing and a good shot of what the front end is doing too. 

http://www.liveleak.com/view?i=5a0_1384459154

I also like the view from Richard Gadson's recent 7.08 at 205+ on a GS1100 pro street bike: 

http://m.youtube.com/watch?v=L-b19UkpXcQ&desktop_uri=%2Fwatch%3Fv%3DL-b19UkpXcQ

I plan to fabricate a small plate to bolt to the left side rear axle block for a GoPro mount.   Will be interesting to see how that works. 
Also want to find a spot to mount it for a good view of the dash and track - not sure the tank mount will "see" over the dash.  Maybe a mount on the triple clamp or the clip on...

George - don't overplan a cafe build -- just roll with whatever comes up at the time!   Two sites with great ideas are wrench monkees site and bratstyle.com

[movenon]

That video is cool showing the stress's on the chain. I will check those WEB sites out. I don't know about building a Cafe Racer, I do appreciate the engineering but the FJ makes short runs real easy. I am thinking about more of a touring / adventure bike for a build.
Don't get me wrong Chris, the FJ stays ......... Hard to beat all things considering.
George

[fj1289]

You wouldn't be interested in a very nicely done KLR650 Tengai would you?   The Tengai was a 2 year special model Paris-Dakar rep.  I bought it already painted (Kawi green) and 685 kit.  I've added crash bars and Wolfman soft luggage.  Also adding ported big valve head to compliment the big bore.  Kept stock cam and carb for throttle response and off road ability. 

[movenon]

You wouldn't be interested in a very nicely done KLR650 Tonga would you?   The Tonga was a 2 year special model Praised rep.  I bought it already painted (Kai green) and 685 kit.  I've added crash bars and Wolfman soft luggage.  Also adding ported big valve head to compliment the big bore.  Kept stock cam and crab for throttle response and off road ability. 

Sounds nice but daring to be different I am thinking about a BMW K75 similar to  http://www.advrider.com/forums/showthread.php?t=740106  or some variant. I tried a KLR before I bought the FJ and for some reason it just didn't "gel".  Hard to explain, when a bike fits you know it first thing. I ran a DRZ 400 for a couple of years and never did like it. To tall etc.. Great in the dirt but around town wasn't to good.  On a lark I went over to look at the FJ I own and knew from the minute I sat on it that it "fit". Years ago I rode a K75 down to Las Vegas and while not a power house I was impressed with how smooth and flat the power band was. Hard to beat those 3 cylinder bikes for running smooth.

Just crap to think about. Right now I am still puttering around on the FJ thinking about the next WCR and maybe a "western parks" tour in the summer.
With all the new members in the Colorado area there might be nice rally there also this next summer.
George

[Flynt]

Here's what you want George…  ltd edition GS Dakar!  Unlike the big GS this one is a simple, stump pulling, 650cc thumper that goes forever and will climb trees. Also very rare, I've only seen one in the wild.



Enjoy shopping!

Frank

[Dan Filetti]

The F650 would be a most excellent bike if you spent most of your time off road.  I think I see where you're going with the K75 -broad seat more comfy ergos, but be aware that bike is a pig for weight.  Hell, for that kind of weight you may want to consider the BMW's big GS. 

Dan

[movenon]

The F650 would be a most excellent bike if you spent most of your time off road.  I think I see where you're going with the K75 -broad seat more comfy ergos, but be aware that bike is a pig for weight.  Hell, for that kind of weight you may want to consider the BMW's big GS.  

Dan

I agree with the weight issue. I just like the concept. The future project is in the "looking and thinking" mode. Not a big thumper fan for what I want to end up with. I had a BMW RT 100 and the weight was about the same as a friends old XS 1100 but because of where the center of gravity was the BMW was much easier to handle. Gutless on power but balanced well. Gutless might be a bit strong, just lower on power....

Frank, that Dakar GS is more dirt oriented than I would like but it looks nice. About the only dirt I will see is fire roads  .

Sorry Chris, I didn't mean to highjack the thread. maybe there needs to be another category for "Non FJ bike projects" ?  
George

[Flynt]

Frank, that Dakar GS is more dirt oriented than I would like but it looks nice. About the only dirt I will see is fire roads  .

You sound like you need a supermoto…



Now that looks like fun!

Frank

[andyb]

And now to combine dragracing and dirty work into one post...

Years ago, I had a friend of a friend with a RM250.  Dirt bike.  Wheelie bars.  Nitromethane.  Yup.  12.x's in the 1/4mile, from a 250.  Silly stuff. 

[fj1289]

George - no worries!  It is the off season after all.  

Andy - sounds cool.  Most of the motocrosser turned drag bike projects I've seen are gear/RPM limited.  Wonder what kind of revs he's turning thru the lights!  

T
Right now I'm thinking thru the off season mods for the drag bike.

First and foremost is getting a better handle on the clutch tune.  I've read just about everything I can about tuning this clutch - and tried to sort the BS from the nuggets.  One interesting thing I've found seems to point towards treating it more like a slider and less like a traditional multi-stage lock up.  Putting just enough static in it to ride back after the run (or just enough to pass the tech rules for your class - most classes require the engine to die if the clutch is released at idle).  Then use the arms, weights, and extension springs to tune the engagement RPM.  May also be getting a little professional help to get the next step or two thru the clutch tuning process and continuing to learn along the way.  

Next I'm thinking of reinstalling the Innovate Motorsports DL-32 data logger.  I had some issues with the DL-32 previously and switched to logging with the WEGO III.   Problem is the WEGO only logs 3 channels - RPM and air fuel ratio - plus a third 0-5 volt signal.  Most people log TPS, but I want to log wheel speed (plus I don't have a TPS anyway).   The DL-32 will log a frequency and convert to a "usable" linear signal - correlating to rear wheel speed in this case.   The rear wheel speed signal is generated by a hall effect sensor and six rare earth magnets attached to the rear sprocket studs.   For the WEGO to log this signal, it needs a frequency to voltage converter.  My attempts at making one have failed miserably, so I'll try adding another box (the DL-32) to the mix.  Pretty sure the previous issues with the DL-32 were related to a bad SD card and compounded by a failing O2 sensor.  

I'd also like to lower the front end some more, and will require several changes to do properly.  First the bottom of the fairing needs to be trimmed for fender clearance.  May also need to move the fairing forward another inch or so (it was already moved forward about 2 inches during the original build).  Finally, need to account for the decreased steering head angle resulting from the from the lowered front end (and possibly raising the rear) since quick steering or "twitchy" and drag bike are terms that do not go well together.   The solution?  Traditionally it has been to rake the front end.  Now  a days "street bike" style drag bikes use triple trees with less offset - increasing trail while also not increasing the wheelbase (especially for bikes running in classes with wheelbase restrictions).   Since I'm using early R1 forks, I've got options.  Yamaha went thru a few phases while trying to tailor the handling of the R1.  They started with 35mm offset triple clamps - same as the FJ (and many other models too) while later years included both 30mm and 25mm offsets.  There's a set with 25mm offset setting in a box of spares waiting to be installed.  Tire to header clearance can become critical - hopefully having the head pipes cut and rewelded during the original build will ensure there's enough clearance without further mods...

And then there's a few more details - like swapping the 16 tooth countershaft sprocket for a 17 tooth.  This will help male sure it doesn't run out of gear at the end of the 1/4 mile, and should make tuning the clutch a little less "touchy".  Also would like to make a fiberglass "seat" and possibly notch the rear subframe to lower the seating height a couple inches.  Make some mounts for the GoPro, and more things I'm sure that will come up along the way...

For now, I've got 2 1/2 weeks to ponder my options due to work.  And time to finish Capt'n Ron's epic travel thread...

[fj1289]

Well, about time to start updating this thread again. The first test n tune days at Bandimere are April 12th and 13th (the 13th is race cars only - running slicks or 11.99 and quicker)

Just ordered the 17 tooth offset countershaft sprocket.  Should help keep it out of redline at the stripe (and be good for 150's if needed). Taking some gear out of it is also supposed to make tuning the clutch a little less touchy. 

I've filed the notches out of the clutch basket.  Now need to finish grinding down the clutch steels - have them ground to size, just need to dress rough edges.   

Thanks to Randy for sending me a trashed input shaft so I could grind the steels to size myself.  May be a bit of a hack job, but seems to have worked well. Started by cutting the end off the input shaft and chucking it into the lathe.  Then stacked a clutch hub with a couple of the original steels that were ground to size (but are now warped), stacked the stock steels on, and finished with a couple of the original steels.  The original steels on each end serve as guides to grind the steels to the correct size. Bolted on the pressure plate and fastened the assembly to the end of the shaft in the lathe. Then, as the whole assembly spins - slowly ground the steels down to size using a 4 inch angle grinder!  A steady hand, good light, and keeping a close watch ensures it comes out well.  Now I just have to dress off the sharp edges created. 

After a lot of reading and thinking on the clutch tune - think I've got a way forward with it.  Plan is to keep running it in multistage mode, but treat it more like a slider by setting it up with just enough attic pressure to be able to ride back after a pass, but tune the clutch using the lockup arms and holdback springs. 
A traditional multistage lockup requires static pressure to get the bike moving from a stand still since the lockup doesn't start to spin until the transmission is turning (i.e. the bike has started to roll).  But a slider clutch that has the lockup attached to the clutch basket can apply lockup force based strictly on the engine speed.
There are a lot of variables to work with - air gap/stack height, total friction surface in the clutch (number of friction plates being used), static pressure, lockup arm weight, hold bald springs, and 2-step RPM. 
Plan is to use the same air gap and number of plates, go back to just 4 static springs, start with 5 washers on each arm (as determined last time out) and swap the 20# hold back springs for 17# to bring the lockup force in sooner.  Then the tuning variables will be arm weight, hold back springs, and 2-step RPM. 
Main goal will be to get consistent launches and be able to make a change and see how it reacts.  At that point the tuning process should become a lot more straight forward. 

I'll also be changing to the non-oxygenated fuel they sell at the track. So another jetting change will be in order too. 

April is soon!!!   

[andyb]

After a lot of reading and thinking on the clutch tune - think I've got a way forward with it.  Plan is to keep running it in multistage mode, but treat it more like a slider by setting it up with just enough attic pressure to be able to ride back after a pass, but tune the clutch using the lockup arms and holdback springs. 
A traditional multistage lockup requires static pressure to get the bike moving from a stand still since the lockup doesn't start to spin until the transmission is turning (i.e. the bike has started to roll).  But a slider clutch that has the lockup attached to the clutch basket can apply lockup force based strictly on the engine speed.
There are a lot of variables to work with - air gap/stack height, total friction surface in the clutch (number of friction plates being used), static pressure, lockup arm weight, hold bald springs, and 2-step RPM. 
Plan is to use the same air gap and number of plates, go back to just 4 static springs, start with 5 washers on each arm (as determined last time out) and swap the 20# hold back springs for 17# to bring the lockup force in sooner.  Then the tuning variables will be arm weight, hold back springs, and 2-step RPM. 
Main goal will be to get consistent launches and be able to make a change and see how it reacts.  At that point the tuning process should become a lot more straight forward. 

I'll also be changing to the non-oxygenated fuel they sell at the track. So another jetting change will be in order too. 

The guys that I've seen run a multistage with that sort of setup find that it's basically a slider by the time the run's over, due to heat changing the spec on stuff.  Gets them through a hand clutch rule at tech, though!

[fj1289]

Made it out to the strip last night!   
I guess the 8th attempt is the charm...and thought work was going to clobber it again last night. 

From the last outing last year, made a couple changes to the setup.  Biggest change is going from a 16 tooth countershaft sprocket to a 17.  Gearing now is 17/43 and should be good for 150 mph at 10,000 RPM if needed.  Also have setup the swingarm to act as an air tank by sealing all the leaks and adding a couple fittings.  Finally changes to VP 113E fuel since I can't run VP Q16 here (the MTBE used to oxygenate it is illegal in Colorado).  VP 113E is lightly oxygenated compared to the Q16 so it will make less power

For the clutch, ground down a set of stock FJ steels to fit better in the Busa clutch basket.  Only change to the clutch tune is going from 20# holdback springs (the ones that attach to the arms making a triangle) to 17#.  That should bring the lockup in a little sooner.  Also went back to 4 heavy static springs and got rid of the slider springs.   

Last night was "Race Car Test" -- limited to vehicles with slicks or running 11.99 or quicker.   Great evening for tuning - never had more than 6 or 8 cars or bikes in line to run.  Also, everyone was pretty well prepared - only a couple cars slow to clear the track and NO oil downs! 

Got 6 runs in with plenty of time between runs for tweaking and cool down.  Bottom line - no nines this time out, but pretty sure how to get there next time. 

Get thru tech with one snag - the new (to me) leathers I picked up off craigslist have nylon zippers - NHRA requires metal zippers.  Oops.  They clear me to run for the night - which really isn't a big deal since I plan to mainly run the 1/8 mile and focus on the 60' and 330' times. 

Finish prepping the bike - and think there's a leak in the air shifter when I put the CO2 cylinder on.  Quickly disconnect the CO2.  Remove the lines from the swingarm and install a single line straight to the shifter solenoid.  Seems to take care of the leak. 

Roll up to the staging lanes - only other vehicle is a Harley with bars.  He's running on a .400 pro tree.  Starter asks me if I want to run the pro tree or wait for the full tree.  What the heck - I'll run the pro tree - won't make a difference on my 60'.   Burn out, line up, wait for the tree to count down - crap!  No count down on a pro tree!  I leave very late, but the launch feels good.  And I chase the sportster down just past the 1/8th where I roll out.   Cruise to the turnoff and go past the sportster who is waiting for his tow back to how pits.  Really makes me appreciate being able to cruise back to the pits on my own -- and not need a start cart or crew either.  Get back to the pits and look at the time slip.  Not bad - happy with the run for right off the trailer.   
60'      1.672
330'    4.349
1/8      6.532 at 112.05
Pretty much on par with the good runs from last time out - and with the new gearing and fuel. 
The launch is still a bit lazy - so the first change is to add more static pressure.  Take off the clutch cover, remove the clutch hat and add 2 medium springs to the 4 heavy springs.  Keep everything else the same.

2nd run.  Short wait in the staging lanes.  Line up with a second gen Camaro with a single centered wheelie bar (which he put to good use!). Burnout, stage, and watch the tree count down this time.  Bottom yellow light and go - and spin hard.  Back pedal the throttle a little and shift. 
Once again chase down the Camaro just passed the 1/8 mile as I roll out. 

Time slip isn't good - as expected with spinning on the launch. 
60'    1.848
330'  4.827
1/8    7.123 at 107.39
The added static did its job - definitely tried to launch harder - just more than the suspension and tire could hold on to.   For the next run I soften the rear suspension link from 15 to 15 1/2 out of 16 marks. Also drop rear tire pressure from 20 psi to 15 psi. 

3rd run.  Lined up with a Nova with a tall scoop and full slicks.  Still spins on the launch - not as bad as last time.  Nova gets a great jump but I'm well past him before the 1/8 mile point. 

60'     1.673
330'   4.289
1/8     6.475 at 111.78
Not a bad run - actually best 330' and 1/8 yet - despite spinning on the launch. 
Changes for next run - take the rear suspension link out to the softest setting (16).  Keep tire pressure at 15 psi - don't know how these tires behave at really low pressures and don't want to take a chance of the bead coming off the rim.  Only other adjustment to help traction on launch is to take out some compression damping - take out 3 clicks of high and slow speed compression damping.   Decide to reduce the 2 step RPM about 500 to soften the hit some. 

Run 4.  Still spins on the launch - and won't shift.  CO2 bottle out already.   Forgot about losing a lot of it with the leak before the first run.  That run is a scratch.

Have to take out some static from the clutch since I've run out of suspension adjustments.  (On the way home think of one other change -- shorten the wheelbase -- but I didn't  have my chain tools with me).  Replace the medium springs with the (very) light springs with a hardened 5/16" washer as a spacer.  These springs are very light compared to the mediums.   

5th run.  Almost end of the night.  Plan to run the full length on this one.
Launch feels very smooth.  Too smooth it turns out.  Look at the time slip - WTF?!
60'      1.922
330'    4.768
1/8      6.989 at 111.04
1000'  8.921
1/4     10.577 at 135.73
All I can think of is the 2 step is too low.  Add back 500 RPM on the 2 step.  Quick turn to make a final run before they close the staging lanes.  (Turns out it was a 2nd gear launch - again - and the times are very similar to the last time out when I did that).

Line up with a car tire old school Kawasaki with bars.  Says he's been chasing his tune all night after installing a new slick - says it falls on its face on the launch now.
Run the full length again.  Launch feels good - doesn't misbehave.  Run feels good. 
60'      1.677
330'    4.342
1/8      6.530 at 112.15
1000'  8.435
1/4    10.071 at 137.09
Not a bad run - but short of where it should be. 

For the next outing - plan to increase static pressure - just not as much as adding the 2 medium springs.  Ordered some 3/4" shim washers in .005", .010", .015" and .025" from McMaster-Carr this evening.  Plan is to remove the light springs and start shimming 2 of the 4 heavy springs to incrementally increase the static pressure.  Other change will be to shorten the wheelbase some to increase traction.   It's about 65.75" wheelbase now.  Removing 4 links should put it about 64.5".   This should help increase the traction available.  Possible downside could be a greater tendency to wheelie - but there's some margin there since it really hasn't tried try to stand up yet. 

Have to get metal zippers added to the leathers to be legal for next time.  Might as well get some of the other mods that will be needed to make them legal for Bonneville too

[andyb]

Good stuff, more learned!

Unless that was typical track prep or you're expecting to bracket race with a little more on the dial, leave it long for now.  There's no reason why you can't get it to hook at that length and weight if the prep is on point.

Sounds right on dialing in the static, baby steps, but you have to blow through firmly a few times to learn just how big a step a baby would take, after all.

Don't like the backhalf on the full run.  24mph seems really, really low to me.  I can't imagine it's blowing through the clutch downtrack, and that isn't the sort of power output that you'd associate with getting the tire to spin (nevermind having a soft shock to boot...).  You're maybe still chasing the fueling a fair chunk?

I forget which tire you said you were using (hookup?) but I'd start getting real leery once you're under 14psi cold.  I think the problem with the usoft's weak beads is now a thing of the past, but at least two machines crossed the finish line in a wheels-up pose that I'm aware of... and that's with PST speeds, too.

Remember that track prep improves as you start getting bigger events in the swing of summer, because the track needs to work well when there's big money events going down.  The other question would be temperature?  If the track here is under 100F or above 140F on the ground, it may as well be covered in oil.

Sounds good though!  Keep chasing it!

[fj1289]

Exactly!

Prep wasn't bad - but wasn't great either.  It is only about three weeks into the season at this point, temp in the 60's, and we even got some snow last night.  So prep will probably get better.

The tire is a Michelin Race 1 I think -- it was the one before the one everyone was using but is now discontinued.  It is a bit on the old side now - probably 5 years old?  Still heats up well and always picks up pebbles on the way back after a run.

The shock is now too far on the hard side I think.  Didn't know how much range the adjustable linkage had - was almost full hard on the linkage with the old 650# spring and couldn't keep it from bottoming.   Put in a 950# spring and it's been better - but I'm full soft on the linkage now and seems like it's still a bit hard for an aggressive launch.   Also wonder if it is also "topping out" and causing a little spin issue for the 1-2 shift?  

A few things bringing the back half down some - 5800' elevation for one, going from Q16 to 113E, and shift light set under 10,000 RPM.   The power jets have gone from 120's  at 3,500' elevation tracks with Q16 fuel to 40's at 5,800' with the 113E.  And that's giving me right at 12.5 on the AFR.   This mile high stuff sucks the horsepower!  This motor pulls well up high - and it's fun to let it eat - I try to keep it down some, especially when I'm focused on the other end of the track right now.   I noticed looking at my notes from last outing I had the shiftlight set to 10,750 on the 10.0 runs (and on Q16) ansd this time I turned it "up" to 9,750 for the final runs.  Overall I think I lost less than I expected to with the fuel change and the gearing change.  

Good point on the wheelbase - I'll keep it where it is.  Think it's time to find an 800-850# spring though. Can't wait to get out again.  Want to get this thing dialed in enough I can focus on bracket racing instead of tuning!