What did you do today? Cobba's rebuild

[Kenny]

Why not fit a sock on the carb trumpets inside the airbox?

[cobbadiggabuddyblooo]

To restrictive

[cobbadiggabuddyblooo]

Round 2 and made up a air filter .
Ramair has a box containing filter mesh and 2 stage filter foam on special at 40% off about 10 days ago so I bought 2 . Bargain at $46 with shipping .
So here is the prototype bolted in place and I've also raised the tank at the front by 10mm to see if I gain more airflow.
I bolted the Akrapovic system back on today too so I can monitor the A/F so I may go for a quick ride Friday to see how it performs.

I'll get some facts n figures on this version then start on stage 2.
I'll need to re route a few cables, chop off the old air box mount, front coil mounts and modify the cable stay from the frame to free up a little space while at Dave Kellett motorcycle engineers.
I need a plate welded behind the head stock just infront of the tank mount to fit the steering damper in place so I may as well get Dave to tidy up those brackets no longer needed..











I'll make up 2 solid pieces I can slip between the tank and the frame so I purely rely on air flow being scooped up from lower down plus air entering from the top and bottom triangles of the frame . I'll look at gains and losses to see where the wind takes me on this .

[cobbadiggabuddyblooo]

Out for a run today with the O2 sensor hooked back up again after the latest mods.
10mm spacer on the front tank mount to lift the front and new filter in place. Idle and pilot circuit still happy at 11.8 to 12.5 but still a little rich on WOT from 3500rpm to 6000rpm as per before .

4th gear roll on Fueling will drop as low as 11.3 at 5000rpm but back into the mid 12's again by 6000rpm but if I roll the throttle on a little slower it keeps it above 12.

2nd or 3rd gear rolling on a little slower out of corners from 3500 rpm gives me more than enough power with the rear end easily breaking traction and front end bouncing off the tarmac.

The cams really come on strong from 6000rpm so running it up to 8-8500rpm keeps me in the power band through the gearbox.
3rd at 8500 A/F starts to creep up from mid 12's to 13
4th gear from mid 12's up to hi 13's - 14 by 8500 rpm ( 220kph )
5th gear I find 220kph onwards my fueling will start to run as hi as mid 14's .
Previously I would be in the mid 13's at 8000rpm in top gear.

Next change I noticed was on over run. Still no real popping or banging in the exhaust but my A/F would easily sit in the 14's and register in the low/mid 15's every now and then especially at higher speeds.
Again up about another point from previous readings without the tank raised.

So I might try turning in the air screw that lives beside the main air jet by a 1/4 turn to see if that keeps things at no more than 14.5 A/F on over run.
Next dyno run I'll set up the 2nd ignition with a bit more advance in the richer zones from 4500 to 6000rpm to see if I find improvements.










Man 220k comes around fast...

[cobbadiggabuddyblooo]

Those from the SE QLD should recognize where the Leopard Tank is on show in the local council parkland.
A little info on the plaque by the tank.

[cobbadiggabuddyblooo]

Handy data to refer back to from GEAR COMMANDER....

GEARING at present is 17 / 41 and listed below on the first photo and 2nd photo is with 1 tooth less on the front and 16 / 41

17 / 41



16 / 41



I also have a 40 tooth rear so the options below are with 17 and 16 tooth front options.

17 / 40



16 / 40



I've had the bike to 230kph with the current 17 / 41 gearing and the speedo was still climbing when I backed off

[wreckage]

I've had the bike to 230kph

Between Esk and Fernvale?

[cobbadiggabuddyblooo]

http://www.musclecardiy.com/performance ... reatments/

Numerous handy link from here too..

[cobbadiggabuddyblooo]

Good lesson on the difference between

DETONATION and PRE IGNITION

http://www.contactmagazine.com/Issue54/ ... asics.html

[coxylaad]

"I'll make up 2 solid pieces I can slip between the tank and the frame"

did you see what I did there

[cobbadiggabuddyblooo]

Good idea, I can make just about enough torque to pull him out of a bog too....

[cobbadiggabuddyblooo]

Another handy link on exhaust pulse, inertial and wave scavenging which I found gives a good overall description on the basic physics to it.

So I have a couple of months up my sleeve at present while I research on how to optimize the Akra system.
But my guts telling me to look at an Over system with this cam set up....
Timing my way around the 5500rpm torque drop/ richer A/F hasn't really gained me anything so I'll try opening the exhaust valve a little earlier and see if I have a 2 fold gain... I'll see if this cam tuning changes how the reflective waves acts on the earlier closing valve and hopefully this can help with the 5500 problem and the 3 or 4 degrees lost in overlap may be offset by less pumping loss up top.

http://www.formula1-dictionary.net/exha ... _perf.html

I know I've posted this link 1 or 2 times before but it's such a good one ....
http://www.epi-eng.com/piston_engine_te ... nology.htm

[cobbadiggabuddyblooo]

Have you noticed the common wear pattern on the TRX and TDM inlet cam journal over cylinder No.1??????
Seems to be an inherent problem on the same inside inlet journal over cylinder 1 as can be seen in the photo below.



The lads from Germany bought this to my attention and have worked out why and a way around this.
When you do an oil change and you bleed the cam oil galley by removing the bolt on the head at the end of the exhaust cam, this creates an air lock on the inlet cam. So their way around this was to add an extra bleed point on the end of the inlet oil galley run just like the exhaust cam has as standard as can be seen in the photo below...
Personally I've gotten into the habit of priming all the galleys with a syringe full of oil and using assembley grease when bolting the cams back in place but this looks like a good option.

[cobbadiggabuddyblooo]

Scotts steering damper was finished off today as well as a few other bits n bobs after my low side on my last track day. Frame and wheels are straight and true once again including the fairing bracket mounting point on the front of the frame welded.

Beauty of the Scotts damper is it has a low and a hi speed damping set up just like most late model shocks. I don't particularly need to use the low speed damping so has no impact when riding on the front end but those times when the head shakes coming out of corners when the front wheel lifts and landing a little crossed up , the Hi speed valving will grab it and bring things back into line.

There's also a sweep function so you can set the range of sweep the damper will engage and release.( road bike set at 90* ) There's damping on the reverse action when centering too which is 1 of the functions that make it different to the off road Scotts damper. ( there's no reverse Damping back to centre )
That's the main difference between the road version and off road damper version.
The little " R " stamped in the front distinguishes it as a Road version. Something to note if your chasing one.

They must be doing something right as Ohlins was making them under license until they went broke and where bought out by Yamaha back in the 90's.

New tyres fitted and went with a pair of Dunlop D211 GP R's manufactured in France (soft front, med rear) which are essentially a pair of slicks with a few grooves cut in them to give them a DOT rating as a road tyre. Bonus here is they are a non directional tyre so after a couple of track days, I can just flip the tyre around and wear out the other side.

I can now continue on the ram air set up I'm toying with.

http://www.scottsonline.com/scotts.php

Scotts Damper operational/fitting Manual

http://www.scottsonline.com/litrack/257.pdf

[wreckage]

Next you'll be getting one of these made up....

http://newatlas.com/drum-charger-cheap- ... rbo/46648/