Topic: Turbo Charged CB550 Landspeed Attempt

[BomberMann650]

Have begun amassing materials for the streamliining build out.  3/16 steel wire for the frame, tubing clamps, and fender washers to start.

This led to an important decision to consider - the windscreen.  Among the Clear acrylic double bubble screens.  The suitable options create a little bit of an identity crisis for this bike!

Is it a honda?  Or is it a yamaha? 

[Old Scrambler]

Try a smoked R69S knockoff ..................

[BomberMann650]

Try a smoked R69S knockoff ..................

I placed the order for the honda shield.

But i'll look at the beemer bit.

[BomberMann650]

Prepping for the body build up.  Fitted 16 attachment points to the frame.   14 tube clamps with rivnuts, and two riv nuts behind the steer tube (8 fasteners per side).  In hopes of having an easily assembled kit for the APS runs.

Yet I waffle back and forth on the front end design.  Fender vs fully enclosed.  Both forms have to flare out to 28 inches to cover the operator.  Just have to decide how to get there

Physics says raindrop>knife.  CFD modeling shows a difference in drag/separation around the wheel and chin fairing.

Oh well, gotta go to the day job now.

[BomberMann650]

Spent the day figuring out the belly pan mounts.  Welding together steel lolli pops and putting rivnuts in fender washer "gussets"
Got the front end triangulated and on center.  Working my way towards the back.  Gotta set up some lines to help reference the wheelbase as i fit things in.

Rulebook has a 1" ground clearance requirement.  Which im not even close to.  Used a cargo strap to tuck the front end and set a line towards the front rim.  Have a second strap on the rear end too

Welding on the ground kinda sucks

[HondaMan]

About ground clearance and Bonneville: the Lakester run by my former employer (and VERY successfully) has a fully-enclosed chassis but with 4 outboard wheels. They found that anything closer to the ground than 4" got routinely torn off in the high-speed runs, usually due to the cracks in the salt surface. Twice they had to go back and walk the course to pick up the pieces (quickly) to avoid having the next guy run over them.

-just a thought.

[BomberMann650]

They must've had a rough track that season.  I recall hearing a few cars scrape but only when driving over the crunchies.
Will double check the clearance of the lowest spot on the belly.

Yesterday was a lot of fun, trying to set up the outside perimeter line of the belly pans "sides"
Lo, and behold.  The main bike is assymetrical.  My "comfortable" handlebar position has one tilted different than the other.  At the foot controls - because of the brake lever bearing.  That peg is thrust outward an extra scoche.  The plumb hanging below steer tree is the most accurate center i could muster.  Along with the swing arm studs.  But i got it together and it looks like its right where it needs to be.

[BomberMann650]

Spent a little time considering Hondamans wisdom.  Then busted out the tape measure.

Confirmed fhe lowest point of the belly pan was closer than two inches to the ground   pushing the envelope more than desired.  (Reference is the bottom split of the jack, close enough to "ground level" between the tires)
So a little nip n tuck came into play.  Shortening the middle support rod, and applying upward pressure on the wires.  Gained a little extra clearance and a flatter 'wing' profile before reattaching the support sticks.  Then added an additional pair to keep it up.
Now its certain, at full squat the bike will have a solid 2 inches of ground clearance.  With the shell on.
The fun part will be trying to remove the belly pan once the side lines are fixed in.  Hopefully won't have to jack up the front end too much to slide it in and out.

[Old Scrambler]

Does full squat mean bottomed..........as after a bump? Be careful to keep a slight 'V' on the bottom and don't create any upward lift from air pressure.

[BomberMann650]

Does full squat mean bottomed..........as after a bump? Be careful to keep a slight 'V' on the bottom and don't create any upward lift from air pressure.

Have been using ratchet straps to compress the suspension.  Referencing scooters photos for axle position relative to fixed points on the frame.

The belly pan i made is a flattened curve.  Not much wider than the tires.  Leading edge behind the wheel originates lower than the trailing edge ahead of the rear tire.  Which should generate some downforce.

Hopefully tomorrow i can begin positioning the windshield.  Will have to craft a nice trellis to support the front fairing.

[BomberMann650]

Got sidetracked with other problems.  Truck developed a misfire and the house lost its heater.
For want of a clear vision on the next part of the body to build.  The windshield remains on the shelf and things are as they were last week.
But, the postman delivered some goodies before turkey day! 

So the bike has a new chain guard now. 
Been having some difficulty with my ac tig settings.  Found out the finger switch wouldn't activate the 4t up and down slope.  Need to order some new electrodes too. 

There are a new set of valves and guides in the head.  Local shop took care of the fitment with their Rotelier machine.  They favor a radiused form tool for cutting seats. Which is a significant update over the factory cut.  The new valves are common motor dotcoms airlock repop. Not as elegant as kpmi, but they feel solid. 

The big news!

Extrude AFM in so cal put the turbo header through their honing process.  Pumping abrasive goo through the pipes to level out welds and smooth the transitions.
Which they did as a congratulations for setting the record!

Their sponsorship is something to be thankful for this holiday.

[richmagee7]

Very interested in how this fairing is going Bomberman.  Congrats on the help from a sponsor.  I had not even heard of that AFM process, interesting.

Rich

[BomberMann650]

Abrasive Flow Machining is pretty neat.

A thick paste blended with varying grain of silicon carbide is steadily forced through whatever orifice can bolt to the machine.  Depending on the process.  It can remove base material, or leave a mirror-like shine.
Since it is a semi-fluid process, the directionality of the media goes in the most natural order of flow. 
Which was highlighted by one of the most boogered up welds.  While the processor didn't completely remove the lump, the media turned it into a shiny dome.  Places where the pie cut sections didn't line up perfectly got neatly rounded over.

Could have given myself more credit for building that sidewider.  While the outside looks pretty agricultural - the roots of the welds weren't all that bad.  The media really went to work inside the merge collector.  Creating a bellmouth at the ends of the primary pipes, and making a smooth exit to the vband clamp.

With the header optimized this way, the ultimate deciding performance factor is now the turbo charger.
Upgrading to a larger turbo is on the back burner until 2026, maybe 2027.  Want to find out if the port work on the vz21 was worth it.

Upgrading the charging system would open a new window of opportunity for power adders.

(Pic of afm working on a cars head)

[BomberMann650]

Got down to rolling wires for the belly pan.

And... Now it looks like a boat.

Nothing is welded yet.  Maybe will try to straighten those lines and bring things in tighter.  Didn't want the toes of the boots sticking out of the body work.  Working back to front however.  Seems things might have snowballed in the creative process

At least boats can fly.

[BomberMann650]

Had some time before the day job to do some pseudo-scientific measurements.
To make sure the intake ports are the same fluid volumes as each other ... (if nothing else)

With a graduated cylinder and a pipette.  Each port holds a minimum of 31 mL h2o.  Then some fractional difference of 1/2 mL among the four.  Which equates to a 1-1/2% difference between the low and high.
There's the masochistic urge to continue splitting hairs and get this margin into the tenths decimal.  Looking and feeling for the slightest variation in port shape to whittle down with a hand file.
At some point good enough will have to be enough.

[dragracer]

I like the way this overall package is coming together. Well thought out for function,form and maintenance.

[BomberMann650]

I like the way this overall package is coming together. Well thought out for function,form and maintenance.

Thanks!

[BomberMann650]

I like the way this overall package is coming together. Well thought out for function,form and maintenance.

This reminded me of another detail to fabricobble together.  A retractable side stand.

While leaning the race bike against the honey bucket was a delight.  May have to borrow from Omar's playbook for the bike to have a leg to stand on.  Rather than waiting for the volunteer entourage to fetch the stand.

Should be simple enough to fix a tube to the frame that reaches the outer shell.  With a simple hinge that can telescope inside during the runs. A few pins and a footie that blends into the fairing ougta do it.

Gonna mull this over a bit. 

[BomberMann650]

Taking a break fro tig brazing the ribs onto the belly pan.
Had a chat with the good dude at speed hertz about the steering under a dustbin.
Seems the wheel movement on their bike is pretty tight.  Allowing for a very slender front profile.

Also yes, have turned to brazing this 3/16 wire.  Because autowelding at 110amps was getting annoying. Gluing with bronze at 55 amps is much less stressful.

[BomberMann650]

Spent the day working on the exhaust pipes.  Blending the welds before taking them to a ceramic coating shop.

All in a bid to avoid making decisions on the front fairing design.
Science says the dustbin has an advantage.  But to make it really work requires sacrificing the steering radius.
First attempt at making the bottom edge of the dust bin was a bigger radius than necessary.  Will have to make another.  Hopefully without turning that into scrap metal.
Determining where the windshield will sit has also been fun.  The honda part blends well enough with the shape of the helmet that it can get pretty close.  Without being too close. 

Hopefully this bottle of argon holds out a while longer.  Gotta call the welding shop anyway, maybe they will refill it

[BomberMann650]

Took the plunge and made the essential bits of the dustbin.
It is now a self supported structure with a windshield.  Not an optically correct windshield, but enough to get on with it.

Standing 42" tall with a circumference of several feet.  This scale of the thing is absolutely bananas.  The practical downside of building a fairing to fit someone with  a 54" chest.
Hopped on board a couple times to collect photos of rider sans gear.  Making sure the front covers the face and shoulders.  Then the side view - wondering if elbows count as forearms

Haven't begun to form the tail end of it yet.  Need to study up on those parts a little more.

Have considered ordering some naca ducts to direct air at the engine.

[BomberMann650]

Not a lot of new ground was broken today.

Realized the current cockpit setup wasn't gonna sit well with the existing seat and tank.  Got distracted making a rider support truss to lay on with the bodywork.  In the process of doing that; noticed the throttle grip is a little farther forward than the clutch grip.  Oh well, devlish detail.  Found a good use for the parts distribution catalogs i've had on the shelf.

Did position a few of the tailpiece supports.  Have a notion to make the tailpiece an internal subframe that the exterior shell can bolt onto.  Because this is the segment that will have the least accessible fasteners.  The nose cone will also have a pair of delightful (sarcasm) fasteners to reach. 

To communicate the shape and scale of the bike to my coconspirators - the ever utilitarian towel came in handy.

[Alan F.]

Invoking The King nets you 5mph top speed.
Thank you very much.

[BomberMann650]

Invoking The King nets you 5mph top speed.
Thank you very much.

Hahaha

Everyone gather round the piano its time to sing some Jerry Lewis

[BomberMann650]

Found another reason to envy those with smaller waistlines.
The dimensions on this birdcage continue to swell.

Am becoming more creative with the ring roller tool.  Getting it to duplicate a radius twice is an exercise in patience.  Other times, its simpler just to make adjustments by hand.  3/16 wire is good for that.

Though the symmetry of the handlebar position has been corrected.  And the ends lowered from the prior setting.  Was still left with a little pudgy spot in the nose cone.  Which requires either working a small lump into the shell shape, or fully committing to the drop tuck handlebar position.
Its not far off of the mark right now.  Going in would just smooth the line on the nose cone.

The tailpiece design hasn't yielded any big eureka moments.  Was a little challenging to get the top lines on center from the front to back.  Dealing with some assymetry in the chassis.  Ran a series of parallel wires from the yokes all the way back and am pretty sure the body line is straight.  Opted to keep the lowest line of the tailpiece just above the track stand spools.  Knowing the suspension will settle 4 inches lower once its under way.  Have been encouraged to study Tom M's  triumph tailpiece as a benchmark for low horsepower high speed builds.

Wonder what the steel yard would charge for a piece of 6" wide channel.  Granted its a little late now to worry about the wheel track offset.  It may still help