Author Topic: Mike Cook's test and tune:  (Read 24384 times)

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Offline Bob Drury

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Re: Mike Cook's test and tune:
« Reply #15 on: July 29, 2016, 08:10:07 PM »
  I once got busted for elucidating in public but in the end I beat it............... or was that hallucinating?
                                                             :-D :roll: :-P
                                                                                            O.R.B., out...............................
Bob Drury

Offline wobblywalrus

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Re: Mike Cook's test and tune:
« Reply #16 on: July 30, 2016, 01:19:16 AM »
That liner is a Honda 450.  That gets me to thinking.  Remember the valve springs on those?  They were straight torsion bars that twisted under load.  That might be what the Target 550 needs.  Shafts in the drivetrain that twist a bit under load to absorb shock.  Of course, they would have enough strength to twist right back to their original shape, like the Honda 450 valve springs.

Offline wobblywalrus

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Re: Mike Cook's test and tune:
« Reply #17 on: July 30, 2016, 01:26:47 AM »
This is how they work. Drive train parts made like this spring can absorb lots of shock so the gears do not strip.  www.chinonthetank.com/2012/12/how-cb450-torsion-bars-work 

Offline hotrod

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Re: Mike Cook's test and tune:
« Reply #18 on: July 30, 2016, 03:48:39 AM »
They used to do that with axles in drag racing too, make them too stiff and they shear things, make them the right diameter (and material) and they wind up under shock and then release the energy on launch without munching pinions and spider gears. It is a common technique in industry too, they make shock couplings which have a rubber biscuit shaped like an iron cross that sits between metal pieces which engage the openings in the rubber. Often used on very large electric motors to keep them from breaking things with their start up torque.

In aircraft they have a similar system to absorb shocks consisting of  disk full of ball bearings and a cross shaped center. Under high shock the ball bearings briefly get knocked out of the way but centrifugal force quickly locks it back up after the shock gets relieved.
In some all wheel drive cars they do the same thing with viscous clutches for the torque transfer split between front and rear wheels.
Above some critical torque they begin to slip slightly but when shaft speeds get close to a match they essentially lock up.

The difficulty would be finding a design intended for the kind of power and rpm required for land speed application, but here are some example styles that are used in industry.

http://www.renold.com/products/couplings/industrialcouplings/hydrastart/
« Last Edit: July 30, 2016, 03:52:35 AM by hotrod »

Offline trimmers

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Re: Mike Cook's test and tune:
« Reply #19 on: July 30, 2016, 08:30:13 AM »
That liner is a Honda 450.  That gets me to thinking.  Remember the valve springs on those?  They were straight torsion bars that twisted under load.  That might be what the Target 550 needs.  Shafts in the drivetrain that twist a bit under load to absorb shock.  Of course, they would have enough strength to twist right back to their original shape, like the Honda 450 valve springs.

Hmmm - The picture posted shows that the Honda is number 450, and it's marked as J/BFS.   If the engine is 450cc's, wouldn't they be running as K/BFS?   As a J/BFS, I'd expect the engine to be closer to 750cc's.    In addition to the Shootout, I see they're also entered for Speedweek, so maybe we can find out in just two weeks!
------------- 1 of just 3 in all 3  -------------
USFRA 130 MPH Club 09/18/2008 136.757
USFRA 150 MPH Club 09/17/2009 152.162
Bonneville 200 MPH Club 09/15/2019 218.600
Best Run: 253.080 MPH 09/14/2019 #6556

Offline Texican

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Re: Mike Cook's test and tune:
« Reply #20 on: July 30, 2016, 09:05:38 AM »
  

   OK, Ladies and Gents:
WE'll give this another try.  
     Sorry I got harelipped yesterday by the old 'unexpected consequences'.
Not much of an excuse, but the best I have at the moment.
Along with all the other problems one of our crew members apparently suffered UV radiation eye ball burning.
Any of you who been exposed to heli-arc welding will understand.

Back to the tiny Honda streamliner...
the top of the engine is about the same size as the box my #14 work boots came in.
I would imagine that with 4 valves per cylinder, the valves must be about the diameter of a
us dime.  Little tiny cam covers about 2.5" high and across.
Sorry, Jon, no pix. Much high trick wiring and tubing and other wazoo stuff.
Unless somebody else was able to get pix, you can see it all at speed week.
They had 2 ocean going shipping containers, plus a 60' 18 wheeler support unit.
  One of the truck-drivers was plenty friendly and somewhat knowledgeable regarding engines,etc.
The tech that spoke the best English said the motor is a 660cc unit.
Ibelieve the goal for speed week is around 3 bills.  ???
They are saying this engine started as a production unit from one of their mini-cars.
I don't know if it's sold in he USA, and don't care to attempt shoe-horning a 5' 17" frame
into death trap with built in hand grenade for a horn button.

Interesting about the similarity between this profile and Speed Demon.
I guess form truly does follow function, eh?
 respectively submitted
Jim

« Last Edit: July 30, 2016, 09:11:24 AM by Texican »

Offline GH

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Re: Mike Cook's test and tune:
« Reply #21 on: July 30, 2016, 09:38:37 AM »
SSS, a few years ago when the Buckeye Bullet was on the salt, we asked if we could look at it. They said, " yes you can, but don't look under the jacket", they had covered up the main controller.

Offline Seldom Seen Slim

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Re: Mike Cook's test and tune:
« Reply #22 on: July 30, 2016, 09:57:19 AM »
I read on Cook's Shootout FB page that evidently "we" -- that is, non-salt attendees for the past few days -- made the Honda team feel unwelcome and unfairly represented -- by the stories that circulated about the cardboard cover-up stuff (as well as other).  I feel bad that unhappy feelings were engendered -  and agree with the FB statement offering apologies and support and encouragement.

I sure hope my idle chat didn't contribute to their discomfort.  Three bills on 660 cc in a car - is gonna be something to see.   Just getting the car running well is gonna be great - a look into a major company's R&D.

Stay tuned.
Jon E. Wennerberg
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 (that's way up north)
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Offline Calkins

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Re: Mike Cook's test and tune:
« Reply #23 on: July 30, 2016, 10:08:40 AM »
Via Mike Cook's Land Speed Shootout Facebook page:

https://www.facebook.com/CookLSS/

Quote
To the Honda Race Team and Crew,

Landspeed Events and the Cook Shootout team would like to publicly apologize for the wholly unwarranted and unprofessional disrespect of your crew and race car in an e-mail sent out by a spectator at the Cook Test and Tune event. We are very sorry that a few bad apples in attendance chose to share photographs and make fun of your temporary R&D efforts without describing the details of why they were necessary and how hard you worked to correct the issues when confronted with the unavoidable difficulties of new car development. Your crew worked countless hours and well into the nights facing several difficult issues. They never gave up. The Landspeed Events staff and fellow racers at the Test and Tune event know and respect how hard you all worked on your car.

Your team was exceptionally professional and displayed the best traits of hard working racers under pressure. Thanks to your extraordinary efforts, your team left the salt with a solid plan to modify and fix the issues for Speed Week. It was a test and tune event and your team utilized it to maximum effect by identifying problems and experimenting with corrective actions as best as possible on the salt. It is common practice in wind tunnel testing to breakout the cardboard and duct tape to make temporary modifications for testing purposes. The fact that you chose to do so on the salt to confront aero and vision issues illustrates the depth of knowledge and commitment your team possesses.

We collectively admire your team’s tenacity. You will always be welcomed at any Cook sanctioned event. Again we are very sorry for the poor judgment of fools who have no idea what your team faced on the salt. Your race team is highly professional and polite, displaying all the finest qualities of dedicated racers who are problem solvers, not problem creators.

Mike Cook and the Landspeed Events team


Justin Calkins - Iowa Falls, Iowa  USA

Offline kiwi belly tank

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Re: Mike Cook's test and tune:
« Reply #24 on: July 30, 2016, 11:01:58 AM »
Really! Getting their feelings hurt over a small comment like that must be a cultural difference, I didn't see any disrespect in the comment at all. They were in the Mecca of back yard racing at Bonneville where improvising is at it's best, sounds to me like they fit right in. Apparently they don't realize it yet.
So if you read this Honda Liner Guys, we applaud your efforts both planed & unplanned. See you at Speed Week.
  Sid.

Offline javajoe79

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Re: Mike Cook's test and tune:
« Reply #25 on: July 30, 2016, 11:25:24 AM »
In "our" cars we had two types of all-wheel-drive couplings.  For low power apps we used duty cycle controlled clutch pack pressure, with normal ATF (fluid).

 For high power apps, we used sealed all-metal plate/disk clutch packs with no springs or actuators.  These locked up ONLY when high enough torque was applied to induce considerable and rapid slip.  The plates were cross drilled (alternately between solid disks).  The hole size was just right to allow the thick silicone fluid to squeeze through some of the holes.

As slip began to occur, the silicone fluid would "roll up" like pieces of rope.  That action would drive the plates and disks (randomly) together (some apart, obviously).  That build of internal pressure would lock the AWD clutch pack until power was reduced.  The harder you tried to make them slip, the harder they locked.

The engineers called it "silicone worms effect".  You could hand turn one of those sealed units if you were really slow and careful.  They locked up really quick and were incredibly reliable.

I dont think they would solve the "hammer and anvil" frequency that can break gears in this manner.  If wheel chatter matches the gear tooth/lash frequency/engine pulse during high torque, it becomes the same thing as an air chisel or impact gun.  It tends to peel teeth always at the same wheel speed and power/rpm application level.  I dont know enough to really make a good guess....but maybe?

Some modern multi-speed automatics have software that reduces engine torque at certain wheel speed/planetary speed/engine rpm conditions to protect various gear pitch issues.  Ravigneaux gear sets is a type that sometimes uses complicated torque control algorithms.

  If you were to measure the blister spacing on the tires, you can calculate the frequency (vehicle speed) where the worst torque hammer events are occuring.  Reducing rate of power application (through that wheel speed range) might be enough to keep teeth on the gears.  It might only be a particular gear choice that starts the hammer event....if this is what broke those teeth.  I know for sure that I can chisel right through pretty tough stuff with my little CP air hammer.  I just have to get the speed and pressure right and good metal peels right away.

I remember measuring the blister spacing on Buckeye Bullet rear tires in 2004.  I calculated their motor 3-phase frequency from the spacing length and their time slip....and realized they were probably in square wave operation at that motor speed.  We talked about it but the exact methods and ratios was their confidential info....just my best guess you know.

Complicated.

That's heavy stuff. Never thought of it that way.
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Offline hotrod

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Re: Mike Cook's test and tune:
« Reply #26 on: July 30, 2016, 02:30:06 PM »
Critical rpm and harmonics can do some spectacular thing. I suspect you are right that it is such a situation combining several harmonics to shred high quality gears like that.
Another place you see that sort of thing is in the torque peaks in a low count cylinder engine under high load. Under certain circumstances (engine rpm cylinder count, crankshaft stiffness) the crankshaft can get into harmonic rotational oscillation winding up like a torsion bar at peak torque then unwinding during the low torque part of rotation. That is one of the reasons (harmonic balancers/harmonic dampers) were developed to cancel out or mute those oscillations so the engines did not tear themselves apart under high load constant rpm conditions.

(oh drat that is exactly what happens when pulling into max effort in the traps in high gear at Bonneville
Long periods of high load at very slowly changing engine rpms -- food for thought)

Offline javajoe79

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Re: Mike Cook's test and tune:
« Reply #27 on: July 30, 2016, 04:43:06 PM »
Critical rpm and harmonics can do some spectacular thing. I suspect you are right that it is such a situation combining several harmonics to shred high quality gears like that.
Another place you see that sort of thing is in the torque peaks in a low count cylinder engine under high load. Under certain circumstances (engine rpm cylinder count, crankshaft stiffness) the crankshaft can get into harmonic rotational oscillation winding up like a torsion bar at peak torque then unwinding during the low torque part of rotation. That is one of the reasons (harmonic balancers/harmonic dampers) were developed to cancel out or mute those oscillations so the engines did not tear themselves apart under high load constant rpm conditions.

(oh drat that is exactly what happens when pulling into max effort in the traps in high gear at Bonneville
Long periods of high load at very slowly changing engine rpms -- food for thought)
the answer seems obvious then...  More power, accelerate faster.  :evil:
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Offline SPARKY

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Re: Mike Cook's test and tune:
« Reply #28 on: July 30, 2016, 05:09:58 PM »
I have had 3 push rods jump out of rocker cups dimple a valve cover and 2 make it back into the rocker arm cups---

hello--- hi dollar push rods
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Offline Jack Gifford

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Re: Mike Cook's test and tune:
« Reply #29 on: July 31, 2016, 12:03:05 AM »
Mike referred to "... an email sent out by a spectator...". I have not seen that email; has anyone seen it?

Anyhow- I think Mike did an admirable job with the apology.
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