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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1017893 times)

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Offline salt27

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1320 on: September 01, 2013, 12:51:18 PM »
Step 2)  After AUS, buy another street bike so I can dedicate the Triumph to racing, only.





Bo, step #2 makes racing much easier.

  Don

Offline peterdallan

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1321 on: September 01, 2013, 01:05:06 PM »
Bo,

It was a pleasure to meet both you and Gretchen at BUB. Sorry the weather shortened both our available run time, but as first timers we learn't it was as hard as we were led to believe, and it took us till about noon on Wednesday to figure out where we were going wrong (or at least believe). We queued on the Mountain Course Mile 1 and were 3rd in line to run with our new settings when the weather closed in. Hey, that's racing, just a shame Bonneville is over 5,000 miles away from us!

Already planning next year, hope to get the bike dialled in earlier in the week.

Peter

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1322 on: September 01, 2013, 10:20:59 PM »
This picture is one Gretchen took right when I found the fuel leak.  I had reserved a spot in line and I would have been one of the first down the track in the morning.  On the way home I said to her "I'll bet you heard the "F" word more at this meet than any of the others."  She said "Yes, and in at least five different accents."

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1323 on: September 03, 2013, 11:44:58 PM »
Freud made a recent post in which he lamented the attempts at replacing the camshaft with more modern ideas.  He had a link to a Swedish company.  I have been trying to find that post with no luck.  Any clues to where it is?

Offline 4-barrel Mike

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1324 on: September 03, 2013, 11:49:30 PM »
Freud made a recent post in which he lamented the attempts at replacing the camshaft with more modern ideas.  He had a link to a Swedish company.  I have been trying to find that post with no luck.  Any clues to where it is?

http://www.landracing.com/forum/index.php/topic,13123.msg231605.html#msg231605

Mike
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1325 on: September 05, 2013, 12:01:46 AM »
Thanks, Mike.  There have been attempts through the years to use pneumatic and other means to control valve action.  This is the first time I have seen this technology available to guys like me.  It does not hurt to ask about it and I will do so.

It is time for me to plan the off season work so I can spend a few minutes going fast in Feb 2015 on Lake G.  The goal is to get into the 150 club and I do not have much money to spend on the bike.  Very little, actually.  I need to figure out how much horsepower I will need.

The first step is to calculate the power I need to overcome friction drag.  Equations from Kevin Cooper's work are used.  They are presented on Page 172 of John Bradley's "The Racing Motorcycle" Volume 1.  These numbers might be an overestimate as I will explain in a future post.  It is a good idea to build enough power in the engine to overcome the drag listed in the table - to be on the safe side of things.  The laden weight is from the truck stop scale measurement and the tire pressure is an average of the 36 psi front and 38 psi rear I use on the salt.

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1326 on: September 05, 2013, 07:56:46 PM »
This second chart shows the aerodynamic drag I need to overcome.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1327 on: September 05, 2013, 08:00:13 PM »
This graph shows the combined friction and aerodynamic drag for various drag areas.  It takes a lot of power to go really fast, or, a really slippery shape.

Offline Old Scrambler

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1328 on: September 05, 2013, 08:39:54 PM »
Bo............just my 2-cents.............flatten the tank and lower the 'bowling ball' of the fairing about 5-inches so you only have about 2-3 inches of wheel travel.  Also check your overall width..........try for less than 20-inches. Then practice pulling one knee at a time to your chest while laying on your back for the next 11-months.  I did and it helps.  Now I just need to lose another 10 or 15 pounds. When I cock my wrists to get the inside of my fore-arms against my tank, I no longer feel air-turbulence on the outer arms and shoulders.  That was good for 1 mph.
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline salt27

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1329 on: September 05, 2013, 09:00:25 PM »
I found that putting a 30 pound lighter and more limber than me 17 year old on the bike was worth 20 MPH.

 Don  :-D
« Last Edit: September 06, 2013, 12:04:04 AM by salt27 »

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1330 on: September 05, 2013, 10:04:56 PM »
My teenager will not ride the bike.  She knows too much about it...

The dashed line shows me the additional speed I will get from more power if I do not make streamlining improvements.  Hotter cams and some different mufflers will give me 10 more horsepower according to Triumph Performance.  This will give me 145 mph, more or less, from 94 hp for around $1,250 (includes dyno time for jetting).  The preceding plus much bigger valves will give me around 100 hp.  I figure this will be $1,500 more, for $2,750.  This added six hp might get me to 149 mph.

My choice is to put the $1,250 on the cams and muffs, to tweak the streamlining a bit, and to use a couple of Old Scrambler tricks.  The added money I would spend on the big valves will not get me much more power and cost a lot.

Offline Jon

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1331 on: September 06, 2013, 02:29:36 AM »
There was a bit of a discussion on the DLRA forum around wind resistance at Lake Gairdner and Bonnevile after our last meet.

Taken from the thread:

Wendover .... August avg temps = 33 C RH = 39% and altitude is 4219 feet.
Lake G .......feburary avg temps = 33 C RH = 57% and altitude is 396 feet.
From this data the following was calculated
Bonneville .... density altitude = 7746 ft..........air density = 0.0594 lbs per cubic foot
Lake G ........ density altitude = 3200 ft..........Air density = 0.0696 lbs per cubic foot

I've not run at either venues but people who have riden at both were talking around a 13% difference.
Similar to recent talk on Milwaukie Midget's build diary around running faster in the hotter less dense conditions.

jon
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1332 on: September 06, 2013, 09:25:04 PM »
It is a bad road in a nasty neighborhood.  I thing Maj has been there.  Type "von Karman street" into your search engine.  There is a u-tube movie about it there, too.

Offline Jon

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1333 on: September 06, 2013, 10:24:12 PM »
I think I missed what I was trying to say Bo.

If the 13% difference exists like people that have run at both venues say and the numbers indicate then running 150mph at Lake Gairdner takes about the same hp as running 169mph at Bonneville.
You will get more air into the motor which is good but you will be pushing more site out of your way.

Cheers
jon
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Offline JimL

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1334 on: September 06, 2013, 11:47:57 PM »
Bo, I have had good luck guessing aero drag HP comparisons with:

Air drag:
Da = (density in slugs) * V^2(feet per second squared) * frontal area(in square feet) * cd (estimated) / 2

Bonneville at about 4100' is .002109 slugs, while sea level standard air is .002307 slugs.  These numbers are at standard temp, by the way.

You can calculate your drag components pretty well if you know speed you ran, and your available horsepower.  

Dr or rolling drag:
I had some numbers to plug in, from a Street Roadster, where I knew wheel horsepower, frontal area, tested cd, and speeds in the miles.  From there, I found about 100lb rolling drag worked within the formula (for that car at that speed.). I dont have permission to identify the car and its exact numbers, but its all just comparison.  Aero drag gets a lot bigger than the roll.

Also, for perspective....during pre SpeedWeek testing of the 2004 Bonneville Prius project, I made top speed push runs with a stock 245 hp Tundra pushing the Prius with no throttle application by the Prius driver.  That Tundra could run about 108 by itself, and would hold 93 pushing the Prius.  Most of that speed loss had to be the rolling drag and with the motor-generator making additional drag in very light regeneration.

Rolling drag changes in relation to how good the aero is, unfortunately, because the rear wheel loads up if your bike aero is poor and too high.  That makes it hard to figure at speed.

HP = (Da + Dr 'which is rolling drag') * Velocity in ft per second/550.

Bottom line is that good aero is cheaper than more horsepower.  You've seen pics of my bike.  It is about 75 HP to the ground, and my best speed this year was 163.829 3rd mile.

My bike is about 22" wide due to wide engine and carbs hanging sideways.  All food for thought and some comparative calculations you can ruminate over!

Hope this will be some fun figuring!  Best of luck, and give me a call some time.
JimL
« Last Edit: September 06, 2013, 11:56:04 PM by JimL »