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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1030300 times)

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1695 on: June 03, 2014, 12:38:00 AM »
This is the back end.  The blunt nosed teardrop shape is calculated to be stable in side winds.  It works so I am not going to monkey around with it and make chimprovements.   

Offline wheelrdealer

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1696 on: June 03, 2014, 08:39:30 AM »
Excellently Executed!

The streamlining is great. Love the rivets.

BR

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ECTA    Maxton D/CBGALT Record Holder 166.715

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Offline Old Scrambler

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1697 on: June 03, 2014, 09:47:21 AM »
Great pic of the 'gray panther'...............looks very fast. :lol:
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 wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1698 on: June 04, 2014, 12:49:25 AM »
Thanks for the compliments, fellows.  There is a quote somewhere on this forum from Enzo Ferrari that says streamlining is for people who cannot build motors.  He would need to improve his game to race at this this place.  A person needs to be good at both to be competitive in the faster classes at LSR.

The motor is next.  Cylinder head flow testing is needed to get serious about performance.  Kibblewhite in Pacifica, Northern California, does my head work.  They flow tested the head for me at no charge.  This is a favor from them for Team Go Dog, Go!

The intake tract was tested with the air cleaner, intake bell, carb, and manifold attached.  Flow is 209.7 cfs at .388 inches maximum valve lift.  This is corrected flow at 28 inches water.  Exhaust flow is 179.8 cfs under the same conditions.  A pipe stub was fitted to the head to resemble a header.

Assumed horsepower increase is 10% due to the switch to oxygenated fuel and the free flowing Predator Sport mufflers.  Peak power will be produced somewhere between 7,300 and 7,800 rpm.  First, I looked at intake flow using PipeMax.  It says up to 198.5 cfs is needed.  As for exhaust flow, up to 148.5 cfs is required.  The cylinder head flows plenty good and the cam lift is adequate.

Header diameter is next.  The 790cc Triumph twins use 1.5 inch dia headers and the 865 twins use 1-5/8 dia pipes.  It would be easy to do a switcheroo between the race and street bikes.  PipeMax says header inside diameter can range from 1.348 to 1.473 inches.  The 790cc engine headers have 1.400 internal dia.  They are OK and there is no need to go bigger.


Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1699 on: June 04, 2014, 11:59:53 PM »
These header sizing programs often give minimum and maximum recommended diameters.  My preference is to keep the dia on the small side.  The air at B'vill is thinner than at sea level so I am less worried about having a pipe big enough to handle the flow.  Instead, the concern is about having enough gas velocity and inertia to maximize the acoustical tuning.  Second opinions are welcome on this.

The flow needs to be about 15% greater for Australian rocket gas than for the usual non-oxygenated race fuel.  There are three fuel valves available from Pingel.  One is their standard street valve.  I was using one of them.  A remote shutoff is needed for fuel class.  There is none on the street valve so I fitted a standard guzzler with a cable actuated shutoff switch.  Last fall I tested the standard guzzler and it flows enough fuel to support over 400 horsepower.  There is no need to use the higher flowing methanol guzzler so I am using the standard one.

The website http://factorypro.co./tech/carbkei.html has float valve sizing info for Keihin flat slides.  A 3.2 mm dia valve will support 39 to 50 hp per cylinder using gravity flow (Page 10).  That size is adequate for standard gasoline.  I need 15 % more flow capacity than this.  A needle valve's ability to convey flow is somewhere between being proportional to its diameter and its circumference.  A 3.8 mm diameter valve has 17% more circumference and 41% more area than the 3.2 mm valve.  It is a safe bet that it is good enough so I am trying to find a pair of 3.8 or 4.0 mm valves.  Keihin makes methanol valves and other parts for very high flow rates.  At this time I see no need for them.

Keihin makes needles and seats for downdraft and sidedraft flat slide carbs with gravity or pressure flow.  I need to be real explicit about exactly what I want.  All of this stuff is interchangeable and it is easy to order and fit the wrong parts.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1700 on: June 06, 2014, 10:11:55 PM »
Lessons learned on EFI.  The new Triumph has Keihin EFI.  There is a program and hardware called TuneECU that loads, modifies, and unloads maps.  It also has diagnostics and other tuning features, like synchronizing the throttle plates.

The bike ran good before I "improved" it.  The changes I made are the ones done to the carb models.  A pair of hotter cams for the 790cc model, removing the two noise baffles in the intake system, and putting on a pair of Triumph TOR off-road mufflers.  All of this I had in my parts collection so no money was spent.  So far, all is OK.

Next, I loaded different Triumph performance maps for fuels with 10% alcohol and 25% alcohol.  I could get it to run good and get lousy gas mileage, or I got it getting good mileage but running bad.  It took some figuring to solve this one.

The EFI cannot directly sense the need for fuel.  It bases its decisions on manifold air pressure, throttle position, rpm, lambda, and other data it collects.  The EFI system was not calibrated for the changes in flow the flow vs manifold air pressure relationship from my intake changes.  The system was confused and it did not always provide the right mixture.

The noise baffles were reinstalled and the adaptation process was made to recalibrate the system.  Now it runs great.  The cams and the off-road mufflers do the trick.

What I learned is the EFI system has the ability to adjust to a small amount of performance tuning.  The changes should be made downstream from the intake manofold- unless the EFI is remapped.     

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1701 on: June 08, 2014, 01:23:13 AM »
The custom helmets with tall eye ports are expensive.  One on the internet cost $1,800.  This morning we had the Triumph Club breakfast and went to the cycle shop when we were done.  I asked some of the guys that race for advice.  They showed me the adventure bike helmets.  Adventure bikes are the big and fast dual sport ones.  The helmets are full face with detachable visors and the eye ports are taller.  The fellows unscrew the visors and toss them.  I found a solid color Snell 2010 approved Arai lid at a reasonable price with the tall eye port.  It is on order.      .   

Offline tauruck

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1702 on: June 08, 2014, 02:56:42 AM »
Good one Bo but man you really pay a price for being tall.

Midgets like me battle to just see over the tank. :-D

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1703 on: June 10, 2014, 10:51:38 PM »
Mike, its figured out now.  I can see when I am down on the tank.  Can't get lower than that.

The street Triumph has Keihin EFI.  It runs in a semi closed loop fashion.  The idle mixture is adjusted to the desired fuel-air mixture using O2 sensor input during a 20 minute procedure called "adaptation."  The partial throttle mixture is adjusted at periodic intervals using O2 sensor data.  I ride north toward Portland from Salem on the freeway.  About 10 to 15 minuted out of town it does the partial throttle adaptation.  The adaptations go well if the mixture is sorta close to the one predicted by the maps.  Otherwise, the EFI defaults to the "limp home" mode and the mixture is set very rich.  Performance and fuel mileage go to Helena.

As can be imagined, the idle adaptation is not much use to us racers and the partial throttle adaptation occurs to late to do any of us any benefit.  Besides, what is this "partial throttle" business?  Absurd.  The O2 sensors are great for the street but not needed for racing.  That can be switched off using Tune ECU.  Most racers do this.

There are tables for each of the two cylinders at lower throttle openings.  These "L" maps are based on injector opening duration vs engine RPM and manifold air pressure.  These are important for street use.  Unfortunately, any modifications to the inlet tract foul up the calibration for these curves.  Us racers almost always modify the intake system so this can be a problem.  Fortunately, there is an "F-L" table that lists the throttle opening thresholds when the ECU goes from the low to high rpm curves.  The changeover point can be set to 0 rpm using TuneECU.  This prevents the use of the "L" tables.  Most racers do this.

The remaining tables are the "F" ones, and there is one for each cylinder.  They are injector opening time vs throttle opening and rpm.  These are the high speed large throttle opening tables and they are what racers use.

There is also an air-fuel table for the engine under load and in neutral.  The desired stoicho ratio is in these tables.  The ignition advance is another table/is can be set in these tables.

The F and L tables can be adjusted in percent by a fuel trim table, and the ignition advance curve can be adjusted in degrees by an ignition trim table.

The TuneECU program can be used to set up the system for racing.  The O2 sensors are disconnected and the L tables are deactivated by setting their operation threshold at 0 rpm.  The mapping is done using the wide band sensor on the dyno and it is used to develop F tables, only.  The air-fuel table is changed to reflect the fuels being used.

This is what I think is happening and I am no expert.  Basically with modifying EFI, unless you are a nerd, the bike will run like a t*rd. 

Offline tauruck

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1704 on: June 11, 2014, 12:14:18 AM »
I don't know how you figure all this stuff but I admire you.

Those nerds come in useful though. :wink:

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1705 on: June 14, 2014, 12:45:46 AM »
There is a lot of false information about these EFI systems that is "common knowledge" in the Triumph community.  The i-net and listening to most, but not all, of my friends was counterproductive.  There are a couple of books on the subject.  The only way I figured out a lot of the stuff was to change the settings and ride the bike around.

My family vacations for the last 30 years involved children so I took the trucks.  Now, none of the kids want to go so I am on my own.  It looks like I will be on the bike every day for a couple of weeks.  This will be the real test of EFI.  There are all sorts of mountain passes I need to cross and one is at 8,000 feet.  A lot of these roads I drove on with my BSA Lightning with monoblocs or the Spitfire with concentrics.  Keihin EFI or Amal carbs, which are best?  The big question.   

Offline Speed Limit 1000

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1706 on: June 14, 2014, 01:07:37 AM »
  Keihin EFI or Amal carbs, which are best?  The big question.   

EFI if you have the ability to tune it :cheers:
John Gowetski, red hat @ 221.183 MPH MSA Lakester, Bockscar #1000 60 ci normally aspirated w/N20

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1707 on: June 15, 2014, 12:14:47 AM »
Advice given to me about this oxygenated fuel is to make sure the system provides enough flow.  It was tested a couple of years ago and it gave me plenty, about 400 to 500 horsepower worth, as I recall.  Some new components are being used so it is time to check it again.

Flow in a gravity system lessens when the fuel level drops.  Usually I have more than two gallons when I run so I will have plenty of pressure.  The test is done with 1.5 gallons in the tank.  This is a "worst case" situation.  The plugs on the bottom of the carbs are removed and little metal chutes will carry the gas down to funnels on bottles.  The vents are hooked up, the fuel is switched on, and it is time to measure how long it takes to fill the bottles.  The left carb flows 18.05 ounces in 22 seconds.  The right flows 18.15 ounces in the same amount of time.

The fuel line connects to a "T" fitting that directs the flow to each carb.  The leg on the T for the right carb is about half as long as the one for the left.  This is why the right carb always flows better.  It is important to check with all carbs flowing at the same time, so as to detect these patterns.

The fuel is switched on by turning the valve under the tank.  It is turned off by the switch on the bars as shown, sorta, in the blurry photo.  This is done to meet a DLRA rule when I was going to race in AUS in the fuel class.  It is not required by FIM.  I am keeping it on the bike 'cause it is a good idea.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1708 on: June 15, 2014, 12:51:47 AM »
The book "Performance Automotive Engine Math" by John Baechtel is used as a reference.

The expected horsepower this year with the oxygenated fuel and the new mufflers is no more than 100.  Advice about the fuel is to assume, for planning purposes, 15% more consumption, so 100 x 1.15 = 115 HP.  I need 115 hp worth of rocket fuel to get 100 HP at the rear wheel.

The info in Baechtel's book is for cars and it is assumed to be based on engine dyno HP.  Converting rear wheel HP to engine HP:  115 x 1.1 = 127 HP.  There are two cylinders on the bike, so each needs enough fuel to support 63 engine HP

Brake specific fuel consumption rates are listed in the book.  A 0.48 pounds per horsepower per hour demand is listed for a performance engine with a good head, like mine.  Bachtel also uses a conversion factor of 6.09 in his formulae.  This is for fuel with a specific gravity of 0.72 at 65 degrees F.  This is real close to the Sunoco Standard used in this test.  No adjustment is needed to this factor.

The calculations for the left cylinder:  (18.05 oz / 22 seconds) x (1 gallon / 128 oz) x (3600 sec / 1 hour) = 23.1 gals per hour delivered

For the right:  (18.15 / 22) x (3600 / 128) = 23.2 gallons per hour delivered

Supported HP = (flow rate in gals per hr / brake specific fuel consumption in lbs fuel per HP per hr) x 6.09

(23.1 / 0.48) x 6.09 = 293 HP per cyl.  Fuel delivery is not a problem.   

Offline Sporty Dan

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1709 on: June 15, 2014, 12:12:32 PM »
Excellent calculations about fuel requirements for hp, Wobbly!  :-D Where did you get your petcock at? And where did you mount the shutoff lever on the handlebars?