Landracing Forum Home
December 17, 2018, 10:34:36 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News:
BACK TO LANDRACING.COM HOMEPAGE
 
   Home   Help Search Calendar Login Register  


(Note: Donations are not tax deductible)







Live Audio Streaming and Archives of Past Events
Next Live Event: TBD
Pages: 1 ... 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 [54] 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 ... 216   Go Down
  Print  
Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 714282 times)
0 Members and 3 Guests are viewing this topic.
Moxnix
Sr. Member
****
Offline Offline

Location: Webster Groves, MO
Posts: 826


Zufrieden mit Mir.


WWW

Ignore
« Reply #795 on: June 17, 2012, 12:31:57 PM »

At what elevation do you abide, Wobs?  Always enjoy your thread, thanks.
Logged

Seen it all, done it all, can't remember most of it.
http://speedbumpsontheroadtoperdition.wordpress.com/
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #796 on: June 17, 2012, 07:25:53 PM »

Thanks for the compliment.  The elevation here is 135 feet, more or less.

There are things I do before exhaust tuning, such as everything else.  The exhaust is the last thing I do.  The jetting should be OK and I should have a dyno printout, too.  These things are what I ask myself when I look at the printout.  Do I need to do any exhaust work?  Do I need to do more than that?

First, I look at the horsepower peak.  Dost it occur at the right rpm?  Exhaust tuning might not be needed if it does.  Then I look at the torque numbers.  My experience is that I cannot significantly increase peak torque with exhaust tuning.  More work than exhaust tuning is needed if the peak torque is too low.

The peak torque is 60.37 on the chassis dyno before the exhaust tuning.  This will be the peak torque after tuning, I assume.  The 60.37 is multiplied by 1.1 to get the estimated chassis dyno torque of 66.4 lbs-ft.  This is entered into PipeMax as an average value.  The desired Peak HP RPM is entered.  This is 7,400.  The "calculate HP and torque" option is selected.  The VE is changed until the average peak torque calculated by PipeMax is the same as the dynoed value.  The VE is 108 percent.  The first attachment shows all of this.

Now Pipemax is asked to calculate the header dimensions.  The second attachment shows the results.       


* Exhaust Tuning 24.jpg (211.32 KB, 768x903 - viewed 119 times.)

* Exhaust Tuning 25.jpg (237.74 KB, 768x849 - viewed 122 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #797 on: June 17, 2012, 07:39:39 PM »

PipeMax has gives me some harmonics and recommended header diameters.  The OEM header pipes with a set of new glass paks are plotted on the graph along with the harmonics.  The cross-pipe is near the 3rd harmonic.  This should work good.  I put the exhaust system on the bike.         


* Exhaust Tuning 26.jpg (262.89 KB, 1024x735 - viewed 127 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #798 on: June 18, 2012, 08:44:38 PM »

The last post gives shows the calcs that were used to figure out the exhaust system.  The dyno runs are done.  The last step is to use the dyno data to recalculate the VE.  The header pipe harmonics are recalculated, too.  These are "As Built data."  They go into the build records.


* Exhaust Tuning 27.jpg (252.84 KB, 768x901 - viewed 111 times.)

* Exhaust Tuning 28.jpg (237.12 KB, 768x962 - viewed 111 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #799 on: June 18, 2012, 09:06:00 PM »

The as built pipe sketch.  For all practical purposes, and when error is considered, the cross-pipe is at the 3rd harmonic.  Dyno tuning with two additional cross-pipes an inch and a half either way would be needed to perfect the system.

The graph shows how I stole torque from the midrange and shifted it to the top end.  This is exactly what I want for LSR and the glass paks with the cross-over pipe will be the race headers.  The Arrow pipes give better torque and power for the street and they will be my road setup.  Maybe.

This engine is putting out 1.8 horsepower per cubic inch.  This is a big number for an air cooled twin that runs on unleaded ragular gas with air filters.  Especially when it is tuned by some clown on his driveway with a bunch of books.  All I can do is mess it up if I work on it more.  This engine is done.  The 790cc motor was "Baby Bear."  This 865cc one is "Mama Bear."  The parts are on order for 994cc "Papa Bear."           


* Exhaust Tuning 29.jpg (227.12 KB, 1024x753 - viewed 108 times.)

* Exhaust Tuning 30.jpg (186.45 KB, 767x1024 - viewed 128 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #800 on: June 21, 2012, 12:20:00 AM »

It looks like the 865 cc motor will be the one I run in AUS.  The head will be taken off this winter to install the racing valve springs and keepers.  This gives me an opportunity to increase valve sizes and change to hotter cams.

My intent is to keep the rev limiter at 8,400 rpm.  Two of the four Pipemax sheets are posted.  Does anyone see any room for improvement?  What in my setup looks good?

Any advice is appreciated.  I do not know what a lot of these numbers mean.


* Cylinder Head Work 1.jpg (210.9 KB, 768x1013 - viewed 101 times.)

* Cylinder Head Work 2.jpg (222 KB, 768x999 - viewed 100 times.)
Logged
Koncretekid
Hero Member
*****
Offline Offline

Age: 71
Location: Yarmouth, Nova Scotia & Lafayette, Co.
Posts: 1064





Ignore
« Reply #801 on: June 21, 2012, 05:24:38 AM »

Bo,
I'm certainly impressed by all the data you've assembled, but I can't help you with interpreting it!  Looks like I'll have to go back to school. Amazing that the "British Custom Exhaust" added almost 10 horsepower in the top end, which is what you need for Bonneville.  It also looks like you would achieve a few more horsepower with a few more RPMs.  I'd tune it for your target speed at the 8400 rpm limiter, and maybe disable the limiter for the final run if it wants to keep pulling.   In any case, you seem to be squeezing more horsepower out and I think you've go a real handle on the direction you want to take.
Tom
Logged

We get too soon oldt, and too late schmart!
Life's uncertain - eat dessert first!
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #802 on: June 24, 2012, 01:05:26 AM »

Tom, a year ago I looked at the ways of making more power.  Bigger displacement was one.  Spinning the motor faster was the other.  More cubic inches looked like the best solution.  There was a lot less stress on the engine if I could keep the rpm below 8,000.   

The first few pages of the PipeMax printout is Imperial units.  The last couple are in metric.  I tossed the metric stuff.  The answers to all of my questions were in the trash can on the last page just after the metric data.  There were instructions on what to look for in all of the data.

Using PipeMax, the #813 cam with the ported head and the 2mm larger intake valves are plenty adequate for the 865cc engine.  Then I entered the bigger bore size and compression of the 994cc engine.  The cam, valves, and ports are adequate for this bigger motor, too.  This is good news.  I thought I would need a hotter cam, bigger valves, and other expensive stuff to go with the 994cc kit.  Things I cannot afford.  I do not need them and the kit is paid for.  All I need to do is to install it.  The big motor will be used in AUS.  Definitely.

The cross-pipe at the 3rd harmonic makes the exhaust system work.  Almost any non-restrictive muffler can be used, such as Norman Hide Toga's, Triumph Performance Predaters, etc.  The British Custums "sleepers" have the best aerodynamics and I could get a deal on them, price wise.  They are OK for racing where noise is not a factor.  They are too loud for the street and the way they are mounted is kinda hokey.  Triumph off-road mufflers with Triumph headers or the Arrow pipes and mufflers are what I use on the street.  They work OK and are fairly quiet.   

   
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #803 on: June 25, 2012, 12:51:49 AM »

Ol' Bob Bakker (BAK189) will be missed at BUB.  He was friendly and I always felt that if I needed something he would help me.  I never did, but it was always assuring to know that he was nearby.

The front fender hit the fairing when the steering was at full lock and the forks were fully compressed.  The middle of the top of the fender is slimmed down so it will not hit.  It is an ugly job.  I tried to make it smooth and the harder I worked at it the lumpier it got.  This winter I will anneal it and beat it with a slap hammer.  That might pretty it up.   


* Fairing Rebuild 161.JPG (300.55 KB, 800x533 - viewed 150 times.)
Logged
Koncretekid
Hero Member
*****
Offline Offline

Age: 71
Location: Yarmouth, Nova Scotia & Lafayette, Co.
Posts: 1064





Ignore
« Reply #804 on: June 25, 2012, 05:24:45 AM »

Bo,
I sure could use some of your metal working skills right now to get some duct work finished on my build.  BTW, you probably won't hit maximum compression while turned to full lock.  If you do, I'd suggest you bail out!
Tom
Logged

We get too soon oldt, and too late schmart!
Life's uncertain - eat dessert first!
Peter Jack
Hero Member
*****
Offline Offline

Age: 75
Location: Calgary, Alberta
Posts: 3551





Ignore
« Reply #805 on: June 25, 2012, 07:09:41 AM »

I'm sure at that point the bailout will be totally involuntary!  grin grin rolleyes

Pete
Logged
saltwheels262
Hero Member
*****
Offline Offline

Age: 64
Location: cumberland plateau
Posts: 1064


LTA 7/2013




Ignore
« Reply #806 on: June 25, 2012, 06:36:20 PM »

ww,
as I read number 803 my thoughts were exactly the same as 804 and 805.

but, you never can tell.

bf
Logged

bub '07 - 140.293 a/pg   120" crate street mill  
bub '10 - 158.100  sweetooth gear
lta  7/11 -163.389  7/17/11; 3 run avg.-162.450
ohio -    - 185.076 w/#684      
lta 8/14  - 169.xxx. w/sw2           
'16 -- 0 runs ; 0 events -- made a 2 state change in ZIP codes

" it's not as easy as it looks. "
                            - franey  8/2007
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #807 on: June 26, 2012, 12:15:28 AM »

Fussy tech inspections worry me more than anything else.       
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #808 on: June 27, 2012, 12:45:27 AM »

The new exhaust setup that makes 84 horsepower gives me awful gas mileage on the street.  Low to mid 30's.  The cross-pipe is at the 8,000 rpm third harmonic length of at 22.5 inches.

A few months ago there were a number of posts when I was monkeying around with baffles in the Arrow headers.  The baffles were deliberately designed so the upstream end would to reflect a wave back to the engine.  Lots of trial and error testing was used to find the optimum length for the baffles.  Gas mileage was in the 40's when I used them and they had the right length.

PIpeMax shows me why the baffles work well on the street.  The 3rd harmonic is at 55.3 inches at 3,500 rpm.  That is the engine speed I usually use when I putter around.  Today I measured the Arrows with the baffles in them.  The distance between the upstream ends of the header pipes and the upstream ends of the baffles are close to this length.  This makes the engine more efficient in normal street use.

It makes sense, considering the cost of gas, to switch the exhaust system and intake bell lengths from street to race configuration and vice-versa as needed.  It is no big deal.  I run one race a year.   



 

   
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 65
Location: backwoods Oregon
Posts: 4784





Ignore
« Reply #809 on: June 28, 2012, 12:12:38 AM »

The white thing is my windshield.  The wood I used for the mold shrank and expanded during the forming process.  There were little recesses across the inside of the windshield at 3/4 inch intervals.  I used poplar for the mold.  Kent plastics told me to use a hard and tight grained particle board for the mold.  They said it would not shrink or swell.  I looked at this stuff in the lumberyard and did not buy it.  It did not seem possible to get a smooth finish on it.  I was not thinking about the primer on top of the particle board.  It would have made a smooth finish and I should have used it.  The upper surface had pock marks from gas bubbles that escaped during the forming process.     

The windshield is sanded smooth on both surfaces with 220 grit paper.  This gives it the white color and I did the work by hand.  The buffer and polishing wheels do not work on this polycarbonate.  They get the plastic hot and they smear it around rather than put on a good finish.

This has been a cold and wet summer.  The berry crop is great.  Gretchen bakes the pies and I pick the berries.


* Fairing Rebuild 162.JPG (258.7 KB, 1024x629 - viewed 111 times.)

* Fairing Rebuild 163.JPG (164.85 KB, 800x533 - viewed 107 times.)
Logged
Pages: 1 ... 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 [54] 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 ... 216   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!


Google visited last this page September 08, 2018, 07:50:19 AM