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Twins Dyno Results Thread

241K views 245 replies 99 participants last post by  CHRIS211083 
#1 · (Edited)
This thread is for folks to post the dyno charts resulting from any runs they have done.

Please list what type of bike, and the specific modifications that were done to the bike, and include a scan of your dyno chart. The idea is this thread will serve as an additional resource for people who want to tune their bikes.

To keep the thread clean and easy to use, comments, Ooh! Ah! posts and questions will be removed. Discussion etc can take place in the main twins tech forum. Feel free to post comments on how the bike "feels" on your own dyno posting.

Interesting reference reading, supplied by mikeinva:

http://en.wikipedia.org/wiki/Horsepower

I will also add links to threads containing dyno runs in this first post:

robnobrakes TORS vs Predators

Bonnie1000th Dyno Run - mega machine 100 plus RWHP

And to get started with charts, here are 2 to be going on with.

First one is from a stock Bonneville, and serves as a starting reference point.



The second one is from a run I did earlier this year on my bike for kicks. I'm glad I did it, because I'm about to monkey with it, so I'll know what I have gained.

In the following run, my bike (2007 Bonnie Black) has merely TORs, a K and N filter in completely unmodified airbox with snorkle still attached, dynojet 108 mains (equivalent to keihin 112.5), standard 40 idle jets, mixture screws 2.5 turns out, Dynojet needles - so not much change over stock - although it feels much "snappier" than it did stock.

 
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#2 · (Edited)
865 v 790 inlet cam

ahem,

Dyno'ng done, so I'll get straight to the point:



red line is best 790 cam run, blue was the best on the 865 cam.

It reflects more or less what happens on the road, I've 'robbed Peter to pay Paul', lost some mid range and replaced it with some top end.

here's another chart with the torque curve, you'll see that torque has been lost lower down to be replaced by more higher up the rev range, crossing over about 5,500rpm:



Fuelling. The main jet with both cams was best at 125. I expected to need more fuel for the 790 cam, but this was not the case. The mid range was a bit of a surprise too. The 865 cam worked best in the middle with a Thruxton needle + 2 shims, the 790 cam was too rich on that and worked best with no shims.

The following chart includes the a/f reading with +2 shims on the bottom, +1 shim in the middle, with just the Thruxton needle at the top. You can hardly notice the difference in power between the three settings:


I've already decided to put the original 865 cam back in when I'm done. What the dyno doesn't really show is the temperament of the bike, the 790 cam turned a slogger into a screamer. I preferred it in 'diesel' mode, as Monttu puts it :D

As I rode up to the dyno shop on a crisp, sunny, November morning at 3'C, the mod I valued most was my heated grips.

ps. The bike was tested with stock silencers (with 'bafflectomy') and a modified stock airbox, which is detailed on this thread with it's own dyno' charts: http://www.triumphrat.net/twins-technical-talk/97291-scrambler-airbox-mod-part2.html
 
#3 · (Edited)
This is my 989 .I am posting 2 sheets to show what the guys running stock carbs how slide opening can change low end power.this is the same motor tuned the same but run by 2 different guys.The bike has flat slide carbs so they open how ever you twist the throttle.The right way to run them is a smooth right hand not jerk them open like one of the guys did.SEE how it changes the low end,then think on stock carbs only vac. and spring pressure contorls them.One more note they both have 790 cams.first is with slides opened to fast
 

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#6 ·
here's my run, starting from an 865cc bonnie, mods include:

904cc wiseco kit
HSR 42mm Mikuni carb kit from Bonneville Performance
Thrux headers, Thrux Predators
Airbox long gone
bigass UNI filters (thanks Carlos!)
2mm larger intake valves, 1mm larger exhaust valves
head ported/polished



I'm pretty happy with the air/fuel ratio, considering I did all the jetting based off my butt-dyno, I'm going to play with some smaller mains and a fatter needle and hopefully I'll pickup 5 or so hp.

Moral of the story: a 904 kit, big carbs, pipes, and some headwork will get you about 50% more power than stock. (A stock bonnie dynos at around 50-55hp)
 
#7 · (Edited)
* 904cc Wiseco Big Bore Kit
* Oversize inlet and exhaust valves.
* Cylinder head gas flowed, ported and skimmed (10.8 to 1)
* Camshafts re-profiled for higher lift and longer duration.
* Crankcase breather size increased from 6mm to 13mm diameter.
* Keihin FCR 39mm flat-slide race carburettors with open velocity stacks.
* Billet alloy intake manifolds (British Customs)
* Fly wheel balanced and lightened 440g.

88.4bhp and 65.5 ft/lbs torque

 
#8 · (Edited by Moderator)
Dyno for cams

Here are my results from a dyno by Ten Swafford of the Legion of Zoom.[luv the title of his company]. He was recommended by Sweatmachine[thanks Jeff] and is very knowledgeable about tuning. Now before you freak out over the A/F understand the reason for this dyno was to give me the numbers I need in order to fine tune the carbs since I just finished an extensive cam change and a port and polish. The first page run was at 4th gear and by the squiggley lines, that is where the bike takes a "dump" before getting the gas required to go. The second and third page is at 3rd gear and she dumps at 4,000rpms. I have a 19t front sprocket just for added insight. We changed the clip setting and she did respond a little but I left a few horses on the table do to SEVERE leanness. After I change main jet, main air jet, slow jet[for better idle] and jet needle size, I'll be doing another series for comparison. I'm pretty pleased with the HP that the street cams and CR-S carbs have delivered. I'm running 115 mains and 60 pilots and plan to buy 135,140 and 145 on the main jet. I hope to crack 70 hp or at least get REAL close.








Full thread and discussion at http://www.triumphrat.net/twins-technical-talk/98968-dyno-for-cams.html
 
#9 · (Edited by Moderator)
My results from Saturday. This is a stock engine Thrux, with airbox delete and dominator sports with no crosspipe on the headers:

1st set of 3 runs:
Mains: 145
Pilot: 42
Shim: 1

2d set of 3 runs:
Mains: 150
Pilot: 42
Shim: 0 (see the severe rich condition at low rpms and how this improved by about 1/3d when I removed the shim?)

3d set of 3 runs
Mains: 145
Pilot: 42
Shim: 0

Ten and I are thinking that I need to find a longer needle. I noticed that Dynojet has an adjustable needle which would seem to be ideal.

Discussion Thread Here:

http://www.triumphrat.net/twins-technical-talk/100024-dyno-results-thruxton-no-airbox.html

Thanks...Jack
 

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#10 ·
This is prior to installing the 42mm Mik's. Stock carbs jetted at 152.5 airbox elim..ai elim..flow work on the head..stock sized valves..preds..ecm unit..







This run is with the Mik's installed. Note that the dyno chart is way off on the scale because the 10,000rpm race bike was on the dyno right before mine. The operator forgot to rescale the graph to 8,000 rpm's prior to running my bike.

End result is 83rwhp and 61lb ft torque compared to 75 or 76 rwhp and 59 lbft torque with stock carbs. The mik's was the only difference between these dyno runs. Same dyno..same operator..


 
#11 · (Edited by Moderator)
T100 865 Dyno Run

Hi,
New to this,
This is the dyno run on my 06 865cc T00.
Moto Twin "pea shooter" silencers,
39mm FCR Flat slides,
K&N's
AI removed.

Carb kit was delivered with 155 main jets, this was very rich so reduced them to 140 and got results as shown.
Hope to crack the 70bhp with re map of ignition and will leave it there. Bike is very usable and big improvement over standard.

BR
Dave.

Discussion Thread
 

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#12 ·
Broke the 70 RWBHP

This is the follow up from last month's run and the results are stunning, IMHO. Ten Swafford helped me fine tune and dyno my bike today. I had 115's for the main[thought they were 125's] and 60's for the pilot. I replaced them with 125's and 62's respectively, tweeked the clips on the needle and got 3.16 RWBHP in return, for a grand total of 70.09 RWBHP at 52.89 Torque. I'm so jazzed, I broke the mark I was setting for. Now with a little tweaking of the ignitor I should get 3 to 5 more!! We did the throttle increments after we finished the set up and got: 1/4 turn-13.2, 1/2 turn-13.1, 3/4 turn-13.3, WOT- 13.0, sweet spot, as compared to 15.7,14.2,13.2and 12.9 respectively. Here's the results.....

 
#15 · (Edited)
I have just returned from experimenting on the dyno.

Filtered: 77.08 bhp, 58.66 ft/lbs torque
Open stacks: 86.34 bhp, 63.51 ft/lbs torque

Shocking result with the Ramair universal foam filters. We could have messed around with the jets, but there is no way the motor would have got near the power & torque obtained with the open velocity stacks.



My engine clearly does not work well with filtered short velocity stacks.

I then fitted the Procom CDI and here are the dyno results.

Procom CDI: 88.43 bhp @ 8286 rpm, 63.52 ft/lbs torque @ 5779 rpm.
Stock CDI: 86.34 bhp @ 7681 rpm, 63.51 ft/lbs torque @ 6725 rpm.



It's interesting that max torque occurs almost 1000rpm lower with the Procom. The Procom allows more revs and hangs on to the power until our self imposed maximum. It would rev higher but we limited the revs to 8,500 rpm.

Oddly, last year we tried the Procom when the motor was at a lower stage of tune, and there was a 1bhp loss throughout the rev range. Now, I've lost a little bit between 6500 and 7000rpm and gained everywhere else. The Procom stays on, as do the open velicity stacks.

EDIT: discussion thread here: http://www.triumphrat.net/twins-tec...ters-loose-60mm-open-velocity-stacks-win.html
 
#17 · (Edited by Moderator)

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#19 · (Edited by Moderator)
These dyno runs were done to get the jetting adjusted properly. The first and second runs have all the "mods" listed in my signature; the first is with the jets furnished by Bela Corse with the air-box eliminator kit (in defense of Mike, all he can do is get the choices somewhere in the ballpark. Dyno tuning is required to get them exact). The second run is with the jet numbers now listed in my signature. My bike will now idle along in first gear at 1000RPM with no stuttering/bucking and will get up to 105MPH in fourth before the rev limiter kicks in. The difference is day and night. The horsepower numbers may seem lower than what others are showing, due to using a different brand of dyno. Maybe Mike in VA can explain it better.---James.



http://i376.photobucket.com/albums/oo203/thruxton-texas/THRUXTONDYNOCHARTS---Jan09_0002.jpg

http://i376.photobucket.com/albums/oo203/thruxton-texas/THRUXTONDYNOCHARTS---Jan09_0001.jpg



Link to discussion thread:

http://www.triumphrat.net/twins-technical-talk/102725-dyno-run.html
 
#20 · (Edited)
2006 Scrambler

Recent Dyno results for my 2006 Scrambler.....

Airbox gutted and modified for L & R inlet
Unifilter (modified)
790 Inlet cam and remapped igniter.
Zard 2:1 Exhaust
135 mains/40 pilots/Thrux needles/No shims.

Relevant thread............ Modded Scram Dyno results

(Stock unmodified Scrambler traces included for comparison purposes)




V.
 
#21 · (Edited by Moderator)
#22 · (Edited by Moderator)
Oh my god top power runs ranged from the first 78bhp up to a high of 82 to a end result of 80 - So I am very pleased with the results. After several dyno runs at different companies all in the UK, all left me feeling ripped off. I found Competition Conversions in Adelaide actually know what they were doing and did not charge me an arm and leg for there services.



The blue is the first run and the red the last.

FCR 39's with Mains 148, needle one slot from bottom, pilot 45, hole in blue line between 2000 & 3000 is slow reacting accelerator pumps (spring is quite weedy) - red line is with accelerator pump made to squirt with thottle opening action (going to source stronger spring

Discussion thread:

http://www.triumphrat.net/twins-technical-talk/105140-latest-dyno-run.html#post1221089
 
#24 ·
Hi Kidz,

Okay, I just made a couple runs at the dyno with me thruxton, now fitted with early 790 cams...nark, d&d pipes, stock carbs (148 mains, 1- 0.020" shim, 42 pilots). Sorry the attached needs to be rotated to view...

The blue run is the 865 cams w/ procom ignitor (last fall)

The red run is the 790 cams w/ procom ignitor (today)

The purple run is 790 cams w/ pieman modified ignitor (today)

On the runs, ignore the stuff below 3000 or 3500 rpms, since Scott the dyno man figured out that the CV carbs like to be whacked open instead of rolled on like he did for the first (red) run....

So...the end result of adding just early 790 cams amounted to an extra 4 ft. lbs of torque down low, no more severe of a torque dip in the middle, and a nice 5 hp jump up top.

The pieman ignitor mod adds a solid 2 hp from 5,700 until 7,300 - at which point it makes 1 hp more until redline. It also appears to add about a 2 ft-lb boost down low. The latter is probably due to being able to retain the TPS/low rpm ignitor map, which the procom doesn't offer...

67 rwhp / 55 ft-lbs and counting. I know there is a bit more power hiding in the jetting since Scott the dyno man said the bike was a tad rich on the needle (mains were spot on), but that will have to wait for another lifetime.

Fitting the CR carbs I have waiting in the wings is next...

Cheers,

--Rich

Discussion thread here
 

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#25 ·
I put my new 904 on the dyno today found out I was way lean on the main jets.Was not a good air day 29.8 air pressure 80 deg but the little motor still ran good.84.67 hp and 63.89 ft/lbs. Here is the dyno run the graph has some missing peaces but you can connect the lines and tell what its doing.If any of you phto guys can fix it please do.

Discussion Thread: http://www.triumphrat.net/twins-technical-talk/109771-904tpusa-with-813-cams.html
 

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#26 · (Edited by Moderator)
If done correctly there will be three graphs below.

The first is for my completely stock 2008 900efi model, the second with peashooters and homemade baffles, the third with peashooters and no baffle (straight through).

The home made baffles were a quick lash up as I find the open pipe harsh on the ear. They are basically a 34mm diameter steel disc with a flat strip of steel welded to it and held 8-10inches into the silencer, the strip is bolted through a hole in the exit end of the silencer. I have added about 6 inches of fibreglass packing which is wrapped and wired to the strip.
The disc is to provide some back pressure to cut some of the popping on the overun and the packing to take the edge of the exhaust note.
No science or calculations were used in the making of the baffles.

For the outlay (about £140 all in plus time on mounting brackets) I am quite happy with the result as I never redline an engine in normal use.

The main thing was that the injection copes with the pipe change and kept the air fuel ratio in the safe area.







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