Author Topic: Post your Dyno Graphs here.  (Read 40983 times)

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Offline Doctor_D

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Re: Post your Dyno Graphs here.
« Reply #50 on: May 26, 2012, 08:44:29 pm »
Not bad for a stocker.

If you nip a few thou off the bottom of the slides, you won't go so lean on tip-in.  (Cycle x provides that service if you don't feel you have the skills.) The rest of the fuel curve is within spitting-distance of perfect.
Take care,
David
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1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline brewsky

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Re: Post your Dyno Graphs here.
« Reply #51 on: May 27, 2012, 04:28:44 am »
Thanks for the comments, David.

I'm hoping the lean bumps are result of the operator trying to get too quick a fist full of throttle at lower rpm (twice), and maybe the accelerator pump circuit is not up to par?

Hate to make an irreversible change to the slide as I'm still planning on exhaust changes.

Will try to attach  cell phone videos (quick time zip) of the runs if I can figure out how.................well, it won't work........will try something else later
« Last Edit: May 27, 2012, 04:30:15 am by brewsky »
66 CA77
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Post your Dyno Graphs here.
« Reply #52 on: May 27, 2012, 04:57:16 pm »
Bill,

A little rich in the midrange? You're almost there!  ;)
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Doctor_D

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Re: Post your Dyno Graphs here.
« Reply #53 on: June 09, 2012, 11:28:38 am »


From the fuel/air reading you can see that I need to adjust the accelerator pump to come on a bit earlier and quit a bit earlier - but after doing that I'm calling this one done.

In any case, 88rwhp and 58lb/ft of torque on a 420lb bike is plenty and only 2 short of my goal.  Power goes "flat" at the top - just like Tige's 915.  Unlike Tige's, my intake and exhaust are open.  Might be approaching the limits of the cam.

I'm done chasing this Twinkie.

Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline bwaller

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Re: Post your Dyno Graphs here.
« Reply #54 on: June 09, 2012, 12:10:10 pm »
I'm done chasing this Twinkie.   ;D


At 420 and that engine... damn straight, that's a nice package. Congratulations.

Offline JohnN

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Re: Post your Dyno Graphs here.
« Reply #55 on: June 10, 2012, 08:56:23 am »
761cc
CR31's
Ported w/ 5mm stem kit
CX7 cam 2 degrees advanced (.380/265 @ .040" lift)
CR750 replica
CB750K2
85 VF500F
66 CA160
67 CT90
2000 Triumph 955i
69 Triumph Bonneville

Offline Bill/BentON Racing

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Re: Post your Dyno Graphs here.
« Reply #56 on: June 10, 2012, 02:54:33 pm »
I'm done chasing this Twinkie.   ;D


At 420 and that engine... damn straight, that's a nice package. Congratulations.
Got me by 30lbs! Also 23 H/P,wow,can't wait til 915cc CycleX and Mikes Stage III head go on! Way to go Dr.D. Great work! Fun fo sure! Bill
BentON Racing Website
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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline MRieck

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Re: Post your Dyno Graphs here.
« Reply #57 on: June 10, 2012, 03:53:05 pm »


From the fuel/air reading you can see that I need to adjust the accelerator pump to come on a bit earlier and quit a bit earlier - but after doing that I'm calling this one done.

In any case, 88rwhp and 58lb/ft of torque on a 420lb bike is plenty and only 2 short of my goal.  Power goes "flat" at the top - just like Tige's 915.  Unlike Tige's, my intake and exhaust are open.  Might be approaching the limits of the cam.

I'm done chasing this Twinkie.
That pump doesn't need to be on long at all. It will kill power and take 1,500 RPM to clear out. Another millimeter of intake valve ( and corresponding bore of the seat/throat) would make a real be difference Dave in regard to making top end power. Anyway.....88Hp/58lbs (real nice) out of an 836 is pretty damn good Dave.
Owner of the "Million Dollar CB"

Offline Doctor_D

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Re: Post your Dyno Graphs here.
« Reply #58 on: June 11, 2012, 06:09:50 am »
761cc
CR31's
Ported w/ 5mm stem kit
CX7 cam 2 degrees advanced (.380/265 @ .040" lift)

You can see John's before and after.  He had a big hole in his curve from an over-rich needle (YY6, clip position 1) that was compensating for a lean slide (3.0).  (Where the blue/green A/F line goes flat, it's richer than 10:1) Trying to hold speed in a tight corner on the track must have been nightmarish.

Lowering the needle should have cleaned up that transition, but got us nowhere.  Then we did a 1/2 throttle 3-7k, 3rd gear pull that was off the charts lean, which was the giveaway. Installing a richer 2.5 slide allowed us to raise the needle and decrease the main jet, and the A/F ratio came back on to the readable scale.

Y7 or YY7 needles and we should be able to flatten out that fuel curve.

« Last Edit: June 11, 2012, 06:24:12 am by Doctor_D »
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline Sam Green Racing

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Re: Post your Dyno Graphs here.
« Reply #59 on: June 11, 2012, 04:08:44 pm »
David, what do you mean it goes flat at the top?

Sam. ???
C95 sprint bike.
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RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline Doctor_D

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Re: Post your Dyno Graphs here.
« Reply #60 on: June 11, 2012, 05:38:24 pm »
Torque can be flat, but a power curve should be exactly that, a curve.  In my limited experience, when HP flattens out for a significant amount of RPM's, there's a restriction in one part of the package.

Sent from my ADR6400L using Tapatalk 2
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline Leino

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Re: Post your Dyno Graphs here.
« Reply #61 on: June 13, 2012, 11:30:32 am »
JMR-Suzuki's first ever dyno graphs, 173 rwhp@ 9600rpm and 137nm @ 7100rpm
Needs some adjustment but I'm pretty happy with the results so far, this particular dyno isn't famous for giving "free horsepower".




Offline azuredesign

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Re: Post your Dyno Graphs here.
« Reply #62 on: June 13, 2012, 12:23:46 pm »
JMR-Suzuki's first ever dyno graphs, 173 rwhp@ 9600rpm and 137nm @ 7100rpm
Needs some adjustment but I'm pretty happy with the results so far, this particular dyno isn't famous for giving "free horsepower".





Pretty impressive, especially when you think there's more to be had.
Good job!

Offline Leino

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Re: Post your Dyno Graphs here.
« Reply #63 on: June 13, 2012, 01:28:47 pm »
Thank you Azure, I'll start with bigger pilot jets and less accelerator pump.
Mike Rieck is responsible for most of the HP, I just put the engine together  ::)  ;)

Offline Sam Green Racing

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Re: Post your Dyno Graphs here.
« Reply #64 on: June 15, 2012, 12:17:58 am »
 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)

It's no wonder you can't keep the front wheel down. ;D ;D ;D ;D
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline Bill/BentON Racing

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Re: Post your Dyno Graphs here.
« Reply #65 on: June 15, 2012, 05:58:30 am »
 ;D No Sh*t!!!!! Very nice,Juha.....and Mike!!! ;) ;D Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline Leino

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Re: Post your Dyno Graphs here.
« Reply #66 on: June 15, 2012, 08:15:39 am »
Thanks Sam & Bill, my long term goal is to catch the quickest Busa in my class some day (it runs 9.1's and over 250km/h) but right now I'm 82hp down in comparison  ::)
82hp and 25 years  ;D

Offline MRieck

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Re: Post your Dyno Graphs here.
« Reply #67 on: June 15, 2012, 08:28:30 am »
I do see the classic RS carb power dip around 6,000. I believe its the engine trying to clear itself from the extra fuel added by the accelerator pump. Changing the pump starting point and shortening the pump duration helps get reduce that.
Owner of the "Million Dollar CB"

Offline Leino

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Re: Post your Dyno Graphs here.
« Reply #68 on: June 15, 2012, 08:33:55 am »
I do see the classic RS carb power dip around 6,000. I believe its the engine trying to clear itself from the extra fuel added by the accelerator pump. Changing the pump starting point and shortening the pump duration helps get reduce that.
This is on my list of things to do before next race  ;)
Thanks Mike!

Offline PeWe

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Re: Post your Dyno Graphs here.
« Reply #69 on: July 29, 2012, 12:51:42 pm »
761cc
CR31's
Ported w/ 5mm stem kit
CX7 cam 2 degrees advanced (.380/265 @ .040" lift)

"CX7 cam 2 degrees advanced"
Is that recommended to get more torque in lower rpms? Tried to advance the cam more?
I'll install a CX7 cam soon and have in my mind to time it to get more power at lower rpm.
« Last Edit: July 29, 2012, 12:54:05 pm by PeWe »

Offline JohnN

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Re: Post your Dyno Graphs here.
« Reply #70 on: July 29, 2012, 05:21:58 pm »
Yes, advancing the cam will start the powerband earlier. It was recommended that I advance it 3 degrees, but when I achieved 2 degrees advance during installation I called it close enough!. I can attest the bike launches much better than it did with the stock cam (and tired engine) but still makes good horsepower. Not fair comparing it to a tired engine of course, but now I leave the line at 5000 RPM and before I would rev between 6-7000.
John
CR750 replica
CB750K2
85 VF500F
66 CA160
67 CT90
2000 Triumph 955i
69 Triumph Bonneville

Offline PeWe

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Re: Post your Dyno Graphs here.
« Reply #71 on: July 30, 2012, 10:05:31 am »
Thanks! 3 it will be, hopefully. :)
836cc, Ported head with larger inlet valves, earlier Action fours SS-1 cam (270 degr, 0.360 lift)

Offline mec

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Re: Post your Dyno Graphs here.
« Reply #72 on: September 17, 2012, 12:40:28 pm »
hello,

did a dyno run with my stock cb750K6,
eveything stock including exhaust with baffles, air filter.
Tovami dyno.

>100.000km, new pistons and rings 6000km.

mec
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Offline voxonda

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Re: Post your Dyno Graphs here.
« Reply #73 on: September 17, 2012, 01:18:38 pm »
Hi mec,

That is one healthy K6 you have there. Almost 60 on the rear wheel is a lot for a standard engine.

Regards, Rob
« Last Edit: September 17, 2012, 01:45:41 pm by voxonda »
Better sorry for failing then for the lack of trying.

Offline Doctor_D

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Re: Post your Dyno Graphs here.
« Reply #74 on: September 17, 2012, 01:26:49 pm »
That torque "curve" is really amazing. 
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando