Topic: Anyone dyno'd their bike? want some resaults..8)

[cben750f0]

just wondering if anyone else here has dyno'd their bike?

    and b4 you start calling me a w@#ker.. i wasnt actually s'posed to get the ol girl dyno'd the day i went to the shop.
   
had gone with a mate to get his SV650S dyno tuned, and Dave from Dynobikes in melbourne, insisted that i put it on... he was very very insistant as it turned out.

well let me tell you the spectical that is a inline-aircooled-4cylinder, motor at nearly 9000rpm!!!!    i thought some sort of mental mechanical beast was trying to saw its way out of the booth... and i was on the outside!!!!
  i mentioned this to dave... who's next comment was ..."come in and hear it from inside the booth!!!!"

    BLOODY "ELL.... i used to have a firestorm... reasonable trick... had it dyno'd and it sounded no were near as out of controll as the 'ol girl!!!!!

   NEway was just wondering if anyone else had a tale,picture or readout for us to check out... peace

[cben750f0]

oh and by the way... she made 10hp less than the SV... not bad for a 28yo bike...

[SteveD CB500F]

So is that chart showing 66hp at the rear wheel ??

Wow !

[cben750f0]

yep....

[SteveD CB500F]

And was it not claimed as 67bhp (at the crank?) when new?

[cben750f0]

yeah thats what i have been told...my history is a little  hazzy... you will understand why i have twin drilled disc brakes now .

   this bike is the best bike i have owned... and as i said i owned a firestorm aswell... i get the same gollies out of the ol girl at 120km/h through a good bit of road... as i did at alot higher speeds on the storm.... AND its comfy....far to many broken bones to be hunched up....never sell her.... it was love at first site... AND she bloody goes.... ..peace

[Ibsen]

Quite impressing. I remember seeing another Dyno test of a 750 F2 from back in the 70's, and that bike did not put out that kind of hp on the rear wheel.
 

http://www.triumf.ca/people/baartman/bike/cb750-77.html

[MRieck]

Mine dynoed at 92.8 with about 57 ft lbs of torque. That's with a 915 kit, big valves, ported head etc. I just rebuilt the engine (still 915cc)and this time it has 5mm valves, really big ports and many, many other tricks. It should break 100HP. 66Hp is very good and that curve looks good- is that secondary curve the A/F ratio? If so that looks abit on the funky side I don't have a photo host but I'll snap a pic of the chart and send it to Terry P to post for me.

[cben750f0]

yeah.. that is the fuel/air...  not real sure how to fix that... but it seems to run alright(when its running)... if anone has an explaination i would be very happy... peace

[MRieck]

An acceleratopr pump would get rid of some that leaness when the throttle is whacked open but that isn't going to happen on those carbs. You shim the needles .020" - I'm sure it would help.

[cb650]

newer dyno'd but there used to be a site that would calculate the hp using weight(with my ass on) and 1/4 mile time and the 650 was a whole 45 hp.  that is at 6k ft and the bike is mostly stock just lightened some. 



                   Terry

[SteveD CB500F]

I'd like to resurrect this old thread and ask if any of the newer members have dyno'd their bikes?

[MRieck]

I wanted to this fall after installing a 5mm valve conversion kit, big ports etc.but it's a little late. I'll get there in the spring. I hope for close to 100HP.

[Sam Green Racing]

The last time the CR was on the dyno was when we fitted the CR carbs to get the jetting set up.
It produced 60 bhp which I would have thought about correct for a bike producing 67 bhp at the crank.
Terry in Aus seemed to think this was a bit on the optomistic side for a stock motor with just carb exhaust and ignition mods.
Is there a ball park figure in terms of % bhp that a bike looses through the transmission that can be taken as an average ?

Sam.

[SteveD CB500F]

I always thought it was 10% (maybe a myth from 70's bike mags?) but that would work out right from what you say.