Dyno Run

[nick40]

Just picked my bike up from TTS in Northampton where its been tweaked and dynod, nothing to try and get anymore BHP just to get it running right and its making 70BHP at the rear wheel,, how far off the mark is this for a 2 valve 900. Guy at the Dyno reckons thats good for its age its a 1997 bike anyone know if he is right?

Nick

[nik_the_brief]

On an M900 the power on a 1999 model was 68.2bhp, with torque of 54.6ft/lb's so that sounds about right. HTH

[DesmoDom]

Well both of my 900ss'ssssssss only made 74 BHP at the back wheel when new, so I think he's right saying it's good for it's age :D :D :D

Baz

[Guzzirider]

A bike placed on one dyno could read 74bhp, and the same bike on another dyno could read 68bhp- dyno readings vary so much.

The important thing is how the bike feels to you- numbers mean nothing.

[spacemonkey]

Just for the record my 39k mile 93 M900 was at 74bhp last year on the dyno. It was 69 before fiddling.

HTH too.

[Zimbo]

What year is the bike? Early (pre late '96) M900s had bigger valves and higher lift camshafts, so should make a little more power than the later ones. If it's a late one, I'd say 70bhp is fairly healthy, earlier ones should make around 72, but as said above Dynos do tend to vary a bit!

[PC Myers]

My '98 M900 (small valve heads) with 7000 miles, K&N pod filters and Factory Pro jet kit made 64.5 bhp at the wheel - dyno operator thought it was a bit low....

[stef]

I am going to setup my own "street dyno".
looks easy enough to me.
i already have the connection to the pick-up coil available, from my dash prototype, so getting something reasonable to work should be interesting.
as long as the runs are consistent, there is no reason why one cannot use this to tune the bike. apparently, the absolute value of bhp are not too accurate (within 4-5%) but since you get this sort of variation from one dyno to the next, it's not really a problem.
consistency would be key though.

all i need now is a "portable" mean to record sound. I have done the relevant measurement with the laptop before, with the bike sat in my garage but i wouldnt want to carry the 'puter while blasting down the road though !
i reckon a cheap MP3 player/recorder with a jack input..