Some of you might be familiar with my bike going back a few years now. Things have changed a bit since and I reckon time for a new thread.
has some hyperlinks to some of the other mods done.
Before all the nay say'ers get up in arms with the "why bother" posts, I do it cause I love mechanics, to learn, and basically because I find it enjoyable... Plus being single helps to throw coin at things other than T&A. If I had a higher capacity bike, I'd still be doing the same things, so no need for any negativity.
So the latest foray into mods... There's been a few "race engine build" threads started, but to date none completed; here's to changing that.
The most recent add-ons have been the addition of custom ground high-lift cams and the IXIL race spec header, so most definitely has to have dyno tuned after install.
The dyno tuner was very knowledgeable and dealt with a handful of CBR500s in his time, was keen to see what this little bike can actually do with a proper tickle. He did quite a number of runs with different configss to find the best combo, not just for top-end but all round tractability. Because my modifications have been progressed over time, and through the course of changes I'd been doing my own tuning via the DynoJet AutoTune, there is no base run available. The "base-run" line in the dyno image below as the tune as it was at that stage.
The dyno run was done at sea level with ambient temperatures of ~22*C. Just completed major 25K kilometer service (26K on the odo) days before; so new plugs and all new fluids (Honda 10W-30 oil).
Some of the key outcomes
of the dyno work:
-1.5-2hp gain having the slip-on baffle installed... a little back pressure can be good.
-'potentially' a couple more hp can be gained with increasing the size of the air filter inlet hole
-Interestingly, most of the fuel map has less
fuel input at any given rpm. (Don't get confused thinking stock runs rich, there's more dynamics at play with this)
Base line runs of stock bikes he said, and can also be found comparatively from other sources on the internet, yield averages at the wheel of 42-43hp and 28-29ft-lb torque.
My dyno chart:
To help make things easier though, I've taken 4 different stock dyno results sourced from the internet, plotted them in Excel and then took the average of them and charted alongside the results from my figures, and derived the below comparative results. Note, my engine has Rev X-Tend enabled to 9600rpm, cut-out for stock is 9100.
So how does my bike feel these days?
It's got more pull than a wild Bangkok night!
With 32ft-lb available from 3600rpm rising to a peak of 36ft-lb between 6600-7800rpm, I can pretty much use one gear higher even with a taller 38T sprocket.
In 6th gear doing 70kph at ~4K rpm it will accelerate to 100kph in under 4 Mississippi - yes, that is an accurate measurement :P
The relaxed riding rev range, i.e. grandma riding commuting duties, is between 2500 and 4000rpm; 3rd & 4th gears has plenty of pull even as low as 2000rpm.
And when you feel like getting on it, it's like it has a little power band after 6K, from that to 6600, it jumps 4ft-lb... you do notice it, thinking "oh hello!" 7K, 8K, 9K, oh that grin factor
Now with the baffle in, it's quieter than before, which is nice when you just want to cruise. And with the better fuel map, I'm anticipating a reduction in fuel consumption too, well, so long as I can log a full tank run without getting too excited with the throttle.
Here's what it's looking like these days