Who said aftermarket cans don't improve 250s?

[babyblade250rr]

To all my fellow 250 riders,

Today i put a free flow carbon fibre muffler on my babyblade, I have herd alot of mixed opinions with mufflers and 2 fiddies perhaps being of no effect, and now ladies and gentlemen after just returning from my first test run here are my results.

sound yes it improves phenomenally alot more of that raw wooommmmffff.

rev range seems to have a consistant hard pull all the way through with no feeling of valve bounce after 14k rpm smooth all the way to redline.

Has fixed the 5k rpm flat spot that seems to common with the babyblades.

Has enabled me to hit top end 180k/hr much much faster than before
(Of course this was tested on a private road!!!!!)

So to sum up for any other 2 fiddy riders thinking about upgrading their cans i say go for it the carbon mufflers are rather pricey but im sure there are stainless ones that give the same results.

Hope this eases any fellow bikers queries on the matter!!

[James Deuce]

It's amazing how noise can can make you feel like you're going faster than you really are.

Were these tests on private roads empirical ones or merely seat of the pants?

Is there a dyno trace comparing power before and after end can replacement?

Congratulations on the loudener though. Nothing quite like spending money on a bike.

[98tls]

If anyone has some time i suggest doing a search and reading the performance return figures on aftermarket cans/exhausts.I delight in reading some of the supposed gains i see posted on bike forums.Its not exactly rocket science to work out, really you only need a basic understanding of any motor to work out that by simply fitting an exhaust can or for that matter in most cases a system without doing anything else you will achieve nothing.By nothing i mean the average bloke on a bike wouldnt notice any difference.

[McJim]

I'd always heard that cbr250rrs are eminently modifyable (is that a real word? - HITCHER!) so wouldn't be surprised at it's ability to be tweaked up to about 50hp or so.

The argument I've often heard is "You only have the 250 for a short while - why drop it's market value with mods?"

Why do mods drop it's market value you ask?

Any modification that increases output will reduce engine life. i.e. 20,000km on a modified bike will cause the same amount of engine wear as say 30,000km on an unmodified bike (dependant on the modifications - using noz regularly will cut your engine life in half).

These are rough numbers pulled out of the air to describe a concept which is true. Any attempt to pretend I intended these numbers to be precise scientific representation will be met with derision.

glad you're happy with your new pipes though...really I am!

[babyblade250rr]

It's amazing how noise can can make you feel like you're going faster than you really are.

Were these tests on private roads empirical ones or merely seat of the pants?

Is there a dyno trace comparing power before and after end can replacement?

Congratulations on the loudener though. Nothing quite like spending money on a bike.

No no dyno trace results are simply from day to day riding of the bike in comparison to can change over, i must say a very noticable difference

[babyblade250rr]

If anyone has some time i suggest doing a search and reading the performance return figures on aftermarket cans/exhausts.I delight in reading some of the supposed gains i see posted on bike forums.Its not exactly rocket science to work out, really you only need a basic understanding of any motor to work out that by simply fitting an exhaust can or for that matter in most cases a system without doing anything else you will achieve nothing.By nothing i mean the average bloke on a bike wouldnt notice any difference.

i don't claim to be an expert on bikes however i would claim i know my bike, it runs the same day in and day out so i guess i would be best the judge of improvement

[babyblade250rr]

I'd always heard that cbr250rrs are eminently modifyable (is that a real word? - HITCHER!) so wouldn't be surprised at it's ability to be tweaked up to about 50hp or so.

The argument I've often heard is "You only have the 250 for a short while - why drop it's market value with mods?"

Why do mods drop it's market value you ask?

Any modification that increases output will reduce engine life. i.e. 20,000km on a modified bike will cause the same amount of engine wear as say 30,000km on an unmodified bike (dependant on the modifications - using noz regularly will cut your engine life in half).

These are rough numbers pulled out of the air to describe a concept which is true. Any attempt to pretend I intended these numbers to be precise scientific representation will be met with derision.

glad you're happy with your new pipes though...really I am!

i don't disagree that this may cause sooner engine wear however as you said you don't have your 250 for long which is true so once i have my bigger bike i will then make my cibby a project hence no real disapointment with value loss

[James Deuce]

No no dyno trace results are simply from day to day riding of the bike in comparison to can change over, i must say a very noticable difference

Without jetting changes you're unlikely to get any gains at all. I'm serious about the noise making you think it's quicker.

With the can and jetting changes you could expect a 1, maybe 2 HP increase at the most. Between 2 & 5% is the typical performance gain from mods of that type.

[NordieBoy]

Without jetting changes you're unlikely to get any gains at all. I'm serious about the noise making you think it's quicker.

Unless it's running rich to start with.

With the can and jetting changes you could expect a 1, maybe 2 HP increase at the most. Between 2 & 5% is the typical performance gain from mods of that type.

Can, jetting and airbox mods got me 10% more power per cylinder.

[James Deuce]

If you can back that up with a dyno chart well and good, but it falls well outside the typical results for a Japanese Multi.

The only improvement you'll see is likely to be getting rid of that mid-range hole that seems to have been engineered into every Japanese multi for the last 15 years or so.

[klyong82]

I agreed with Jim2. The can will improve mid-range response but not much in terms of performance gains. A full system exhaust, air filter and jetting will make a difference in performance on a larger cc bike but unfortunately not much for a 250. But hey the loud sound will allow drivers to hear you from distance now.

[imdying]

Stopwatch, handful of tools, end of story.

[NordieBoy]

If you can back that up with a dyno chart well and good,

Yep.

but it falls well outside the typical results for a Japanese Multi.

Multi?

Singles rule.

[ManDownUnder]

Without jetting changes you're unlikely to get any gains at all. I'm serious about the noise making you think it's quicker.

Yup - ditto that! The very reason I split in the highest gear possible... quietly pootling along at 60kph is a lot "safer" than doing it in 1st or second

Not having a go anyone - it's simply part of being human. Things get interpreted according to the evidence and if something sounds fast ... it feels fast.

[terbang]

On the old 1200 bandit I had I fitted a Yoshi pipe. Dynod it and 'ping 8 HP'. Though with a fuel injected Hayabusa the cans just make noise. A lot depends on the bike and the origional mixture setup. With carbs you tend to be setup from the factory lean down low and in midrange. But the main jets control the higher end where the can tends to stifle performance. Simply put, the price of keeping noise and emission levels low, is lower horsepower.