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!!!!!):innocent:

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!!:rockon:

[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.

[bimotabob]

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.

Yeh I remember the sales ads saying bandit steals 12HP with yoshi or something and a dyno chart next to it.
But I heard from an owner that his low end grunt suffered noticibly.

Some sports bikes have very restrictive mufflers.

I imagine the high reving CBR will make quite a racket at 18,000rpm
All good:yes:

Regards
BB

[terbang]

Not too bad, just shifted it all up the rev range a bit higher thats all. But the noticable thing was it's ability to perform more like a four should and produce lots of power right up into the high rev range. The Gen one bandits were way detuned from the origional Gixxer engine and part of this (well aparrantly 8 HP worth) was achieved by the can.

[babyblade250rr]

well i guess the moral of the story is it may or it may have not improved the bikes performance certainly feels like it however!!! the main thing is i'm pleased with the outcome regardless of concious or subconcious improvement:p

but thanks all for your positive input always good to hear a debate from both ends of the courtroom!!

just remember at the very least the next kb event you will hear me commin haha:rockon:

[The Everlasting]

I've seen a few bandit 250's on trademe with aftermarket cans,where could I get one?

[davebullet]

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.



Before I put the 2bros on the SV, I could only go 80kph in first.... now I can go 120kph in first. It's more than doubled the speed I can go in first gear with the same redline!!! Even neutral is a bit quicker than before :laugh:

[SS90]

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.



50hp,????ß not unless he fits a 400 engine there McJim.....more like 35 to 40 hp...maximum

[McJim]

50hp,????ß not unless he fits a 400 engine there McJim.....more like 35 to 40 hp...maximum

http://www.bikez.com/motorcycles/honda_cbr_250_rr_1994.php

Interesting - it comes with a peak power of 45hp and you could only modify it to a max of 35-40hp? Better go check you toolkit dude. I wouldn't recommend you for tuning. :rofl:

[YellowDog]

If the can sounds great and makes you feel great - nuff said.

[The Everlasting]

http://www.bikez.com/motorcycles/honda_cbr_250_rr_1994.php

Interesting - it comes with a peak power of 45hp and you could only modify it to a max of 35-40hp? Better go check you toolkit dude. I wouldn't recommend you for tuning. :rofl:

Haha yeah,massive fail from SS90...:lol:

[R6_kid]

I've seen a few bandit 250's on trademe with aftermarket cans,where could I get one?

You can get them on TradeMe, but I prefer Ebay for 'known brand' exhausts.


Before I put the 2bros on the SV, I could only go 80kph in first.... now I can go 120kph in first. It's more than doubled the speed I can go in first gear with the same redline!!! Even neutral is a bit quicker than before :laugh:
This was my original reply...
You're completely full of shit. You got a 40kph gain... thats a 50% increase, but I doubt you got that from an exhaust alone - which generally yields 4-8hp, another 2-4 with an air filter, and maybe another 2-4 with proper fueling.
Then I re-read what you had written and this is my new reply:
ROFL!



http://www.bikez.com/motorcycles/honda_cbr_250_rr_1994.php

Interesting - it comes with a peak power of 45hp and you could only modify it to a max of 35-40hp? Better go check you toolkit dude. I wouldn't recommend you for tuning. :rofl:

Stock peak power is 45hp at the crank (claimed). After 20yrs I'd consider 40hp at the wheel to be a damn good achievement. My mate got 36rwhp from his stock CBR250RR, but dyno figures are only reliable if you are looking the the affect of changes, or doing back to back comparisons on the same dyno.

Use this page here (http://www.factorypro.com/dyno/true1.html) to get an idea of what real HP figures to expect. Note that the FZR250 (the only comparable bike to a CBR250RR) made a whole 33.8rwhp, the 2008 Ninja 250 with a claimed 28hp got 25rwph after rejetting but got up to 32hp+ with some serious work.

[SS90]

http://www.bikez.com/motorcycles/honda_cbr_250_rr_1994.php

Interesting - it comes with a peak power of 45hp and you could only modify it to a max of 35-40hp? Better go check you toolkit dude. I wouldn't recommend you for tuning. :rofl:

Jeezus mcjim, you really believe that power figure?

I have operated dyno's for the last 12 years or so (in NZ and Europe), and NEVER seen more than 40PS from a 4 stroke IL4 engine (despite many claims) most put out around 38PS, and I can't remember ever seeing 40PS ever.

You realise that manufacturers measure at the crank, right?

If you have ever had a look (in an an experienced tuners eyes) at a Japanese 4 stroke IL4, you will see that there is sweet FA you can do.

I have posted a dyno graph on another thread a while back.... I assure you that 45PS from an IL4 is not "FACTORY", and doubt you will ever find a dyno graph to prove otherwise......I have heard "my mate did a dyno run of "yyxx"ps, etc,but, still, have never ever seen proof of this.... I am happy to be proved wrong.....

[SS90]

Stock peak power is 45hp at the crank (claimed). After 20yrs I'd consider 40hp at the wheel to be a damn good achievement. My mate got 36rwhp from his stock CBR250RR, but dyno figures are only reliable if you are looking the the affect of changes, or doing back to back comparisons on the same dyno.

Use this page here (http://www.factorypro.com/dyno/true1.html) to get an idea of what real HP figures to expect. Note that the FZR250 (the only comparable bike to a CBR250RR) made a whole 33.8rwhp, the 2008 Ninja 250 with a claimed 28hp got 25rwph after rejetting but got up to 32hp+ with some serious work.

I posted a dyno run of a cbr250RR on a thread a while back (can't be arsed looking for it just now), and from memory, around 36PS.

Guys, don't believe this 45 rear wheel horsepower bull shit.

250 IL4's generally have from 32 to 38 PS, not more.

and, as far as "tuning" goes, there is sweet FA you can do, they already com e "highly strung" from the factory...... god, they rev over 18,000, what else do you want?

[specter]

HA! why waste precious big bike money on a 2fiddy... my advice wait for a very cold morning and go for a cane, reap the benefits of dense air! :bleh:

[motorbyclist]

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.


+1

Apparently that 5k flat spot is due to noise/emissions testing



Interesting - it comes with a peak power of 45hp and you could only modify it to a max of 35-40hp? Better go check you toolkit dude. I wouldn't recommend you for tuning. :rofl:
:slap:


HA! why waste precious big bike money on a 2fiddy... my advice wait for a very cold morning and go for a cane, reap the benefits of dense air! :bleh:

+1 again

[enzedone]

HA! why waste precious big bike money on a 2fiddy... my advice wait for a very cold morning and go for a cane, reap the benefits of dense air!

I must say that this is correct. I'm no mechanic, and I'm only riding a 250. But leaving home at 3.30am and riding down the motorway towards Albany, there's a really nice cold spot, and the bike seems to run way better. Sitting on 100km the revs drop about 800rpm in that weather.
I have just replaced my filter with a K&N, and that has made things better, revs seem to be a lot smoother.
I have a Yoshi slip-on, but it was on there when I bought the bike. I like it compared to that ugly large terd hanging off the original.
I have been looking at getting a full system, either a Yoshi, Area P or Two Brothers.
All I can say is, buy from overseas. You should be able to get a full system here for about $85-130 USD (shipping costs).
Sorry to all shops here, but the savings are HUGE!
I can land an AreaP full system here for $841 and a full Yoshi for $877. Where in New Zealand can you get that?......No where.....screw the so called buy NZ, please it's not even made here anymore, and if retailers stop ripping us off I would go back to buying from local shops. But now most of my stuff is bought from overseas.

[onearmedbandit]

Sitting on 100km the revs drop about 800rpm in that weather.


Did you change the gearing on cold early mornings as well? Because that's the only way you'll see any change in x revs at x speed.

[steelestring]

true that..... what about weight savings? those standard pipes weigh a bit too eh? Compared to a aluminium one peice?

[enzedone]

No gearing change. Another thing I notice is coming home from work, more traffic, more wind from all the cars/trucks seems to knock the bike around as well, making it work harder.
Original pipe compared to the carbon slip-on.....unreal!

[onearmedbandit]

No gearing change. Another thing I notice is coming home from work, more traffic, more wind from all the cars/trucks seems to knock the bike around as well, making it work harder.
Original pipe compared to the carbon slip-on.....unreal!

Sorry, that was tongue in cheek. The revs your motor does as a certain speed is solely dependent on gearing, from internal ratios, primary drive and final drive ratios, and overall tyre circumference. The amount of power your engine makes has no effect on gearing, so how you seem to notice an 800rpm drop just from different ambient air temp perplexes me.

[Miscreant]

Sorry, that was tongue in cheek. The revs your motor does as a certain speed is solely dependent on gearing, from internal ratios, primary drive and final drive ratios, and overall tyre circumference. The amount of power your engine makes has no effect on gearing, so how you seem to notice an 800rpm drop just from different ambient air temp perplexes me.

I fear you lost him again.
I love it when people feel the need to share their stupidity with us on the Internet for all time.

[motorbyclist]

I must say that this is correct. I'm no mechanic, and I'm only riding a 250. But leaving home at 3.30am and riding down the motorway towards Albany, there's a really nice cold spot, and the bike seems to run way better. Sitting on 100km the revs drop about 800rpm in that weather.

:slap:

you'll find that simply isn't the case unless the clutch is normally slipping and the cold spot causes it to engage...... what you may find is the engine speed picks up, causing you to back off the throttle to maintain your speed... alot like cresting a hill


Another thing I notice is coming home from work, more traffic, more wind from all the cars/trucks seems to knock the bike around as well, making it work harder.


:slap:

are you splitting between two oncoming lanes of traffic?

travelling in their wake actually helps you, even if it can buffet you around a bit which makes is a bit more tiring as a rider - heck I got my little 100cc honda up to 100kph while drafting behind a speeding milk truck! I also seized and broke a piston circlip it about 30 seconds later and totally ruined the motor lol

maybe you should look into getting a mentor....