What's a 'good' sports exhausts and what's 'dyno' all about?

[byke95]

I've just read The Doctors thread on how he's lost a lot of BHP on his CBR6. Kickstart mentioned that most sports exhaust makers don't have a clue...

So, two questions really:

1) What brands of exhaust will actually benefit your bike?

2) If you deceide to buy a aftermarket can what do you need to do in order to make sure it's working well? I hear the word dyno a lot but I'm not to sure what this means and how much it costs?

[Type_Mo]

Get yourself an Akrapovic Exhaust
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- Typhoon ?0 - Yamaha DT125R - Aprilia SR125 - Yamaha DT125R - Honda Hornet 600 -

[Kickstart]

Hi

You will get a small amount of extra power from a race can. Biggest advantage is that they are cheap and light.

For a decent amount of extra power then you are looking at a full exhaust system (and it is the lengths of the pipes and how they join that gives you the power, rather than the dodgy bean can on the end), and then you need one that is designed for power (plenty are just designed to replicate the original). You will need to get the bike set up for a decent sports exhaust, and you will also likely loose low down power to gain top end power.

Akrapovic seem good, and do a few other makes. But they are not cheap.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[craigs23]

A full Yoshi made a few wonders to my bike, along with neccesary carb mods. Might follow with some dyno time if I find problems with the delivery (so far, it's way better than me).

[byke95]

Full Akrapovic system and then onto a dyno, that'd be well over £1000 right?

Might just buy a Z1000 / speed triple as my nest bike and keep the standard cans on there!

[LeonClayton]

there is definately a cringe point when you hand your pride and joy over to cresent and see what they do to it on the dyno.

The results were stunning but i wish i handn`t watched, lol

[craigs23]

My Yoshi set me back just over £200, Stage 1 Dynojet was £80 (new).

[MattyB]

by the way, a dyno is a machine that calculates your engines power, in Kw or Hp, aswell as Torque levels

i assume it's the same for bikes as it is for cars, with differences.
it's 2 rollers which have senors inside them, the bikes rear wheel sits inbetween the 2 rollers and you slowly build up RPM (IN GEAR) which will spin the rollers, and figure out your power figures

hope i cleared that one up for ya

[LeonClayton]

heres the output of mine to give you a feel for what they do

https://homepage.ntlworld.com/leon.clayton/bike/GSXR750K4.jpg

[lilredmachine]

People get their sports exhausts on, with lots of loud noise, stick it on a dyno to discover that they have surprisingly lost a few horsepower on the one that the company that made the bike spent hundreds of thousands of pounds developing to be both potent and quiet. Don't get me wrong, certain systems will produce more power, as well as sound great and sticking it on (and more importantly getting it tuned) a dyno will provide good results, but don't expect instant power increases by just chucking one on.

Incidentally, when we had a dutton, the little 1300 had an extra 16hp dragged out of it just by timing and air filter adjustments.

Dyno videos. https://www.bristoldyno.com/videos/
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Bikes: too many, too much for one man to maintain anyway.

[craigs23]

The seat of my pants dyno says my exhaust/carb mods were a definate improvement - more power and torque everywhere, plus a midrange that made me think I was approaching 9k plus when infact I was just breaching 7.5 (and where the first proper kick comes in).

It's going to be a good year for biking...

[Kickstart]

[Jack_Cheese]

[Kickstart]

Hi

Looks like it is in the units you say, but the scales are very different.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Jack_Cheese]

Lol cheers, i am a friggin idiot after all then.

Jack
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www.bikepics.com/members/jackcheese <--- NOW FOR SALE! 51 Plate Cagiva Planet 125
Quacker_boy: "Jack, you really are a dick!"

[craigs23]

[Wooly R6]

just won my scorpion can on mcn auctions!!!! £50
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R6 has been sold - 2004 Honda VFR VTEC now sold too - no bike at the moment

[johnsilva]

try this!


https://www.bikechatforums.com/viewtopic.php?t=56295&sid=0ad05ea5e5a4aa5865db09731b66f6d8
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Current Bikes: ZX7R P5; KR1S C2; GPX250R F3
Previously: CBR400RR-R; YQ50 Aerox

[Wave2k]

Akrapovic
Yoshimura
Micron
Scorpion
a few of the ' good' make zausts, but its gonna run shite no matter what if its not set up properly.
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Ducati 1299 Panigale
2009 Corvette C6 z51
RS125->CBR400->RXS100->GSXR750K2->Ducati749S->CBR600RR5->TL1000R->DRz400->RSVR1000->Honda VTR SP1->CBR400->GSXR1000K6->Honda H100->CBR600RR3->Ducati1299

[Andy C]

I have just the scorpion can and they say no rejetting is required, i know my bike hasnt been rejetted but i cant seem to get more than 130mph out of her when i know i should get 140mph standard , seems fine though rev range but didnt ride it standard so nothing to compare it to...

i may go for some dyno time summer time
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99 RS125 --> 02 SV650s --> 03 Speed Four --> 92 RXS100 --> 93 CB400sf --> 01 CB600f Hornet

[mr.tattoo]

a dyno run wont just tell you your power, it will tell you if its running to rich or LEAN, which is normally the case with race cans. get a race can on any bike and set up PROPERLY on a dyno and it will run much better.

[road runner]

The most important thing to get right is the bikes air-fuel ratios.these need to be correct right through the rev range.
Fitted a full ti-force race exhaust,modded air box,power commander with a custom map done on a dyno and a few other bits.
power before mods were done was 155 bhp, 99ftlbs torque at rear wheel

after mods and set up on dyno 180bhp,109ftlbs torque at rear wheel.
The £150 custom map sounds expensive but the performance gains were worth every penny
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Live life like yer ass is on fire

[sickpup]

[ZRX61]

The business end of my Muzzy:
https://img.photobucket.com/albums/v317/ZRX61/crash2004.jpg

side view:
https://img.photobucket.com/albums/v317/ZRX61/crash2001.jpg
It wasn't actually running when that pic was taken.....just breathing heavily..

[Zimbo]