Anyone know of an exhaust system available for the XX that actually caters to a modified engine?

Akra & Micron only make a street exhaust, designed to enhance midrange performance, and some top end power.

Muzzy's advertises race performance, but I don't have any experience with their systems.

Anyone have any other choices? How about Yosh? They advertise a race system.

All exhaust systems for XX are 4-2-1 variety and designed to work well with stock motor,cams unlike zx 12 where you can buy pipe from Muzzy for bored,stroked engine with race cams.
Carburated XX have 1-2 and 3-4 primaries merging together while F.I model has 1-4 and 2-3 type collector,the later suppose to give better midrange at the expense of some topend.
Yosh RS3 race is 4-2-1 type with 1-2 and 3-4 type of collector and tail pipe is 2.25 inch.If interested I could give you other dimensions.

Thanks for the info.

Is the Yosh pipe the one you're using?

I contacted Muzzy about their pipes, and I forgot to tell them what year, so he emailed me back asking that bit of info.

I'm interested to hear what Yosh and Muzzy have to say about their systems, as well as what Micron replies with. I won't hear back from Micron or Yosh until after the New Year. :sad:

Muzzy says that their systems "shine above the rest", especially on modified engines, and will outflow any other system.

Claims a 10% increase in power on a stock engine, more on a modified one.


What to do, what to do............. :???:

Well,what is your goal? Drag race type of powerband or nice wide roadrace powerband? Exhaust systems are not really rocket science,your gain some on top end you may have a hole somewhere in powerband.
I would ask them about dia. of the header pipe and type of the header.
Muzzy used to deal with roadracing but now they do drags,theirs pipes seems to be well made and have reasonable price tag although little loud.

The bike is going to make enough torque, no matter what, so maximum gain at the mid to higher rpm is the goal.

Not only will primary diameter make the difference, but so will collector length/type.

The Muzzy system pairs the cylinders like the carb XX did, too. Not sure how this would affect power, but it's kind of interesting.

On the dyno today, power fell right off above 10k, so more flow would definitely be a benefit.

Yoshimura RS3 race has 40 mm I.D headers,lenght-22 inches.
Secondary pipes are 50 mm I.D,lenght 6 inches.
On stock bike pipe makes good power all the way to rev limiter,it does not fall off.
Pipe uses baffle-type collectors,that is where primaries terminate abruptly.It relies of sucton wave to scavenge cylinders.It is suppose to work better on short duration cams.Stock cams are like 230/237 at 0.04,I guess that is short.
The other type of collector is merge one where primaries blend into each other,they rely on gas momentum to scavenge cylinders.It works better on topend.Yosh pipe for R1 is of this type,Muzzy`s pipe for mod. ZX 12.
BTW intake cam for carb XX has couple more deg.of duration.

Here goes Chris AGAIN, trying to reduce his bikes HP :wink:

Chris have you mailed Pete with the 1200 'bird at Blackbird Spares in the UK?, sure he could point you in the right direction as he has access to different exhaust systems and plumped for the Akra race giving 176 hp. There's a dyno printout on the page as well.
http://www.blackbirdspares.co.uk/demobike.html

It seems as though they all went with the Akra (at least the UK bikes did), but "my guy" insists on the Micron.

All of the systems I've mentioned are built for a stock engine, and could really fall off quickly with a modified one. Some of these guys don't even list a race baffled system.

HP = airflow. The more HP you want to build, the more air you're going to have to get in/out of the engine.

Once I finally settle on a pipe, the airbox will be my next project............

I'll contact the guy at UK Spares and see if he experimented with other pipes.

North,

When setting up my bike on the dyno with the Akro it did have a HP falloff but was at 10800rpm. There was a custom map made for my bike to maximize power instead of a stock downloaded one. The guy here in So. Florida who builds and sets up must of the successful race bikes locally supposedly has the only Dyno in the SE states with the ability to make accurate custom maps for specific engine setups. I say supposedly, since I dont know that to be a fact.
I do know that all the bigger names in racing locally take their bikes there for final testing before races. Barry Henson has run his Bird there as well as a couple privateer AMA racers just for the Maps.
When I was deciding on the pipe for my bike He, (Kevin Blais) (Blais Racing) told me that in his experience, if I wanted max power achieved, then I should put on a Micron system and the Akro was his next choice but preferred the build quality of the Akro over the Micron.

My .02

I've actually got the phone # for the tech dude at Micron, (who, BTW, rides a XX :grin: ), so I'll try to call him on Monday or Tuesday.

If not, this will have to wait until after the New Year.

One word.... MICRON'S!!!



I prefer the Carbon Fiber models... Fixes the midrange hole and sounds tits!

Unfortunately, slip-ons just ain't gonna cut it.............. :roll:

I've now learned that the Micron uses a larger mid pipe than the Akra, which should help flow. Have to find out if the primaries are larger, as well.

Akra primaries are 38mm I think,probably too small for your needs .

CHRIS, WHILE YOU'RE DOING ALL THIS SHIT, WHY DON'T YOU SEND YOUR HEADS OUT AND GET THEM PORTED AND POLISHED, ALSO GET SOME BIGGER INTAKE AND EXHAUST VALVES PUT IT?????

DO THE SHIT RIGHT!!!!!!
OR I'LL COME UP THERE AND, AND, AND ................................................





FORGET IT!!!!!

Don, if you only knew................... :wink:

The project will unveil itself when it's time.

I think I've finally decided on a system, and been offered an excellent discount on it as well.

Dean, are you saying that Yosh and Muzzy are not the way to go? I hope so, because I'm steering toward another system recommended by another member that I've yet not seen installed on the XX.

Give you a hint, it's fully titanium, and has tapered head pipes......... :grin: