Ninja 250 Exhaust

[StewieeeG]

Hey all, I got a 2006 Ninja 250 engine with cut down wiring loom especially made for a buggy. and I am aiming to mount this engine in my Edge Taipan Buggy. It has the header pipes on it already and I am wondering if it is worth fabbing up a header to join two into one and then bending it so I can fit a slip on silencer onto it.
I can post some photos tonight of where the engine will sit and where I need to route the exhaust pipe.
I read the article on backpressure and pipe size just now about what difference it makes. and I was wondering if anyone could help me select a pipe that would fit the stock pipes and wouldn't affect the power?
Thanks, Stu

 

[OzFab]

Na, TWIN PIPES RULE! The downside is you'll need two mufflers, that is if you really need mufflers... You could make your own...

The other option is to have an adaptor made to fit the header pipe up to 2" pipes for a big fat noise...

 

[StewieeeG]

haha they look sick I must admit!
I probably should have mufflers just for the convenience of all within earshot haha I would get dual mussarri's then.

That big fat noise sounds loud I better have a muffler.
Do you know how to make your own muffler?

 

[OzFab]

I made one for my daughters kart which works well & a slightly larger, untested version but, the principle is the same...

 

[mymumisaman]

Motorbike engines are sensitive to ""adjustment "" any changes to the standard exhaust will require the Carb to be fiddled with to get the engine to run smooth. So my advice would be to try and keep the exhaust as close to standard as possible. A 2 into 1system would have to be well thought out whereas a duel exhaust would simplify the transplant.

 

[StewieeeG]

That muffler looks pretty sick I must admit!

Yeah I don't mind fiddling around with the jetting. I will have to anyway because if I put an after market system on and use a high flow k an n filter without the stock airbox it will flow more air both ways. So there's a jetting change already.

I might just get the inside and outside diameter on a muzzy system and get the same size pip to match and do a quick bend to make room for a slip on or two. And the slap both mussaris on.

Sent from my GT-I9100

 

[itsid]

there shouldn't be much of a problem, since the ninja 250 is a four stroke engine,
so as long as you get the exhaust gases out of there you'll have more than enough power

Would be different on a suzuki rgv 250 for example which is a two stroke and thus more delicate when playing with the exhaust.

'sid

 

[StewieeeG]

Yeah true. I thought of cutting the join in the tube and turning the pipes a different angle from the engines to make more clearance. Is thee any problem with this?

Sent from my GT-I9100

 

[fowler]

What do u mean u need two mufflers for twin pipes

U don't need any mufflers on a buggy

Straight though twin pipes

U will get more flow with twins

What happened to the stock mufflers?
I'd just hit up gumtree for two mufflers off any bike 250cc or bigger

As modelengineer said
Bikes are sensitive
In particular if u are running two pipes into one

If u have ever heard of fitting extractors onto a car
And if u know what they do

It's just as easy to get it wrong

 

[StewieeeG]

I guess, except it is quite loud. Pretty deafening tbh.

I didn't buy it with stock mufflers I bought it just the engine wiring and carbs for 760 au which is fairly decent. Done about 27000 km on it. 2006 model.

I haven't heard of fitting extractors?

Sent from my GT-I9100

 

[fowler]

Well to put it simply
(No we don't need the standard 3 page argument)

An engine is designed so the exhaust valve isn't quite **** as the intake opens

As the exhaust gas rushes out it created a little suction that helps the flow of intake gas (fuel air mix)
It's called scavenging (no not back pressure)

Anyhow u still have to get the exhaust away from the engine as quick as possible
But as each cylinder fires there's a constant smashing of gases as each of the lets say 4 pipes on a 4cylender run into 1

So they are designed to be the same length
As each cylinder fires at differant times exhaust from each cylinder reaches the collector at different times
Ones that are done really well will take into account the firing order and be tuned so the rushing gases of one cylinder enter the collector just as the next cylinder opens the exhaust valve
Creating a bit of suction and increasing the scavenging


This is where the 19yo take their civic to Adolfs express exhaust and pays him $40 to make a set of "extractors"
Then they find they have gained alot of noise but acctually lost power because Adolfs had no clue what he was doing

Long story short
Make each pipe exactly the same length
Or just keep the stock pipes as they are

Cut the joiners between them and run them out the side or somthing
No reason u must run them underneath

 

[StewieeeG]

I actually thought of that if I did decided to do a 2 into 1 pipe. But I think I shall just leave them as it is as I fired it up today and it sound sweet with just the headers.

Sent from my GT-I9100

 

[OzFab]

You think it sounds good now? See post #2

 

[StewieeeG]

I never said anything that they don't sound good. They sound great!
I fired it up when my neighbours were starting their CRF motocross bikes up and couldn't hear a thing except for the grumble of the ninja. Even with earmuffs
They sounded so quiet afterwards

I was just concerned about the noise levels.
As they are just ridiculous :/
Also good in some ways if I go with mates I will drown out their bikes

Sent from my GT-I9100