Exhausts.... I'm confussed.com

blagger · Post by **blagger** » Tue Jan 09, 2007 5:12 pm

Hi

Can any 1 help. i'm lost in the world of end cans.

here is the back ground.

If you have read my other post about my exhaust project for my gk73a your know i want to make my system as a 4 into 1 style...

At the moment my system is as follows. from the engine the downpipes go into a collector box then from there the left and the right link pipes connect to each side of the collector. the link pipes and cans for each side are as one unit as standard. so i want to make my own link pipe about 2" diameter to connect to the right had side of the collector and i will plug off the left hand side...

i have heard of this way before from another forum i have joined for 400 grey import bikes and they have said it works fine...

now the end can part...

i have been advised by a helpfull member here that i will have to be careful to what end can i put on as a mis-matched can will cause the bike to lose power.

but on the other hand on the another forum they say i can use any can any size as long as its for a 2" fitting and it will be ok...

here is the link to the topic i posted on other forum

http://www.400greybike.co.uk/Forum/topi ... C_ID=52838

I can't believe it's not butter! being a novice i will take any advice i can get. but i wasn't sure if there is a standard rule for the type and the size of the end can.

for example like a slip on can for YZFR6 would only work on an YZFR6 or would work fine for a ZX6R or other sized engine bike say 750 or 900 as long and the fittings where the same on the link pipe.

hummm i hope i'm not confussing u lot 2 I can't believe it's not butter!.

cheers for any help received

Nessus · Post by **Nessus** » Wed Jan 10, 2007 9:29 am

Hi there,

I really don't think that the type of end can would make much of a difference - if it's a striaght though race item. My brother grafted an old Firestorm can onto his old CBR600 and it made no difference at all (apart from being far too long and looking a bit silly).

What's more likely to affect the performance is tinkering with the downpipes. Is there a company that makes aftermarket 4-2-1 systems for your bike, or do you have to do it yourself?

coullstar · Post by **coullstar** » Wed Jan 10, 2007 9:41 am

From what Ive seen in the past exhaust tuning is a bit of a black art that almots seems a bit miss or hit and would involve some trial and error if you are starting from scratch.

Best go with experience from other people with similar bikes.

CBRXX · Post by **CBRXX** » Wed Jan 10, 2007 10:42 am

If your doing this to increase performance of the engine you'll be wasting your time and could make things worse.
Decent exhaust systems are designed to be pulse tuned i.e the length of time it takes the pulse from the gas leaving the exhaust port to reach the silencer and bounce back to the exhaust valve to aid scavenging the combustion chamber. (have a look at some of the aftermarket 4 branch manifolds fitted to cars or bikes, the pipe from each port to the collector is the same length)
These are normally designed as a compromise between as flat a power curve as possible and peak power at a certain rev range, hence the introduction of variable length exhaust ports to allow peak power at an extended rev range, flattening out the power curve whlilst allowing power to increase.
Using the method you describe will only benefit in reducing overall weight of the bike I'm afraid.

blagger · Post by **blagger** » Wed Jan 10, 2007 5:19 pm

Kool.. a big thank you for the advice..

I have been looking for places that do aftermarket systems for the gsxr 400 but they are mainly for the gk76a version ( '90 - onwards ) if i wanted to try and fit something like that i would need to change the oil pan and sump as the collector is a flatter design on the my gk73a than the newer gk76a.

If your doing this to increase performance of the engine you'll be wasting your time and could make things worse.

i'm not to bothered at the moment about trying to increase the power of the bike i'm wanting more the louder accoustic sound of the exhaust (sad i know).

:I can't believe it's not butter! :I can't believe it's not butter! :I can't believe it's not butter!

I really don't think that the type of end can would make much of a difference - if it's a striaght though race item.

What's more likely to affect the performance is tinkering with the downpipes.

So from what i gather as long as i leave the the front end of the exhaust (downpipes and collector) as standard i should be ok with making a link pipe to go from the collector to the end can and this wont effect the performace for the bike much. the worst case is for me is to mess my bike up a lose all power I can't believe it's not butter! don't want that to happen.

Thanks again for the advice, you are all such a handy helpfull bunch

and if any1 would like to suggest any other pointers i would glad to hear them

CBRXX · Post by **CBRXX** » Thu Jan 11, 2007 10:19 am

gsxr400rider wrote:Kool.. a big thank you for the advice..
So from what i gather as long as i leave the the front end of the exhaust (downpipes and collector) as standard i should be ok with making a link pipe to go from the collector to the end can and this wont effect the performace for the bike much. the worst case is for me is to mess my bike up a lose all power I can't believe it's not butter! don't want that to happen.

Thanks again for the advice, you are all such a handy helpfull bunch
and if any1 would like to suggest any other pointers i would glad to hear them

I'm afraid not your down pipes were designed specifically for twin exhausts and the standard cans although these will have been a big compromise between meeting emmisions and noise regs combined with performance so the silencers will be quite restrictive.
If your just looking for a nice rip I'd just change the end cans (ask anyone with a V twin what kind of difference these can make to sound), and if set up properly you may release more power by getting more free flowing cans, if there aren't any specifically for your bike look for ones from a bike with similar capacityxrev range cause these will be designed to cope with the same amount of gas flow.

missile · Post by **missile** » Thu Jan 11, 2007 2:19 pm

You are welcome to my silencer if you still want it?

blagger · Post by **blagger** » Thu Jan 11, 2007 7:43 pm

i don't really want to do this but what about if i just cut out my baffles from my standard cans to give me more sound. would any1 recommend this

Post by al » Thu Jan 11, 2007 10:24 pm

IZINBARD · Post by **IZINBARD** » Fri Jan 12, 2007 3:15 am

Or if you want to do that, buy a second hand can and f*ck that up, so that you can sell on the bike with everything standard as well as being able to get an MOT.

Best bet, buy a secondhand Art race can and fit that. 105 db

Izz,

blagger · Post by **blagger** » Fri Jan 12, 2007 3:57 pm

kool i will have a ponder and have a think over it. and see what the best option is... i don't want the exhaust to be overly loud so it will attract unwanted attention like from P.C Plod but lounder than what my standards can are....

P.S Cheers for the can missile for me to have a play about with.

Nice meeting you today.

missile · Post by **missile** » Fri Jan 12, 2007 5:01 pm

Pleased to give it a good home. If you decide it is not any use try it on eBay. It came off a 2003 FirePlace and someone may be in desperate need of a standard can to pass an MOT. I believe these cans cost Â£250+

Or when people ask what you ride, you could make on you are building a Gay Blade bit by bit