Modified Exhausts

[Fight_fan]

Howdy folks! Just wondering what experience/advice u might have regarding modded exhausts. I really wanna try to organise a 'shorty' for my 7/11 that exits just past the rear set! I spoke to a local exhaust guy & refused to help me as there was "no way of goin about it without fucking the power & making the bike run like shit!" (exact words)
Iv seen a bunch of guys doin it so there must be some way around it[?]
I kno fuck all about exhausts but figured someone here would be able to help me out!...Hopefully...:D

[Lucas]

http://www.streetfighters.com.au/ASF_HT_shor_can.asp

[Fight_fan]

Cheers Lucas! Already saw that one...Was thinkin about shortening the whole system tho! If u check out the pic I posted u can see what im gettin at...

[Jockney Rebel]

generally [ and i have limited expertise at this ]try tokeep ur headers the stock length as this is what effects ur performance, i believe its something to do with scavenging the spent gases out of the engine also its important to keep all four headers the same length

[Deano]

the system that is on it is a micron 4-2-1. i think what needs to be found out is that if you were to cut the inter pipe a few inchs after the 2-1 merge and weld on a little shorty will this cause fueling issues or big holes in the power or torque.

the headers and 4-2-1 design will remain untouched it is just the link pipe section afte the 2-1 to the can?

is that right lance?

[Bear]

I agree with him ^^ :)
Modify anything from the headers back. It's not a dangerous or risky game as your local exhaust fella reckons.

Here's some basic principles to go by:

For more torque and bottom end = lengthy can and narrow exhaust tubing (to do with the back pressure wave).

For power at higher revs = short can, short system over-all and remove any flow obstructions like the catalytic converter (get them gasses out of there as quick as you can).

That's very broadly speaking. There is s science to exhaust tuning.
Search the web. There's heaps of info about.

[Deano]

have also heard that a little backpressure will help to stop exhaust valve seat recession.

[xjrjack01]

I recon somethin like this only with a growler can, be as noisy as but at least it would look the part.
http://ausfr.com.au/cart/shopimages/zx10r_08_mega.jpg

[Fight_fan]

quote:Originally posted by Deano

the system that is on it is a micron 4-2-1. i think what needs to be found out is that if you were to cut the inter pipe a few inchs after the 2-1 merge and weld on a little shorty will this cause fueling issues or big holes in the power or torque.

the headers and 4-2-1 design will remain untouched it is just the link pipe section afte the 2-1 to the can?

is that right lance?


Spot on big fella! :D

[Fight_fan]

quote:Originally posted by xjrjack01

I recon somethin like this only with a growler can, be as noisy as but at least it would look the part.
http://ausfr.com.au/cart/shopimages/zx10r_08_mega.jpg


Thats kinda what I was thinkin design wise!

[latheboy]

I did the same thing and TK has done it too ... I cut the can in half so its 150mm long and cut 150mm off the pipe so that it exits under the rear set, when i put it on the dyno it was lean as all hell and the power was down about 4hp... Tuning the exhuast is an art form that i dont think ill ever get and i dont have the time to put into either... So i made a few different ends for the can till it was pretty good then a quick jet and i was back to where i started... All up about 3 hours work, nothing really but you'll need to get it on a dyno if it leans out it might throw a leg out of bed and that would be ghey

[Fight_fan]

Cool! Thanx Ivan! Yeh I figured it may drop a little Hp but im so worried about that as I am the bike runnin like shit! Can the carbs be tuned to compensate some? Apparently it already has n existing jet kit!

[zx12argh]

put a turbo on it - that would be short and quiet all at once.
I'm sure there would be other benefits too...

[Fight_fan]

quote:Originally posted by zx12argh

put a turbo on it - that would be short and quiet all at once.
I'm sure there would be other benefits too...


Lol! Cheers Pete! Im not worried about it bein loud as fuck tho mate!
...Would be interesting tho!:D

[TurboKat]

I just bolted my Shorty Can straight to the collector on the stock headers so I effectively only lost about a foot or so worth of straight pipe, it might have gained or lost me a few HPs or Torques but with a big bore engine it's pretty hard to notice with the arse dyno.
I've done a WOT plug chop & they read very slightly lean but not enough to worry about, I'll set it up perfectly when I get it on a Dynamo meter.
I always thought Deano's exhaust was as ghey as aids, it just looks completely wrong & lets the whole bike down. It's about time someone owned it who has a sense of style & is not a big fat homo. [:0]
;)

[Fight_fan]

Yeh that was sorta my original idea TK! I knew it wouldnt be gr8 4 the bike performance wise but I didnt think it would be as bad as what the exhaust guy was making it out to be!
I was talkin to deano yesterday, he said he still has a few parts that he was planning on using to make the shorty back when he had the bike & could put it all together 4 me! I'd rather pay him to throw it together if its not too much hassell than fork out for my local guy who'l prolly fuck it up & just blame it on the design! There is no one else near by that could do it for me anyway!
I'd do it myself but I need to learn to weld 1st! Its on the cards but im impatient! [:I]

[Large]

quote:Originally posted by TurboKat

I just bolted my Shorty Can straight to the collector on the stock headers so I effectively only lost about a foot or so worth of straight pipe, it might have gained or lost me a few HPs or Torques but with a big bore engine it's pretty hard to notice with the arse dyno.
I've done a WOT plug chop & they read very slightly lean but not enough to worry about, I'll set it up perfectly when I get it on a Dynamo meter.
I always thought Deano's exhaust was as ghey as aids, it just looks completely wrong & lets the whole bike down. It's about time someone owned it who has a sense of style & is not a big fat homo. [:0]
;)


You guys should get married[:p]