Straight pipe backpressure problems?

[hughmcm]

Hi everyone, I'm new to the forum but hoping someone might be able to help.

I have a 1996 ZX6R which I use for track riding (not racing). My main goal is to indulge this hobby without spending large amounts of cash, track pace is secondary.

I had an off while riding the Phillip Island Grand Prix circuit (Turn 10 for those that know the track) and did some damage to the right hand side.

I easily (and cheaply) sourced (from wreckers mostly) the replacement parts I required (bar, lever, peg, brake pedal) however I also smashed up the silencer and have been unable to find a replacement.

I fabricated a replacement myself out of straight pipe and was hoping someone might be able to tell me what effect this might have on the bike. I'm not so much concerned about a potential drop in power (track pace is secondary) but being a self taught "mechanic" I'm concerned about potential damage that may be caused by not having the correct exhaust system and any backpressure issues that might arise.

Alternatively, does anyone know where I might find a replacement silencer to suit?

I have attached a photo to show where the custom pipe starts and length etc.

Thank you in advance to anyone who takes the time to offer advice.

[98ninja]

viewtopic.php?f=21&t=17919

It kindof addresses your issue

[BrettZZR]

I guess the most important part of your question (to you) is will it do any harm to the bike?

I don't think so, but I'm no expert. Might be good to do a dyno plot and include a plot of your AFR, just to make sure it has not leaned out anywhere. If you have the ability (ie on the bike) to adjust the parameters, might be worth setting it up optimum, because this would make it more durable and go better, and more pace is always more betterer...

My understanding (partly reflected in that thread) is that this set-up will deliver the best power at peak revs, but you can lose a fair amount of poke in the mid ranges because the scavenge cycle (during overlap etc) wont work as planned.

(-8

[Gosling1]

get rid of that abomination and find any absorption-style muffler ( straight-through with all the little holes and exhaust wrapping to 'absorb' the noise). Just get any muffler/exhaust shop to knock up a short adapter to your engine pipe. It will work and look far better than the dog currently bolted up there. ( Dog - a hot-dog without the hot)

That straight- through pipe will drop your power considerably, and could cause engine damage from running too lean.

[dickfaber]

get rid of that abomination and find any absorption-style muffler ( straight-through with all the little holes and exhaust wrapping to 'absorb' the noise). Just get any muffler/exhaust shop to knock up a short adapter to your engine pipe. It will work and look far better than the dog currently bolted up there. ( Dog - a hot-dog without the hot)

That straight- through pipe will drop your power considerably, and could cause engine damage from running too lean.

agreed, but it will sound fcuking horn while it lasts!

[Nelso]

get rid of that abomination and find any absorption-style muffler ( straight-through with all the little holes and exhaust wrapping to 'absorb' the noise). Just get any muffler/exhaust shop to knock up a short adapter to your engine pipe. It will work and look far better than the dog currently bolted up there. ( Dog - a hot-dog without the hot)

That straight- through pipe will drop your power considerably, and could cause engine damage from running too lean.

agreed, but it will sound fcuking horn while it lasts!

Disagree. All the bikes with these type of straight through cans at the track, are obnoxiously loud and sound like shit. Bikes sound much better with some sort of muffler on them. Without it, they sound tinny and too high pitched.