Underslung exhaust?

[mr-munro]

Hi all , my rx has gotten a bit too loud now it has the lfan 150 in it and I'm looking for a new exhaust. as normal I'd like to keep the high flow part and just lose the volume, I have a H-bomb on it now that was fine with the 146bbk etc but it's just too loud with the 150.
As I'm up for a new pipe anyway I've been toying with the idea of going for a custom underslung exhaust sort of like the buell's used,clearance should be ok as the rx doesn't see much offroading.
I made up a quick one this arvo on my egay junker just to see what it looked like:

[/IMG]

Just wondering if anyones tried it before and what it was like?

 

[pbk]

hey mate an underslung exhaust like that in the pic WILL make it louder

as it has a shorter pipe it makes the route shorter making air escape from the engine quicker making it way louder

 

[SnItChY]

first question is , if you dont do much off roading why are there knobys on your rim's
second question is if you make the pipe shorter dont you think it will be louder ??

 

[pbk]

snitchy he did state in that pic is just of hes cheap egay bike just to see what it looked like

 

[mr-munro]

Just to clarify my thought patterns, I was thinking of dropping down from the port and either splitting the pipe into 2 and running 2 silencer next to each other under the bachplate, or running 2 silencers in sequence with a 180 bend.
after experimenting with the H-bomb I found that if I put about 150mm of pipe after the can it almost halved the noise levels, just haven't got the room in the standard spot.
was also thinking that moving the can closer to the head, would move the power band up higher the same way tuning header length on a car does.

 

[no_crf50_here]

Cory from Mild to Wild has done this mod on his RX, i do have photos of it somewhere....

 

[Dabomb]

Interesting theory, that silencer looks a bit ugly sitting under the engine, tho it is your junket.

2 silencers in parallel off the header pipe, under the bashplate would look different, have dig son.

See how u go and return with pics!

 

[mr-munro]

Just an Update:
I couldn't get 2 matching mufflers that would work and within my budget so I had a go with my old KTM 525 muffler.
I shortened it by ~150mm down to 300 long and used a couple of mandrels I had laying around, got it on there and I'm fairly happy with how it's looking so far. It still needs some work like the welds finished up a bit and I need to move it back about 20mm ( fouls front tire under compression turning left) but otherwise it's ok.
Started it up and it's louder than the stock RX exhaust without the baffle but a lot quieter than the H-bomb, so looking good for volume as well.

exits just to the right of the back wheel.

I'll remove the mounting tabs when I've settled on how it's going to be supported.

 

[mattbombers]

i rekon that looks good

 

[corey58]

mi vert pictures by crobi84 - Photobucket

rx pipe pictures by crobi84 - Photobucket

they good good, if you used a good well packed can they aint loud at all


tho one a 2valve you should have a longer pipe, as on a four valve the pipe length does not matter at all

 

[mr-munro]

Finished,

I repacked the muffler and it's made it a bit quieter than I hoped but it's still louder than the stocker.
I didn't gain any weight over the stock pipe, actually lost .2kg but it's heavier than the H-bomb by about .4kg.

Here's a quick vid to hear it although it sounds quiet in the vid it's louder in person.
it's only a phone vid but better than nothing:

 

[byh0005]

that sounds nice and am i seeing things or is your foot peg moving when you rev it?

 

[mattbombers]

looks like its just vibrating...
sound sweet

 

[mr-munro]

Cheers guy's and yep it's just vibrating.

 

[james_troke]

that is pucking madd