Exhaust Mod

[Nemo]

Hi All

I wanna mod my exhaust so it runs cans left and right.

I have a spare exhaust and the plan was to cut the downpipes from both, and use 2 from each pipe to get the lengths similar then have them joined by a Y piece so its like 2 , 2-1 exhausts.

Has anyone tried this and found any problems on the way or tried this and can say " you do it this way" ?

Was gonna run high level cans but that means losing my rear pegs and passenger carrying ability, unless anyone can get round this one too !

Anyway , any feed back would be welcome

Cheers

Mark

[mossy1200]

you will need to go 4 into 1 then into two or fab a balance box.If not you will never get it tuned.

[Nemo]

Ok

As for Balance box

Can I go the way of a (very) old cb500 I had with a balance pipe between the 2 2-1 sections ?

Or does it need to be a complete "box" ?

[mossy1200]

Ok

As for Balance box

Can I go the way of a (very) old cb500 I had with a balance pipe between the 2 2-1 sections ?

Or does it need to be a complete "box" ?

If i were to do it i would use stock headers seperated from exup collectors.Weld the four headers inside areas together so they line up.
These inside areas need to be prewelded so that your collector can be welded arround the outside and there will be no air leeks.
I would use mild steel rectangle to wrap arround the welded headers shaping as you work you way round.I would then get two pre made 2into one collectors and do the same(weld them into line of four.Now you have an outlet from your collector to join your two tail pipes.


weld green first....Then pipes are a group....then weld mild steel arround the blue shaping as you go......replicat output using two premade Y pipes

[yamaha_george]

Ok

As for Balance box

Can I go the way of a (very) old cb500 I had with a balance pipe between the 2 2-1 sections ?

Or does it need to be a complete "box" ?

If i were to do it i would use stock headers seperated from exup collectors.Weld the four headers inside areas together so they line up.
These inside areas need to be prewelded so that your collector can be welded arround the outside and there will be no air leeks.
I would use mild steel rectangle to wrap arround the welded headers shaping as you work you way round.I would then get two pre made 2into one collectors and do the same(weld them into line of four.Now you have an outlet from your collector to join your two tail pipes.


weld green first....Then pipes are a group....then weld mild steel arround the blue shaping as you go......replicat output using two premade Y pipes

Hi,
The only other worry is that the two output pipes are not so large as to drop the pipe pressure and the "wave" inside the pipe and ruining what Yamaha set out to do with the EXUP valve. I seem to remember a number of good book titles in the WIKI Tech section on exhaust pipes & tuning

[yamaha_george]

If you dont ride passengers then you can run the high mount.

Hmm I do like to "ride" my pssenger

[Nemo]

Well the Exup aint a problem , coz its a Genesis.
I have run a high pipe on an old FZR750 I had but that had no passenger seat.
This one is gonna have a rear seat so I was sort of looking like the pegs on my NC24 where they wrap over the end can

[PIMPMYFZR]

[/quote]

Hi,
The only other worry is that the two output pipes are not so large as to drop the pipe pressure and the "wave" inside the pipe and ruining what Yamaha set out to do with the EXUP valve. I seem to remember a number of good book titles in the WIKI Tech section on exhaust pipes & tuning[/quote]

I have seen alot of people on the R1 forums disable the exup complete so that the butterfly stays open always if i read correctly .. some swear it makes more power i'll have to look it up still dont get the concept of it just no its supposed to adjust the back pressure or somthing

[DonTZ125]

I'd be willing to bet that disabling the EXUP makes the engine FEEL like it's producing more top-end, as there is a sudden 'hit' as the pipe comes on-line. Back-to-back dyno pulls, EXUP operating and pinned, WFO and half-throttle, might yield some fascinating tidbits for discussion.

[mossy1200]

I'd be willing to bet that disabling the EXUP makes the engine FEEL like it's producing more top-end, as there is a sudden 'hit' as the pipe comes on-line. Back-to-back dyno pulls, EXUP operating and pinned, WFO and half-throttle, might yield some fascinating tidbits for discussion.

funny thing is mine develops more hp everywhere.More so in the middle.Torque is up everywhere aswell although before dyno tune I lost 7hp.

[sweekster]

I'd be willing to bet that disabling the EXUP makes the engine FEEL like it's producing more top-end,

This is a good way of explaining it. I had a full Yoshimura system on my 94 1000 when I bought it. It had NO low end....ran great above 5k rpm though. I've since removed that system for a functioning EXUP system and the Yoshi headers are now on Mossy's race bike.

[Nemo]

Back to the main plot.............

Is this my only option ? Building a collector box to accept the 4 downpipes and then having twin exits from that ?

An old vf500 I owned had an aftermarket exhaust on it, that had a cylindrical collector on it with a side exit for the mid pipe and end can. A cylinder would be easier to make , any views on this one ???

Remember its a pre exup !!!

[sweekster]

It did get a bit off topic. Sorry about that...I think your original idea would be the best way.

[Nemo]

By my original idea , I take it you mean the suggestion from Mossy to build a collector box ?

If thats the way , does anyone know a collector box from another bike that can be modded ?
Something maybe like FJ1200 or the likes ?

Cheers

[sweekster]

Well I was thinking a 4 into 2 with the left and right exit. This is what you want, right?