Making A 4-2 Exhaust. How To Do It?

I'll be wanting to make a 4-2 exhaust at some point in the future for a Fourth Generation 750 streetfighter. I want the routing of the pipes from the rear cylinders going through a custom tail along with a subframe I will fabricate myself. The front cylinders will be routed under the frame and coming out just behind the right footpeg. 

The outcome should look a bit like the Honda or Ducati MotoGP racers.

[image: 2013-ducati-desmosedici-gp13-specs-and-p]

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I'm leaning slightly towards the look of the Ducati tail as it looks a bit more finished. I'm not going to be running big, fat mufflers either. I'll likely end up with a baffled tip or something of the like.

So, what I need to know to make this happen is what kind of pipe diameters, header lengths, where to merge the pipes, and total pipe length so I can end up with some decent power in the end. I don't need to gain any, but would like to keep losses to a minimum. Would anyone have any information on this sort of exhaust build?

its simple..

 you use a "Y"  pipe to connect the front 2 cylinders ditto for the rear..

then shape away!!

makem short! makem long! makem backwards and pointing to the sky!

makem how you please .  :fing02:

look in the galley of member  

VF1000R  

its simple..

 you use a "Y"  pipe to connect the front 2 cylinders ditto for the rear..

then shape away!!

makem short! makem long! makem backwards and pointing to the sky!

makem how you please .  :fing02:

look in the galley of member  

VF1000R  

Well, sure, I'll use a Y-pipe to connect the headers together, but what I'm looking for is info on pipe lengths, diameters, and when I should connect pipes together so I can keep what power I have left on a twenty year old motor.

http://www.centurype...zing-and-Length

 a good place to start your ideas.. this is mostly cars .. 

now ..dont forget you cange the baffles and use a disk system to fine tune your set up.

 or even a bunch of bolts to add back pressure.

 my pals HD gained 6 hp at the bottom end simply by adding a bolt  through the end of his pipe ..

 he had NO baffles.. and i wraped them in heat wrap. 

http://www.vfrdiscus...opic/60905-rv4/

go to a junk yard and get some diesel truck exhaust make 2 stacks running up from the rear foot pegs -at a 45 degree angle--and don't forget the flappers up top they would create some backpressure----that would look sweat-trim them down-I would do that to mine but do not have the skills-- :unsure:  - i also heard that chain link fence pipe is good for the lowdrag harley look-but they may scrap during a low leaning corner-pipe is pipe- why waste money i think 2 inch is all you need---- post some pics please-- :cool:   i am looking to make a rear slip on system for my bike and was going to use to supertrap mufflers with the open end cap-one each side--just for the sound mainly would like the bike to be very loud!! :cool:  remember you may need to rejet or tune after a full custom system  good luck-- :cheerleader:

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Better  not  slide  off  the  seat  !!!!!

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these bike would have more torque if they had some connecting pipes.

Mine was 4-2 when I got it... Someone just cut the exhaust before the 2-1 part... it was terrible. I'm not sure if it was because of their amazing(ly terrible) ability to only use welded angle cut pieces of straight pipe, or because of the actual plan. I replaced it with the complete stock 4-2-1 later. I'd love to see what you come up with though.

Sent from my SAMSUNG-SM-N900A using Tapatalk

"Show-only"...

I thought this thread would be about which cylinders to connect in the 4-2 sequence?  OEM did it one way, TBR/Erion did it another, IIRC...

Ciao,

I can't speak for Erion but TBros used the OEM cyl connection sequence, at least on this high mount header.

[image: Exhaust.jpg]

For a 4-2 idea, check out VF1000RS profile & pics. http://www.vfrdiscus...10340-vf1000rs/

It wasn't the VFR800 headers; maybe the 750FL-V?  I have a pic on my site of the TBR low-left system for the 750, which was actually a 4-1.

Ciao,

swallowtailed

swallowtailed swallowtailed

swallowtailed