A 4 into 4 exhaust system possible?

[Neosophist]

ah okay, cheers and you just weld the collars on right?

This 'just' comment caught my attention.

This is one of the hardest parts. Getting a decent weld on the metal, and depends on the metal you are using.

Dont' take this as a put-down, just some advice.

Firstly, remember when I keep saying, don't rush.. remember those two words. Slow is the key.

Secondly, are you planning on doing any of the welding etc by yourself? If so are you upto the task, if not price it up first before you start.. it will be expensive.

Anyhow..

If your even remotely serious about this project, design it fully before even buying anything or you will be just wasting money.

Measure how much pipe you'll need and what kinds of bends and where, what diameters you'll be wanting and material type and thickness.

Price it all up, if your not welding and cutting and bending yourself it'll probably be well over 1000gbp to get somebody to work with you joining it all up.

RCV4's fancy bend was many cut pieces of TI connected together to get the proper angle, paying somebody to do that will cost a fortune.

Now that costs are out of the way you need to look at exhaust theory.

The length and diameters of the pipe will have a big effect on how the engine runs. Have a look at G-force performance as they have a good article on their lastest exhaust.. how after making it super curley and fancy they had to have it remade a few cm's shorter or longer in some place as it dramatically affected the engine.

If your not concerned about rideabliltiy or power then ignore all of that, but it seems fairly important to me that if your going to the time, trouble and cost to make something one off that it should maximise engine performance, not kill it.

Be prepared to alter your design when it kills the engine power too, this all adds money and development costs. Since a few people have designed some systems in the past you may have soem rough numbers where to start with your system but unless you've been making systems for a long time or have a degree in mechanical engineering and understand gas-flow well (which is still something of a wizardry to me) then expect some re-designs needed.

My advice is to not underestimate and rush to get something cheap and cheeful put onto the bike, but be aware before you start that it might be trial and error if you want a system that will work well, so you'll need to budget for re-redesigning things, ideally dyno time too and somebody familir with making exhausts, on the surface it seems quite easy to just get some pipes cut to fit but underneath it is quite complicated.

If you do make something pictures are always good!

[NZgatch]

My dad has made more than a few exhausts for bikes and cars over the years. He used to make them out of poos mild steel first, longer than his calculations showed. He would then spend some time experimenting with jets and cutting 1/2 to 1inch off at a time to get the primaries back closer to the calculated length. Once he was happy with the state of tune he would then get into duplicating the exhaust in s/s or Ti or steel or whatever, with all of the bends and proper fits. Very time consuming and not necessarily scientific to the letter, but he never had any complaints.

[thunderace]

Just a thought here....

Would it not be a lot easier to run a 4-2-4 system? Run the rear two cylinders off to the side and the front two underseat? I say it that way round because if you decide to run the rear two underseat, you'll end up with one tight mother of a U bend

R&D would be much cheaper too as you could use the existing headers.

[xivlia]

hmm i was thinking of using the rear as underseat.. but i shall see, il look closely today and see how it will bend up etc, if its too tight then il use the front as under seater. what do you mean by R&D?

[thunderace]

Research & Development

[rcv4]

The rear cylinders need to go.under the seat or it will bollox the lengths,are you going for 4 into 4 or 2-1
-2

[kevprojex]

I bet a 4 into 4 system with a v4 motor would sound awsome .

You mean like this Kev?



Na not a girly custom style , two under seat and one either side rg nsr style , ive heard a few vmax`s with 4 into 4 pipes and they sound awsome .

[Neosophist]

I bet a 4 into 4 system with a v4 motor would sound awsome .

You mean like this Kev?



Na not a girly custom style , two under seat and one either side rg nsr style , ive heard a few vmax`s with 4 into 4 pipes and they sound awsome .

Ah you mean race-style! :D not just any 4-4! I see

I just meant Honda had already done at least 1 4-4 system :) I think the sound should be similar though (4-4).. the 750 above is the same as my uncles and it sounds good, it's a 180 firing bike though

My friend has an RG400, that sounds pretty sweet too, but square 4 noise not V4 360 ala NC30.. would be interesting to see one up and running! :)

[xivlia]

hmm, im probably gonna do a 4-4 system and not a 2-1-2. but i will have to see and plan it all.

[rcv4]

Are you thinking one on each side for the bottom or two on one side? .....personally I would go two under the seat and one either side,short motor go style Meggas.