Anatomy of a Hayabusa exhaust system

[TempOzzy]

Cheers for the advice from the guys above.

Yes, as predicted by Camel, I was thinking of essentially making my mufflers purely cosmetic. I figured guys are running shorty's/megaphones on the street that would effectively provide no muffling. I also considered that the noise would probably not be too bad at idle, and at WOT the noise would be being projected behind me so may not be very loud to my ears. So yes, it is likely that those who hear my bike will know/suspect that exhaust is not normal, but those that just look at it will think it's stock.

I did think it might be worth using perforated tube, and filling the cans with high temp insulation that is used on gas turbines at my work. This should allow me to ditch most of the metal from in the cans (and its weight), but still provide some muffling. After the response here today to my suggestion, I'm thinking a non-muffled Busa is probably going to be too loud for anyone to tolerate on the street (including myself).

I'm intrigued by the double layer mid-pipes. They certainly keep the diameter quite narrow before the muffler. If these were to be modified to remove the inner pipe would the surface temperature get too high? Or would there be other problems I cannot foresee? I'm thinking that straight through mufflers will allow higher velocity, so the heating of the mid pipes will be reduced, and opening them up to the outer skin should allow for better flow. Will be looking forward to hearing if Camel's right boot starts to melt...

[Camel]

I don't think the heat will be too much of a problem. The outer pipe is there for purely aesthetic reasons, nice and shiny and phat! Double-layered bling - just like Harley pipes! The thing is that the Hayabusa mid pipes are high quality stainless steel, not chromed shitmetal. They will work well but will undoubtedly discolour. But I've always liked that blued look. If theres a risk the heat might damage something I'll just put exhaust wrap on it. I like that look too!

Picked up my 2" diameter donut today. I need the donut to ensure I get equal length pipes into the 2" collector and still fit within the tight confines of the catalytic converter shell.



I'll cut segments from the donut and weld them in the desired plane to match up with the stock, gutted, stainless steel mid pipe.

First I need to make a jig to hold the headers in position while I remove the catalytic converters from another set of stock headers I've got stashed away.

Hey Fester, I checked out that website, love the pipes on the Porsche tractor! (Yes, Porsche made tractors once!)

[CaptainRob]

I don't think the heat will be too much of a problem. The outer pipe is there for purely aesthetic reasons, nice and shiny and phat! Double-layered bling - just like Harley pipes! The thing is that the Hayabusa mid pipes are high quality stainless steel, not chromed shitmetal. They will work well but will undoubtedly discolour. But I've always liked that blued look. If theres a risk the heat might damage something I'll just put exhaust wrap on it. I like that look too!

Picked up my 2" diameter donut today. I need the donut to ensure I get equal length pipes into the 2" collector and still fit within the tight confines of the catalytic converter shell.



I'll cut segments from the donut and weld them in the desired plane to match up with the stock, gutted, stainless steel mid pipe.

First I need to make a jig to hold the headers in position while I remove the catalytic converters from another set of stock headers I've got stashed away.

Hey Fester, I checked out that website, love the pipes on the Porsche tractor! (Yes, Porsche made tractors once!)

I liked the porsche tractor exhaust sitting on the granite kitchen bench - obviously an understanding wife!

[storm]

Busa is not loud at all.I run slash cut hot bodies megaphone.compared to Harleys my bike is tame.I have had my friend ride it and listened to it can't hear it coming till about 50 mtrs.
Unbaffled is illegal.hot bodies have a perforated pipe that's the baffle.no issues with cops etc. so a opened up OE exhaust should be quiet relatively speaking.

[Camel]

Okay, started on the header jig tonight. Started with a few chunks of aluminium plate that I'd prepared earlier and attacked them with a 42mm hole saw....



Then drilled.....



Here they are propped in position. I still need to tap them to 8x1.25 so they clamp the pipe and can be secured to the base plate.



I still need to make clamps for each outlet from the cat and clamps to hold the headers firmly in position where they bolt to the head.



The objective is to be able to remove the cat shell without disturbing the mounting positions.

[Fester]

Hi

Ge can still see that there are magicians and thinkers.
What still grown here and get changed and designed for our dear Busa.

I likes it themselves that they want to share with everyone else everything.
This brings us still closer together over the world our group of exceptional machienes.

It's just a shame that so many km or mile between everyone lies.
Had that now it would not be a fun gang.

[Camel]

Hi Fester, I can't say I'm a magician, probably more of an exorcist, trying to exorcise demons from Hayabusas. Spent most of Saturday trying to find out why Crozzer's Busa was running so unbelievably rich. Found a few things that needed fixing but in the end did a full erase of the ECu and reflashed it with a crisp map. That fixed it.

Kept working on the jig, tapped all the holes and bolted them together, they hold the exhaust firmly in position.



While marking up the front jig I discovered that the crosspipe sits at a slight angle. That necessitated some fiddly adjustments while boring the jig.





It all worked in the end. Just need to fabricate the jigs to hold the end of the catalytic converter in place.



Camel

[Fester]

That's why I'll make my exhaust heater this time
Firstly, I wish they did make it myself, but I did not make the tool
Buying one was not in my book and I did my taste
For some but I prefer one in titanium
And as I have written before, I think truly wants a 4-1-2
I know 4-1 is better but I insist 4-1-2
To exhaust my work as much as possible and without any pressure off and not too much to change my view of hayabusa

[pan]

Any updates? I love this thread!

[Camel]

They're coming! Spent the weekend taking the kids to netball games, rebuilding the washing machine, cleaning all the dust out of my overheating computer, burning off scrub, fixing the mower, servicing the family car and redesigning and strengthening my Makita 1214 sliding compund saw so it would cut aluminium without going wobbly on me!

[pan]

Priorities Camel! Sort them out!

[Batfink]

Priorities Camel! Sort them out!

+1

[Rudi Le Roux]

Is there any update Camel?

[Camel]

Yeah, got a heap of stuff to upload, killed my laptop (fitting new keyboard and damaged a ribbon cable made from unobtanium!!!) and had to get a sata docking station to access my Busa files and fix the family hack PC so I could get past the mal/bloat/spyware. Just fixing my Bike Notebook tonight, reinstalling ECU Editor, Woolich Racing software, Suzuki Diagnosis system so I can get some logging in for changes this weekend. Did I mention the work I had to do to my Makita LS1214 sliding compound saw so it can cut thick chunks of alloy without flexing? That took a fair bit of work. Should be able to upload more on the exhaust on Sat'dee. Stay tuned!

[Rudi Le Roux]

Thanks Camel , looking forward to the update!