Converted Rc45 Exhaust On Vfr825

Anyone that has been following the post about over boring a Gen 5 over at http://www.vfrdiscus...red-a-56th-gen/  will know that my current project has been to build a new 4 into 2 into 1 exhaust for the 825 motor.

I took a semi easy way out to attain this by buying a set of pipes from an RC45 and modifying them to suit the Gen 5 engine in the Gen 6 frame.

I was going to TIG the pipes up but my TIG skills after 30 years are nowhere near good enough these days and my hands are not a steady as they used to be so MIG is the direction I ended up going with.  Not as neat but most effective.

The original pipes were left exit with a twin CF muffler setup and I needed to convert this to right exit and also to maintain my centre stand.

Added to this I wanted to split the mapping in my RapidBike Racing across 2 maps, one for the front and one for the rear cylinders, each with a wideband O2 sensor.

This gave me the option to use unequal length pipes to fatten up the mid-range a little and to allow me to keep the centre stand.  This means that the rear pipes have to sweep forward and around the front of the stand pivot.

So what I've done is balanced the primary and secondary total lengths by having shorter primaries and a longer secondary on the rear compared to the front.

Here are some photos of progress so far.

The pipes are complete and ready to be cleaned up and bead blasted.

[image: 57.JPG]

The original RC45 pipes

[image: 20150523_123441.jpg]

Lefthand side with front O2 sensor

[image: 20150523_123455.jpg]

Rear exit for mid pipe

[image: 20150523_123503.jpg]

Centre stand buffer bracket

[image: 20150523_123528.jpg]

Righthand side with rear O2 sensor

[image: 20150523_123708.jpg]

Tri-Clamp joint between front and rear pipes

[image: 20150523_123925.jpg]

Right view with centre stand down

I'm going to electro-clean them up with phosphoric acid and then get them bead blasted.

Once that is done, It will be time to fit to the hike and work out what I need to do with the bottom radiator hose as it cannot run behind these pipes.

I'll keep everyone posted.

Cheers

Phil

:lurk:

Strong work, I haven't checked the other thread in a while but this is good reminder

You realize that making semi-custom headers for 5th/6th gens could be a nice little business :)

You Sir, are an inspiration! 

Nice work!!

Jim V

Sorry but making custom pipes is not a goer!

No one could afford the cost of single one off's

I've spent a lot of hours doing what I outline above and if I was to cost it out I'd say it would be like 4K.

There is over $500 USD worth of mandel bends and other bits in there as well.

Time on my own projects doesn't count, but if you are doing it for others it does.

Hence why we need a company the does this for a living, and has the equipment, to come to the party.

Cheers

Phil

Well I've been fitting the modified RC45 exhaust to the bike today and have discovered that there is a slight difference in the exhaust port layout between Gen6 and Gen5 heads, at least wit the rear head.

This has meant cutting and redoing the rear pipes and it has moved the rear collector back making my mid pipe not fit.

Probably got something to do with the 16mm height difference between the 2 model heads.

With normal headers you probably don't see that much of a problem, but with the stub system that I'm using, everything has to line up exactly.

Last job to do is make a new final bend from the last collector to the mid pipe and remake the centre stand stop bracket etc.

Kind of a bit of a bummer after all the work I did on the spare motor and jigging it all up.

But nearly there.

Once the final bend is complete, I then need to work out the bottom radiator hose routing in front of the headers instead of behind.

Made a nice little heat shield for the rear master cylinder out of carbon fibre sheet as the original was not going to go anywhere near fitting.

Turned out great and will do the job protecting the MC and lines.

I'll take some shots tomorrow with everything buttoned up and post.

You Sir, are an inspiration.

Got everything finished and the radiator hose sorted.

Fired it up and I have a small leak in one of the rear headers so still a bit of work to be done.

Lucky the weather forecast is crap for the rest of the week.  Just need to get a leave pass from the wife!

Here are some shots of the completed job.

[image: 20150601_184134.jpg]

[image: 20150601_184145.jpg]

[image: 20150601_184213.jpg]

[image: 20150601_184237.jpg]

[image: 20150601_184253.jpg]

[image: 20150601_184314.jpg]

[image: 20150601_184334.jpg]

[image: 20150601_184349.jpg]

Sweet Phil, nice job. I see the rad hoses missed the pipes on the other side, so no real drama. I will be really interested to see how this performs, with the big bores greater compression & shorter primaries, combined with the 6th gen injectors it should really rev & make good power. The big bore should alleviate the issues with the 45's pipes on standard engines.  Get the fueling sorted & let us hear it. very impressive work.

I'd bend that center stand stop up a bit or trim the rubber buffer.  other than that looks great.

Keep up the good work.

just wow...