V4 Exhaust layout...

HONDA has not always had dynos, computers, and physics wizards.
The physics may be of little help anyway.

What works is trying different combos and riding the motorcycle.
When honda started out there were no computers or programs developed yet.
They still managed to win races.

There is no motorcycle exhaust system longer than the motorcycle.
Almost every muffler you put on a motorcycle can limit its power.
The exhaust is made of metal tubing. It is not that mysterious.
It is a tube and has smooth bends and there is some back pressure.
How much back pressure has a lot to do with the intake box.
It is not that mysterious.

A good builder, and good rider can come up with a system that will win a race.

Even fuel dragsers have very short exhausts and that has not changed since I was 16 - despite all the computers ,dynos, programs, drivers,and physics wizards.

I even know a physics wizard that help design a reactor, and I had to help him put his VW bug engine together or it would never have gotten on the road. The physics wizard would just theorize about it all the time.
Luckily he is in a PH.D program now.

 

What kind of bender?
Can it bend .065 wall stainless tube?
You would need a real mandrell bender and someone who knows how to operate it.

 

Honda 2RC143 1961.
Nothing fancy here.
No computers no programs for designing exhuasts.
They did have a dyno though.
But it was a mechanical dyno - not like the ones we have now.

 

You mean with a TUBE bender. They do not make exhaust systems with PIPE.

 

"Anyone know what models had those Honda 90 degree V4s "
Honda 750's (edit mistake - previously said 954) designed to compete with the Harley-Davidson XR750 on the one mile dirt oval.
The XR750 was legendary.
Go to http://pwheelie.blogspot.com/2009_01_01_archive.html
Scroll down to the 13 th photo. IT was a v twin made from a CX650.
Honda hired Freddie Spencer to ride it.

Still could not beat the H-D XR750 below.


HONDA did make 15 of these 750 v twins though.

Wish they would sell them to the public.
http://www.cmsnl.com/news/freddie-s...750d-racer-at-stafford-in-the-uk_news614.html

 

Duly noted. Tube bender it is.

 

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Not sure I'm following this. My question is regarding the crank design. The VF series has a 360 degree crank and the VFR (IIRC) has a 180 degree crank.

My question has to do the both the crank and firing order as this has an effect on the design of the exhaust system.

Thx!

 

To clarify the stock system for the VF series is 4-1-2.

Post #16, in this thread, shows detail cutaway photos of the stock collector box.

 

I hope I was not too hard on you invisible cities. Sorry.

 

I like that description invisible cities! Absolutely right.

 

AND...The vf1100 even had a different firing order that the VF1000R's.

 

Have you noticed the new Aprilla v4 has equal length headers?
The collector box is directly under the engine so the 4 headers CAN be equal length.

 

Good intel thanks. I don't have the specific specs for the kR or the other larger VFs, I have only confirmed the VF500F which has a 360 crank and a 1-4-3-2 firing order. From what I have read paring the 1|3 and 2|4 cylinders is the first step. From there it gets a bit fuzzy as to whether a 4-2-1 or 4-2 (AKA two 2-1s) is the best setup. The 4-4 as you note is also an option though on a VF500F this would be tough to pull off aesthetically.

On a side note, I did find this handy chart describing our beloved VFs as 'droners':

 

Interesting data invisible cities.
Below is a photo of the Aprilla RSV4 exhaust system which does have equal length headers. I sure would like to know what diameter those tubes are where the 2 dumps into one.

It is a 65º v 4. Do not know the firing order.
Cannot find the firing oder anywhere on the net. (just says computer controlled)
I guess you have to buy the shop manual?
But notice those 4 torque cones? (next to the exhaust flanges)
Are they torque cones?

 

Here is another interesting design: photos taken of a custom RC45 exhaust system (the RC45 sharing the same 360 degree crank and 90-270-90-270 ignition timing sequence as the VF).

(source:BusyLittleShop, VFRD)






These show some mad skills on a tube bender ;-)

 

Computer controlled tubing bender?

 

Aprilla has built a V-4 the way honda should have.

 

M

IC what is the rear cowl on that 500.

 

It is very nice looking, I agree. Captain 80s will need to provide the answer!

 

I was checking exhaust systems in uk ebay. I found this page. It might be of assistance to you or others. If you scroll down they have some vfr systems. I have had parts sent from Australia and UK to California. I think pounds to dollars is about 20 percent more....something like that.

regards,

Karl

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