Hi Guys,

I'm thinking of building stainless steel headers for my 1000F H and wondered if anyone has built a system with two separate exhaust like two into one each side. I like having the two mufflers but can't see why they can't be independent. Any feedback would be much appreciated.
Cheers,
Robbie

 

Robbie, these bikes were the fastest production bike before they were knocked off the perch by the blackbird.
To achieve this, Honda fitted them with the best exhaust system. Personally, I wouldn't mess with it.
Also the CV carbs are finicky when it comes to intake and modifying back pressures with the exhaust system.
Every time someone gets in here in the forum and wants to know how to make theses bikes faster I have to ask a question.
These bikes top out at 176mph, where are you riding where you need to go faster?

 

Thanks for the reply TimBucTwo,
I'm not trying to make it faster, I'm just interested in making exhaust headers that are easier to make and the back pressure should still be the same from what I can see.
Cheers,
Robbie

 

Leaving stock would be an option if parts were available, I think original mufflers are getting hard to source nowadays. Another reason to keep stock is the fact stock bikes seem to run more smoothly, I had to get a set of Vibranator bar weights to help to keep the buzzing down. I do however like the sound of my Remus pipe more than the standard job.

 

I don't rightly remember but going to the stick coil mod, there's a wasted spark set-up here with #'s 1-4, and 2-3 wired together. I don't know for sure but that may have some bearing on how you plumb your system to maintain proper back pressure and scavenging.

Don't quote me on any of this, but in my mind, it is a matter for consideration.

Somebody here can clarify it better

 

Thanks for that Wooferdog. The standard system goes 2 into 1 then those 2 go into a junction box then split back to 2 again, so the back pressure would normally happen where to 2 go into 1 wouldn't it?

 

Stock? 4-1-2

4, is near equal length headers 1, is the collector that uses all of the benefits of the exhaust gasses to benefit intake pressure. 4 into 1 before the 2,. The inner volume of the collector would be key here..

Going 2-1, twice.. If you approximate the volume of the stock collector by halving it and building a 2-1 collectors by increasing their length, you might be able to simulate stock, pressures and/or better performance?

So you can have Cyl's 1-4 running each header pipe into a chamber that is half the volume of the stock collector and do the same with 2-3

Might really just comedown to which side you wanna' them to blow out of

 

The headers go 2 into1 then 2 into 4 then 4 into 2, there are only two pipes going into the chamber. 1 and 2, 3 and 4 are 2 into 1 well before the chamber. On the H-J 1987 not sure about the others years.

 

One of the biggest things to consider is firing order and the timing of when a high pressure enters a collection point in a system. If the timing is off, you will loose HP. When things are working properly with correct timing, the low pressure behind the high pressure helps draw the next high pressure coming down the pipe. This is how tuned headers work. When done wrong, its like stuffing a potato in the pipe, highs collided and cause a blockage.