exhaust

[iwanajohnson]

has this been tried or is this just a basis off of book knowledge?

[Fast Fred]

fedex sayin, they got ya covered.

[Mark75H]

has this been tried or is this just a basis off of book knowledge?

Are you saying something must be tried to prove that it will not work?

"Book knowledge" is often the result of other's hard work, trial and error.

A motor with the port timing and rpm range you are using - will need a set of pipes that will not fit inside the housing.

You are certainly welcome to build the device you have envisioned and see for yourself ... but if that is your approach ... why are you bothering to ask?

[iwanajohnson]

fedex sayin, they got ya covered.

that's great news to hear. if ya see this today fred gime a call. sam not tryin to dog ya was just askin there, you know more than I do and I don't know much about expansion chambers. sorry that came across wrong. I just still don't understand how a tuner that is just a pipe that flares out at the bottom can help to get your back pressure. that's what I was sayin more than tryin to say ya was wrong there. thanks

[Mark75H]

That is a much more direct question that is a lot easier to answer

The little pipe that flares out at the bottom provides more back pressure than nothing. The flair may help back pressure stay nearly the same over a wide range. Fishing/pleasure motors can't be fully optimized as far as tuners go because the outboard manufacturer has no control over whether the motor will be used on a 200 pound boat or a 2,000 pound boat. The tuner has to be able to flow enough to avoid damaging the motor in either case.

You could probably get a little extra punch with a reduced size tuner, but to optimize it, you'd have to do it yourself

[iwanajohnson]

i get what your sayin about them havin to make a generic tuner. I've got a shorter one made. was just look at a book on expansion chambers and wondered if the pipe in the mid was possible.

[Mark75H]

why would you make the tuner shorter? do you think it is too restrictive?

an internal expansion chamber would be possible, but only if the leg was longer - much longer. Plus the leg would have to be fat enough for three expansion chambers. Back in the days of the Kawasaki triples a lot of 3 into 1 pipes were tried, but none worked as well as 3 separate pipes.

[iwanajohnson]

[QUOTE=Mark75H;33668]why would you make the tuner shorter? do you think it is too restrictive?

i run a jet pump so I need a lot of low end and that's the best way to get it out of those exhaust tuners. this is the style were runnin

[Fast Fred]

thats a screamer pipe. jet pump, purpose specific, 2to 1 gear reduction, pump
stall after 6000 rpms crank speed, more exhaust pressure sooner, need her to get on the powerband rightaway. long pipe hear would be best

[Fast Fred]

did see a header bolted to the bottom of the exhaust adapter, it turned out the back through the back of the mid, and then a bit up with an expando-can on it,
was tall but it worked. looked like a baseball bat .