SN internal exhaust tube vs. RN exhaust tube.... v.should I change from a SN to a RN

[Kennay]

Well, I am going from the 650 to a 760, and was wondering if the stock 90 squarenose stainless tube would hinder the 760 at all.

Should I go to a roundie since it's a considerable amount larger?

 

[Rickster]

Go with an x-metal side rear exhaust!

:thewave:

 

[2lick]

I would say yes. When I did my square nose again last winter I took out he stock exhaust glasses over tho holes and then put in some 2.5 inch aluminum pipe of my own.. very easy to do pipe was like 8 buxs..... put it in then when it is sticking out of the back run your saw up the back of the ski... nice and flush cut....

 

[Kennay]

Is that what you are running Rick? Ii sort of want something with an external flange so I can rivet it into the hull, and then seal it instead of having to worry about glassing a tube into the hull and it cracking and all that jazz.

 

[2lick]

i know what you mean I had mine cut up at the time so i glued heavily inside of it and out side..... It is really holding strong.. i finished it off with a blowsion bling outlet cover.....

You could always get a stock RN tube and glue it in.... I tried to put one in first but the angle didnt match up and i decided it was cheaper to do my own..

good luck

 

[2lick]

ah ha!!! I found pic of mine.....

http://picasaweb.google.com/addicted2tech/Defoaming

In hind sight i definatly cut the hole bigger than needed... measure twice cut once lol

 

[Matt_E]

I am most likely wrong, but I have a hard time seeing how the smaller Squarenose tube would restrict flow.
It's not like there's a bunch of high pressure flow going on.

 

[Kennay]

I am most likely wrong, but I have a hard time seeing how the smaller Squarenose tube would restrict flow.
It's not like there's a bunch of high pressure flow going on.

I just don't see why Yamaha would have changed it and cost themselves more money if it wasn't something that needed to be addressed.


Nick, that looks pretty good man. I might go that route if I can't find other options that I like. Seems plenty cheap...

 

[Rickster]

Is that what you are running Rick? Ii sort of want something with an external flange so I can rivet it into the hull, and then seal it instead of having to worry about glassing a tube into the hull and it cracking and all that jazz.

YEs, that is whatI am running.

The ski will sit there all day in a tailspin, without any cavitation.

A great mod for those that do not like the noise of a front exhaust.

:beerchug:

 

[Kennay]

How much did that thing run ya if you don't mind me asking?

 

[wydopen]

just run it like it is..

 

[Rickster]

How much did that thing run ya if you don't mind me asking?

It was somwhere around $100-150, but I do not know if he keeps these in stock, as he had to weld one up for me.

 

[Kennay]

Is there a flange on it or did you glass it in? I really don't remember looking at it too well in Daytona...

 

[Kennay]

And actually it really doesn't matter! Yikes....100-150 for a piece of aluminum tubing with one weld LOL! I'm one of them po' folk

 

[kevbo]

The smaller SN tube will have no effect if a tuned pipe is used, neither will the stock waterbox. You will save some weight and keep exhaust out of the pump if you remove that heavy tube and install an elbow in the engine compartment.

 

[njfl]

Go with a 3 or 4 inch thin wall aluminum tube. The thin walled aluminum will be significantly lighter than the stainless and the volume contained in that tube will be less volume filled with your foam. :biggrin:

Seriously though, Think about your b-pipe stinger. I don't have one with me, but I think its even less than 2" diameter, so why do you need 2.5 after it?