Telescoping pipe over header

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Wayne,

If I was you I would do just the opposite.

Make the pipe fit the same size as the exhaust port of the case.

Enjoy Testing,

Mark Sholund
 
Mark is right > on 1 of my .21 riggers I noticed the pipe I expanded to slip over the header did not proform near as good as the one the same size as the header , Both Pipes are the Same pipe and length ............
 
So if my pipe fits over the header without any mods, is the header I am using too small? My pipe is the CMB AB 67
 
I always telescope if possible esp on a scale boat.So much heat kills couplers,ive not burned a scale coupler in years
 
Wayne,

You need to make a smaller inlet section for that pipe.

You will see the difference if you test them back to back.

It is all about pressure wave travel without restriction back to the motor.

Just like the conical header thread.

Keep On Testing,

Mark Sholund
 
Interesting, because my stock CMB 67 pipe telescopes over my stock CMB 67 header..... Have noticed the same with some of my Novarossi pipes and headers too. With that being said, I completely understand what Mark is saying.
 
Wayne, Have you tried what you have yet? I do not think it was a accident that the AB pipes telescope over the AB headers.The headers were pretty thin .025" or .63MM on a side. Butting the pipe and header together provides more problems. no ease of adjustment and normal use will cause nice sharp burrs on the rear of the coupler and front of the pipe- and blown couplers. I'm with Mikey on this one.
 
I have only run mine telescoped at this stage, boat goes pretty well set up this way, just thought I would see if it could go better
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Interesting thread Wayne ,I wonder the same..

Mark my bouchie pipe is slipped over my 22mm header about 1" ,,and I have a 13cc macs pipe which also slips over the header.. I guess I could run the pipes direct to the exhaust port and lose the header .what would you suggest?

David
 
David,

That is the way Scott designs his pipes to be run that way, no header.

If you don't think this is important just keep doing what you have always

done. Knowledge is power remember that?

Just Trying To Help,

Mark Sholund
 
I think this issue is quite simple!! As long as you keep the header portion of your pipe out of the Convex area of the tuned pipe your okay. As soon as your header gets into the Convex area of the pipe you will interfere with the returning waves and performance will be reduced. I tried it with a VAC 45 Nitro pipe and the differance was signifacant. Tim
 
I have only run mine telescoped at this stage, boat goes pretty well set up this way, just thought I would see if it could go better
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hi mate

ive ran the ab pipe on my twin butted up to the header and it doesnt take long for the 2 ends to burr over with all the vibes, now im running the new macs pipes telescopic over the header with the id of the header slightly chambered, tbo i did notice a change for the better when i telescopic the ab pipes over new headers before i went to macs 13cc
 
oh 4 the love of......

telescoping is better,thats y all the new stuff is like that.if u preffer blowing couplers and loosing half your speed after 2 laps then yes butt the 2,also destroy your pipe and send molten metal into the exhaust,radio interference , o n did i say blown couplers?

watched a guy run yesterday (he REALLY wanted to test some ops bi-metals) and watched him go thru 3 couplers in 2hours n half of that was fixin stuff.....like the blown couplers lol every time having to clean up the inlet of the pipe. also the radio glitched a little

tho the problem is when u want to try diff pipes by diff manufacturers

and yes dremel the end of the header as thin as resonable, and try to give it a taper. some come tapered
 
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What if you cut the header so that it stops at the start of the frist cone? Also put a taper on the end of the header.
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