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Help! Exhaust Expert Required...

Posted: Wed Jul 27, 2011 7:40 pm
by GregD-UK
Hi all,

OK, done my mille single-sided setup. Got two stubby TwoBrothers M2 Carbon cans on it. Bespoke link y pipe done. Went for a ride, BIG Problem, the heat on the top can is 72 Degrees, bottom can 40 Degrees :smt017

Top can has an extra 3-4 inches extra. See Pic.

http://imageshack.us/photo/my-images/717/shotgun6i.jpg/

Would like to actually speak to someone regarding my issue... Please pm me your number so I can discuss. Before my top can melts!!!

Thanks men.

Posted: Wed Jul 27, 2011 8:02 pm
by Nooj
Best people to talk to would be Two Brothers. Wonder if there's some imbalance in the gas flow caused by the different length link pipes?

Posted: Wed Jul 27, 2011 8:02 pm
by Aladinsaneuk
I suspect that you are effectively putting the whole exhaust through the top pipe - perhaps a split section in the collector to direct the exhaust gasses equally?

Am willing to bet that the force coming from the top pipe is substantially more than from the lower pipe...

Thoughts...

Posted: Wed Jul 27, 2011 8:56 pm
by GregD-UK
Hi all,

Yeap Alad+Nooj, I was thinking of putting a straight piece of stainless sheet through from the base of the v section down towards the collector down the middle of the pipe. Easy enough for my amigo to do :smt002

Cheers men...

Posted: Wed Jul 27, 2011 8:57 pm
by Kwackerz
is the gas recirculating from top pipe into bottom? ive seen that on a hilevel before. the exits off the link pipe direct into the top/bottom pipe, the pulses create vacuum in one can as it passes and one can serves to feed the other. looks impressive...
venturi effect or somesuch..? i'd look to the bespoke pipework..
pics of set up?

**edit. just seen the pic .. yup, the angle is deffo the problem.

Posted: Wed Jul 27, 2011 9:20 pm
by D-Rider
Yes - the line of the pipework to the top pipe is very much in line with the pipework of exit stage of the previous section whereas the pipe to the lower can appears to have quite an angle to the previous stage.

Fluids don't like changing direction unless they have to so the theory that most of the gas will be travelling to the top pipe makes a lot of sense.

Image


.... a bit like the way I believe the balance pipes work that you and I have had added to the mid section - the gas doesn't split to go down them but rushes past the end reducing the pressure within them (Bernoulli) and thus scavenging the other pipe to which the "balance pipe" connects.

Posted: Wed Jul 27, 2011 11:08 pm
by Falcopops
Since those in the know have covered the original question, I'll not offer any uneducated ramblings.

That's a damn fine looking bike you've created.

Are you going to have a hanger for the cans? If not I'd reckon you'll get a break in time at one of the connections or sharp bends just MHO

Hanger...

Posted: Thu Jul 28, 2011 1:10 pm
by GregD-UK
Hi all,

Yes Falcopops, I am measuring this w/end for the hanger. Hopefully, I shall ask (very politely) WilloP if he could fabricate one for me :smt003

So, the solution maybe to split the link-pipe right down to the collector, thus, halving the gases and hopefully "Balance" the exhaust setup :smt017 I need to do this before I go and get the thing refuelled and maybe TB's done...

Posted: Thu Jul 28, 2011 6:57 pm
by Kwackerz
That would seem the plan. As with fluid, rivers, etc consider the flow of the gas, whether it will prefer to push to one side of the pipe as it exits a bend..

have fun. I would.. if it was me.. consider splitting it in the vertical plain and drawing it round to the horizontal plane in the pipe to split to upper and lower exit. The main thing with pipes, from my learnings from Jorge, is that wherever there is a change in direction, there is a loss in power. the tighter the turn the greater the loss. similarly there is a tuned length to a pipe and a can/s set up. The gases need to be able to get out by a certain distance or again too much power is lost. Bore size, length, can length...shape...

Welcome to the dark side. have fun.

Posted: Thu Jul 28, 2011 9:48 pm
by GregD-UK
Hi all,

OK Kwackerz, I was just going to split it from the base of the "Y" to the collector horizontally. But, I would of had to guestimate the split, as it wouldn't be 50/50. The hotter gases would rise to the top of the pipe, maybe 60/40 % in favour of the lower pipe.

But, now I have taken the view that you pointed out by spiralling it to the vertical would make it easier for the gases to be split equally, no need to adjust or make continual adjustments to get it right. My hopefully still friend will have to spiral the split from horizontal to vertical in a short length of 58mm pipe :smt017 This means a copious amount of tea, choccy biscuits and pwetty pweases methinks.

Let you know how I get on....

Posted: Thu Jul 28, 2011 10:32 pm
by Kwackerz
from horizontal to vertical..? i assume youre working from the link pipe towards the collector rather than with the flow of exhaust from the collector to the link pipe....?
Yeah i know what you mean!

:smt005