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PostPosted: Fri Oct 29, 2010 6:22 am 
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1275cc
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Location: Plumpton, NSW
DTrain wrote:
how does having having two restrictions equate to having more power than one?


Maybe it hasn't got the power to cope with a fully sik 4"cannon straight through, and likes a bit of back pressure?

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PostPosted: Fri Oct 29, 2010 8:57 am 
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1360cc
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Location: Special Tuning Sydney
mattsmadmini wrote:
now the next part... do i weld the bottom of the manifold to the connecting middle pipe or clamp the beh-jesus out of it?


Clamp and use exhaust manifold sealant, and shed loads of it. If you weld it it will never come off ever again! I welded my Y piece to the 2" exhaust pipe section though cause it hangs way too low to have a clamp.

My preference is to have a 2 box because it's just excessively loud with single box.

As for performance, there's no difference at all since the hot dog that goes before the muffler is a straight through type, 2" all the way through. Can't see how this would hinder gas flow... Important to look at the mufflers you are buying carefully

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PostPosted: Fri Oct 29, 2010 8:49 pm 
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Location: Bald Hills, Brisbane
1310/71 wrote:
DTrain wrote:
how does having having two restrictions equate to having more power than one?


Maybe it hasn't got the power to cope with a fully sik 4"cannon straight through, and likes a bit of back pressure?


pipe size remaining constant so same amount of back pressure. i understand the difference would be miniscule but i dont understand how you can gain power


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PostPosted: Fri Oct 29, 2010 8:55 pm 
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Location: Under the bonnet son!
I've never had a twin box RC40 you know, but I wouldn't mind giving it a try...

Can you buy the RC40s center box seperate to the full systems?
Are they made such that if you cut a sufficient gap in the pipe, that the center boxes just slip on?

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Last edited by Mick on Fri Oct 29, 2010 9:52 pm, edited 1 time in total.

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PostPosted: Fri Oct 29, 2010 9:43 pm 
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OK, Me blonde. Is there more grunt with one or two RC 40's?

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PostPosted: Fri Oct 29, 2010 10:09 pm 
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Location: Brisbane northside
When my RC40 died I got the local exhaust shop to put a larger and baffled aftermarket muffler in. It made it quieter and the wife is much happier about the noise. Cost $120 fitted. Good value methinks.

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PostPosted: Sat Oct 30, 2010 8:56 pm 
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It is well documented in the UK the twins give you better power than the single. I have the Calver report here somewhere.

Don't know how, it just does(and is quieter too!) :D

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PostPosted: Sat Oct 30, 2010 8:59 pm 
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Location: Canberra ACT
"How loud is loud?...." single box RC40 is illegal in the ACT - as one of our club members found out.

Can you buy the pieces separately?? Yes, at Minispares - especially when you ask for a hacksaw to separate the twin box unit they'e trying to sell you.

Cheers, Ian


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PostPosted: Sat Oct 30, 2010 9:05 pm 
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Single box RC40 is only about as loud as the original Cooper S was. :wink:

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PostPosted: Sun Oct 31, 2010 7:33 am 
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1071 wrote:
"How loud is loud?...." single box RC40 is illegal in the ACT - as one of our club members found out.

Cheers, Ian


How loud it is depends on a few other factors - especially engine spec - apart from the muffler.

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