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twin 3 inch to big???? 

 

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 Post subject: twin 3 inch to big????
Posted: Thu Feb 18, 2010 11:03 pm 
Oompa Loompa
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would twin 3 inch be to big an exhaust for a boss with minimal mod ie 4in1 headers, k&n panel, twin air box snorkels???

 

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 Post subject: Re: twin 3 inch to big????
Posted: Thu Feb 18, 2010 11:05 pm 
Getting Side Ways
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hey its a V8, there's no such thing as to loud

 

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 Post subject: Re: twin 3 inch to big????
Posted: Thu Feb 18, 2010 11:08 pm 
Oompa Loompa
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:lol: :lol: :lol: :lol:
thinking more performance wise but thanks anyway

 

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 Post subject: Re: twin 3 inch to big????
Posted: Thu Feb 18, 2010 11:48 pm 
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Yes.
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 Post subject: Re: twin 3 inch to big????
Posted: Fri Feb 19, 2010 11:58 am 
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XR9UTE wrote:
Yes.


I would have thought it would be a little dependent on the muffler types used. If they were straight thru then yeah it's probably a bit too big, but 2.5 probably wouldn't be.

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ToranaGuy

 

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 Post subject: Re: twin 3 inch to big????
Posted: Fri Feb 19, 2010 12:31 pm 
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Twin 3" for a practically stock BOSS is pretty massive lol. Twin 3" on pretty much any stockish V8 is overkill.
If the plans are to keep it as is, twin 2.25s would be more than sufficient with some decent high flowing boxes.
Whats the point in fitting big piping only to have restrictions at the muffler boxes? I'm sure it'd cost more $ as well as costing performance as you're going to lose all exhaust gas velocity in the big piping, then hit a restriction at the mufflers?

 

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 Post subject: Re: twin 3 inch to big????
Posted: Sat Feb 20, 2010 2:24 pm 
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A twin 2.5" is the way to go. The problem with twin 3" is you've actually lost all that velocity(and with it torque) before it gets to the mufflers. The mufflers are a relatively long way back in the system where the gases have cooled and dropped in velocity so, whilst good quality, high flowing mufflers are needed the size of the pipe is actually doing all the damage first. Even the header makers have now started "pinching" the collector to bring the torque back up.
Oh don't bother changing to aftermarket cats just mod the pipe size into your stock cats to suit whatever headers you are using(I'm using the smaller tube difilippo headers with the pinched collector on my Pursuit). Also make sure you have a H-pipe or X-pipe in the system. I haven't seen any real benefit of an X over a H design either so I wouldn't worry about which one you have...usually a H-pipe can be situated closer to the engine which is always a benefit.
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 Post subject: Re: twin 3 inch to big????
Posted: Sun Feb 21, 2010 12:38 pm 
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Just for something to think about. On FF, CAT600 is building a twin turbo FG XR8 that will be pumping out well over 500rwkw and he's using twin 3" exhaust on that. Twin 2 1/2 for nearly stock is more than enough.

 

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 Post subject: Re: twin 3 inch to big????
Posted: Sun Feb 21, 2010 12:41 pm 
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That is of course until the detonation king tunes it :lol:
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 Post subject: Re: twin 3 inch to big????
Posted: Sun Feb 21, 2010 6:37 pm 
Oompa Loompa
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thanks for the replies sounds like twin 2 1/2 is the go

 

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 Post subject: Re: twin 3 inch to big????
Posted: Mon Feb 22, 2010 12:09 am 
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XR9UTE wrote:
A twin 2.5" is the way to go. The problem with twin 3" is you've actually lost all that velocity(and with it torque) before it gets to the mufflers. The mufflers are a relatively long way back in the system where the gases have cooled and dropped in velocity so, whilst good quality, high flowing mufflers are needed the size of the pipe is actually doing all the damage first. Even the header makers have now started "pinching" the collector to bring the torque back up.
Oh don't bother changing to aftermarket cats just mod the pipe size into your stock cats to suit whatever headers you are using(I'm using the smaller tube difilippo headers with the pinched collector on my Pursuit). Also make sure you have a H-pipe or X-pipe in the system. I haven't seen any real benefit of an X over a H design either so I wouldn't worry about which one you have...usually a H-pipe can be situated closer to the engine which is always a benefit.

Twin 3" is different with turbo's...
I have 3" twins also...

 

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 Post subject: Re: twin 3 inch to big????
Posted: Sat Feb 27, 2010 5:07 pm 
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XR9UTE wrote:
That is of course until the detonation king tunes it :lol:


Its not getting tuned in Wangara is it??

 

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 Post subject: Re: twin 3 inch to big????
Posted: Sat Feb 27, 2010 8:40 pm 
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XH5LWEPN wrote:
XR9UTE wrote:
That is of course until the detonation king tunes it :lol:


Its not getting tuned in Wangara is it??


Who knows?
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 Post subject: Re: twin 3 inch to big????
Posted: Sat Feb 27, 2010 8:49 pm 
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the Di Filippo big boy is a twin 3" and the note from that will float ya boat all day long

 

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 Post subject: Re: twin 3 inch to big????
Posted: Sat Feb 27, 2010 9:57 pm 
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Any data on how that twin 3" goes in regards to low to mid torque and HP?
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