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Location:
Cabramatta, NSW
Registered:
May 2002
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 Twin vs single system
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Mon, 24 January 2005 11:42
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Hi all,
Just idle time, thinking about getting rid of the fake twin system on the s00b with a real one.
Standard system joins somewhere up in front (I haven't gotten that far underneath the car to see) and then splits again just after the rear diff.
My question is, what are the benefits of going for a twin system on an H6 as opposed to just going a single.
Will having only 3 cylinders on each bank cause too much pulsing? I'd like tuned length headers to remove that ghey boxer burble.
I don't really know much about exhausts so I don't know the effect of having only 3 cylinders in each exhaust system will be like.
The weight of a twin system is a bit of an issue, but I already have a fake one on the car so I don't think weight will be that much more.
Engine is a 3.0L making 180kW & 297Nm if that will help.
I've also posed the question to Brett Middleton of the Middleton Rally Team (MRT):
| From Brett Middleton |
| From Nark |
Hi Brett,
Are the headers tuned length? I really hate the boxer burble, so would like something that'd make the car scream rather than throb.
Are the exhaust kits available for the 3.0L? If so, do you have a dyno graph showing the difference?
What I'd really like is a true twin system rather than the split one that the car came with. Any chance of you creating something like this in the near future?
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Headers are designed for TORQUE.
We do ALSO offer a tuned header, however its performance varies with model.
Yes the 3 litre kit is complete, please call us, data and dyno info postred soon.
A TRUE SPlit system will be worse than the kit we offer.
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Sounds a bit suss to me, especially that last line.
But then again, I don't know much about exhausts.
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Location:
Brisbane
Registered:
February 2003
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Re: Twin vs single system
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Mon, 24 January 2005 12:30
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you might want to search v8 (and ... oh my god... v6 commode) forums to see what they say about split systems.
my (limited) knowledge of this was that without the balance pipe you get serious resonance in both sides of a 'split' system
you'd probably be safer to get decent headers that feed into a decent sized (but not large enough to drone so 3" would be the maximum, maybe even just 2 3/4") single resonator & exhaust. you could take the edge of the bark with twin CATs at the end of both header-collectors.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Twin vs single system
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Mon, 24 January 2005 12:33
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Look for pics of a V8 supercar on its lid 
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Location:
Somewhere on a dirt bowl ...
Registered:
August 2004
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Re: Twin vs single system
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Mon, 24 January 2005 13:07
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| Nark wrote on Mon, 24 January 2005 22:42 |
My question is, what are the benefits of going for a twin system on an H6 as opposed to just going a single.
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V6 and v8 info but i cant see there being anything different on a boxer 6.
In a nut shell more power and torque. But you'll need a crossover or balance pipe of around the same size as the exhaust. (Can go a little smaller for the sake of clearance but not bigger). Located around where the gearbox is.
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Will having only 3 cylinders on each bank cause too much pulsing? I'd like tuned length headers to remove that ghey boxer burble.
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That i wouldn't have a clue of but on an 8 it sounds dead sexy.
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I don't really know much about exhausts so I don't know the effect of having only 3 cylinders in each exhaust system will be like.
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That my friend is a case of trial and error which means $$$$$. But in in a case like this you'll be able to use the front and rear of the standard exhaust.
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The weight of a twin system is a bit of an issue, but I already have a fake one on the car so I don't think weight will be that much more.
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On a 3.0L motor, on average, the ideal pipe size would be around the 2.5in, while with twins its around the 2in size. Its a little more weight but its easier to find the room to fit.
"Headers are designed for TORQUE" - Hummmmm, yes and no. Its more or less an age old fight of torque and horsepower.
"We do ALSO offer a tuned header, however its performance varies with model." - ?????? different factory work maybe? Like cams, intake.
"A TRUE SPlit system will be worse than the kit we offer" - This bit is true, very true. Without the balance pipe you'll wind up losing power and not gaining anything.
One other thing is that when asking for a dyno sheet also ask what else has been done. More so if the gain looks to true to be good.
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Location:
c'town, NSW
Registered:
May 2002
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Re: Twin vs single system
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Mon, 24 January 2005 21:35
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van dorkus, check planetsoarer they go on about crossover pipes a fair bit.
crossover pipe = teh win
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: Twin vs single system
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Tue, 25 January 2005 00:11
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Aiight. Will do more research into crosspipes.
Robbo_RA40, some good stuff at planetsoarer. That V8 Clubsport PDF is quite interesting.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Twin vs single system
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Tue, 25 January 2005 00:48
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How much do you want to spend?
A full twin system, with balance pipe, and custom tuned extractors will cost about $2500, if not more.
Maybe $500 less if you can get the extractors off the shelf.
Not really worth the $$ IMO.
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Location:
sydney,nsw.oz.
Registered:
July 2002
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Re: Twin vs single system
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Tue, 25 January 2005 00:58
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Nark,
Have a look at a Porsche, after all they are a Boxer 6 cylinder.
Whatever Porsche do must be the best !
I think it's quite funny that the new sOObies are only a fake twin system !
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Twin vs single system
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Tue, 25 January 2005 01:08
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| FWDCelica wrote on Tue, 25 January 2005 08:58 |
I think it's quite funny that the new sOObies are only a fake twin system !
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Not really.
I'd say they do it for costs.
Cheaper to run a single cat and resonator than two.
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Location:
sydney,nsw.oz.
Registered:
July 2002
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Re: Twin vs single system
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Tue, 25 January 2005 01:40
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True, it would be cheaper to have 1 cat/resonator.
But it seems to be a trend for Jap cars at the moment to have dual outlets/rear mufflers
(eg. Honda Accord Euro, Mazda 6, Honda S2000)
Does twin mufflers/outlets really improve a the performance ?
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Twin vs single system
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Tue, 25 January 2005 01:42
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It decreases performance slightly.
You are splitting the exhaust flow up after forcing it together.
Not good for flow.
However, it enables you to run 2 2" mufflers, instead of a single 3".
A single 3" will create more drone.
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Location:
Wollongong
Registered:
November 2004
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Re: Twin vs single system
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Tue, 25 January 2005 02:42
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Run the twin system is my advice, but also join it up to equalise it...
A lot of the V6 Commodore guys equalise (Join them up) at the cat...
The headers run off the engine, drop down under the car, and join into the single Cat convertor, from there, the guys will alter them directly after the single cat, and split them again...
Remember this, when you split the system into the 2 pipes, halve the size of the engine to get how much exhaust gas should go through each...
You have a 3Litre, so effectively, each pipe breathing a 1.5L 3 Cylinder engine...
An engine of that size, 2" is at the top of what you want in N/A...
Now I'm assuming your Sooby is turbo, so the 2" pipe will be perfect for it...
Where the pipes are joined though, you will want either 2.5" or 3" (3" if turbo) until it splits again...
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Location:
Wollongong
Registered:
November 2004
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Re: Twin vs single system
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Tue, 25 January 2005 02:44
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| CrUZsida wrote on Tue, 25 January 2005 12:42 |
It decreases performance slightly.
You are splitting the exhaust flow up after forcing it together.
Not good for flow.
However, it enables you to run 2 2" mufflers, instead of a single 3".
A single 3" will create more drone.
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The other problem with splitting the exhaust up, is the heat losses...
In the exhaust you want the gases (And pipe) as hot as possible so they exhaust gas is expelled as quickly and easily as possible...
As you cool the gases, they condense, and slow down, they then create greater back pressure... Of which makes breathing for the engine hard...
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Twin vs single system
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Tue, 25 January 2005 02:49
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| Kyosho wrote on Tue, 25 January 2005 10:42 |
A lot of the V6 Commodore guys equalise (Join them up) at the cat...
The headers run off the engine, drop down under the car, and join into the single Cat convertor, from there, the guys will alter them directly after the single cat, and split them again...
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Why would anyone want to join it up just before the most restrictive part of the exhaust?
Run twin cats, then into a single.
I'd say the commoboys do it because it saves them $250 in not buying another cat converter.
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Location:
Brisbane
Registered:
February 2003
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Re: Twin vs single system
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Tue, 25 January 2005 06:34
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if anyone recalls the pictures of the new v10 BMW engines recently posted, they might remember that they had the CATs right up close to the engine with the O2 sensors just ahead of them - most efficient place for the CATs to work properly, keeps the heat from under the car (read: SA bushfire), leaves firewall between CATs and cabin rather than thin floorpan.
i'd suggest something like that ... 2 x CATs up close-and-personal with the the ends of the collectors - after them, it's all just noise control.
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Location:
Cabramatta, NSW
Registered:
May 2002
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Location:
Wollongong
Registered:
November 2004
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Re: Twin vs single system
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Tue, 25 January 2005 07:19
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| CrUZsida wrote on Tue, 25 January 2005 13:49 |
| Kyosho wrote on Tue, 25 January 2005 10:42 |
A lot of the V6 Commodore guys equalise (Join them up) at the cat...
The headers run off the engine, drop down under the car, and join into the single Cat convertor, from there, the guys will alter them directly after the single cat, and split them again...
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Why would anyone want to join it up just before the most restrictive part of the exhaust?
Run twin cats, then into a single.
I'd say the commoboys do it because it saves them $250 in not buying another cat converter.
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They usually do it that way if they run a cat back exhaust twin system... They will generally keep the standard cat, or get the LS1 cat witht he single exhaust...
Much cheaper...
But yes, generally 2 cats would be better... Big high flowing ones...
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Location:
Somewhere on a dirt bowl ...
Registered:
August 2004
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Re: Twin vs single system
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Tue, 25 January 2005 18:37
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| Kyosho wrote on Tue, 25 January 2005 13:42 |
Run the twin system is my advice, but also join it up to equalise it...
A lot of the V6 Commodore guys equalise (Join them up) at the cat...
The headers run off the engine, drop down under the car, and join into the single Cat convertor, from there, the guys will alter them directly after the single cat, and split them again...
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What your saying is basicly a "X-pipe"
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Where the pipes are joined though, you will want either 2.5" or 3" (3" if turbo) until it splits again...
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I'd try a 2.5" cat a 3" might lose some power.
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I Supported Toymods
Location:
south Melbourne/KL
Registered:
June 2004
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