The OFFICIAL VE ALLOYTEC V6 SUPER MASSIVE FUN HAPPY TIME exhaust thread!!!!!!!11!!!!

[itsArthurKomar]

well u cant get bigger extractors for better flow in the 3.0l sidi unless somme one experimented on their own engine and machined it to be wider for better flow if you know what i mean. so unless thats possible without ####ing up the engine to the max, your pretty much limited with a catback which means you are not able to get the most out of your exhaust

imo its a great design!

you want to keep exhaust gases as hot as possible for as long as possible. fancy pipework outside the engine = greater surface area = greater cooling effect. with a single port, all that hot air is concentrated down a single path straight out the rear end. ok, you cant customise the 'extractor' portion because its inbuilt... but it's unlikely they've used an inefficient design in there. most exhausts you buy aftermarket arent specifically tuned to the car you are putting them on anyway (unless you are paying $$$), so all in all the newer 'single port' setup isnt a bad thing and their wouldnt be much improvement (if any) to changing the current setup (other than to make it more efficient at holding the heat in it better/longer).

 

[itsArthurKomar]

Why not ? :S are you 100% sure about it ? Im not saying your wrong, i have no clue but it sounds bit odd to me :S but then again ur the one with the car loll

yeah mat extractors r inside the block, and theres only one pipe coming out at either side

 

[TinSnips]

imo its a great design!

you want to keep exhaust gases as hot as possible for as long as possible. fancy pipework outside the engine = greater surface area = greater cooling effect. with a single port, all that hot air is concentrated down a single path straight out the rear end. ok, you cant customise the 'extractor' portion because its inbuilt... but it's unlikely they've used an inefficient design in there. most exhausts you buy aftermarket arent specifically tuned to the car you are putting them on anyway (unless you are paying $$$), so all in all the newer 'single port' setup isnt a bad thing and their wouldnt be much improvement (if any) to changing the current setup (other than to make it more efficient at holding the heat in it better/longer).

Thought I'd add to this, though more for the sake of conversation. The benefits of a well designed header is more involved than just keeping the gasses hot. They produce a scavenging effect which helps to draw exhaust gasses out of the ports, rather than solely relying on the engine's ability to push them out. So the fact that the 3L has a single port suggests, to me at least, that it may not be making full use of the physics available in clearing exhaust gasses from the motor. Obviously, this is heresay as I certainly haven't studied how they are designed on the sidi, nor am I an expert on fluid dynamics, but aftermarket headers are designed in such away as to take advantage of this scavenging effect. Similar theory to x pipes to draw gasses out of the cats. It increases the velocity that the gasses can travel through the system, therefore making it more efficient. I would have thought that the cooling effect would occur primarily further back in the system, which means it's important to not have a rear section that is too large for your engine's output, though not so small as to cause back pressure.

 

[LachieSV6]

hence why the 2.25" twin cat back is better suited for the SV6 over a 3" exhaust system. Performance wise and sound wise

 

[Jarp]

Similar theory to x pipes to draw gasses out of the cats. It increases the velocity that the gasses can travel through the system, therefore making it more efficient.

Wonder if the 3ltr uses xpipes in the sytem to peform this task already or could be utilised to do so? The next gen turbo 3ltr I think still uses the same manifold arrangement so must be fairly effecient.

 

[astroham]

so ... i have the 3.6 sidi with a 2.25 system ... i was told the 2.5 was too big ... given that yours is a smaller capacity, i would say that 2.25 is probably fine ... or maybe a 2 inch system ... but the 2.25 is probably cheaper and easier ...

 

[James19]

thanks for the help guys

and special thanks for all those pointers BLUES BROTHERS

 

[mwood]

Ve commodore dual exhaust

Hi there i have a 2007 Commodore Omega and I'm looking to put a dual exhaust on it as the stock only has a single. Anybody know where i can get a kit and would there be any really difficult it about it such as components in the undercarriage being in the way.

 

[TinSnips]

all bolts up fine. you'll need a system from an SV6 or up (they'll all fit, so long as you match the body type) and these (part numbers sourced from Holmart, not holden parts)

1) 1 Rubber Exhaust Mounts (22674119) $11.00 each

2) 1 Rear Exhaust bracket. (92066860) $22.00

3) 1 Left Hand heat shield. (92252128) $39.00

4) 1 Diff double exhaust hanger (92066857) $16.00

You'll also need the rear bar insert to allow for the dual exits - around 60 bucks from holden, from memory, assuming you have a sedan.

 

[captaincupcake]

what tinsnips said. although you can just cut the diffuser if you want to cut costs. U can get the ssv system from holmart. Just dont go expecting to get good sound out of a genuine GMH exhaust system.