Exhaust questions

[vs2nvi]

I am curious, i am considering running Twin Exhausts on the car on each side, like the Sv6's have, and was interested as ive done some research into it. whats the best way to go about this without dropping preformance by removing back presure?? has anyone else done this? any info or advice would be grouse but i really would love to know the best way to go about have twin exhausts on the car for each side

[Z2TT]

Thing you have to consider first, is there room on the other side for the actual pipe to go through?

[vs2nvi]

thats why im asking cause i have seen identical model car running the set up... but then im not sure if the had to do any other modifications to get the pipe though....

[vs2nvi]

this is exactly what i was looking to do http://forums.justcommodores.com.au/...l-exhausts.jpg

[wraith]

No point on a 6. All you will have is an exhaust that's overly loud and with terrible drone. How ever it is possible.

[VT-565]

Pretty sure the fuel tank is offset to the drivers side, may not be enough room.

[HamaTime™]

There are a few people that have done it. But the question is: Why Why Why Why Why?

Will be the worst sound on a V6 - not to mention the 'LOSS' of performance.

[VLC86]

you'd have to get it made to get around the fuel tank and stuff. And drone would be terrible. ]

Just weld twin tips to a pipe and somehow mount it on the opposite side and make it look like the exhaust comes out both sides

[soop]

wtf?
You won't loose performance and it wont drone if you do it right.
Drone comes from poor mufflers and to a lesser extent having either a big single pipe or two pipes running side by side.

The easiest way to do that, is to run the pipes side by side down the normal route, then run the drivers side pipe around the back of the fuel tank. (The back being towards the rear of the car)
It will break the pulse of the exhaust note up a little too.
You won't loose power doing this, you might not gain much, but if you use the right sized pipe (2 1/4 should be heaps) it should go okay.

[VT-565]

I am curious, i am considering running Twin Exhausts on the car on each side, like the Sv6's have, and was interested as ive done some research into it. whats the best way to go about this without dropping preformance by removing back presure?? has anyone else done this? any info or advice would be grouse but i really would love to know the best way to go about have twin exhausts on the car for each side

Just reading this, do you want dual exit exhaust for the look?
What I am getting at is that a standard exhaust can be modified to dual exit.

If you want a dual system for *ahem* performance reasons, then it will be a more costly exercise for you.

[soop]

Dual exit wont effect performance at all, totally an aesthetic deal.

[vs2nvi]

its more for the look and the sound, ive looked into more recieved a quote from a place in vic called glenroy exhaust for 650 supplied all parts and fitted exactly like the picture i posted

is that a decent price?? also if anyone does know of a better exhaust shop (aka bit cheaper) in vic let me know

[ephect]

is that price, supplying 2x cats or just 1? what type of muffler(s)? how many mufflers? just to get an understanding of the price

[HamaTime™]

wtf?
You won't loose performance and it wont drone if you do it right.
Drone comes from poor mufflers and to a lesser extent having either a big single pipe or two pipes running side by side.

The easiest way to do that, is to run the pipes side by side down the normal route, then run the drivers side pipe around the back of the fuel tank. (The back being towards the rear of the car)
It will break the pulse of the exhaust note up a little too.
You won't loose power doing this, you might not gain much, but if you use the right sized pipe (2 1/4 should be heaps) it should go okay.

I fail to see the logic in this.

You Wont Lose power, 2.25" should be fine

2.25" is the stock pipe size, and it has a single pipe. Now split the system so the same volume of exhaust is travelling down two seperate pipes as your suggesting, so basically your running the same volume of exhaust gas down effectively 4.5"s of pipe? Velocity is all but gone? Therefore throttle response and low down accelleration power/response is also gone?

Either I'm missing something completely with my 11.45pm logic, or... :S

I didn't say anything about drone, should be quieter if it's running through twin mufflers. As for sound, I haven't heard a full twin system sound amazing on a stock 'ish' ECOTEC or V6 at all to this time.

[soop]

The standard system is at best 2.25". The bends aren't great.
I work it out like this, 5ltr engine has been proven to benefit from a twin 2.5" exhaust. Which is 1" per litre.

3.8 rounded up to 4ltr split it in half and you've got twin 2". If you're going el-cheapo and run press bends it will squash to about 1.78". SO if you run 2.25" pipe it will squash to about 2". Therefore you're never going to have a pipe that's pathetic. Which is the case with factory exhaust systems. As they're only designed to get the exhaust from point A to point B in the cheapest manner possible.

[ephect]

i dont remember exactly, but its to do with the amount of air it flows. 2x 2.25 doesnt equal 4.5 in flow. a 5lt loves a single 3" or twin 2.5" as these roughly flow the same amount. similar to a single 2.5" or twin 2.25" for a 3.8lt

from memory is something along the lines of fluid dynamics

[vs2nvi]

The guy i got the quote from didnt really elaborate... right now im running straight pipe, my orginal idea was just the same on the other side so i got the loudness/look. but this is why im asking advice as thanks to all the comments im learning it much more so i have basic idea of what im doing. Ill email the glenroy exhaust guy or pop in and ask questions, see what they say and ill let you all know, but yeh i know the tank does leave little room but if its been done before done again :P :P if anyone knows a cheaper place though even if somehow the can replace my centre muffler with one that has 1 = 2 so i can run 2 pipe to the back or some ill be happy :P just want real loud... also one other question ive heard vs v6 commos with exhausts systems the you can hear the engine firing when they change gears etc what exhaust are they running?

[ephect]

here is an absolute cracker of an article to read thru which will give you an advanced knowledge of exhaust systems

Auto Exhaust Science

[vs2nvi]

wow some really good reading there thanks alot champ :-P
As for the 650 to get it done down in glenroy exhaust, its supplied all parts and fitted so id be presuming the cats etc... bah decisions decisions all i know is i want that look and fingers crossed the sound is louder more gruntier then what i already have.

[wortus]

[QUOTE=HamaTime;1700704]I fail to see the logic in this.

You Wont Lose power, 2.25" should be fine

2.25" is the stock pipe size, and it has a single pipe. Now split the system so the same volume of exhaust is travelling down two seperate pipes as your suggesting, so basically your running the same volume of exhaust gas down effectively 4.5"s of pipe? Velocity is all but gone? Therefore throttle response and low down accelleration power/response is also gone?

The cross sectional size of a pipes is not a linear relationship. Area of a circle is proportional to it's radius squared.