Exhaust research - FYI

[boofhead]

I selected max HP at 5500 rpm; So
Header:
Primary tube 1.58 (torque) to 1.75 (hp) [upper revs]
Length: 34 inches maximize torque
Collector: 2.5 - 3 inches that is 20 inches long

System 2.5 (mandrill bent if possible).
H pipe 20.4 inches or X pipe 81.7 inches as measure from primaries go into the collector.

Total length of exhaust from end of primary pipes based on harmonics 20.4, 40.8, 81.7, 163.3 inches.

Obviously the installer will just install it best he can though it is easy to determine the location of the H or X pipe as an example. Also, do not worry that your headers do not match as we need to make stuff fit first.

Hope this was interesting.

[Ausjacko]

Hybrid has sorted the link to the sheet here: http://www.mustangtech.com.au/Downloads ... id=26.html

Available in Downloads under tech stuff.
Cheers
Jacko

[ozbilt]

Hybrid has sorted the link to the sheet here: http://www.mustangtech.com.au/Downloads ... id=26.html

Available in Downloads under tech stuff.
Cheers
Jacko

So it was you that crashed the forum ........

[Astro]

I selected max HP at 5500 rpm; So
Header:
Primary tube 1.58 (torque) to 1.75 (hp) [upper revs]
Length: 34 inches maximize torque
Collector: 2.5 - 3 inches that is 20 inches long

System 2.5 (mandrill bent if possible).
H pipe 20.4 inches or X pipe 81.7 inches as measure from primaries go into the collector.

Total length of exhaust from end of primary pipes based on harmonics 20.4, 40.8, 81.7, 163.3 inches.

Obviously the installer will just install it best he can though it is easy to determine the location of the H or X pipe as an example. Also, do not worry that your headers do not match as we need to make stuff fit first.

Hope this was interesting.

Thanks Boof

Would like to give it a go - will have to ask how receptive

the the exhaust guy is about building someone else's system specs.

Not sure if they put that much thought into it or just weld it in to suit the body.

Cheers

J

[boofhead]

They will likely want to weld it to fit the body. You have the headers already so really the easiest part of the plan is to get them to do is the position of the H or X tube other areas you will likely have little choice.
Other possibilities that can be beneficial is the muffler construction and baffling system. Some designs are more restrictive than others. Lastly I suggest you get them to weld in a AFR sensor bung with a plug in it. Just in case you want to add an AFR meter (help with tuning) and/or have it there just in case you go EFI at some point in the future. Minor job easy to do at the time.

[Ausjacko]

Big Mc, timing is everything they say ;-) As I was reporting the error, Hybrid was trying to fix it. Or I could have that a little out in terms of cause and reporting ...

[boofhead]

Jacko - Good work for adding to the tech library. I own that book (among many) that the article hence formula had come. I liked the way you used formatting to get the pipe size translated. Boof learned something which always lifts my day. I am now using that idea in my own spreadsheets.

[Shaunp]

Love that roush setup

The whole car would be a dream build for me 2nd to a Daytona Coupe ........

A mate of mine from Telstra has built one on a kit from Canada I think, Porche axle of some kind, but he is running and LS3 crate engine it was the easiest way to get it through engineering, think it has a Vette front end

[ozbilt]

Love that roush setup

The whole car would be a dream build for me 2nd to a Daytona Coupe ........

A mate of mine from Telstra has built one on a kit from Canada I think, Porche axle of some kind, but he is running and LS3 crate engine it was the easiest way to get it through engineering, think it has a Vette front end

If I build, it would happen in California where I just make it happen & drive it.

Lots of dreams, however life is reality & a few others have me building their cars (and that will probably never cease ....... )

[Shaunp]

Thought I had a pic of Robs car but cant find it, nice thing though.

[hybrid]

The whole car would be a dream build for me 2nd to a Daytona Coupe ........

A mate of mine from Telstra has built one on a kit from Canada I think, Porche axle of some kind, but he is running and LS3 crate engine it was the easiest way to get it through engineering, think it has a Vette front end

If I build, it would happen in California where I just make it happen & drive it.

Lots of dreams, however life is reality & a few others have me building their cars (and that will probably never cease ....... )

You really need to get yourself that 65 so all the people you have helped can pay it forward. Although you probably wouldn't want us hacks putting our paws on it

[Ausjacko]

Hey Boof, the formula to find the next largest pipe size was a bit of a challenge. I was introduced to CSE (control Shift enter) formulas and arrays; always something to learn in Excel.

[ozbilt]

A mate of mine from Telstra has built one on a kit from Canada I think, Porche axle of some kind, but he is running and LS3 crate engine it was the easiest way to get it through engineering, think it has a Vette front end

If I build, it would happen in California where I just make it happen & drive it.

Lots of dreams, however life is reality & a few others have me building their cars (and that will probably never cease ....... )

You really need to get yourself that 65 so all the people you have helped can pay it forward. Although you probably wouldn't want us hacks putting our paws on it

When & if I do get a 65 over here, it would be great to see a bunch of you pitch in. I would probably enjoy it as much as you all would .......

[cage]

Boof, why do you need the X or H in the pipes? Whats wrong with them being independent of each other?

[boofhead]

The easy answer is you do not need one. It is like wanting a blond with big tits - you do not need one but it sure helps get your motor running.
[Note: Maybe thats just me....]

Basically what is happening is your adding in a balance pipe into the exhaust system. Assume the engine is firing alternative banks all the time (which is not always the case). So you have a situation for a dual exhaust where, without a balance tube, one pipe has pressure in it while the other has none or very little. This is inefficient. So what a balance pipe does is allow the exhaust flow to go down the pipe with the least back pressure. So
1) Lowering the back pressure increases the flow, while
2) the change in pressure is also a point where a further exhaust pull can occur to help remove the exhaust gasses.
Both points helps improve exhaust system efficiency.

There are other side benefits;
1) The exhaust note will be quieter (as both mufflers are working on each ignition event),
2) The sound will be smoother less barky or sharp sounding.

Not necessary but worth the small effort.