DIY exhaust project help

[L2VXR]

My very slow going DIY exhaust project has found some space in my schedule and i need some info

i bought some wortec quiet boxes off ebay only to find that they are both the same side (see pic)



but the actual boxes look the same so if i flip one over everything is OK except that the hanger
is now in the wrong location and the bolt face is 180 out of position
this i can fix quite easily with a bit of cutting and welding but i need some mesurements from a proper box
so if any ones got one in there shed/on car could you post up the mesurements A/B/C for the pic below




also I've already made up an X pipe ( 2.5" ) but know nothing about them I've just seen pictures and I made my own interpretation,so do any of you now if this would work OK or have i wasted my time




Project cost so far £16

Thank in advance

Edited by L2VXR on Saturday 21st March 16:00

[stigmundfreud]

good work!

[slackalice]

I hope you don't mind it in english

A = 6 1/4"

B = 3/4"

C = 3 6/16"

These have been taken from a new 10" oval box, B is angled slightly.

Hope this helps, nice work by the way.

[ringram]

Yeah nice welding dude. However why are you not making a 3" exhaust? 2.5" is for low powered cars like supercharged ones etc

My Difilippo is like 2 pipes which curve together to touch and where they touch is sealed with weld and Im guessing open inside the weld. It looks a lot like this one

[L2VXR]

slackalice said:

I hope you don't mind it in english

A = 6 1/4"

B = 3/4"

C = 3 6/16"

These have been taken from a new 10" oval box, B is angled slightly.

Hope this helps, nice work by the way.

Thanks for that

ringram said:

Yeah nice welding dude. However why are you not making a 3" exhaust? 2.5" is for low powered cars like supercharged ones etc

Im not planing any big mods (not till i win the lotto anyway) & the fact i aquired about 30' of 2.5" stainless tube free of charge so i just thought i would use it

ps ; i did the cutting and tacking but not the welding but i know a man who can

Edited by L2VXR on Saturday 21st March 17:45

[J. J.]

Looks good so far, but why do you want centre boxes when most just end up in the shed - or are you going for centre boxes only?

[MyM8V8]

I like the full x-pipe, nice job. That looks like a superb bit of Tig welding there mate.

I was going to make one similar but was too lazy and bought a magnaflow. What a piece of st that was! Needless to say I won't be fitting the abortion. I'll gladly give you £16 for yours though ...

Are those boxes straight-through though or baffled?

[L2VXR]

Im not looking to make it loud im just after a v8 sound put may fit cutouts for fun,

the boxes are straight through

[Drew SS]

are u running cats and just a question how loud would it be if theres was no cats or mufflers...

[L2VXR]

Drew SS said:

are u running cats and just a question how loud would it be if theres was no cats or mufflers...

Yes,car is completly standard im just tinkering with making an exhaust because i have the materials to play with

and VERY LOUD

[MyM8V8]

L2VXR said:

Im not looking to make it loud im just after a v8 sound put may fit cutouts for fun,

the boxes are straight through

Are you from the "Sheeps Head"? If so I'm just down the road from you. I wouldn't mind having a look at the x-pipe.

[stevieturbo]

Very nice work !!! how do you cut the pipes etc ??


There are a variety of X designs....I too an baffled as to what is best.

My friends DF, has 2 90's, back to back, with only an 25mm diam hole joining them. Sots almost like a mini balance pipe, as opposed to a true X.

I made my first X with two 90deg bends, joined with their backs cut open so it effectly became a small chamber.

Some are made like that, some arent.

Here is a stunning project, fitting a BMW M5 V10 into an earlier chassis.
See page 6 for some amazing exhaust work. Im currently trying to make a new X with this in mind, although Ive decided to open it out fully so that overall diameter of the two 3" pipes is maintaned as well as the X junction.

Given the quality of the fabrication work shown here already....I'll keep mine hidden lol.

http://www.cardomain.com/ride/2929437/11

pic of the front section from that build.

[Boosted LS1]

^ That tig welding is really neat.

[L2VXR]

MyM8V8 said:

Are you from the "Sheeps Head"? If so I'm just down the road from you. I wouldn't mind having a look at the x-pipe.

No im not from the dark side,im in the valley road area of loughborough if you know were that is.I've seen your ute parked outside rep air a few times but not stopped as didnt want to disturb you at work

stevieturbo said:

Very nice work !!! how do you cut the pipes etc
I made my first X with two 90deg bends, joined with their backs cut open so it effectly became a small chamber.

Given the quality of the fabrication work shown here already....I'll keep mine hidden lol.

I used the same 2x90deg bends just cut then in a different position if you look at pic 1 you should be able to see what i mean, just cut them with a saw and tacked them back to back with a bit of fitting

don't be ashamed of anything you've made at home I do have a bit of an advantage with some of the kit/people i can lay my hands on

[MyM8V8]

I wondered if there are any boffins who could explain how these things really work. I do get the situation with the H-Pipe and "kiss" pipes. The kiss being a siamese of the dual system, like Richs' DF. From what I've gleaned exposing the two banks negative pulse waves to each other (via the H or kiss) helps with scavinging the opposite banks exhaust ports - obviously without interfering greatly with the mass flow.

A full "X" on the other hand would seem to completeley mix the two systems gas flow completeley, and I am interested in how this would affect the negative pulse waves? I have heard HP gains from using these devices are minimal and they are fitted more so, to help with attenuation when using straight through systems and boxes.

Anyone else for a contribution here?

L2VXR. Yep I know the place very well. Lived here 45 years. Pop in sometime for coffee, if I'm in, and bring your black beauty with you. Must say I've not seen it around but I'll keep my eye out for you.

[Boosted LS1]

^ I think in simplistic terms an X or H pipe allows the exhaust gas to pass down the path of least resistance. In a way this is like increasing the exhaust pipe capacity. The gas is coming down the pipe in lumps the size of a milk bottle every 90 degrees if you get my drift and they start stacking up. Nipping across to a low pressure section in the other pipe must be attractive as a way of getting into atmosphere.

[stevieturbo]

Dont forget....only one cylinder fires at a time. So in theory...an X should allow one cylinder, to exit into the pair of rear sections of exhaust. SO less restrictive.

Sometimes doesnt always seem like it makes sense though...

I think an H is more about pulse tuning or balancing of some description..


In reality, testing is the only real way.

On the flip side....a new development are termination boxes.

http://www.gofastnews.com/board/engine-technology/...

http://www.gofastnews.com/board/technical-question...

Theory in brief....each cylinder opens into such a volume...that effectively there is no restriction, just like open pipes.

Edited by stevieturbo on Monday 23 March 18:13

[Ferb]

stevieturbo said:

Here is a stunning project, fitting a BMW M5 V10 into an earlier chassis.
See page 6 for some amazing exhaust work. Im currently trying to make a new X with this in mind, although Ive decided to open it out fully so that overall diameter of the two 3" pipes is maintaned as well as the X junction.

Given the quality of the fabrication work shown here already....I'll keep mine hidden lol.

www.cardomain.com/ride/2929437/11

As you said, stunning project

[MyM8V8]

stevieturbo said:

Dont forget....only one cylinder fires at a time. So in theory...an X should allow one cylinder, to exit into the pair of rear sections of exhaust. SO less restrictive.

Sometimes doesnt always seem like it makes sense though...

I think an H is more about pulse tuning or balancing of some description..


In reality, testing is the only real way.

On the flip side....a new development are termination boxes.

http://www.gofastnews.com/board/engine-technology/...

http://www.gofastnews.com/board/technical-question...

Theory in brief....each cylinder opens into such a volume...that effectively there is no restriction, just like open pipes.

Edited by stevieturbo on Monday 23 March 18:13

I think I have it?

The full X-pipe becomes the end of the collector, in effect, much like the resonator box in your example above. That is the point at which the negative pulse wave would be produced. If correct, this means that the placement of the x pipe will be critical to the effectiveness of negative wave scavenging?

[Boosted LS1]

^ But I think that once you get to involved with things like scavenging, pressure waves and pulse tuning etc you'll soon realise that a system will always be a compromise so the best you can do is stick to something which seems sensible and practical. So quality, decent flow, decent fit, sound proofing and a reasonable price are the main factors to consider. Do that and you'll probably have something as good as the branded products.