more supercharger talk

[truckinwagen]

I am a good enough welder, but I don't have access to a wire feed here, I have a stick welder, and have done lots of exhaust work with it, but the stainless downpipe deserves better than that.

as for the cost of the coupler, the reason they cost so much is because they are so short, less than 4" long.

no one has any locally that fit the bill(are all 6" or longer) and JCW ships very reasonably through USPS.

I am seriously thinking about just replacing the flex sections with solid tubing and making a brace to the block, that would cut costs down quite a bit.

[truckinwagen]

hell, I might get some stainless electrodes and do some test welds on a couple pieces of tubing I have lying around to see how well it works.

I hate to pay other people for things that I can do myself.

[macka]

hell, I might get some stainless electrodes and do some test welds on a couple pieces of tubing I have lying around to see how well it works.

I hate to pay other people for things that I can do myself.

go with the 1/8th rod

[truckinwagen]

why not 3/32?

I usually use 3/32 on mild steel exhaust parts.

[Rabbit on Roids]

the motor mounts will be all but solid when the diesel goes in(hockey pucks) so I am not too worried about it breaking, I might put a support from the back of the block to the downpipe too.

as for the flow, the two 1.5 pipes do not equal a 3" at all, the 2.5" will flow much better than the two 1.5" flexes.

the intercooler pipes on new fords are kinda squished down towards the end, and all the big name performance guys make replacement intercooler pipes for them. and all the ones i have seen, they transition to twin 1.5 inch pipes from the 3" coming from the turbo. it flows better than the oblong 3" 2 smaller pipes flow better than one big one. and thats a great idea on the hockey puck engine mounts. be sure to post up when your car starts rattling its self apart.

[truckinwagen]

two 1.5" pipes will not flow like a 3" one.

the cross section of a 3" pipe is much bigger than two 1.5" pipes.

the two 1.5" pipes will fit inside a 3" one with lots of room around them(get a piece of paper and a compass and try it)

the two separate pipes have much more wall area compared to cross sectional area than a single larger one, this adds friction to the moving air, impeding flow.

(all those classes in fluid and thermodynamics of ducting systems were not for nothing!)

not to be a jerk, but the truth is the truth.
-Owen

[Turbinepowered]

as for the flow, the two 1.5 pipes do not equal a 3" at all, the 2.5" will flow much better than the two 1.5" flexes.

By the math.

The cross-sectional area of a pair of 1.5" diameter pipes is approximately 3.53 square inches.

This is roughly equal to a 2.125" diameter single pipe (3.55 square inches).

By contrast, a single 3" pipe has a cross-sectional area of nearly 7.1 square inches. 

[gldgti]

I am seriously thinking about just replacing the flex sections with solid tubing and making a brace to the block, that would cut costs down quite a bit.

now theres a good idea :-) better flow and longevity (since flexes will inevitably break, they must - the laws of physics ensure that). if you make it solid and brace it from the 90deg bend to the rear gearbox mount (simlar to an n/a downpipe brace) you'll have a win.

[Rabbit on Roids]

ok, ok, i believe you. and its your build. so i cant make you do something.

[lord_verminaard]

That's a ripoff, I went to the local exhaust fabber and bought a 2.25" ID 8" long braided flex coupler for 25 bucks, no shipping and that's usually the killer. Look around and see if a local shop has one .

Here's my piece welded in to the DP,

I'd be mad if I paid to have something welded and it looked like that....

Brendan

[Rabbit on Roids]

if it were someone that didnt know jack *** about welding and didnt charge anything, i wouldnt be mad, but to pay a professional to do work like that, i would throw it through his front window.

[truckinwagen]

I think he welded it himself, as he was saying that with a wire feed exhaust is not a big problem to weld.

I am thinking about getting the right electrodes and sticking the downpipe(after some practice passes of course)

[rabbitman]

That's a ripoff, I went to the local exhaust fabber and bought a 2.25" ID 8" long braided flex coupler for 25 bucks, no shipping and that's usually the killer. Look around and see if a local shop has one .

Here's my piece welded in to the DP,

I'd be mad if I paid to have something welded and it looked like that....

Brendan

My feelings are so hurt (jk). yeah I welded it myself, I'm not an expert but I can make stuff stick together......all the the little welds are 'cause I had to tweek it little by little to make it miss the body. So I'd cut it halfway through and bend the crack shut and weld it ...........it works

PS. That stupid neckdown at the end was to hook it up to the stock exhaust, since then I've necked it up to 2.5

[truckinwagen]

no, that actually looks pretty good.

as I said I use stick for everything, so my exhaust parts(being such thin pieces) tend to look like ass, but perform great.

it is settled, I am making it solid.
all I need to do now is find some 2" stainless tubing and a 2.5" flex coupler.

[lord_verminaard]

Eh, sorry.     I don't know anything about stick welding so I can't comment.

This was my first attempt at a downpipe.  My first real attempt at welding anything really:



I just finished the rest of the exhaust yesterday.  Pretty excited.

Was that TT downpipe you got for a Mk1 or Mk2?  I'm pretty sure I have one leftover from my Scirocco, I don't think it has any flex sections on it, just a ball-cup style flange at the end.  The one you have sorta looks like an oem dual-downpipe, but I could be wrong.

Brendan