You dont leave any insides at all, you cut them right back to nothing, which is only achievable when you use bends rather than straight pipe for a collector, I see.

Ok so Tim or anyone who can do it how do you guys get a round pipe to fit a T28 flange, a regular one not a split one?

3" pipe has a smaller circumference than the hole, I use the plate you can see to hold it in the vice and just heat and bash, but this doesnt work on bends at all, so for tight fitting downpipe that are close to the shelf pie cuts are always required unless I fork out 300 for a donut...?

Also When I panel beat the resulting pipe back into a circle so it fit the next piece of a downpipe the flange always bloody warps as shown and I need to face it again.
http://s3.postimg.org/gxgbonkcz/20130504_131336.jpg
http://s3.postimg.org/yyzgmgedv/20130504_134201.jpg
http://s3.postimg.org/4y4thces3/20130504_135154.jpg
http://s3.postimg.org/q6ihyrt8z/20130504_142527.jpg

Dann

For the bell mouth T28 down pipe flange I use the oval to round piece from ATP if there is room which there rarely is but in your picture above it basically is the same as what you are trying to do. For locations that do not have room for that ~2" long piece, I use ATP's tight radius (3" CLR) 3" mandrel bend and heat & hammer. Yeah the section thickness isn't uniform throughout but so what, it is a nice tight bend. And it is quite difficult to get the down pipe pointing where you want it as you are forming the oval with your hammer.

http://absurdflow.com/miata/begirepl...aulBEGIdp1.JPG

http://absurdflow.com/miata/begirepl...aulBEGIdp2.JPG

http://absurdflow.com/miata/acpst2/acpst2build6.jpg

Well I do leave the inside points, I just cut it out. You see, if you leave it in there, you're forced to weld on the inside of the collector to finish them, and of course you have to weld the inside quarters of each pipe inside of the collector, when you join it to the 4 tubes. My method is to cut out the triangles, weld them onto the finished headers, fully, and then weld the collector on the outside. It saves me at least an hour of tedious welding, and makes for a nicer product.

To answer your question about making a pipe fit, I like to do it like this, with an air hammer and map gas:

http://i104.photobucket.com/albums/m...D0DB07EF58.mp4

Can someone show me how to Imbed the video? I can't ever get it..

Here's the flange after I fused the edge around.

Attachment 185480

A pencil torch (like weldcraft WP-26P) is what you need to weld inside the collector. Best purchase ever!

Wouldn't it just be easier to make 4 cuts and do all your welding with ease though?

My flanges look like this.

http://www.streettuned.com.au/images...5ex_flange.jpg

If they were like your id never have asked.

Yours are piss easy where are they from?

Dam I love this thread, wish I had something clever to add :P

Dann

fark... i do that with a 12mm round bar and a hammer and map gas.

I need to get me one of those that was SOOO easy and fast.

Dann

Sorry, what are you specifically refering to here?

Dann

Haven't done much in the last two weeks. Knocked out a reroute spacer yesterday. Need to make the weld-on bung for the sensor.

Attachment 185479

The triangular center pieces from the collector tubes, where they meet and create that long point within any substantial collector. When you weld a whole collector you usually have to get inside of it to finish welding the seams where that point is. It also requires welding the inner portions of the tubing from the header when you attach it, unless you resort to a slip on style collector; a compromise most will make to avoid difficulties. I like to tack those pieces together, and when the whole collector is welded and sanded, I cut it out with a thin cut off wheel.

You can see the collector with the pieces cut off here

Attachment 185478

Now imagine you have this little pyramid now, and you have your headers totally done, with 4 tubes coming down and ending flush. I clamp all the tubes tight together, and weld on the triangle piece, as well as the "inner" tubing welds, right in plain open space. Then once it's totally welded, I place the collector around it and weld it. The advantages are not having to weld on the inside, which will up your quality unless you're a freakin master. Also not having to rely on slip on joints, or being forced to space out your tubes from one another. You can have them all In contact like this, which makes fabrication easy in turn.. As you only grind it flat until its perfectly in line with the end of the tube. Hope that sums it up.

Ohhh niceee!!! Plan on making any more and if so, how much?!?!

Sorry, but you are wrong.

There is pipe leading up to that always and it still scavanges from the upper manifold.

Matt

Sorry, but you are wrong, lol. Scavenging relies on gas velocity. When you pile the exhaust gasses into the turbine housing at sharp angles it loses so much velocity that you lose some of your scavenging. Don't take my word for it, call Burns and ask them to spec you a collector with approach angles that sharp and listen to them laugh at you.


I'm not saying you havn't made power with those, or even that they're not better than some other options, but they're a long way shy of the best possible option.

You aren't getting any scavenging on a turbo car. That's how the turbo works, the pressure in the manifold is greater than the pressure in the downpipe. The turbine ruins any scavenging effect.

Equal length is good because the pulses will arrive simultaneously.

Nitro Dan, and anyone else watching, here is some pictures showing what I was describing

You can see I fully welded this piece before I put the collector on, ie, no internal welding.

Attachment 185470

Attachment 185471

Attachment 185472

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Attachment 185476

Attachment 185477

But you still loose exhaust gas energy in a merge like that, and thats whats important. When you cram them all in like that they loose a lot of velocity which is part of the energy equation, it doesnt have as big of an effect as heat or pressure to turbine energy but its in there.

"loose" != "lose"

Boost I know nothing about headers, but that one is gorgeous. It's sad that its not for a miata engine. I'm hoping V8 in one though?

Nah, not a miata unfortunately.
I'm contemplating a miata with a 1uzfe with itbs, a true 4-2-1 180* header system with an x pipe, and a dry sump so I can cross the tubes under the engine. It would have a glorious sound like that of an f430 or better, with I'm guessing at least 350whp on an un-opened engine. Should be the hell of a car if I ever do it.

Holy crap, that is some gorgeous work on that header. Mad props.

why the merge to a small diameter then the step back up?

To keep high gas velocity at the collector point, this will increase scavinging on the other primaries near the one with the gas flow, past this collector point the larger diameter tubing has lower velocity and back pressure.

Does this count? Not something I've made (yet) but it's a cheap way to spot weld your car.

It does increase velocity as stated, with improved scavenging. the reason why is because the exhaust is only open 1/4th of the time in each cylinder, so you dont need to have such a large tube collecting. theoretically you could get all of the pulses to line right up as they pass through the merge collector, and not loose velocity at all. Velocity is always lost a little though. However, having it taper from 3-4" like that is a performance benifit. Back pressure and exhaust velocity are different, though they can still of course affect each other. Expansion chambers help scavenging, it's the reason why stepped headers make more power. (Increasing diameter)

There is a patent on the design, but there are headers out there with small anti reversion "pots" on each runner. its like a small baffled expansion chamber.

I forget the manufacturer but its a high-end Honda header manufacturer.

Edit: found it... its Hytech.

here is a cross section of the pot (or so I call it)
http://www.hytechexhaust.com/images/...eversion01.jpg

What did you use to form the 3-4" long taper truncated cone?

I have my theories, but I want to ask lol.

I've seen them, or something like them before on a 1 off mercury cougar road race header. And at the same time an article saying that anti-reversion devices on headers were really only a band aid for improper design.

The problem is that exhaust tuning (properly) just means trying and checking based on some other projects and their final outcome.

because the headers are so particular on all motor cars to the use, rpm, setup, etc the proper design will change every time you change something else.

These chambers will help account for small changes in supporting parts without having to redesign and test the header every time you do say a cam or intake manifold swap.

THAT is the reason they band-aid design... not that your header may or may not be completely wrong.

If I recall correctly this design used check balls in the ports.

[IMG]http://i857.photobucket.com/albums/a...ps517d4b7f.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps46425eff.jpg[/IMG]

A good friend of mine who knew Jim Feuling (designed the above engine), and worked as an powertrain engineer for GM in the 1960's -1980's said that anti-reversion cones in the ports are only practical on turbo engines with extremely high exhaust manifold pressures. And that modern turbo designs have higher intake manifold pressure relative to exhaust manifold backpressure during acceleration, thus eliminating the need for an anti reversion device.

In my opinion a stepped diameter junction between the exhaust port and exhaust manifold is a simple solution that offers a good compromise between flow and anti-reversion.

I grabbed a piece of 4" tube, and cut a long pie shaped notch with the cut off wheel. I simply calculated my desired circumference and subtracted it from the existing circumference to find my value. The cut took out roughly 3" of material at the smaller end. I put it in the vice and tacked it together, and got it back round on the anvil with a hammer, as squeezing it in the vice so much does make it an oval. Then I cut the ends so it they were flat (making the taper creates an interesting shape at the ends of the tubes. Then I pass it on the belt sander by eye, and it's good. Surprisingly not hard, took about 30 mins each probably.

Here's a few pics of the header completed

Attachment 185465
Attachment 185466
Attachment 185467
Attachment 185468

And of course the reason I have customers is because I was simply asked to replicate this old mild steel header. He wasn't expecting me to fix the skewed runner angles and build a proper collector.

Attachment 185469

I want to build headers now for my bronco... its the only v8 I have.

Some Miscellaneous Miata work.

My version of Frog Arms
[IMG]http://i857.photobucket.com/albums/a...ps392025a4.jpg[/IMG]

Turbo Manifold for a custom B6 engine build.
[IMG]http://i857.photobucket.com/albums/a...ps575132c9.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps7ab765c9.jpg[/IMG]

Some door bars (not real happy with the design, but it works good)
Attachment 185464

Cage install for CSU Fresno's vehicle development program.
[IMG]http://i857.photobucket.com/albums/a...ps0d2fa4d1.jpg[/IMG]

Car rotisserie.
[IMG]http://i857.photobucket.com/albums/a...ps8b539d0f.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps09c89cba.jpg[/IMG]

Re-enforced PPF.
[IMG]http://i857.photobucket.com/albums/a...s/CIMG4693.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...s/CIMG4692.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...0120137-00.jpg[/IMG]

I've got a few other Miata items under construction...

Some old Porsche projects.

[IMG]http://i857.photobucket.com/albums/a...ps0fb1d36e.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...psbe8615b8.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps5fcf1489.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps0382b6b4.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps8826f095.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps5ed1ad01.jpg[/IMG]

[IMG]http://i857.photobucket.com/albums/a...ps0849f74e.jpg[/IMG]

That Porsche reminds me of Lightyear's CF car.

You're copying and pasting from photobucket, just paste it into the message box, don't press the image button. That'll get rid of the extra [img][/img].

Those who have liked my facebook page would have seen these a few days ago, but I made a 3" inlet pipe and a 2.5" cold pipe for a turbo B16 CRX.

Attachment 185455
Attachment 185456
Attachment 185457
Attachment 185458
Attachment 185459
Attachment 185460


There is not a lot of room in a CRX with a full radiator with electric fan for a full 3" intake, but this setup greatly improved this setup. Prior to my sytem it used 2.5" piping with a section of the stock inlet pipe to the turbo and a 2" cold pipe with a hard transition to 2.5" at the throttle. The customer mentioned that the performance gains were noticable with the butt dyno so that makes it all worthwhile.

Figured I'd take a few shots of this beast with a light polish, ready for racing. Ill post a video of the run once it's tested

Attachment 185426
Attachment 185427
Attachment 185428
Attachment 185429

Dam that is serious. Looking forward to the video.

Beautiful work man

^ that customer actually reported a drop from a consistent 9.18 to a consistent 9.12, from the exhaust upgrade alone. Keep in mind, i was simply asked to replicate that setup, its truly not ideal, not being equal length, or long enough for that matter. Just goes to show what a difference having a proper collector will make.

So much eye candy.

Some of the little things:

had to relocate the wastegate actuator, so i made a new bracket.
http://imageshack.us/a/img842/5701/t...torbracket.jpg

http://imageshack.us/a/img24/8813/turbobracket.jpg

simple manifold reinforcement:
http://imageshack.us/a/img18/1402/si...dreinforce.jpg

What i do all day, everyday:

True duals 2.5" stainless steel 05 Tundra.
http://imageshack.us/a/img38/2265/tundrassexhaust.jpg

Stainless backsplash for a friends kitchen:
http://imageshack.us/a/img153/2941/sskitchen.jpg

Veggie omelet burrito/Taco:
http://imageshack.us/a/img824/623/ve...letburrito.jpg

Unfortunately my work doesn't touch the skill-set I've been seeing on this thread. I'm very jealous.

Heres some mufflers for a ferrari 365 gtb4 daytona. I'll post pictures of the whole system when I have it all completed, quad pipes.

Everything is stainless.

started by forming the end pieces.
Attachment 185392
Attachment 185393

cut and rolled some cans out of 16g, with some extra.
Attachment 185394
Attachment 185395

Beads rolled, holes punched.
Attachment 185396

hand rolled and welded perforated tube.. (this was hardly by choice, i'm on a time restriction here, and couldn't get the material I needed.)
Attachment 185397
Attachment 185398

Mufflers packed with Stainless steel packing
Attachment 185399
Attachment 185400

Tips fabbed up, with flared transitions.
Attachment 185401
Attachment 185402
Attachment 185403

I wanna learn to make mufflers meow.

He pretty much went through the fab part. The ones I made out of aluminum were easy design wise, just take a whole bunch of labor time. Packing is the tricky part, the easy button is to just buy burns packing.

Some equal length headers with stepped primaries for a 95 camaro. Space simply wasn't available down low on the passenger side, so they went up.

Attachment 185370
Attachment 185371
Attachment 185372
Attachment 185373
Attachment 185374

Thought I'd share this too, since sometimes I loose my lighter
http://i104.photobucket.com/albums/m188/zanderguerra/BC54BB52-12CB-4C9A-BEE8-07BFEF57EB7C-286-00000017ADCFE764.mp4

How do you weld regularly and not set that jew fro on fire?

Some pretty sick fabrication going on in this thread. I'm sure I said that already a few times.

Here's a PWC dolly I made before the winter. Quickly disassembles and hangs on the wall.

http://www.absurdflow.com/misc/skidolly1.jpg

http://www.absurdflow.com/misc/skidolly2.jpg

That's why I only use the tig welder. I'm afraid.

Nice work. That looks pro.

It would have been slick to weld some tabs to the bottom frame and the padded cradle and then pivot-bolt the uprights to that, so the whole thing would scissor down flat for storage. Even set the uprights inboard so that when "up" the legs would extend down even with the long lower rails, with a pin to lock them. (Although it would have to be aluminum to lift it all up and hang it though..

Pathetic compared to some of the other stuff in this thread, but I recently repaired a split JR header. Welded around then some reinforcement tabs to hopefully strengthen it up a bit. Here's some free advice: Don't drag your exhaust around a lap of PIR supported by nothing but the header.

Attachment 185366

Welder: $80 reconditioned HF flux-core 110v MIG.

V6 accord for some HELLAFAB!

Pics:
Attachment 185362
Attachment 185363
Attachment 185364
Attachment 185365



Stainless intakes sound so good on Hondas. A LOT nicer than aluminum and its raspiness.

Not as pretty as some of the stuff on here but I'm building a single turbo setup for a 2011 Nissan 370Z

This is the merge and up-pipe. Pretty much done except there's a flex pipe on there now.
http://farm6.staticflickr.com/5458/9...37b5317c_z.jpg
IMAG1074 by Gorillazfan, on Flickr

Here's the down pipe
http://farm4.staticflickr.com/3790/9...47a8c6fa_z.jpg
IMAG1153 by Gorillazfan, on Flickr

Not to shabby for a MIG
http://farm6.staticflickr.com/5333/9...668636d2_z.jpg
IMAG1160 by Gorillazfan, on Flickr

^ I wanna see this project

Its not much at the moment. Ill throw more pictures up then.
Basically its a modified Borg s256, 1000cc ID injectors, tial ewg and bov, all custom piping. Shooting for 450-500 safely on 93. And then 500-550 on e85.

We've gotten some hate for not using the precision 6266 everyone else does but they rate that at like 990hp capable. This Borg, with upgrades, should take us to 600whp and hopefully with e85 and ebc make full torque 1000rpm sooner then any other kit

Attachment 185361

Made an intake for my 12v cummins.

So being a welder by profession does not help when you're shittered drunk...

Whipped up a little cart for the Tig machine today. Used the Miller 211(i love this thing)

But as i said, being drunk does not help anything.

Attachment 185349

Attachment 185350

Clearly it's not done yet. I started hearing gunshots (yes, really) plus it was getting dark.
Going to put a bit of sheet metal down on the bottom, and get some 1/8x(whatever the casters i have is) and make them stick out a little from the frame. After getting getting as far as i did i realized it was a little tippy. That will all be solved after i mount the casters.
Might put a few hangers on the sides for all the different lines and what not.

Will try out the plasma cutter tomorrow to cut the sheet metal. Using that little itty bitty compressor you see next to the Miller. We'll see how it goes...

Pfft. Gunshots... I hear gunfire almost every time I go to my shop. Can't let a little gunfire interrupt your productivity.

My temporary exhaust until I have time to finish the rest of it. It definitely quiets the car down over my open and turned down downpipe :eek: nothing like open exhaust turbo cars spoolin up though...
Attachment 185347
Attachment 185348

Sobered up for a few minutes and finished this.

Gonna get a bottle, then i'll be almost ready to make some exhausts.

Attachment 185343

Used the plasma cutter. It worked great, and my little air compressor believe it or not, was more than enough.
Attachment 185344

Attachment 185345

Attachment 185346