My manifold so far
 

here is my manifold design so far. wanted to go with somthing a little better than the tipical log style. hope it works out
http://i96.photobucket.com/albums/l1...o/DSCF0369.jpg
http://i96.photobucket.com/albums/l1...o/DSCF0375.jpg

the turbine inlet flange will be between cylinders 1 and 2

looks decent to me, why did you decide to do it this way and not the traditional log style though?

the differences are slight but theoretically it should help the spool rate and give a little more hp. not looking for a big improvment but i know its better

Should look pretty nice when you get done with it, bet that was fun grinding out those angles.

helllll no it wasnt :td:

yeah your b6 will spool alot quicker now that you have all th eexhauste routed back into it :gay:

here is what i have
 

Look at the beautiful welds, they may be ugly, but they will hold. Not bad for my first time welding ever, as sad as that is.

I wish you wouldnt have ground them down, could have given you hints but from the little i see. Higher heat, play with the wire speed and slow down.

You guys using stainless? I was just going to use sch.40 mild steel. Should last a long time,no?

id love some tips loki, i will not grind the next ones down. My main issues was splatter, i need to buy some weld kleen, I am also using flux core only. Im gonna get some argon/co2 some time and do dual shield. The heat seemed fine, was burning through on some of the thinner parts.. my feed may have been a bit high.

200gs, im going all mild steel, the engine flange is a doner from a stock 1.6 manifold, the pipe is sch 40 black pipe, the elbows shown are stainless, but im going to buy some mild steel ones to use insted, i just happen to have those laying around.

I did my whole manifold with flux core, mig i think is easier, but i love the point and click aspect of fluxcore and the ability to weld outside without shields. I used the shit that you dip the tip in to keep spatter down and it works decently well, and harbor fright or farm and fleet

will have to try that, what type of welder do u use, i have a 180amp chicago electric from harbor freight, it was 600 new and i got it for 200 from a guy on craigs list, it was a great deal, had like no time on it, still had the price tag on it!!

thread hijacking at its worse:gay:! never grind welds on manifolds only bad things can happen when you do that. that is the kind of design that i am trying to avoid. here it is half welded, cant weld the rest until i find the location for the inlet flange and cut the hole. should be done in a few days ill update then...

http://i96.photobucket.com/albums/l1...o/DSCF0378.jpg

nice welds, looks good!

do you think runner #2 should have face inwards towards runner #3 and #4 the flow can all meet into the center of the chamber and exit in the middle? As it is, it seems #2 and #1 will be disprutive of each other, plus #2 will flow weird turn.

All you have to do is flip it around correct?

Arent the orifices on the backsides of those runners a little small? Youre going to end up with a ton of turbulence in the 4-3 and 3-2 section because the exhaust gas is going to squeeze down to fit through that small cutout and then expand again in the next section.

Youre going to end up with a restriction outside each cylinder instead of a single restriction at the turbine wheel- so your manifold will end up absorbing a lot of the "work" that should otherwise be driving the turbine- work that will be expressed as heat. And since it wont be even across all the entire head (1-2 cylinders will flow a ton better than the 3-4 IMO) you may end up with different EGT and knock characteristics between the front and back of the head.

The whole point of the non-log manifolds is that the exhaust pulses take an equal amount of time to directly reach the turbine instead of the cylinders dumping their pressure into a communal pool which empties into the turbine- your design doesnt bring the benefits of the equal length design and introduces complications that the internally smooth log design lacks.

Shits looking hot! BTW, nice ITB's in the back.

I was thinking the same thing. Gonna run the ITB's with the turbo? Sweet...

Who's flange?

I'm going to be taking my XS Manifold and attempt something with that.

The flow should already be turbulant I would be surprised if its not. I have given some thought to actually creating the most turbulant flow possible to increase heat transfer through the turbine.

I read somewhere (I think it was autospeed) that the log style design with the center runners coming straight out, actually lessened the impact of the outside cylinders "aimed" at eachother. Making it sound as though log manifolds aren't built like that just because they're easy to build that way.

the holes that i cut out i made sure weret he same width as the tubing so i there is no restrictions, i had ot do some more grinding even after that picture was taken. thx guys. wow i have a hard time believing that using t's for 2 and 3 works better than this, well see.

brainiac as for what you said. the flange ill be between 1 and 2 so all the runners point to the collector

As I watch this thread and continue benchracing in my mind, I have a couple of questions that probably border on threadjackery... unswayed, here they are:
1) How hard is it really to fab an equal length manifold? Seems like you could just make four equal piles of weldels and tack away.
2)Failing a full equal length, what about a dual-Y design?

This sticks in my mind, since the issue with logs, be they cast or tubular, doesn't appear to be pulse related so much as flow related toward the collector. I think this design is a step in the right direction, directing flow toward the turbo, but the constant length of the piping seems to be working against you. Either an equal length or dual-y would give you the option of a real collector.

As someone who's done little more than check the oil (nothing more than that, actually!) how much room is there to get creative on the exhaust side of the engine bay?

by the by, that intake is pretty sexy looking!

Getting creative is kinda tough. If you have AC and PS then dropping the turbo lower gets to be a bitch. A custom mixing manifold is sometimes needed as well for clearance. Here is my old manifold and some other pics to give you an idea.
Attachment 217257
Attachment 217258
Attachment 217259
Attachment 217260


Here is a nice log setup Flipside did.
http://www.flipsidecustoms.com/Galle...nPinaMiata.htm

I am getting closer to fabbing my own manifold and this makes me very excited. :)

I also just rode in my friend's 300hp FM II Miata last night and that about pushed me over the excitment edge.

Thanks for posting Wot. That's sexy work, to be sure... but I gotsta keep my AC and PS, so it looks like a log might be my only route. How bout topmount for an equal length?

Both Top Mounts and Ram-Horn Bottom mounts have been done or could be done.
-Michael-

http://www.y8s.com/gallery/turbo/manifold02

Here is a nice topmount tubular from a forum member.
Thanks y8s

Thats a great mig welder for the money, I have one, it absolutely was the buy of the year when I paid $400 for mine new. It's been as low as $299 on sale (in the 170 amp model) but has been discontinued as a 180 amp. The 180 amp version had adjustments and a spot weld feature not found on the 170 amp version.

Mark

wow a turbo can hang down there :) loving it. ramhorn ftw. equal length is extremely hard to make. btw if you think there easy your not thinking in depth enough :)

yeah, i thought of that after i posted.

one of ETD's early products.
http://etdracing.com/manifold.html

How was it? Were you running their turbo as well?

It's ok. fitment wasn't perfect since they put the WG port on the #4 runner too close to the head. I couldn't mount my wastegate! It also was super warped at the head flange. It's off the car right now so I can deal with that. I got it so long ago that I got it for really cheap. like $400 ceramic coated.

I'm tempted now to make my own though after seeing all these great threads.