New Project im doing for my brothers car. Just figured id share it on here.















just started on it today. hope to have it done soon, make a jig and hopefully sell a couple.

 

if you do this will it still have the boxer sound?

 

Make sure you bevel those weld joints. I built a subie manifold, really need to do it while the motor is in the car. Keep us updated

 

weld joints will be beveled. care to explain why you say the engine really needs to be in the car? are there clearance issues you see that i may run into?

 

the boxer sound you speak of comes from the unequal length manifolds, its the exhaust pulses running into each other, so weather or not its equal length or not will dictate if it has that subaru sound

 

from what i can see so far you look like it will clear, the core support is one thing to make sure your collector will clear. another thing is building a good jig to keep the distance of the 2 head flanges perfectly aligned. sense the 2 flanges are spaced so far apart just a little warping and its game over. hope this helps!
here is a quick pic of the one i built. not finished in this pic...

 

awesome work. Thanks for the pic. Was planning on putting a flex joint on each pipe so there would be some "play" between the two head flanges.

 

What diameter pipe is that? 1.5" SCH 10?

 

1.5 sch40 here is the up pipe for it, also sch40. here is a pic of the bevel on the up pipe. big bevel, single pass. really hope this helps you along your manifold journey!

 

i was running all the straight pieces through the lathe and machining about a 30* angle to each end of them. Maybe i need to increase it to about 40* for more of a bevel. its harder to see in the pics than in person.

 

The reason all those bevel in the pics are so big is because its sch40. I use a deeper/smaller bevel on sch10 and weld between 70-85amps, while purging. Then your good to go. Hope this helps.

 

Nice start to your suby! They are a completely different animal compared to inline fours when it comes to accurate fixturing and mass production due to the obvious tolerance stacking that occurs between the bottom two head flanges and the top turbine flange.

I spent a ton of time over a period of about two years ironing out the Full Race suby div up-pipe and lower I designed. We tried just about everything you can do with thick wall, flexes, compensating. My advice to you is to just make sure there aren't any gaps when completing the final welds. Gaps will F*** you on these. Flexes will help but any misalignment will put unwanted stress and might cause flex failures. If possible try to use internally braided flexes, your going to be putting them under extreme heat and pressure, get the strongest possible.

On a side note here is a fully divided race suby setup I just finished.


Notice the step up in secondary tube diameter after the collector, a must have IMO.


Good luck, looking forward to seeing a finished product and if you have any questions just ask

 

Tox what are you using to make your bevels, I was reading and someone mentioned if there not perfect your arc will tend to wander a bit?

OP off to a nice start on your manifold, good job!