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Well i had a spare EA82T up-pipe in the shed and i remembered how horrible the last one i dissected was.
(This was my last attempt at modifying it for a TF035 turbo)


So im gonna make up a jig and make a couple of headers from scratch, with the intention of selling one (and the one i made last year)

My design will be 1.75" pipe, with all mandrel bends, will have a smooth flowing collector and will have 4 hole mounting flanges for the heads


Here are some pics of the factory one.

Taking off the first piece of heat wrap.


With all the heat wrap off.


The factory "T" intersection


The passenger side bend

Gannon I've just been thinking about the header issue but have not got around to cutting a std one up to see how bad they really are .
You may be able to tell me what the pipe diameters are , that bare one of yours looks reasonably big where it runs around the front but rather spindly where the short sectons exit the heads .
People say that there is small diameter tubes inside the things but I'm not sure if they're only inside the head flanges and turbo one .

I was thinking along the lines of a WRX crossover pipe with the bellows in the middle and getting similar sections fabbed up as what EJ turbo engines have as cast sections - to suit the siamesed EA82 exhaust ports .
It may also be possible to use a modified WRX up pipe , do they generally also have a bellows section under their insulation ?

Cheers A .

i looked at the wrx up pipe, got my hands on one but didnt look like it would suit. tough heat shields and also watch out coz the bug eye ones have a cat in em. failed idea for me.

the naked up pipe reminds me of those hairless cats when compared to a real cat !!

That big section is supposedly a heatshield, but it facinates me how they bent one tube inside the other. Maybe it is hollow, what would be the reason for this?

The first one i build will probably be crush bends, cos buying mandrel bends is bloody expensive, (at $25 each and i will probably need 8 of them, thats $200 straight up)

From memory the inner ones have seams so may have been inserted before they were welded to the crossover section .
I could be wrong but the std down pipe may have had them too and I think I remember AJ asking me if they rattled when the engine was running because I think they did when the DP was out .

He told me that Subaru are smart the way they made exhausts with things like how and where hangers are welded towards the front .
Its normal to want to keep as much of the heat energy in the exhaust as possible particularly if the thermally driven gasses are driving a turbocharger .
If the gas cools it contracts and loses some of its velocity and ability to keep the cat up to temp .

The reason I like the WRX crossover and up pipes is the bellows sections , they make for a bit of "give" in the system to help prevent cracking with heating and cooling cycles . The WRX crossover also has its own insulation so you wouldn't have to make anything if it could be made to work .
I don't know its pipe size but you'd think it would be a bit larger than the EA82equivalent being from a larger higher output engine .
I'll have to cut one up eventually but does anyone know the ID of the EA82 header crossover pipe ?

As to those inner tube sections , again don't know but it may have had something to do with keeping the bends/junctions supported and the heat inside the pipework .

I think overall if the pipe sizes were made adequate and that hateful three way junction under the offside head made into a more pronounced "Y" shape (as in the engine pipes directing their gasses towards the up pipe) it would function acceptably .
To try to prevent expansion and contraction breaking the thing "soft spots" like the bellows's are probably needed in the crossover and up pipe sections .
Insulation is going to be important to keep the heat in the exhaust gas and protect everything near the header .

A nicety would be having a removable (flange jointed) up pipe like WRX's have so you could play with turbo mounting flanges without removing the whole header pipe .

Just my thoughts , cheers A .

See my post -> showthread.php?t=3644&page=13

No one wanted to part with cash.......

I vaguely remember the thread but don't recall there being a price mentioned . If you want to PM me one I'm interested and can keep a lid on it if required .

Yes I like that design , was it the one you mentioned in your cars specs with 2.25 engine pipes and 2.5 up pipe ?
Also would you think there'd be cracking issues as it expanded and contracted over time ?

Thanks Extreme RX , cheers A .

Wow that pipe looks sweet Justin. Its somewhat how i imagine my design to be like.

Believe me, if i didnt have the facilities to build my own, id buy yours.

Can i have your opinions.... will it be worth my while to go with mandrel bends, or are crush bends gonna be good enough?

The Price was around $600 + P&H

The main Pipe Size is 1.75" merging to a 2" collector at the base of the turbo.
I ran a 3" bell mouth dump pipe on my wagon with the rest of the system being 2.5"
With this 'up pipe' the motor would pull about 5 to 6PSI @ 1400 Rpm.
I was running a Haltech F3 EMS & the car achieved 128.2Kw @ all 4 wheels on 10PSI boost.
There was about 8 months of R & D put in to that pipe design. And may failures.

As for cracking - i have not had a issue yet the pipe has done 65,xxx Kms & is as good as the day i had it made.

Mandrel bends are the only way to go. You will find that some of the bends you will buy won’t be tight enough curve.

Any more questions please feel free to ask.

Yes Michael South who is quite successful at rallying WRX's in production classes (I think I put up a link to his site here at some stage) was thinking along the same lines tube diameter wise for an EA82 header .

I want to try a VF10 and possibly a VF8 since Gee was kind enough to send both to me and I'd be interested to hear your opinions of those turbos on your header design .

My exhaust is 2.25 from the turbo back though the swivel joint (behind/next to the gearbox) , and the cat are 3" , just what was on hand at the time .
I would like to try 2.5 from the turbo to where my present exhaust steps up before the swivel joint and leave it 2.25 behind the cat .

If your exhaust people have jigs for that header I'm interested to hear if they'll make another one up , I don't think I could beat that on price given the development need to make one from scratch .

Lastly did you do anything to insulate your header to keep the heat in and prevent cooking other things near to it ?

Thanks again , cheers Adrian .

Gannon or Extreme Rx , can you tell me what the pipe diameters are on the std header at the small head flange bends and more importantly the ID of the crossover pipe .
May as well know the up pipe or is it a shaved cats tail ?

Cheers A .

I have a feeling that the up-pipe is 1.5"
The bend just below the head is hard to tell cos its not round, but probably around 1.75"

Will check it out tomorrow