After much looking around that WWW thing, i am still searching for images of exhaust mods after fitting EJ25 into a T3 Caravelle.

My thought is after manifold adding a center HiFlow Cat at rear near gearbox. Then reverse exhaust lines out arse end with small muffler ending in two outlets.
Is this possible?
Problems?
Any one done it?

Do u know what I mean?
I know what i mean?

I'd look into a different header too. I'm thinking about a 4into1 style. be good for a cat setup too.

re the twin outlets, I would have thought a tuned length setup would work better

Note Patent Pending, slimey people..

Anyhoow,

I am unsure if this is possible, i have a mate with the EJ27 Vortex engine and he has dual outs, but i know nothing about this engine. That is what i have based design on and that alone.

Apart from that.
if tuned single length is the only option.

Would be something similar to stock VW Caravelle out (different from heads of course) which keeps clearance and allows easy flow, but too that i would add a small offset center chamber to swirl the juices around and give a nice burble. whole system would run from 2 1/4" to 3" or more. Singular HF Cat and Magnaflow muffler. SS as well.

I will draw another its easier.

cats need to go pretty close to the engine before any muffler. they need the heat to work properly. so the first idea is really out.

for a 4 cylinder, a 4-2-1 or 4into1 setup works much much better than 2-1 setup and twin outlets (ala baja/buggies canons). if you look under any of the current crop of twin outlet equipped 4s, you'll find a 4-2-1 into a split final muffler or tail pipe.

I was out at eastern creek at the tasman revival meet on fri/sat/sun and every four there (barring some very old and nasty things) had 4into1s (v8s had 2 lots of 4into1s). so your second idea is probably marginal too.

sorry if I'm sounding all negative.

btw, for the most part, the factory header is probably garbage once it's modified even slightly like it is on our cars.

So i bit the dust.

I had such nice images in my mind about final product. Oh well

Yeh Factory header, from subi has been modded to follow stock caravelle outlet exiting out the right hand side.

OK so new system should be 2 1/4 from headers into 2 1/2 through to 3,4 " outlet... Stock 4 into 1.
As above 4 into 1, is it still possible to throw in a center chamber to give the burble effect?

I was wondering how does one achieve a higher pitch, rather than a low down burble?
Know what i mean?

get a good book...

http://www.amazon.com/Scientific-Exhaust-Systems-Engineering-Performance/dp/0...

or have a read of this...

http://www.billzilla.org/engexhaust.htm 

Both are based on a 2 1/4 system all the way to exit from inlet.
Is this possible; what is actual inlet size of OEM Subi manifold?

And if less than the above mentioned,
Is it wise to go from stock size??? to say the 2 1/4'

Oh yeh found this link as well as your links, so i think i am opn the right track now.

http://www.isuzuperformance.com/isupage/tech/exhaust.html 

http://autoaccessories.lifetips.com/cat/61897/exhaust-systems/ 

Both pretty much give same advice.

interesting that he poo poos 4-1 systems over 4-2-1 systems.

I understand why, but every serious race car I've laid eyes on has a 4-1 system, why makes me wonder if he's as on the ball as he says...

check this thread out...

http://www.bmsc.com.au/forums/rallying-technical/18798-exhausts-4-1-vs.html 

Damm pete.

Here i was thinking i was getting it to the design stage

According to the Link.
No one really has a certain thing, do i join 1&4 or 1&3 and so on. As 1 & 3 are on almost on the same stroke it would make more sense do do it this way.

Too many possibilities I am sticking with the 4 - 2 -1.

But here is another one for u.

Why cant I / we use an expansion chamber of the longer side 1&4 inlet?

Thus almost removing the need for exactly equal lengths of exhaust pipe, which by the way would include some sort of a full circle or donut on shorter side, either that or a major loop.

I dont know about you but i just dont have that kinda room. I still like to do most of my own tinkering.

mine will be a little different...that flange on top of the up pipe is for the turbo...but i did take onboard the info about 4-2-1 and merging at half length will be making this out of 40mmNB pipe...about 1 5/8" kept the pipes side by side for best clearance...pretty much equal length


[img][/img]

what did you draw that with?

Yeah that looks like a good setup... Solidworks?

just autocad 3D...pretty huh?

looks quite good actually, are the primaries equal length? what length are they? remind what size engine you are using it on again?

hi Pete yes sticking a TD04 on the EJ22 in my kombi and see what happens

just doing the drawings to see how everything fits but won't be able to finish them until i drop the present exhaust off and do an accurate measurement


[img][/img]


[img][/img]


speaking of which...does anyone know how much the cylinders are offset each side?

sure beats my penciled sketches

Yeh i have auto cad but i like the old school approach

Quick quiz.
where does one source SS flanges for inlet manifold?

That's a good idea rocknrob but really doesn't apply to me as i am NA.

Any chance of knocking something similar up for us NA peoples?

Just noticed; wheres the cat?

Also if u cut the turbo up pipe off,
that's what myn pretty much looks like at present. Join it up to the stock J pipe and then exit stage right same as stock T3 Caravelle / Transporter.