Subaru exhaust

Post by **klatuu** » 20 Apr 2006, 13:25

Seeing as I am the newest here I just thought I'd contribute a bit.

If you are going down the Legacy 2.2 route get the downpipes too, they both connect together into a collector with the lambda probe in, buy a Renault 21 (2 litre) back box, I got mine new for a tenner, they have a loop that goes over the renault axle and about a foot of straight pipe going in to the box, cut off the axle loop about an inch into the straight bit, do not throw away.

get a flange made to match the end of the subaru exhaust (6mm plate with a two inch hole in the middle and three 8mm holes spaced equidistant around the outside.

Buy a 90 degree bend and a length of straight and a couple of exhaust clamps from Demon-tweeks here

Cut the 45 degree angle from axle loop that came off the renault back box.

roughly assemble the system with the exhaust mounted to the engine, (mount them as they should be in the car this means that they will be pointing towards the front of the van) using exhaust clamps to hold it all together, the stuff bought from Demon-Tweeks has a larger diameter on one end to enable it to slot all together, start with the 90 degree bend and put the thin end in the flange, fit everything else to it in this order, flange > 90 degree bend > 45 degree bend > Straight > Back box.

the outlet of the back box should poke out just underneath the rear skirt of the van, the mounting bars on the back box should almost be directly underneath the right hand engine mounting rail in the van.

Get it tacked up, refit check for accuracy, weld it up (Mine was tigged and looks like the DB's).

Finally get a thick bit of 1 inch flat bar, about 12 inch long, wrestle with it for a bit and bend it into a extended Z shape ( pull both ends of the Z until it is nearly flat), drill a couple of holes mount it to the van and get a suitable rubber from your local discount exhaust company.

What does it sound like???? I have to rev the engine sometimes to make sure it is still running!!! Its very quiet.

Post by **Diamond Hell** » 20 Apr 2006, 13:50

Are you taking the exhaust forward?

Sadly this won't work on a Syncro.

It would be interesting to see pictures of the completed system - a picture tells a thousand words etc - and you're trying to describe something pretty complex there!

Post by **klatuu** » 20 Apr 2006, 15:50

Its funny when you are trying to describe something you can see it in your head but after you have read it later it doesn't make that much sense.

Any way ...

The Exhaust downpipes are fitted to the engine as they are in the car, and as the engine is mounted backwards the exhaust starts by pointing to the front of the van, the first 90 degreee bend brings it to the right, so the exhaust now points at the inside of the offside wheel, the next 45 degree bend brings it round a bit more so the exhaust now points to the back offside corner of the van, ( there is more clearance on the right hand side of the engine in my van). The straight tube is just to place the backbox near the back of the vehicle, and the mounting hangers of the backbox are directly under the offside engine chassis member.

The 90 & 45 degreee bends bring it under the diff, how does the diff on a syncro work is there a half shaft coming out of the front?

The exhaust hangs a bit low but no lower than the subaru sump, consider it an early warning system for the sump!

IT was done to get the van on the road, when I have more time I'll probably make something a bit 'tidier'.

Here is a picture pre weld, there has since been a little bit cut off the straight pipe that goes into the backbox.

Post by **Hacksawbob** » 21 Apr 2006, 08:31

Wiki'd

Post by **HarryMann** » 21 Apr 2006, 08:42

Looks a nice solution to get the car on the road and tested.
No good for a syncro I suspect and with a shortened sump, probably too low for a 2WD long term.
Exhaust are a pain aren't they

Post by **Diamond Hell** » 21 Apr 2006, 08:45

nice..... for a 2WDs

Post by **klatuu** » 21 Apr 2006, 10:58

Why thank you guys, I was half expecting some u.t.o.a. purist to say, 'oh no that wont work, blah blah, back pressure, blah, no cat, blah, too short.

Whatever.

It works, its quiet (too quiet?), the van is MOT'd, runs fine (needs a speed sensor), the only thing I'd say is that the right hand side bar on the backbox mount (the bit where the rubber mounts to) is a bit long (needs shortened and rebent) so the backbox sits a little bit lopsided.

I'm just happy that someone might find it useful, It'll prolly come up for sale, when I get a new one.

Post by **HarryMann** » 21 Apr 2006, 13:56

Richard can supply a suitable speed sensor...

http://www.rjes.com

Post by **autohausdolby** » 25 Apr 2006, 11:17

I heard about this on www.retro-rides.com - good work!

Post by **autohausdolby** » 27 Apr 2006, 08:07

Money sent fella

Post by **Diamond Hell** » 27 Apr 2006, 08:42

I just took delivery of this:

Bit shorter, but should be sweet.

Post by **klatuu** » 27 Apr 2006, 09:11

Mmmmm...Pretty

Now I may be incorrect but I would be conerned about the difference of lengths of pipe from the manifolds, having a long pipe from one manifold and a short pipe from the other would create an imbalance in back pressure and make the engine uneven, the only way I would see it working if correctly, would be for the short pipe having a large I/D.

Post by **Diamond Hell** » 27 Apr 2006, 09:29

Well while I agree with you in principle (and this subject will send Clive/Harryman into an orgy of technical wittering) Smallcar have done over 100 conversions using this exhaust and their conversions do seem to be very well regarded.

We'll have to see in a couple of weeks

Post by **starspider** » 27 Apr 2006, 10:48

Thinking back to the days long ago when I played with hotter engines Ibelieve there is a formula for working out the lenths of exhaust pipes to get the harmonics of the pulses working together, perhaps Small car have used this or arrived at the lenths that work by guess and god

Post by **Horza** » 27 Apr 2006, 12:59

I could be mistaken but in the picture of the origional downpipes/collector box the downpipes don't seem to be the same lenth either, not as pronounced but still diferent.