Offroad-Express

Hi everyone, names Josh, thought I would join ORE after browsing some of the awesome content, seems like a great community.

I'm orignally from Christchurch and now living in Wellington, have been living in California for the last few years.

On my 3rd WD21 now - a 1988 w/ a new blacktop TD27t. I saw a few threads on dump pipes - I think someone has a diagram of the dimensions for the turbo flange?

If you could post them up or PM me I'd be very happy! I scored some 3" mandrel and need to get it made up before installing.

Cheers

buy a gasket for one and trace around it, or take it to an eng shop with laser or plasma profile cutter

Hi Josh,
Autobend stock a laser cut flange for the dump pipe off the turbo.
It's not very clearly listed in their catalogue, so may be worth double checking it's the right part.
Think it was about $40, so not that cheap... (I don't have one yet, as I decided to finish a few other things before making the dump pipe).

Dan

I think Uniweld in Riccarton Rd, Chch has a copy of my one, give them a bell?

Awesome thanks for the suggestions so far guys, really appreciate it

Hi Josh,
I fitted my autobend 2.5" system ('Rage' system) in the weekend. I took the time to make a jig of the manifold, and also did a accurate trace on to paper of the turbo end. I'll get it tidied up and uploaded in the next couple of days.

One thing I learnt is that the new dump pipe will have to have the pipe-pipe flange lower down the pipe. the existing dump pipe is so shallow that having the flanges in the same place would not acheive much in making it flow better (pipe would bulge out, then curve back in again), and my current system was built as a dirrect bolt-on to the factory dump pipe. Maybe with the movement in the flexi under the vehicle I can tilt the new downpipe closer to the firewall to accomodate the better dump pipe....
Frustrating that Autobend did not make this last little bit of the system - just 8 inches of pipe between their own flange and bigbore system!

Just a thought, but there are two types of turbo fitted on the TD27 - ones a Hitachi, the other... maybe a Garrett?
Maybe someone knows if they use the same dump/manifold cast pipe?

Danielbeek - thanks v much, that would be great. I can see how the downpipe would affect flow. My current exhaust is cobbled together and rusty, and I'm going to drop it all out. I have another 12" mandrel bend to join the to the dump, then a flexi, 2.5" reducer, 2.5" standard exit, possibly single muffler...

Bought the engine minus turbo, 90% sure the one we put on is a Hitachi HT 18 - good call

I've turned the sketch in to something a bit more useable, see attached 'exhaust flange (25 percent)'. The scale bar should help with correct scaling if your printer is not calibrated.

I've included the original 'print' taken off the dump pipe also, if you prefer that.

The stud holes appear to be 10.5mm and 9mm, though I recall the nuts all being the same size. Maybe just the shank on the stud was larger, but thread the same???? Might pay to undersize them and drill last when dump pipe is off.

If anyone wants the traced image in a vector format for editing, let me know.

I could not upload in full size, so reduced to 25% of original.
The full size of traced image is: 1478 W x 1820 H pixels
The full size of smudgy print is: 1815 W x 2187 H pixels

With this design it is an easier cut and gives you more meat to weld the dump pipe onto.

kiwipete wrote:

With this design it is an easier cut and gives you more meat to weld the dump pipe onto.

Between the large span of the stud holes. Scallop that part out like the gasket so you can change turbos without removing the dump pipe first. This lets you get at the nut on the 4 bolt turbo flange

Cheers,

When I did my dump pipe I used a 3"od 90 degree weld fitting from Steel & Tube and pressed the flange end sort of thinner and oval to fit the flange.Its a lot thicker material and should last for ages.

danielbeek thanks very much! Will keep y'all posted!

Nice job

Heres what I am thinking for the flange, based on Daniel's diagram and kiwipetes meaty flange. 5mm thickness ok?

To me, 3" OD seems a tight fit around the bolt holes, have you guys run into any problems with welds interfering w/ the bolt holes? I dont see how the nuts would fit true with such little wiggle space. Or do I use hollow spacers on the flange side of the studs?

I like the ideas of piggybacked bends or pressing it oval, but for this I want to go the most simple way possible.

Cheers

ps finished painting the Pathy w/ lacquer in the weekend. Colour is Toyota Dune Beige 416, looks very unique, will upload pics when the weather gets better

Solution








10mm plate worked for me. I had two cut and sent one to Chch to some guy that has a mean D21

Cheers,

Very cool. That looks like 2.5"? One of those puppies would be nice but I dont see it happening without unloading a wad of cash

Yep, 2.5. Not that expensive. Flange $50, 2.5 tube cheap as chips. Fabrication around $100. Best performance modification by far

Cheers,

Hey Simon, looks nice. who fabbed that for you? Does the lower flange sit in the same place as on the factory cast pipe, or a bit lower?
Cheers.

It was fabbed by a local exhaust shop, but I have made a few others with the skills and equipment from http://www.bartsauto.co.nz/
The lower flange is not in the same place as the factory one but makes it easy to remove the dump pipe with very little effort (great for replacing turbos )
Make the whole system 2.5 or it won't make that much difference.

Cheers,

Got the 2.5" exhaust already sorted.
Went for a autobend jobby, which came out pretty good - reasonably easy fit and good sound (deep drone at some RPM, but not too loud).
Was going to just get the parts at Chase, now just trying to figure out where I can best get the welding done.
My local Pitstop did some other work for me recently - they were cheap, but unfortunately not so accurate...

Have a traced dwg made in solidworks, traced over "exhaust flange (25 percent).jpg". I tried adding to post, doesn't seem to allow dwgs.

I can email to anyone, if they need it or post somewhere.