Diesel SS 2½” exhaust, higher boost, more power!

[Gnarlodious]

New exhaust system for my AAZ! Seeing 3 lbs more boost, lower EGT, more power, higher revs and less smoke at the top end! Big improvement over the 2" pipes.

Above see the parts used (the shiny bits), except for the long 90º piece which was excess. My metal guy chopped them up to make the oddly shaped compound angled loop under the '83 carrier bar as shown below:

To the right the downpipe comes out of the turbo, I had him weld in an M18 SS bung for a future exhaust sensor. This section is connected to the turbo flange by V-Band clamp which makes rotating odd angles so much easier. The under-the-carrier section takes 3 pieces cut and welded together artistically. It goes into a 10" flex section:

You can see the engine carrier bar below behind the flex tube. It was important to me to vacate the space under the exhaust manifold as it gets pretty hot and the pipe through there interfered with the turbo drain tube. The 90º angle hangs off the frame box and is then V-Band clamped to a Moroso Spiral Flow muffler. Surprisingly effective for a small muffler. Apparently it works by shunting half the flow through a phase-shifting helix. The rest is pretty standard exhaust. This arrangement leaves a lot of space under the license plate/coolant reservoir area.

If you don’t have at least 2½“ exhaust pipes on your 1.9TD you are not operating at optimum. Determined empirically, because I ran the 2” pipes for 3 years.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[dkoesyncro]

I'm curious to the exhaust note the spiral makes, do you like it? What were you using before?

[Gnarlodious]

Definitely sounds more like a clattering diesel but without excess exhaust noise. The old muffler was a Magnaflow glasspack straight-through type. The worst muffler for a diesel, but the exhaust shop that did it was ignorant. The spiral muffler sounds the same as the old one, but now my turbo whistles noticeably louder. Mostly it is smaller than the old one. Also the spiral is open-chambered, so it won’t restrict. The glasspack tends to collect soot from the diesel at my elevation, and gets restrictive. Also the additional bends on this system absorb noise.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[beach_creature]

Looks good.
Can you post some more photos of it when you get a chance? More of the bends around the carrier bars, the flex pipe, and exhaust mounts.
Very interested in this.
Thanks!
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84 Westy
1.9TD AAZ
5spd manual with Locking Peloquin TBD

[Zeitgeist 13]

I'll confirm the straight-through glasspack condemnation. I really regret going with one on my TDI swap. I'm currently in the process of completely re-doing my intake and exhaust systems to further mitigate noise. I'm running 2.25" tubing.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[outcaststudios]

thread delivers.
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'88Doka JX td
'69 westy
(rip)couple bugs
(rip)three type III"s
(rip) '81 vanagon
a bunch of french stuff,and 9 motorcycles.

https://www.thesamba.com/vw/classifieds/detail.php?id=2573791

[dobryan]

I need a cold shower.....
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[valvecovergasket]

awesome stuff! i love vbands for custom exhaust work, and it makes service a lot easier as well

can you post some more pictures from further back when you get a chance?
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MegaSquirt resource - SpitfireEFI.com

gone, but not forgotten: '83 tdi westy - swap thread

[vwwestyman]

[eleven]

Excellent... This is on my list, along with a re-do of the intake to add an intercooler and proper filter box.

Nice work.

[metropoj]

Beauty stuff.

I need to build a similar exhaust for a 1.8T once it is mounted in the van.

I've read a few people piecing together from generic type off the shelf, Lego it together, and then get it welded up all proper like.

Where did you get your bits from ?
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John.
86 TiiCo powered Westy.

[big swifty]

Muffler details please.
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Evan
1987 Vanagon Syncro // Westfalia pop-top graft // Factory new ALH. 11mm IP. AFN 110 RC 2,3,4 // S7 turbo// Titan P502's
2013 Golf 4d TDI. No mods. Yet.
[1991 Jetta coupe TD. Giles Superpump. Custom tall 5 speed. SOLD

[Gnarlodious]

Turbo out:

Downpipe:

Under carrier bar (small corrugated tube is diesel heater exhaust):

Exhaust pipe going back:

Flex section:

Muffler hangar and V-clamp:

Hangar off frame:

Spiral muffler (Moroso 94054) and tailpipe. Note clearance to get a socket in the 12point crankshaft bolt:

Tailpipe hangar:

Tubes I got from http://www.allpurposepipes.com and all other parts from Amazon. A hint on the tubes, they are very hard metal and your metal shop will need a saw with fine teeth, or abrasive cutter.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[Gnarlodious]

Just an update on this, after running for a year I am very pleased with 2½“ pipes. NO OIL BLOWING for a year! I did not realize my engine was suffering from unusually high internal pressure from the small exhaust. During my summer trip over the Rockies I was able to floor the pedal all the way up and not get excess EGTs like before. This system was something like $700 but well worth it. If you are building an AAZ, especially with a modified injection, you really need 2½ pipes.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[erste]

That exhaust looks really good. Nice work!

[Zeitgeist 13]

Now I feel dumb for sticking with 2.25" exhaust.

I don't have too many oil leaks, except for persistent valve cover gasket seepage. I still don't quite understand the linkage between exhaust diameter and oil leaks.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Gnarlodious]

That’s what I had before this upgrade, 2¼“ pipes. Back pressure, apparently my smaller pipes were not letting the turbo find a low enough pressure on the spill side. I don’t know what your Waldo pump entails but if it is modified for perfiormance then a deeper breathing engine is a good idea. What diameter pipes did the stock ALH come with?
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[valvecovergasket]

[ALIKA T3]

[Gnarlodious]

Ouch, that’s rotten. The spill side of the turbo MUST see as little back pressure as possible. If you are running a glasspack sort of muffler it makes a restriction. It's a common muffler shop mistake to put a glasspack on a diesel because the fiber collects soot which aggravates the back pressure. This sets off a cycle of poor combustion and even more soot… repeat.

I fought with oil leaks for 3 years, trying all sorts of solutions. Excessive exhaust pressure causes blowby and oil coming out various seals and openings. I was seeing prematurely black oil, high EGTs, black smoke and low boost pressure until I increased the exhaust flow.

The only downside to a bigger exhaust is the engine makes less heat, which I notice in the winter!
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit