TDI Exhaust Modification

I am going to be doing some maintenance work on my 2000 TDI soon. It's going to be getting new axles, sway bar bushings, fuel filter, timing belt + etc., and flywheel + VR6 clutch.

While working on the car, I was thinking about doing some work to the exhaust system. My question is this: what can I do to the exhaust system to hear more engine (louder) and the turbo spool? I love the sound of diesel pickups at idle, with just a little bit of turbo whistle. I know I probably won't be able to get the turbo to whistle like a big rig, but is there anything I can do to the exhaust system to hear the spool, such as replacing the muffler / straight pipe w/o muffler, etc?

When I got the car, it had about 110K miles on it. It runs great, but it doesn't look like it was maintained the best. One thing I noticed shortly after getting it was the anti-shudder valve was sticking (by searching the forum after one day it decided not to start for me) and upon removing the intake manifold, I managed to get around a quart of carbon buildup from the manifold and valve (there was between 1/2 and 3/4" on each of the walls at most places). How likely is it that the cat is clogged up as well? Also, I tried to research but didn't get much relevant information: does anyone know if punching out the cat would give any gain in MPG or affect the sound?

Thanks,
Mike

If you install a 2.5 inch exhaust after the converter with no muffler, it will sound really cool. The problem is, there will be a drone at higher speeds. So, to that end, add a straight through muffler at the end to stop the drone, but keep the cool turbo whine.

whos sells the complete 3" stainless turbo back

I don't think there is a 3 inch for the ALH engined cars. There is a eurojet 3 inch for the PD cars but it was determined that it is 2.5 to the flex pipe and then 3 after that. Getting a true 3 inch the WHOLE way is are as the mounting is hard. Not to mention 2.5 is plenty for our cars unless you are doing some major power mods. Tectonics tuning sells a nice 2.5 turbo back that you can go with or without a CAT and it has a straight through muffler as an option along with stainless as an option. The euro jet from what I can tell is straight the whole way and you have to add a exhaust tip pointing down to prevent melting the bumper. Euro jet is a LOT cheaper then the tectonics though but unless you have a PD engine it doesn't matter. There is also other venders that have 2.5 exhaust and I am sure local places could make the size you want. Just get mandrel bent.

Why not just the mufflerectomy?
Straight pipe w/o mufler will give you the whistle you are looking for.
Or so I have been told.

DBogo said:

whos sells the complete 3" stainless turbo back

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eurojet does. your going to need a o2 bung plug for the downpipe if you have a ALH

IMO if you want custom Exhaust that is super nice I would visit Matt Whitbread. He did my turbo back and I'm extremely happy with it. Sounds great and the whole thing is 304 SS so I'll never have to replace it
It's well worth the drive. One more option for you. Otherwise like some others have mentioned you could just do a mufflerectomy.

Just my .02

glitdi said:

Why not just the mufflerectomy?
Straight pipe w/o mufler will give you the whistle you are looking for.
Or so I have been told.

Click to expand...

+1 !

Why spend hundreds of dollars? $30 worth of pipe and a couple minutes with a sawzall will get you nice turbo whistle, a little more engine sound, and not necessarily ANY drone. The myth that not having a muffler = drone bothers me. My mufflerectomy produces zero drone. (hint: don't point your tail pipe at the ground inside of the bumper valence)

I was pretty sad when I added my downpipe and lost my turbo whistle though. On the stock downpipe / cat, a simple mufflerectomy gives really nice whistle and "hoot" sounds during gear changes.

Leo819 said:

eurojet does. your going to need a o2 bung plug for the downpipe if you have a ALH

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ALH's don't have O2 sensors, but BEW's do.

right now i got no muffler and no cat and it sounds mean but i want it deeper its slightly ricey sounding

mrchill's right...mine sounds exactly like a diesel pickup from the back...from the front all thats different is that you can really tell its a clatterin diesel...even a lay person knows it sounds funny

Click on the exahust link in my signature - there's links (in the link) to a few different youtube videos of mufflerectomeys etc as well as my car.

If you like to fabricate - I'd suggest building your own in 3" all the way. Downpipe is the most difficult, but the rest is easy. Don't do 4" unless you like a challenge.

If you just want to bolt on and sound cool, cut the cat and muffler and be done with it. Don't permenantly fasten the tip until you drive it for a while and see if it drones or not. Do not have a 90 degree turndown - straight down - under the car, turning it sideways at a 45 degree angle worked best for me, but some are different.

This will have a very cool whistle at idle and be aggressive under moderate load and reasonably quiet driving normally.

I'd suggest driving it for a week/tank of fuel before finalizing the tip as the sound will change as things settle in and get soot on them.

vwmikel said:

ALH's don't have O2 sensors, but BEW's do.

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right but the eurojet's DPs have the bong. I brought this point to thier attention.

Leo819 said:

right but the eurojet's DPs have the bong. I brought this point to thier attention.

Click to expand...

Sorry, I think misread what you wrote.

I chopped off the muffler today and welded some straight pipe out to the back of the car then turned it down so the tip of the muffler is just about vertically flushed with the rear bumper (just a bit behind where the stock turned down). Everything still looks like it is OE, but it sounds much better with a bit of the turbo spool coming through. Cruising with light throttle the car is extremely quiet, and idle isn't much louder than before; it just has a much nicer tone. I even managed to recycle the old exhaust hangers from the muffler, so everything is still using the rubber hangers, so no exhaust mounting issues either. Definitely worth the $20 it cost for the pipe.

+1 vote for home made custom exhaust. It's cheapier and sounds more brutal. check (of course there are less cylinders in 1.9tdi)

cheap SS mufflers

DBogo said:

whos sells the complete 3" stainless turbo back

Click to expand...

I just bought and installed a beautiful all SS muffler with dual slash cut outlets from Ebay for $31 total (free shipping) the inlet is the correct size to slip over exisitng pipe and all you need is about a foot of exhaust pipe from the scrap pile at the local muffler shop.
Sounds sweet and the turbo spools much quicker !

shizzler said:

+1 !

Why spend hundreds of dollars? $30 worth of pipe and a couple minutes with a sawzall will get you nice turbo whistle, a little more engine sound, and not necessarily ANY drone. The myth that not having a muffler = drone bothers me. My mufflerectomy produces zero drone. (hint: don't point your tail pipe at the ground inside of the bumper valence)

I was pretty sad when I added my down pipe and lost my turbo whistle though. On the stock down pipe / cat, a simple mufflerectomy gives really nice whistle and "hoot" sounds during gear changes.

Click to expand...

+2 on being disappointed after I installed my nice PP 2.5" down pipe. Lost the nice hoot back as well ....... so yeah ...... unless you have major mods, stock downpipe gives you nicest sound.

I have a PD with a downpipe no cat/muff. I have it split into duals at the back of the fuel tank (closest to motor). It terminates toward the outboard L/R of the rear bumper flush to the outside edge and bottom of the valance with two stainless Vette style dual tips (both sides functional). The car sounds great except for crusing between 78-83 MPH or so there is an annoying, almost unbearable drone.

I think this spring i will change to a 2 1/2 straight back with a small magna flow ss chambered muffler. I am soon upping the ante with PD 150 injectors, ported head and Passenger Performance Intake so take advantage of those mods the least restrictive system possibile would be best. Think i will get some kind of a stainless dual tip for asthetics.

I think this spring i will change to a 2 1/2 straight back with a small magna flow ss chambered muffler. I am soon upping the ante with PD 150 injectors, ported head and Passenger Performance Intake so take advantage of those mods the least restrictive system possibile would be best. Think i will get some kind of a stainless dual tip for asthetics.[/quote]

I'm doing something similar. PD 150 injectors but with the PD 150 mani. I have a PP down pipe, Magniflow cat & 2.5" Eurosport catback. It may take a couple of months to get it all installed. I'm curious how it will sound.

shizzler said:

+1 !

Why spend hundreds of dollars? $30 worth of pipe and a couple minutes with a sawzall will get you nice turbo whistle, a little more engine sound, and not necessarily ANY drone. The myth that not having a muffler = drone bothers me. My mufflerectomy produces zero drone. (hint: don't point your tail pipe at the ground inside of the bumper valence)

I was pretty sad when I added my downpipe and lost my turbo whistle though. On the stock downpipe / cat, a simple mufflerectomy gives really nice whistle and "hoot" sounds during gear changes.

Click to expand...

100% worth it. Have to many comments "That's the best sounding VW I've heard!" all the time... DId mine a few months ago.

Turbospool said:

+2 on being disappointed after I installed my nice PP 2.5" down pipe. Lost the nice hoot back as well ....... so yeah ...... unless you have major mods, stock downpipe gives you nicest sound.

Click to expand...

Just bolted up my IDParts 2.5" SS DP w/ magnaflow cat - its a whistling.

TopherDI said:

Just bolted up my IDParts 2.5" SS DP w/ magnaflow cat - its a whistling.

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Yes turbo whistle ...... but no hoot back between gear changes, right? Does it drone at 1900 rpm-2100 rpms? Mine did.

Turbospool said:

Yes turbo whistle ...... but no hoot back between gear changes, right? Does it drone at 1900 rpm-2100 rpms? Mine did.

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.....but you don't have a cat. That might make a drone difference.

Reading this thread inspired me enough to go ahead with the mufflerectomy on my Golf. I was a bit hesitant as it's an auto and exhaust mods on auto cars can sometimes sound like crap so i added a red bullet resonator just to keep the auto drone down. Pleased to report that other than a slight drone at around 1800rpm it sounds great especially idling and at full pedal. didn't notice too much more turbo whine unfortunately but that wasn't the main reason to do it anyhow. It does pull noticeably better above 2700rpm so it's definitely more fun on the highway less so in the city. I also stuck the tip past the rear valence and didn't point it down hoping to cut down on the soot collecting on the hatch. We'll see how that goes.

Turbospool said:

Yes turbo whistle ...... but no hoot back between gear changes, right? Does it drone at 1900 rpm-2100 rpms? Mine did.

Click to expand...

Tough to make the comparison - because as of right now I think that when I did the mufflerectomy the sawzall must have at least started the break in the weld from my stock cat to the pipe that leads to the tail pipe section. So it was quite a bit louder than if it had just been a regular muffler delete.

I tried to stay at 1900-2100 on my way home yesterday and there was no discernable drone - disclaimer: I have been driving with the car blowing straight out of the stock cat right beneath my ass and that was so loud that my ability to draw a reasonable comparison may have been comprimised.

Edit: 2.5" dp is way less restrictive than stock and I can really feel a difference in spool up and for that matter throughout the rpm range.

My current setup with the cat and reducer to the stock tailpipe is really quiet, sorry for the long winded explaination, but that's the story.

darkhorse said:

.....but you don't have a cat. That might make a drone difference.

Click to expand...

I would agree.