2013 TDI jetta sedan DPF delete questions

[TDeleani]

Car noob here, doing my own research on how to get this done myself. Looking to delete the egr/dpf and use a stage 2 tune, and I was wondering what the difference in options are? For example I see straight pipe, high flow cat, resonator, both high cat and resonator, using stock muffler, etc. My goal for my TDI is to reduce smoke out the back, while fixing the issues that come with the dpf. I don’t mind a little extra sound ofc but also looking not to spend a pretty penny for performance, mainly economical (I have also seen the eco kits).

I was hoping someone can explain to this noob the differences in the type of delete kits, and if anyone has recommendations on which kit to get (in the US).

2013 Jetta TDI sedan (for off road use)

 

[Beewi]

Your stock exhaust includes an H2S catalyst, a NOX catalyst, and a diesel oxidation catalyst (DOC). Deleting leaves only the smallish catalytic converter thats on the midpipe. This stock part is undersized for the unrestricted flow that comes with a delete, and is replaced with either a straight midpipe, or one with a large, high flow catalytic converter. This knocks down some of the 'diesel exhaust smell'. Some people say it's a godsend, some say that it doesn't matter, but if you're sensitive to the smell of diesel fuel, maybe shell out for one.

Deleting makes the car sound different, not too much louder, but different enough that you may notice a drone or whine at speed. A resonator is a section of exhaust engineered to counter those specific noises, and improve the quality of your ride.

Retaining the stock muffler means just that: the parts you get go almost all the way to the rear of the car, where they attach to your muffler, which keeps the car at the stock volume. "Performance" exhausts or full straight pipes, do away with the muffler and just send the exhaust straight out the back of the car with no baffles or mufflers to cause back pressure or impede the operation of the engine. They are also often wider diameter to let max gas flow through. They also make your car loud and obnoxious. No one but possibly you will find it cool that your car is loud enough to wake a sleeping baby at 2 am when you redline it in 3rd.

Most of these options are just quality of life stuff, but don't get a full performance kit if you want to keep the muffler on the car. It won't fit.

 

[TDeleani]

Your stock exhaust includes an H2S catalyst, a NOX catalyst, and a diesel oxidation catalyst (DOC). Deleting leaves only the smallish catalytic converter thats on the midpipe. This stock part is undersized for the unrestricted flow that comes with a delete, and is replaced with either a straight midpipe, or one with a large, high flow catalytic converter. This knocks down some of the 'diesel exhaust smell'. Some people say it's a godsend, some say that it doesn't matter, but if you're sensitive to the smell of diesel fuel, maybe shell out for one.

Deleting makes the car sound different, not too much louder, but different enough that you may notice a drone or whine at speed. A resonator is a section of exhaust engineered to counter those specific noises, and improve the quality of your ride.

Retaining the stock muffler means just that: the parts you get go almost all the way to the rear of the car, where they attach to your muffler, which keeps the car at the stock volume. "Performance" exhausts or full straight pipes, do away with the muffler and just send the exhaust straight out the back of the car with no baffles or mufflers to cause back pressure or impede the operation of the engine. They are also often wider diameter to let max gas flow through. They also make your car loud and obnoxious. No one but possibly you will find it cool that your car is loud enough to wake a sleeping baby at 2 am when you redline it in 3rd.

Most of these options are just quality of life stuff, but don't get a full performance kit if you want to keep the muffler on the car. It won't fit.

thanks for the information. Very informative. I agree, that I don't want an obnoxious sounding car, but at the same time I do enjoy a nice sounding exhaust system. Based on the limited research I've done I've decided for now to go with one with high flow cat + resonator and keep the stock muffler to reduce the sound, yet I've heard that it still sounds quite nice.

Do you happen to know the main difference in going between 2.5" and 3" diameter kits? is my tdi sedan compatible with both?

 

[Beewi]

So that's a actually a pretty complicated gas flow question. By going wider, the linear velocity of the gas in the pipes decreases, which decreases the effect of the gases leaving the exhaust dragging gases out of the manifold at the back of the engine. It's possible to actually lose some torque by going with a super size exhaust, but in practice a 3 inch shouldn't make any problems. Small exhausts may create back pressure and choke up the engine at high rpms. But again, if you're not doing really silly thing then you won't notice.

Either diameter will work, assuming that the down pipe that replaced the DPF is correctly sized for your car's turbo, and that the pipes are the correct length. The real difference in 2.5 vs 3 inch will be that the 3 inch will have a lower pitched sound, and will likely have a higher price.

 

[oilhammer]

You may not even be able to source these parts anymore, just FYI.

The size of the pipe is pretty meaningless, as the turbo is teeny tiny anyway. The larger size pipes are also harder to fit in some places. The stock sized pipe, which is plenty, is 55mm. But since nobody seems to be able to think in Metric, or source Metric pipe stock, they revert to what is available in the ancient inches, which goes 2, 2.5, 3. 55mm is closest to, but slightly more, than 2 inches, so they jump up to 2.5 inches. Which is about 4/10th of an inch larger than the stock pipe. 3 inches is overkill. It's a 2 liter engine that doesn't really spin faster than 4500 RPM most of the time, and certainly doesn't even need to spin that fast to make the most of its power.

 

[luncefordjw]

I am about to continue my journey of emission adjustments on my 2012 VW Jetta. I installed the EGR straight pipe, and just got my MK6 DPF delete Buzzken pipes from www.aftermathtuning.com today. My question for the group is, what should be done first, the Stage 2 Malone tune or the pipes install? Does it matter?

 

[turbodieseldyke]

Tune first, if possible.