Exhaust tailpipe options

[Steve Addy]

I've been toying with the idea of running a rear muffler from the B3 (AAA or 9A engines) with the angled tip. I always liked the way the angled tip came out from the rear of the car. Also, I like the shape of the broad tip employed on the AAA (VR) cars too.

For anyone who's not familiar with this here's a pic. It doesn't really show much but it's the best I could come up with in short order:

The only problem I have with this is whether (like on my Mk2 D with straight tip exhaust) or not this will promote exhaust odor in the cabin with the windows down at road speed.

So, what I'm asking is for comments from people running non-stock exhaust systems that use a straight or angled (to the side) rear tail pipe for feedback on this situation.

If there's any question about odor in the cabin from exhaust getting pulled in through the window I'll opt for a factory style rear muffler with downward facing tail pipes and be done with it. It's not that big of a deal visually that I'm going to really care all that much.

Thanks for any and all comments!

Steve

 

[TonyJetta]

My tip is straight. Just DON'T angle the tip down, like a turn-down, towards the road. The sound reflects right back under the chassis and will drive you nuts (ok..nuttier...we own TDI's, right?!) in <10 miles!

I am also running a cat-back straight pipe, 2.25" dia. A little loud for 5:30 full throttle blasts in the 'hood, but fine anywhere else.

I don't notice any diesel in the cabin while driving...only when stopped while I have a tail-wind.

Tony

 

[cal327]

I have a 2.5 turbo back straight pipe going straight out the back and no odor and the noise is not bad at cruise but it is loud when I want it to be

 

[TDIDaveNH]

I'm not a fan of the OEM config with double turn-downs. At the time the B4 was white and I was always getting soot on the back- not just on the left side but evenly coating the entire taillight/trunk lid area. No soot however on the sides- at all. The soot always formed a clearly defined line between where the side of the car ended and the back began. as for exhaust smell in the cabin I would get it once in a while but mostly due to the trunk not being closed all the way. I've seen no evidence of soot entering through the rear door seals like it used to on the A2 Jettas

Lots of different ways this can be done, but I'm happy with 45 degree side-exiting at the bumper corner- I have never needed to clean soot from the trunk again. Granted the car I'm driving now is grey but I see no soot and haven't since changing the exhaust.

Whatever you do, push the exhaust into 'clean' air.


As for my system, it's a stock system w/cat cobbled back together sans muffler and suitcase muffler just as a temporary one while I find the time for fabricating one from SS. Perhaps in the spring time but that one will also exit in the same location.

 

[Steve Addy]

Thanks for the comments guys, I appreciate hearing from people who have straight tailpipes.

As for the factory exhaust, I've never had any soot on the back of the Mk3 with the downward facing tips and I've never minded them visually although they're pretty much invisible under there.

As I said before my main concern is to not have exhaust fumes in the cabin like I had with the Mk2 when I drove with the window down. I'm also more likely to go with the central muffler this time around because of noise suppression.

I had thought about going bigger on the exhaust but I just don't see that as being of much benefit since I will likely only go for one of the lower chip tunes but I doubt that I'll do much more than that. I only really want this car to run well, I don't really have any intention of doing much modifying on this.

Steve

 

[Abacus]

All mine exit down and I have never had an issue, and all have a larger diameter. The wife's is sporting a cat and single rear muffler, my sedan has a larger cat and no mufflers, and the wagon has no cat and a single rear muffler. None are any louder than stock and none create a drone of any sort. None also get soot on the rear of the car and I do not smell it.

I've never run one with a straight exit exhaust because I have seen people who have and the rear of the their cars was always covered in soot.

 

[surfbus]

When the suitcase part of my muffler cracked apart I had a muffler shop chop and weld an axle back straight pipe similar to your image. It has kept exhaust fumes from getting sucked under the car and back into the front corner air vents. The OEM design muffler shape curls downwards and behind the back bumper skin which is no good. The new look has gotten me some compliments but best of all it has a functional purpose.

 

[TDIDaveNH]

This is why the rear belly pan is important to have on.

 

[bmwM5power]

If I were you I would personally do this http://forums.vwvortex.com/showthread.php?5225427-F-S-B4-Remus-Axle-Back-Exhaust-****NEVER-EVER-INSTALLED!!!**** and a straight pipe all the way. I had Remus before and absolutely love it

 

[Steve Addy]

This is why the rear belly pan is important to have on.

There's no rear belly pan for the variant, only for sedan.

If I were you I would personally do this http://forums.vwvortex.com/showthre...-Back-Exhaust-****NEVER-EVER-INSTALLED!!!**** and a straight pipe all the way. I had Remus before and absolutely love it

Love it but my exhaust has to be low budget this go round. I may do something more later but for now it just has to be basic exhaust. I have a good Leistritz VR rear muffler and was planning on taking that and the car to a local muffler shop where I know the guy and have him construct everything in between the downpipe and the VR rear muffler.

As for whether the downturned exhaust tips cause problems on the B4 because of where they are I can't say, but on the Mk3 there's no soot on the back and no odor in the cabin from the windows when on the road.

I think since the B3 bumper skin recedes back underneath the car more than the B4 that the factory style exhaust might just project through the bumper whereas the B4 does not. I would need measurements from the B4 rear mounting point to the bumper edge in order to determine that, and I don't have that information.

Steve

 

[Steve Addy]

A decision has been made, I'm going to use the VR rear muffler I have and add a 4" center resonator and delete the suitcase muffler under the back seat.

I've been comparing pictures of the B3 and B4 rear mufflers and it's pretty clear that the tail pipes of the B4 tdi muffler don't line up with the B3 cutout at the rear bumper.

Steve

 

[thechoochlyman]

I plan to be putting a cat back on my car later this month, and I want to go ahead and get a nice tip for it as well.

How it is now:

The tip I'm looking at

I'm just a bit concerned about how close the tip will come to hitting the bottom section of my bumper without that slight turndown still on it. Has anybody used a holesaw or something similar to cut a radius in the bumper for the pipe to clear it? I'm really not wanting to, but thought I'd see what others have done. I may just go like Dave and put a 30 degree bend in it to run out the side. I have problems with it dragging the ground sometimes as it is.

EDIT: Here a few more interesting choices.

 

[Steve Addy]

The tip I'm looking at

I'm just a bit concerned about how close the tip will come to hitting the bottom section of my bumper without that slight turndown still on it. Has anybody used a holesaw or something similar to cut a radius in the bumper for the pipe to clear it? I'm really not wanting to, but thought I'd see what others have done. I may just go like Dave and put a 30 degree bend in it to run out the side. I have problems with it dragging the ground sometimes as it is.

EDIT: Here a few more interesting choices.

The first tip with the rolled edge I like. I've been admiring the exhaust hanger attachment near the tail pipe though too.

I haven't talked any more about the muffler here but I did post up something about it in the conversion forum. So far I haven't detected any odor from the angle of the exhaust so I'm hoping I can keep it around.

As for the soot, well I try and keep the car washed so I'll just have to deal with it then. I'm on a little virgin voyage trip with the B3V right now so maybe I'll have some evidence of soot when I get back to Des Moines later in the week.

Steve

 

[thechoochlyman]

The first tip with the rolled edge I like. I've been admiring the exhaust hanger attachment near the tail pipe though too.

I think I'll be going with that one, especially since it's got the built in clamp. I tend to prefer the straight edge personally.

Yeah, I was kinda pissed about that... I liked the price of the job, but the quality of installation wasn't that great. At least it's not really visible, and hasn't fallen off yet!