How's the smell with your downpipes?

[thetuna]

I'm fairly new to my car and I thought I'd be satisfied with just a tune for a while... but the itch is already back and I think I'll scratch it with downpipes

I don't care about passing emissions or changing the sound (as long as it doesn't drone too badly); really the only concern I have is the smell!

After reading through a bunch of threads it looks like some people notice the smell, some don't; some care, some don't.
I'd rather not drop ~1100 on a pair with cats if I don't have to, so I figured I'd take a poll.

[Colt]

I'm catless with N54 midpipes and I wish it was louder. The smell I don't really notice. Sometimes in stop and go traffic, throttle on and off, you will smell it a little but it's not something I would beat myself up over. I daily drive it as well..you won't know if you like it or not until you put them on. People on the forum can't tell you something about the smell (if they like it or not); your personal opinion is going to be different one way or the other.

[blaster3500]

I have catless on my n54 e90 and notice a little difference but to be honest if I wasn't looking for it or the I bought the car like that I would not think anything was wrong. I have driven full catless car and it is a huge diff. I wouldn't think twice about putting catless downpipes on again

[Miko226]

I have catless downpipes and muffler delete the smell is not bad at all although coming from a catless V8 mustang however I still have 2 cats and a resonator of which would like to rid the cats and get an n55 mid to replace it..

[E30 Racer]

If you're that concerned about the smell, chances are good you'll be one of the guys that finds it noticeable (I'm the same way). It's not horrible, but can be annoying in heavy traffic or if the car is idling in the garage.

[135Pats]

It smells.

[Eyeman]

I still have the stock midpipe cats. I pretty much just notice the smell at drive-in restaurants. I guess the extreme stop and go combined with bouncing off the restaurant walls, etc makes it bothersome. I drive alot in regular city traffic mainly with my sunroof fully open, sometimes windows and and I don't smell a thing.

[Edogg218]

Originally Posted by Eyeman

I still have the stock midpipe cats. I pretty much just notice the smell at drive-in restaurants. I guess the extreme stop and go combined with bouncing off the restaurant walls, etc makes it bothersome. I drive alot in regular city traffic mainly with my sunroof fully open, sometimes windows and and I don't smell a thing.

+1

[katsooba]

Zyclon B!
but i love it.

CP-E 5" DP on n55

[siegester]

If you have an n54 with stock midpipes you will notice the smell a lot less. This is due to the midpipes on the n54 having secondary cats. N55 cars don't have secondary cats, so the smell will be much more prominent.

[andrew777]

It definitely smells, but it doesn't bother me. At first my OCD side would kick in and make me think my life expectancy is getting shorter from the fumes, but now the smell is refreshing since it's unique to my car(none of my friends/family are catless).

[bdoooh]

Like others have said, if you have the stock mids I don't think it would be that bad. I'm catless on an N55, it's not the worst but its there. It's bad in the garage if you back in. And let's say you pull forward in the street and then back in, you'll smell it because you'll drive through the smell you just blew out haha. I just wish it was quieter on an N55.. With the windows up you won't smell it that much, sometimes you'll get w whiff.. But again, this is coming from an n55 with no resonators or cats in the mids.

[mikead_99]

I voted don't notice, which isn't quite true as there is some very mild additional smell, but I'm also another one of us with secondary cats still installed. Although I wish they were less restrictive, I'm very happy they are still in line for that reason.

[bdoooh]

Originally Posted by mikead_99

I voted don't notice, which isn't quite true as there is some very mild additional smell, but I'm also another one of us with secondary cats still installed. Although I wish they were less restrictive, I'm very happy they are still in line for that reason.

Do you feel the secondary cats are all that restrictive? I'm considering replacing my N55 mids on my N55 with N54 mids to tone down the sounds & tone down the smell with those secondary cats.

[Colt]

Originally Posted by bdoooh

Do you feel the secondary cats are all that restrictive?

I do. Makes the car sound raspy too certain times

[Lmaiuri]

Like french fries ya bish.

[ilikebmxbikes]

Peoples exhaust set ups will smell differently. It isn't solely attributed to catless downpipes. Catless Mid's and mufflers will vary your results.

[mikead_99]

Originally Posted by bdoooh

Do you feel the secondary cats are all that restrictive? I'm considering replacing my N55 mids on my N55 with N54 mids to tone down the sounds & tone down the smell with those secondary cats.

Well, looking at that mid-pipe/secondary cats/resonator assembly it does look restrictive with the aftermarket DPs and exhaust inline. Not enough to make me want to replace them though, I don't know that a care about the few hp I may gain removing them. Most of the gains are found from getting rid of the primaries. Resonators would probably help as much as the 2nd cats to keep the sound at bay, but I get enough of a smell with them in there that I wouldn't want to have them off.

[bdoooh]

Originally Posted by mikead_99

Well, looking at that mid-pipe/secondary cats/resonator assembly it does look restrictive with the aftermarket DPs and exhaust inline. Not enough to make me want to replace them though, I don't know that a care about the few hp I may gain removing them. Most of the gains are found from getting rid of the primaries. Resonators would probably help as much as the 2nd cats to keep the sound at bay, but I get enough of a smell with them in there that I wouldn't want to have them off.

That's sort of what I am thinking.. I'll pickup some N54 mids & throw them on my N55. Losing a few hp isn't a big deal, I probably won't feel it anyways. And the reduction in diesel sounds & smell might be worth it.

[BRR]

I've noticed the smell is worse with dci rather than. Drop in filter in stock airbox.

[amsnow440]

If you run E85 it smells good!

Like it was mentioned earlier, if you have the N54 mids you don't really notice it on pump.

[lowbudgethero]

I smell some more fuel than stock at startup, but not nearly as bad as a full catless car. The N54 mids do their job.