[D's Bimmer]

Since my car is in the shop getting cleaned up from a Serpentine Belt "explosion" my ace mechanic asked if I wanted to put a downpipe on the car given that the bottom was dropped out and the labour is already covered.

Mike at N54tuning hooked me up. We have it installed next week.

Hope it is everything I hear about it. Might need to put resonators on the car as the Performance Exhaust is load already.

MHD Tune coming next week as well.

Hope all goes smoothly.

Does anyone ever regret installing Catless downpipe???

[D's Bimmer]

In reading several threads on here, just how bad is the "smell"? I understand it is stronger for the n55's as we do not have secondary cats. Is this true?

I am hoping it is worth it and not a major irritant.

[bahn]

Originally Posted by D's Bimmer

In reading several threads on here, just how bad is the "smell"? I understand it is stronger for the n55's as we do not have secondary cats. Is this true?

I am hoping it is worth it and not a major irritant.

I dont mind it, my wife on the other hand hates it.

[diesel3443]

I dont mind it.

[Peen]

Downside - It's VERY loud on cold start, with E85 and especially in a parking garage. MHD fixes that though.

[D's Bimmer]

Originally Posted by Peen

Downside - It's VERY loud on cold start, with E85 and especially in a parking garage. MHD fixes that though.

I am having my car coded with MHD while it is in the shop. Looking forward to seeing how she performs!!!!!!

I will likely get resonators to reduce the sound a little. Might look into adding a secondary cat of sorts to see if that would address any smell issue. But I have no idea about any of that yet so need to do some research and take it into a performance Exhaust shop.

[AtlasM]

I have secondary cats in my stock xDrive exhaust. Still get a bit of gas smell like when I pull into the garage but it's not overpowering. No complaints from the wife about it. I also get to tell her I'm trying to be sorta good for the environment since I still have some kind of cat in there.

[Boosted2000Si]

Very loud on cold starts
Stinks badly
Burns your eyes
Sends black smoke everyone on acceleration


Id like to know how bad a serpentine belt explodes where they have to pull the cradle.

[D's Bimmer]

Originally Posted by Boosted2000Si

Very loud on cold starts
Stinks badly
Burns your eyes
Sends black smoke everyone on acceleration


Id like to know how bad a serpentine belt explodes where they have to pull the cradle.

I posted up pictures on another thread. It was bad and is common when it happens.

[Turbod]

Originally Posted by Boosted2000Si

Very loud on cold starts
Stinks badly
Burns your eyes
Sends black smoke everyone on acceleration

Originally Posted by D's Bimmer

Since my car is in the shop getting cleaned up from a Serpentine Belt "explosion" my ace mechanic asked if I wanted to put a downpipe on the car given that the bottom was dropped out and the labour is already covered.

Mike at N54tuning hooked me up. We have it installed next week.

Hope it is everything I hear about it. Might need to put resonators on the car as the Performance Exhaust is load already.

MHD Tune coming next week as well.

Hope all goes smoothly.

Does anyone ever regret installing Catless downpipe???

The smell is mild if your car is in good working order. The cold start is loud but it only lasts 15 to 30 seconds. MHD's cold start noise reduction works great and will solve that issue. The pipe from N54tuning is a great piece and I think you'll be happy with it.

[jairomvp182]

i have x drive with secondary cats, no smell at all, i will never go back to stock,

[rich_mane]

I don't mind the smell at all and I don't stick my face near the tailpipes so my eyes don't usually burn from it haha.

But I love the sound the catless downpipe gives you. I have an Active Autowerke 4" and the sound it makes is just amazing even with the rest of the exhaust stock.

[drallafi]

The smell is pretty noticeable since I drive with windows down all the time.
Also I get nervous whenever a motorcyle cop is behind me; I feel like they're going to pull me over.

[D's Bimmer]

Originally Posted by Turbod

The smell is mild if your car is in good working order. The cold start is loud but it only lasts 15 to 30 seconds. MHD's cold start noise reduction works great and will solve that issue. The pipe from N54tuning is a great piece and I think you'll be happy with it.

Thanks for the feedback. Definitely will post up my thoughts in a few weeks. My mechanic says I will be very happy with it. The sound is amazing. The smell is highly overrated as an issue is says.

[D's Bimmer]

I am curious if I find the smell to be an issue, is it possible to add in a secondary cat to deal with that without hampering performance too much. Do I have it right that the e92's have secondary cats?

[JLGM4]

Originally Posted by D's Bimmer

I am curious if I find the smell to be an issue, is it possible to add in a secondary cat to deal with that without hampering performance too much. Do I have it right that the e92's have secondary cats?

Honestly, I'd just wait until you get the downpipe on to see what you really want. Cold start is pretty brutal and I apologize to my neighbors in my head every morning, but with the windows up there is no drone and you get some great sweet spots in the rpm band that really scream when you get past 4k rpm that I personally was really missing out on when I just had the PE. The best way I can explain it is rather than the turbo air noise overriding the exhaust when I had the PE, the exhaust note definitely shines through like it should with the added catless. Yes you have a secondary cat on your e92. I wouldn't add another, if anything I'd add a resonator.

[D's Bimmer]

Originally Posted by jairomvp182

i have x drive with secondary cats, no smell at all, i will never go back to stock,

Thanks. You have a great looking and sounding car man!!!!

[jairomvp182]

Originally Posted by D's Bimmer

Thanks. You have a great looking and sounding car man!!!!

Thank you very much!

[D's Bimmer]

Originally Posted by jgottsman11

Honestly, I'd just wait until you get the downpipe on to see what you really want. Cold start is pretty brutal and I apologize to my neighbors in my head every morning, but with the windows up there is no drone and you get some great sweet spots in the rpm band that really scream when you get past 4k rpm that I personally was really missing out on when I just had the PE. The best way I can explain it is rather than the turbo air noise overriding the exhaust when I had the PE, the exhaust note definitely shines through like it should with the added catless. Yes you have a secondary cat on your e92. I wouldn't add another, if anything I'd add a resonator.

I agree with you in that I will wait a little while. Let me get used to the new sound and feel.

I am about to program the car with the new MHD Tune for the N55. This way I can really take advantage of the downpipe. With regards to the Cold Start option, I understand I can delete that through MHD. Is the Cold Start simply to allow the cats to warm up? And if so, since I no longer have them, I can activate the Cold Start Delete option and muffle it down a little at startup.

[Bours]

I have a e90 x drive the n54tuning catless dp and it sou ds amazing with stock exaust and smell only when i back up with windows down..smells good tbh


Will i make more power if i remove secondary cats ?? More noise ? What happens ?

[EZgo]

This thread has me questioning whether I should install the DP I have for my 2011 335i convertible. My wife drives it to work everyday and has a very professional position. I don't want her looking like driving up all loud Fast & Furious style. Also, concerned about the smell.

I had DP's on my 2007 335i convertible and the sound was fine and we rarely ever noticed any sort of smell. No problem if it's comparable to that.

[Ozzie335i]

The loudness is only when you start the car for 30 seconds or so, and at WOT. As far as smell, go with a e85 blend. Get the A 74 solution and pass inspection. Then move on to the next mod.