[335pm]

Hey guys just wondering if chopping the cats off from my stock downpipes would be a good idea. Would it be as affective as aftermarket downpipes since they are 2.5 inch. Dont see it worth $800 plus labour to install. What are your opinions?

[_ink]

Good luck trying the get the bends of the pipe to fit without crushing them, this ain't an easy thing to do!

However, you could try gutting/punching the cats out?

[fo55il]

Tbh. I would have preffered diy if i had time and equipment.

Do u have workshop and pipe equipment.

[woosh]

Originally Posted by 335pm

Hey guys just wondering if chopping the cats off from my stock downpipes would be a good idea. Would it be as affective as aftermarket downpipes since they are 2.5 inch. Dont see it worth $800 plus labour to install. What are your opinions?

Nah, don't do that. A guy in Sydney (IIRC it was Clinton) tried it once and said it was a waste of time

[DR-JEKL]

It was only 2 years ago we paid something like $1600 installed for DP's, nowadays everyone is being a cheap arse on a BMW.

Sorry dont go hacking up a bmw imo, with all due respect if you cant afford to do it right just leave her oem and do other cheap BFYB mods instead (E85 etc)

[fo55il]

dr j. A 335 cost a shit load lots too. Now a new honda is more expensive.

Anyone can afford a bmw, chop it and gang bang it these days. *Gets off high horse*

[donR]

I think gutting cats is really only done when they are pre-cats so you still have your main cats downstream. I think in the N54 the downpipes contain the primary cats and maybe it only has the two cats so chopping them would mean no cats and smelly ones at that

I notice new COBB downpipes come with high flow cats internal so explains why they cost so much.

I assume you could source your own hi flow cats and get an exhaust shop to weld them up either on the downpipe or somewhere else and possibly save a bit of money but I don't think much if you can now get N54 downpipes for $800.

[ATTN]

fk that, imo get a cheaper DP vs doing what you're asking.. what a mission to do.

[fo55il]

If i worked at an exhaust shop i would diy. Only because i rather make something myself

[DR-JEKL]

Originally Posted by liteonled

I think gutting cats is really only done when they are pre-cats so you still have your main cats downstream. I think in the N54 the downpipes contain the primary cats and maybe it only has the two cats so chopping them would mean no cats and smelly ones at that

I notice new COBB downpipes come with high flow cats internal so explains why they cost so much.

I assume you could source your own hi flow cats and get an exhaust shop to weld them up either on the downpipe or somewhere else and possibly save a bit of money but I don't think much if you can now get N54 downpipes for $800.

E92's have rear cats also (E90's dont AFAIK) and tbh I didnt notice any funky exhaust odour after the catless DP's. I do however get black sooty shit sprayed on my garage floor upon startup when adding the bmw pe that i assume the cats/oem mufflers use to collect...

[bsm135]

If you're going to take out your stock down pipes to "de-cat", you might as well replace them with new ones.

The labour is the same either way, except you should be guaranteed fitment with a decent branded down pipe.

[335pm]

Okay, so ill just be ordering new catless ones. Only reason i wanted catless was so i can use 2 step. Apparantly if i have cats it would destroy them

[RuthlessE92]

Dude you can do it if you're good with measurements. The cats are straight no bends. Chop it off and replace with exact same length pipe. I know fabricators that do it all the time. You need to make a jig setup to get it right

[DR-JEKL]

If you're tight for $ keep your eyes out for a used set.

For what a used set goes for these days I wouldn't bother with hacking up oem pipes which wouldn't be as effective imo as a dedicated DP.

[Kiwi Peter]

When it comes to dump pipes and DIY good luck. We have had more than a few DIY dump jobs turn up on tilt trays, in a million bits with the embarrassed owner. good luck

[waterbottle1]

second hand VRSF is an option . cheap

[335pm]

Originally Posted by waterbottle1

second hand VRSF is an option . cheap

You selling yours?