[matty81]

Hey all,

Just wondering if anyone here is running a catless downpipe? I'm seriously considering getting one when I get a remap for the extra bhp and mainly the sound. There doesn't seem to be much choice in the UK but a few on ebay for around 200, would it better to stick to a known brand it would it not really matter?

Cheers

[GEP77]

You're probably better off looking in the n55 tuning section. Most of the people running catless / high flow cats will be in the US. There are quite a lot of aftermarket products for both, although it does seem that high flow cats are more numerous than just open downpipes.

For what it's worth I wouldn't bother though. Unless you find a friendly MOT station - which is getting less and less likely given the renewed focus on NOX emissions by the government it won't ever pass an MOT without a functioning cat.

I'm not familiar with your car, but generally if you want more real world performance the thing that the F3x needs more than anything else is the suspension sorted. If you want more noise then there are plenty of aftermarket exhausts which will no doubt give you what you're after without affecting the legality of your car.

[matty81]

Yeah the emissions thing did put me off a bit, a already have ACS springs and the MPPK, but the m performance exhaust is pretty quiet, hardly any different to stock, so just wanted the car to sound a bit beefier. Maybe a sports cat would be the way to go, ive seen a few for around 300-400 do you think they would be any good?

[NISFAN]

Originally Posted by matty81

Hey all,

Just wondering if anyone here is running a catless downpipe? I'm seriously considering getting one when I get a remap for the extra bhp and mainly the sound. There doesn't seem to be much choice in the UK but a few on ebay for around 200, would it better to stick to a known brand it would it not really matter?

Cheers

I suggest you listen to a B58 with catless DP first. It sounds terrible IMO, ridiculous amounts of popping and crackle, 1.1 litre Corsa with drain pipe exhaust style.

There are also technical issues going catless....CEL's, lots of them. You have to make sure that the map overrides all the BMW watchdogs that monitor cat and engine function.

And finally your insurance will be completely void as your car would be illegal for road use. Check insurance T&C's they all mention this.

If I were you I'd look at a sports cat to keep it all legit, but even those aren't necessary unless you want to squeeze the last 5-10hp out of a tune.

For sound, you can delete the two resonators, or go for a full cat back system.

Edit: you have Bmw MP exhaust and N55. Follow advice above.

[GEP77]

Originally Posted by matty81

Yeah the emissions thing did put me off a bit, a already have ACS springs and the MPPK, but the m performance exhaust is pretty quiet, hardly any different to stock, so just wanted the car to sound a bit beefier. Maybe a sports cat would be the way to go, ive seen a few for around 300-400 do you think they would be any good?

Definitely ask on the N55 tuning section of the forum. I believe the M performance exhaust for the n55 left the mid silencer in place. Deleting that might be an option to start with.

[matty81]

Originally Posted by GEP77

Definitely ask on the N55 tuning section of the forum. I believe the M performance exhaust for the n55 left the mid silencer in place. Deleting that might be an option to start with.

yeah it has a resonator in the mid pipe, some people have removed it but say it only adds about 10% in sound, the mpe seems much louder on the 340i, maybe ill look at cat back exhaust systems and leave the cat in place,

[matty81]

So this sports cat might be a good option for 320

http://www.ebay.co.uk/itm/BMW-F30-33...3D263104327769

[NISFAN]

This guy is selling one too.

http://www.2addicts.com/forums/showthread.php?t=1396152

[matty81]

Originally Posted by NISFAN

This guy is selling one too.

http://www.2addicts.com/forums/showthread.php?t=1396152

Thanks mate. I think this may be the wa to go. Loads of people with 135s have them and say they sound really good

[LiquidMercury]

Getting my VRSF catless dp installed this week (320i) so I can tell you what the sound (and smells lol) are like by the weekend. I went with x-ph.com for my DP (getting my ER CP and FMIC installed too from same dealer I purchased off of).

[matty81]

Cool I looked at vrfs when I was thinking if a decat but only one place here sells them and they are more expensive than in the us

[CazuaLLUK]

matty81 dont you mod your car more than me!

[matty81]

haha ive got a long way to over take you!

[Kid_droid]

I have been looking for decent catted downpipe in the UK but the prices are too much at the moment. but 600 plus before labour cost for a downpipe is a little too much for my bank.

Catless is cheaper, but I do not want MOT stress.

[matty81]

Yeah same, ive found this Richter one for 435, at the mo I think I'm gonna get that one,

https://www.jb4shop.co.uk/products/c...-m2-sports-cat

[matty81]

that and a JB4/remap should be close to 400 bhp

[cesare87]

Worth every penny on a n55, that's all I'll say.

[WTruter]

Has anyone fitted a decat with the MPPSK? I'm interested to see what it does to the sound. (As the MPPSK is basically a straight through when valves are opened).

[M3anLantern]

Originally Posted by WTruter

Has anyone fitted a decat with the MPPSK? I'm interested to see what it does to the sound. (As the MPPSK is basically a straight through when valves are opened).

+1 as keen to have someone else who knows more guinea pig this before I try this.

I've seen a lot of videos and details on the issues (a lot of CEL's as Nisfan has said) but can't really know the difference in sound without hearing it in person. I'd love it if someone in the UK has MPPSK and a VRSF catted downpipe as that is the setup I think I'd want.

[NotGotABimmer23]

Originally Posted by dk1894

+1 as keen to have someone else who knows more guinea pig this before I try this.

I've seen a lot of videos and details on the issues (a lot of CEL's as Nisfan has said) but can't really know the difference in sound without hearing it in person. I'd love it if someone in the UK has MPPSK and a VRSF catted downpipe as that is the setup I think I'd want.

Its going to be LOUD.

[M3anLantern]

Originally Posted by kylemacca01

Its going to be LOUD.

I want louder but the thing is I don't know how loud, LOUD is without hearing it in the flesh! Hopefully some kindred spirit on here has done this already.

[NotGotABimmer23]

Originally Posted by dk1894

I want louder but the thing is I don't know how loud, LOUD is without hearing it in the flesh! Hopefully some kindred spirit on here has done this already.

A few on baby bmw have done downpipe, I think general consensus is it sounds like a tractor.