[Alex.Devol]

Anyone know any ways to get the best exhaust sound from a 325d when replacing the exhaust? If theres anything that can be done when building a custom exhaust or if there are any particularly good aftermarket ones out there? Last car was a V8 petrol and i miss the sound.

[Dr Dave]

Alex - you aren't going to replicate the V8 soundtrack with a diesel - imo diesels sound gash with big bore exhausts etc etc perhaps I'm getting old?!?

[wayne71]

I'd get some v10 mp3's piped in through the speakers

[Alex.Devol]

Hi Dave, and of course you're right If only there were v8's out there that got 45mpg, but I am replacing the exhaust anyway for aesthetic & to help complement a remap so I'm hoping there's a way to improve the sound a bit. I love this engine but have to admit it can be an ugly sounding thing.. if anyone's had any experience improving diesel acoustics without making their 3er sound like a civic or impreza I'd love to know.

[Alex.Devol]

Originally Posted by wayne71

I'd get some v10 mp3's piped in through the speakers

Hah. Aren't they actually doing that on the new m5?

http://i.autoblog.com/2011/09/23/active-sound-design-enhances-v8-burble-inside-bmw-m5/

[acerboo]

ive spent a small fortune trying to do this! (wasted my money!!)listen to hotcoupe's video on his 335d, sounded like a spaceship when i heard it at brands hatch one day.

[Dave3]

If your trying to compliment a remap, surely the exhaust should have been done first? Maps are designed to get the best of what you have, changing the set up in anyway could do the opposite to what you want?

You can get a decent sound (for a diesel) but you need to get someone who has done it before to that exact car

ofcourse these are all opinions on here, its enirely up to you

[Alex.Devol]

Yeah it's to help benefit an upcoming remap, in about a month the car will be remapped after all changes are made, air filter & exhaust etc. On that subject I'm considering adding limited slip diff to help with traction, it's the only mod I'm planning that might come afterwards and Im still not sure if it matters whether or not that's done before or after the remap.. From reading up a bit more it seems like there actually are some really nice sounding diesel BMW, hotcoupe's for example.. But all seem to be 335s.. Since they are both 6pot 3 litre engines would the same sort of sound be achievable with my 325?

[Dr Dave]

I don't see why not.

Just don't go adorning your motor with lots of silly "M" badges, OK?

[Hotcoupe]

Originally Posted by Alex.Devol

Yeah it's to help benefit an upcoming remap, in about a month the car will be remapped after all changes are made, air filter & exhaust etc. On that subject I'm considering adding limited slip diff to help with traction, it's the only mod I'm planning that might come afterwards and Im still not sure if it matters whether or not that's done before or after the remap.. From reading up a bit more it seems like there actually are some really nice sounding diesel BMW, hotcoupe's for example.. But all seem to be 335s.. Since they are both 6pot 3 litre engines would the same sort of sound be achievable with my 325?

Alex,I can only echo what Jeff (acerboo) said about exhausts,and the potential to waste money.

To achieve your goal,and increase the performance of your car,I'd forget any aftermarket back boxes etc,and go for a straight through custom exhaust system.
Find a good exhaust fabricator and have the pipework,backboxes replaced with a straight thro pipe from the DPF straight through to the rear,you could go for a straightforward single pipe with single/ dual tips,or if you prefer a twinpipe system (the single pipe from the DPF would split half way down the car) with either single tips,or doubles,any of the above won't make a difference on the power side,but could impact aurally.

The benefits of the above are,quicker spool up time on the turbo/s which reduces lag,an engine that revs better (due to the non restrictions of the now missing backbox/s)and arguably better MPG and more power.

A good custom straight through system is good for approx 10/15bhp.

An LSD is certainly an excellent mod (should be a standard feature,or at least an option on a RWD car,especially a BMW),one I would 100% recommend if you can afford it.
I don't think it matters whether it's fitted pre or post map, but you'd enjoy your car better if it was fitted tomorrow!

[Dr Dave]

Oooooh! Twin pipe conversions. Tut Tut

[Alex.Devol]

Originally Posted by Hotcoupe

Find a good exhaust fabricator and have the pipework,backboxes replaced with a straight thro pipe from the DPF straight through to the rear,you could go for a straightforward single pipe with single/ dual tips,or if you prefer a twinpipe system (the single pipe from the DPF would split half way down the car) with either single tips,or doubles,any of the above won't make a difference on the power side,but could impact aurally.

The benefits of the above are,quicker spool up time on the turbo/s which reduces lag,an engine that revs better (due to the non restrictions of the now missing backbox/s)and arguably better MPG and more power.

Thats exactly what i was after, thanks! The exhaust will be custom, just wasn't sure if there is anything specific i should be asking for to achieve a good sound, aside from how i want it to look.
I'll post once its fitted, it will be a twin pipe, but no M badges i promise!

[BanziBarn]

I know the consensus is that you can't make the dervs sound good but this sounds pretty good to me? Obviously not as good as a petrol car but certainly much better than my 330d.

[Alex.Devol]

Not the worst sounding car.. Your 330d probably doesn't get followed around by a cloud of smoke though.. What is it that causes that? Removing the dpf?

[Skylinescott]

Yes, im pretty sure that is caused by removing the DPF. I think removing the DPF will give a slight sound difference too, as i have been looking on YouTube and most of the good sounding 6 Pot Dervs dont have DPF's, only a straight through system.

Orrr screamer pipe it... would sound like a jet plane.

[111singh]

Originally Posted by Alex.Devol

Thats exactly what i was after, thanks! The exhaust will be custom, just wasn't sure if there is anything specific i should be asking for to achieve a good sound, aside from how i want it to look.
I'll post once its fitted, it will be a twin pipe, but no M badges i promise!

Hey Alex, would love to see and hear your comments about this custom exhaust as i was considering something like this myself. Definitely want a remap therefore an exhaust upgrade along with a few other bits is on the cards.

[jamesbilluk]

Originally Posted by BanziBarn

I know the consensus is that you can't make the dervs sound good but this sounds pretty good to me? Obviously not as good as a petrol car but certainly much better than my 330d.

This E420 CDI does sound good too

[Skylinescott]

James that e420 is a v8 diesel :P

[craig2859]