E85/E86 Exhaust modifications

C

Conquistador

Member
Anyone modified their exhaust? :D

On every car I've had, I've modified the exhaust in some way. I just can't help myself! Last car was an Audi S8 - kept the original tailpipes but removed all silencers and resonators to make the V10 sound a bit more meaty :evil: (they are surprisingly tame as standard unless you boot it, then it screams!).

But anyway, I was passed by a E85 2.2 with a non-standard exhaust last night which sounded great so wanted to explore the options available for my 2.2. I'm quite sure I want to change the thin bare metal tailpipes for the 2.5/3.0 thicker looking tips too.

Removing silencers? Remove the rather large rear backbox?

What can you all recommend?
 
I removed about half the wadding from the rear silencer with MachineMonkey and was extremely pleased with the results.
Any form of backbox / silencer delete will drone to hell and back imo.

Machine Monkeys your man for tips too - quality bits of kit! :thumbsup:
 
I've modified 2 standard 3.0l back boxes with good results.

The first I just chopped off the top and gutted it, then welded the top back on so it's completely empty. This gives a nice rumble on tick over, louder than standard through the rev range and not too much of a drone on the motorway.


The second I gutted the same again but then welded in straight through pipes inside the back box giving a standard "looking" box but with the noise of a back box delete. So should pass an MOT :thumbsup: I then stuffed in a load of wadding to dull the drone out a bit and welded the top back on. This is much louder, popping and gurgling, the odd bang, lots of noise on and off the throttle. Sounds the nuts in my opinion, but quite loud.

I've also modified these boxes specifically for a Quad conversion and then bought a pre made Quad kit from the Machine Monkey. Top man - Top kit.

In the end, after deliberation I've decided to keep the first box and at some point will sell on the beefier sounding one.

No doubt the Monkey will be along soon enough for some great advise. :thumbsup:
 
today i have removed the back box and it sounds crazy good :driving:, first i was thinking about opening the back box and take out everything, but it only gets up round 7dcb so my mechanic made me two pipes and now it sound great. Cheap and great solution.
 
Would both the mods above, back box delete and taking out the externals still be able to pass track day noise limits of 100dB's?

Which gives the least drone?
 
What does a bypass pipe mod actually entail? Anyone around derby, Notts, Sheffield, Chesterfield got exhaust mods? Would like to hear them in the flesh. I do like the sound of the exhaust but I can tell it has more to give, I like a burble or two.
 
nick&sandra said:
Hi

All this sounds good and dandy, but I bet in real life you are loosing BHP and just make more noise!

The standard 3.0i exhaust in standard form is just fine ... supercharging is the only way to go on a z4

regards

Nick
Click to expand...

Just fine in your opinion, good for you. I don't think that's what the OP was asking. Plus how can you compare a supercharger for thousands of pounds to a back box delete for a couple of hundred? In real life you wouldn't notice a BHP drop, if there is one, which I don't think there is (wiki link me to an explanation on back pressure please do). (Yes I am in a bad mood!)

I had a back box delete done by the way on my 3.0si, great mod and easy to reverse, go for it!
 
nick&sandra said:
Hi

All this sounds good and dandy, but I bet in real life you are loosing BHP and just make more noise!

The standard 3.0i exhaust in standard form is just fine ... supercharging is the only way to go on a z4

regards

Nick
Click to expand...

Pretty random comment Nick.!!

The guy wants and bit more sound and you tell him to fit a supercharger lol.

Glad your not a doctor. I'd go in for a headache and come out with a boob job :poke:
 
I added some Remus back boxes which sound good but I did that on purchase of the car so I dont know what difference it made..duh .
I'm sure there will be youtube videos of all the different exhaust mods.
Good luck with it :thumbsup:
 
Yorkie Z said:
I'm loving what I done to mine :driving:


http://www.z4-forum.com/forum/viewtopic.php?f=2&t=62691&start=60
Click to expand...
I checked your thread out a few months ago, did you weld the backbox up after each attempt until you got it right?
 
Mark83 said:
Yorkie Z said:
I'm loving what I done to mine :driving:


http://www.z4-forum.com/forum/viewtopic.php?f=2&t=62691&start=60
Click to expand...
I checked your thread out a few months ago, did you weld the backbox up after each attempt until you got it right?
Click to expand...


No I used exhaust filler. It worked for about 10 minutes and then failed. Gave me long enough to get the sound I wanted thou :-)
 
Ah right good idea....so in your opinion, to get a nice throaty sound/burble (and pass mot, speed of modification) what would you do?
 
The straight through for me was a little loud. I didn't want the car to be making loads of noise at low revs because you feel a bit stupid (IMO). With what I done on mine it sounds normal at 2k but comes alive after that. Also gives you a few pops and crackles which sound great :-)
 
I have Supersprint headers, staggered Magnaflow cats, OEM resonator, Supersprint Y-pipe, and Supersprint race exhaust.

[youtube]GQku3zFUa_8[/youtube]

[youtube]n9VUSyE7N9I[/youtube]

[youtube]bbmnlwmpbrU[/youtube]

The two most important things are deciding if you ever plan to do aftermarket headers, and incorporating some sort of crossover in the exhaust. Aftermarket headers effectively double the volume of the exhaust setup, and they can introduce drone and raspy/fiery pops. If you want to do headers, do them FIRST, then choose a muffler to compliment it. Many people make the mistake of doing a race muffler first, and then doing headers... then it's just too much. Do headers, and then decide how much more you want with a muffler.

Having a crossover not only adds power (when paired with equal length headers), it significantly improves the sound. Without a crossover, the engine will sound like two 3-cylinder engines rather than an inline six.

All in all, I gained ~35 bhp with my setup. A naturally aspirated car would see about 20 bhp.

[youtube]roqXCCtc23M[/youtube]
 
Thanks all. I'd maybe consider supercharging if I had a larger engine, 3.0-litre for example, but for the 2.2 I'd be happy with just a little more noise and pops from the exhaust.

I think I'll probably go with a straight pipe and remove the large silencer completely. Droning at low or high speeds won't really bother me so I'll more than likely go down this route in the next couple of months. :thumbsup:
 
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