Exhaust options.

[MikeFish]

How much difference can there be to say a Milltek non res and the OEM sports system with the centre sections taken out from a power / mapping gain point of view? I can't believe there would be that much difference specially with the valves open.

Andy, I don't believe there is much difference if any at all between the OEM system and a milltek cat back with or without centre res and flaps open. This is all about sound and not power. The power gains come from the milltek turbo back ie by replacing the downpipes with whatever arrangent of cats they have with a set of sports cats. I doubt the main Audi cats are restrictive, I reckon if there is a pre cat or similar then that is where the loss is happening.

[vestax32]

[quote="MikeFish"]I had the centre resonator removed as well as the 2 boxes in front whatever they are.
It sounds great now. I have the valves disconnected and didn't notice any drone at all. I did nearly 200 miles today but it was all A and B roads, no motorways so there was not much cruising at 90ish bit I did get some speed and didn't notice any. In fact if I shifted into D instead of S (but valves still open) you could barely hear it. Not too loud but it can now be heard inside the car a little bit and much louder pops.[/quote

Sounds just right, will explore this avenue I think. Car being delivered on Friday next week, excited is an understatement ;o)

[MikeFish]

Hopefully this is a better picture of the inside of the front boxes. I'd assume any sort of cat will have sone sort of baffle or filter through the centre of it whereas this clearly doesn't. I'd expect the same from a resonator but could be wrong. Anyone know what the purpose of this is? There are holes around the edge and its thick and heavy so must have some sort of purpose.

[MikeFish]

I've just looked inside the big centre resonator and it looks pretty much the same but on a bigger scale so I think these front boxes are also resonators.

[boff]

Buddy so the engine "pulses" the exhaust flow even at a gazillion rpm is "lumpy" the purpose of these boxes is to absorb that pumpiness, and therefore smooth the flow of gasses.

It gives a steadier tone, but also works to clear more gas from the engine - like "buffer"

B

[boff]

I think I am so going to enjoy what i have, until I can akra the system with the audi sport exhaust

[alexrs6plus]

Mike, do you mind me asking what the final price was and where you got the exhaust done please?

[MikeFish]

Alex I've PMd the details of where I had it done but it doesn't require any special skills, any decent exhaust fabricator will do it eith ease.

I paid 360 in the end (200 for main res, 100 for smaller then add vat). That is the upper end of prices I think. I haven't seen it yet though as I was in a hurry to get to MRC but I believe the front part is welded through the he welded a set of flanges either side of where the centre res was so you could re install it easily at a later date if required.

[boff]

Hmmm - OK - Mike, I'll reserve judgement until we meet fella, from what I have read the car is too quiet; I try to err with caution on warranty, hmmm - tempting

[MikeFish]

Just been out in It again. Getting even better I think, the missus just said how much better it is now.
I gave it some revs while parked, sounds soon much better, popping and banging much louder. Still not heard any droning but you can defo hear it while accelerating in not sport mode (valves disconnected) but once you stop accelerating and just cursing it is much quiter. Connect the valves and I imagine it will be almost silent with valves closed.

[alexrs6plus]

Cheers mike

[boff]

http://fourtitude.com/news/Audi_News_1/ ... rformance/

[MikeFish]

Good news for those that want the Akra, but I prefer the sound of the milltek, and even better is the sound I have now.
I doubt the akra will add any power unless they've made it turbo back which is unlikely for the $9000 dollars stated.

[vestax32]

Just been out in It again. Getting even better I think, the missus just said how much better it is now.
I gave it some revs while parked, sounds soon much better, popping and banging much louder. Still not heard any droning but you can defo hear it while accelerating in not sport mode (valves disconnected) but once you stop accelerating and just cursing it is much quiter. Connect the valves and I imagine it will be almost silent with valves closed.

Mike, so I'm guessing if I do the same as you have done to my standard non sports exhaust I will end up with the same sort of effect? I presume the only difference remaining after the mods could be the back boxes, as we still haven't established wether or not the back boxes differ between sports and non sports exhausts? So if anything it could be slightly quieter overall, but still a drastic improvement?

[Andy_W]

With the valves open should be a massive difference I would think. I would certainly give it a go before buying anything and see if you like it.