# TT RS - Stock Exhaust Modification?



## Janker (Oct 27, 2006)

Has anyone looked into (or done) a modification to the Stock TTRS exhaust back box internals to achieve a better sound? - I've been reading up and the Stock v Audi Sport exhaust and it looks to be just a small internal change to the same back box (2 or 3 stamped dimples shown which version you have) - other than that its the same.

I'd be surprised if no one has cut open a stock TTRS back box and modded it? The 911 Turbo boys have been doing that for years, I did mine on a 996T and it sounded amazing.

Modding Stock system would arguably have the following benefits:
1) Keeps stock cats / system for MOT (option to remove secondaries I guess, but that might require a friendly tester?)
2) Very low cost option, labour only so in region of £300 I'd have thought
3) Stock from an insurance perspective (all cut / mod / weld work is done from above / top so invisible once refitted)
4) Easier to sell car as not really 'modified' with aftermarket parts - just sounds nicer
5) Retains the Flap / Sport button (I'd only gut one side of the box so Normal and Sport tones available assuming that's how its configured internally?)

Stock systems can be had for £100 on ebay - seriously tempted to buy one and get it modified...  Even better if someone wants to donate a back box...?

Other option - Aftermarket back box (only)

I'm surprised no one makes just a replacement back box for the TT to swap out the stock exhaust - same foot print with the valve but with less internal baffling and wadding - reckon for £650 or thereabouts these would sell well. The aftermarket exhausts seem like massive money at £2k+

Just a thought anyway..

Perhaps we're overdue a TTRS aftermarket and Stock mod sound clip thread? :twisted:


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## qooqiiu (Oct 12, 2007)

I've gone through lots of variations, so here's my thoughts.

Completely stock system. All cats in place and factory sports back box. 
Not nearly loud enough for my tatste.

Stock system with secondary cat delete pipes and factory sports back box. 
Louder overall with a real nice tone Change when accelerating. A little drone at around 2k rpm but I actually liked that.

Aftermarket Downpipe/ sports cat and factory back box. 
Almost as quite as stock.

As above but fully de catted = best yet. Doesn't drone any more than stock with secondary cat delete pipes. Still I crave more volume.

As above but with the resonators removed and replaced with through pipes. 
More volume which was about right to my ears but under acceleration there was a nasty sounding rasp. Some might like this but it sounded uncultured to me. I had the resonators re installed a week later. A thread on vortex forums has two guys that have done that mod a few years ago and one said that it sounds like a powerboat under acceleration and it kinda does. But that's not cool as this is a car!

I have now sitting in the garage the new revised scorpion cat back exhaust. Just a single back box design now instead of the 2. Also only a single resonator instead of 2 and this system is only available in resonated flavor. Scorpion say that the non res they trialed droned too much so only offer it in res form. I'm hoping this mated to the APR DP fully de catted will give the sound I crave. The next time I have a day off I'll fit it and take a video.

I would not open the back box and remove some wading. I think it'll sound shit.


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## qooqiiu (Oct 12, 2007)

https://forums.vwvortex.com/showthread. ... 590?page=3

Worth a read and pictures of the back box cut open.


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## Janker (Oct 27, 2006)

qooqiiu said:


> I have now sitting in the garage the new revised scorpion cat back exhaust. Just a single back box design now instead of the 2. Also only a single resonator instead of 2 and this system is only available in resonated flavor. Scorpion say that the non res they trialed droned too much so only offer it in res form. I'm hoping this mated to the APR DP fully de catted will give the sound I crave. The next time I have a day off I'll fit it and take a video.
> 
> I would not open the back box and remove some wading. I think it'll sound shit.


Be interested to hear how you get on with that, what's the price point? Is it 2nd cats back (assuming you had them)?


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## qooqiiu (Oct 12, 2007)

The beauty of the APR Downpipe is that it has a splitter section that allows you to use the factory rear section or an aftermarket cat back system.

Scorpion and Milltek are your only realist option for a back box. New scorpion is 80mm. Their old cat back was 76mm. It's about £900.

There may be others but that means importing them.


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## Enky08 (Dec 7, 2018)

TTRS Stronic

oem non sports exhaust - too quiet

oem downpipe decatted and scorpion secondary cat delete pipes fitted with oem non sports exhaust - great noise on full throttle but still a bit quiet. Low rpms sounds tinny and high pitched, not like any exhaust noise I've heard before. Little bit of drone at 2krpm but not loud enough to be annoying. This is all with sports button NOT pressed as I can't stand the harsh magride.

Have you already done the flapper mod I take it?


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## Janker (Oct 27, 2006)

Have you already done the flapper mod I take it?[/quote]

No not done the flapper mod yet, does that make much difference with the stock exhaust?


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## qooqiiu (Oct 12, 2007)

Flapper mod is just the valve in the left part of the back box open all the time. So whatever yours sounds like with the sport button pressed is what it'll sound like all the time.


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## Danny1 (Sep 2, 2010)

Flapper mod = the vale open all the time isnt it as far as I was aware, pressing S doesnt open the valve all the time, its just open at idle and in 1st, and then when you use more throttle in the other gears it opens etc??

I have a full 3" turbo back valved scorpion titanium system and it sounds epic, I dont think anyone would want anymore sound :lol:

I think people dont bother modding the standard system because there is so much performance to be had from changing the downpipe and getting rid of secondary cats, then add to that you use the standard tail pipes its a win win because it all looks OEM.


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## r_turner01 (Sep 12, 2018)

Mine has the supersprint one if any thing it's a bit too but for my liking. Louder than factory but not as loud as some I've seen


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