Novice To Moding - Miltek Exhausts & The Differences

[HullRs3]

Ok, I am going to have to be honest here people. I know sweet F.A. about exhausts and the different types, and which ones are better.

I was under the impression that the Miltek Cat Back Exhaust was probably the best to by for the RS3, but being around £1,000 not everyone goes for this option, so am I right that a Miltek Cat Bypass Exahust is just as good, just not as expensive?

I haven't a clue with regards resonating and non resonating exhausts really, & I also know you can get them in different finishes - black or chrome.

I want to replace my standard exhaust hopefully sometime this year in the next few months, possibly between July & before AIP if possible. This gives me plenty of time to save up an extra funds.

Basically, was slightly disappointed when received my car as it didn't sound anything like Audi RS3 playing in the snow in Canada - YouTube but just kept my disappointment surpressed. So looking for an exhaust that will not p*ss off the neighbours whilst in standard mode until I get to the end of my street, then I can wake the living dead as it were whilst keeping the flappy valve device in the existing exhaust.
I am not at the moment looking at turning my car into a jet propelled rocket ship, so fitting an ECU is not on my list of priorities, although I do not want to spent mega bucks on an exhaust..... The £1,000 quote I believe was from a local Audi Specialist Performance & Prestige garage.

So those who have there's modified which is better, or any advice please people?

Many Thanks,
John

 

[Kelza]

Hi mate 1k is just for the cat back, cat bypass is about £190 and just gives you a louder exhaust note ....
Audi RS3 Sportback S tronic Milltek exhaust
Non-res is the louder exhaust ....
i see your not too far from statllers in sheffield ,u should pop in and chat to steve jnr..
http://statller.net/

 

[Dan930]

A milltek catback exhaust will give better flow for the exhaust gasses & better sound,or if you really want to open up the exhaust gasses then get a full system(catback+sportscat).think it's around 2k,a cheaper option is to get the cat gutted by mrc,they charge around £400 to do the job...

 

[lae203]

John - I went for the cat back exhaust from Miltek, with secondary bypass pipes and resonated. This in my opinion gives the car a very 'classy' note, rather than a boy racer sound. I've had it fitted since early Jan and I love it, makes the car sound awesome - if you do get it you won't be disappointed. It's also fairly easy to fit, took around 30 minutes. On price I think I got all the work done for around £900, bought the parts online and then my cousin was able to do the fitting.

 

[klauster]

I must be the only person on here to think the Milltek RS3 system actually sounds worse... I had a non res milltek on my RS4 and that sounded amazing with the flaps open... not sure I can say the same about Milltek's attempt on the RS3. I have ended up going for the secondary cat bypass for now....

 

[lae203]

Maybe its not fair to try and compare the RS3 note to that of the RS4. As I've come from a Mini JCW to an S3 then an RS3 I might be a little less experienced, but for now the system is perfect for me.

 

[MBK]

I've had a few Milltek systems (modified Scoobies etc) in the past and I wouldn't personally spend the cash just for extra sound. If you were going for the remap too then it starts to make more sense (though I'd stay away from that with this prop failure issue that has arisen). There was an RS3 at Oulton Park a few weeks ago with the Milltek cat back and the added noise was quite subtle. I'd try and find someone who's already had this done and see what you think then. The cat bypass pipes sound a good deal if it's just the sound you are after.

You can't trust the sound on Youtube clips etc, it's as easy to adjust the sound as it is to photoshop an image.

 

[Mr_Freeze]

Glad you started this one john.

i'm trying to understand this as well, so refering to the picture on the website, can someone confirm my suspicions?

I'm guessing:-

A is the OEM exhaust

B is the cat Back system

C is the bypass pipes

So can you install the Bypass on the original. and in doing so i guess you have to cut the original as i see no joint just before the back box?
In cutting the original is it possible to remove the bypass and refit the original if needed using sleeve joints (if they exist)?
Will the Bypass fitting cause the car to fail an MOT on an emission test?

 

[CatnipRS3]

Glad you started this one john.
So can you install the Bypass on the original. and in doing so i guess you have to cut the original as i see no joint just before the back box?
In cutting the original is it possible to remove the bypass and refit the original if needed using sleeve joints (if they exist)?
Will the Bypass fitting cause the car to fail an MOT on an emission test?

Hi Mr F!

....yes you can install a bypass pipes (consist of 2 x pipes) on a OEM exhaust, they come with a flange fitted to one end and the other end joins onto the existing pipe with the original in-line collar fixing so they just replace the secondary cats and job done!....Milltek and Scorpion both sell these...they also fit each manufactures replacement systems.

Regarding the MOT then I'm not sure, but a friend of mine has a TT-RS with them on and his car passed the MOT with them in-place.

 

[Kelza]

milltek Secondary Decat pipes,not mine

 

[Mr_Freeze]

Hi Cat,

so if i understand you correct, there's another section to this which i missed off the original picture.

I'm guessing that "D" is the bypass pipes, so if thats the case, what is the section labelled "C" called?

 

[Macdaddy]

I must be the only person on here to think the Milltek RS3 system actually sounds worse... I had a non res milltek on my RS4 and that sounded amazing with the flaps open... not sure I can say the same about Milltek's attempt on the RS3. I have ended up going for the secondary cat bypass for now....

Nah i have to agree, I think the cat bypass sounds just right. The non V engined cars can sound a little bit farty with a full system i think.

 

[Dan930]

But would you get better gains in bhp & lbft if you get the milltek sportscat & turbo elbow instead of replacing the bypass pipe?i know it costs more..

 

[CatnipRS3]

Hi Cat,

so if i understand you correct, there's another section to this which i missed off the original picture.

I'm guessing that "D" is the bypass pipes, so if thats the case, what is the section labelled "C" called?

View attachment 12493

"D" Is correct!

"C" is a MAIN cat replacement pipe, so once fitted the car will have no cats at all, well assuming you have the secondary cats bypassed also.

 

[P_G]

"C" is not the main cat replacement pipe, it's replacement of the resonators on 'B' (the two cylinders prior to the merge / bend into one pipe to go to the back box) in the cat back system to make it non-resonated. Main cat replacement elbow is about half the size of 'C'

 

[P_G]

I'm not convinced by the sound of the Milltek RS3 sytem either, the Scorpion one sounds much better but it should do being Titanium and the price that it is. But then I have always wondered about the merits of titanium exhausts cost to benefit on family hatches. GTR's and GT3RS fair enough but an RS3?

To the OP, anything you change after the primary cats will give you limited gains but more / better noise. When you fettle the main cat that is where the power gains are. However be aware that there is currently no aftermarket exhaust that is type approved for this car so if you do not have a friendly MOT station in a couple of years time or get stopped by the lovely VOSA people they can ask you to take the CAT out and put back to OE and if you do not then fine you £5k per non-type approved cat. It's a small risk but a risk nonetheless.

Gutting the primary cat would get you round this because the OE part is in place (albeit empty) but it would fail emmissions if you have removed the secondary cats as well (good thing with secondary cat bypass is the increase in emmission with them not being there is nominal and within tolerance even though it is technically 'a race part'). Personally I couldn't be doing with the hassle of changing it in an out every tme for MOT. For me there are enough gains to be had with intercoolers, turbo's, induction / filters, remap etc. not to really bother. A good cat back, performance filter and remap plus intercooler would give you the same if not better gains than a poor map and a race / gutted cat. And by changing the primary cat in any way shape of form you will need a remap as well.

 

[45bvtc]

Will the Bypass fitting cause the car to fail an MOT on an emission test?

Mr_Freeze raises a very good question: as from January 1st 1993 the following has been applicable to "ALL 4-wheel, petrol driven, passenger carrying motor vehicles" sold within the EU:

"On the 26th June 1991 the Council of European Communities introduced an amendment (91/441/EEC) to an earlier Directive (70/220/EEC) relating to measures to be taken against air pollution by emissions from motor vehicles."

What this meant was that from January 1st 1993 all motor vehicles sold within the EEC had to employ a catalytic converter within the exhaust system in order to reduce exhaust emissions. However, during 1993, dispensations were issued to allow vehicles that had been manufactured before 1st January 1993 without catalytic converters, to be sold.

This dispensation would NOT apply to an RS3!


The existing rules applicable to the exhaust system when undertaking an MOT inspection are clear, and begin:

1. Check the security of the exhaust system

2. With the engine running, check the exhaust system for leaks

3. On vehicles that qualify for a full cat emissions test, check the presence of the catalytic converter


And the existing rules for rejection begin:

1. An exhaust system not adequately supported

2. A major leak of exhaust gases from any part of the system

3. A catalytic converter missing where one was fitted as standard!


So take care: even if a friendly MOT testing station provides you with an MOT certificate, a roadside inspection (even post accident) could mean that you're RS3 does NOT comply with current rules/legislation and may be deemed "unsuitable for road use".

Note: In 1993/4, the Type Approval of several motor vehicles was my responsibility...

 

[P_G]

Whilst 45bvtc is right the legislation was brought out when cars only had one catalytic converster, the B7 RS4 had 4! The RS3 has 2; if the main cat is undisturbed and the secondary one removed it will still pass emmissions. If you alter the primary and have no secondary you'll have problems. If you look at the way the secondary cat is installed and designed, it does look like an afterthought to try and further reduce emmission for Euro IV regs. as there are no sensor near it suggesting the bulk of the emmissions is dealt with by the primary cat.

 

[45bvtc]

I'm so with P_G in his logic and argument, however...

The crazy issue in all of this is that a catalytic converter is an unnecessary item. Engine designers were developing lean-burn low-emission engines in the 90's but, as the EU had already financed the build of a catalytic converter factory (in Belgium?), the EU introduced legislation to ensure the products of that factory were fully used.

So, P_G is quite right when he refers to the volume of emissions now produced by modern engines, it's just sad that we're governed by those di*kheads in Brussels, or is it Strasburg (depending on the month of course - don't get me started...).

However, I strongly advise caution as the 'trade' are well aware of the OEM exhaust arrangements of modern cars and that last thing I would want is for my insurance company, after some 'pillock' has used my car for braking purposes, to tell me that my non-OEM exhaust system has invalidated my insurance, and I'll bet those bas#ards would...

 

[P_G]

It goes without saying that all mods should be declared. Don't expect the cost of them to be though.

 

[nile]

Hello everyone, I just want to point out the label on the secondary bypass pipes, I have the cat back res with pipes fitted for at least a year now, sounds amazing I luv it.
But I was in for the 15k service the other week, complaining of brake noise and maybe a wrapped disc, the tech had the car up on the ramp and noted the bypass pipes both have a label saying not for road use!
Then he refused to test drive the car for the other issues I described.
Maybe there are other miltek road use pies, not sure but I collected my oem pipes from unit20 so audi can tick their box.
The exhaust spec was sent to my insurance and noted, but this was a shock and I inisisted on seeing the steel labels myself in the workshop.

 

[P_G]

The plates in question are on all the Milltek cat bypass pipes. However that said I would be interested to see how your dealer believes they invalidate the entire warranty of the car to the point they refuse to work on it? They will only affect the rear exhaust system and have sod all to do with your brake issue or any other issue you may have. If they don't budge take it elsewhere. From experience aftermarket exhaust systems and air filters do not invalidate the warranty on Audi's.

 

[Blackbird400]

Hi Mr Freeze,

We met at Audi International. You probably realise by now that "C" is the non-resonated version of "B" and that "D" are the cat bypass pipes and you are correct in assuming "A" is the OEM part. There is a join just before the back box and Milltek supply clamps to hold it all together, including clamps for the tailpipes.

I have the Milltek non-resonated system and have bypassed the secondary cats. The system is louder with the sport button "on" (both flaps open). It's like turning on a sub woofer. With the sport button "off" you loose some of the deeper bass notes, particularly noticeable at idle.

The exhaust sound can be a little boomy at times with the sport button on. Above 5000 rpm it seems to make little difference (sound wise) whether it's on or off (I'm not sure whether both exhaust flaps will be open at higher revs anyway?).

The car now sounds so much more interesting, particularly under load and hard acceleration, with a noticeable bark from the back-box when changing gear at higher revs. Annoyingly it sounds even better from the outside. If you want to quiet things down, just turn off the sport mode.

 

[45bvtc]

Hello everyone, I just want to point out the label on the secondary bypass pipes, I have the cat back res with pipes fitted for at least a year now, sounds amazing I luv it.
But I was in for the 15k service the other week, complaining of brake noise and maybe a wrapped disc, the tech had the car up on the ramp and noted the bypass pipes both have a label saying not for road use!
Then he refused to test drive the car for the other issues I described.
Maybe there are other miltek road use pies, not sure but I collected my oem pipes from unit20 so audi can tick their box.
The exhaust spec was sent to my insurance and noted, but this was a shock and I inisisted on seeing the steel labels myself in the workshop.

Do you mean these nile? Mine fell off prior to fitting...

A small hammer and sharp chisel did it for me

 

[DAYTONA 500]

Blackbird400 are you the guy with the Suzuka RS3 Mr_Freeze and I were talking to?.

 

[monkeyboy_marcus]

Secondary cat bypass pipe is the best mod I've done for the least cash. £200.00 plus fitting for a much improved sound and if required for MOT purposes, this can be swapped back temporarily to the stock item. Didn't affect my insurance premium and my local Audi dealership haven't mentioned it either. Quiet enough at low speeds too, so doesn't upset the neighbours. Can't say I've noticed any performance gain but that wasn't the reason for doing it for me. No label/tag on my Miltek pipe either...

 

[Kelza]

Anyone been for a mot with bypass pipes fitted yet ?

 

[45bvtc]

I'll be putting mine back on for my first Audi dealer MOT in September - a 20-minute job for me - and they'll be off again an hour later - another 20-minute job for me...

 

[Kelza]

Hi john my mot is due in 2 weeks lol

 

[45bvtc]

Hi john my mot is due in 2 weeks lol

Well, I really am NOW waiting on you John...

I've already asked Stafford Audi about presenting BLUEY for MOT with the secondary cats missing and their response was totally non-committal, only saying that their authorised MOT inspector "is not a stupid man."

However, I may take BLUEY to Stafford Audi sans secondary cats for an already invited "complimentary Audi health check" and see the reaction from the MOT man: BUT, my own hands-on technical knowledge says that irrespective of what NOx comes out from the back-end the MOT man must COUNT (1, 2, 3) the number of cats (primary and secondary in accordance with documented type approved data for a UK supplied Audi RS3) fitted.

OK, I know already, give your local man £25 and go blind in one eye and/or forget how to count; but for me, I like Stafford Audi and: 1) I'll be having them MOT BLUEY, 2) I'll not want to embarrass them by offering them a car with just one primary cat, 3) I'll not want to embarrass myself either, and 4) it'll only take me 20-minutes or so to fit and/or re-fit my secondary cat by-pass pipes.

Already looking forward to reading of how you get on with your MOT John, and where it was that you took the car, and if your man passes the car off with the secondary cats missing - which he really should NOT!

Lots of experts out there John, lets see how you go...

 

[Kelza]

Hi john , I will take my oem pipes incase they need to change them over for the mot I will be getting a full system miltek so that will be fine for the next not

 

[MrAudi]

my 3 has no cats AT ALL, but I've got until sept next year but might try my luck as unless you actually physically take the exhaust off you can't tell that the cats are missing

 

[Kohaku]

Although I no longer take an active part on here due to my 100 hrs .pw. caring duties,I do as an owner still read all the threads.

My reason for this post is my little bit of good fortune today. Warranty about to run out.so off to Truro Audi. with my 3 remaing gripes,and I am ****** fussy.all or nothing.and its.either Black or Ibis White (which it is)

1.Air Con.not working properly two centre vents gone to sleep. Has always made a weird noise from that direction.so have left A/C on for past 12months,which seemed to almost cure the problem antil last week when packed up.

2. Seat Belts did not retract with normal vigour,as if was all too much effort for them.I first discovered this last year.when cleaning around passenger door interior and found replica of belt fastener impression on door pillar and inner door edge (£180 to fix that)

For those like me who do not garage their loved ones...are you aware of the amount of damp that comes in.leave something on the seat at night,like a small thin pillow.and then check it in the morning after a wet night. I was shocked. So I put this down to the S/B problem...Sure enough. the stripped the lot down and applied a dry lubribcant, and they assure me that the problem will be cured...I await the evidence,probably tommorrow will tell.

3.Rusty rear wheel hubs ( again ).they have stripped them all down and painted the rears silver,must admit they do look first class.

Now for the good news Re MOT Bypass pipes.Mine has the Scorpion .about £25 to swap them over.I was aware that my MOT was very close.and aware that I will probably have to get them swapped twice,before and after MOT ( all in hand,well near the front of my mind, about 10th on the to do list )...Get a phone call from Truro Audi. are you aware that your MOT runs out 2moro.would you like us to do it now for you.........I thought here we go more aggro coming.test failure etc, Okay go ahead.what will be will be..beyond caring about anything now,except the car of course.phone call again 2- 3hrs later.. All done sir.PASSED MOT.with bypass pipes still on..I said how about the emitions,nothing to worry about its passed.however there were a couple of minor leaks.he did say where.presumably nuts my need another turn or two

So the cost of the double swap over which was NOT REQUIRED.paid for the MOT..


Finally keep reading about all this brake crap.I had the squeal initially had had the full recall done a year ago..My theory ( probably wrong ) but....who did the bedding in on your new kit...How many still with the squeal DID NOT do it themelves,I expect the majority will say they left it to Audi..I would put money on it... I did the full job,infact 10 times in total. up to 60 form braking down to about 10/15 mph..... Never had a problem since..If you think of it are Audi gonna have the time and the right conditions to do a proper job,I doubt it.Bearing in mind you have to pick the right time and the right place to be driving around like some drunk idiot.I remember on one of mine runs was still doing the 60 but was turning off in about 40 yrds.

Thats it folks. Be lucky,Drive safetly.not carefully..and remember.Brake change down.Apex.......and Whoosh.

Off to start cooking... yet Again.

 

[45bvtc]

GREAT news Ian, seriously hope that you and yours are well...

 

[Kelza]

My rs3 passed it's mot with flying colours with bypass pipes on

 

[S3 AD]

I have always been tempted by the secondary cat bypass pipes - for better noise only really, but I didn’t want the messing around with MOT's, however now it seems there is a decent chance of getting an MOT without changing I think I am sold on getting some. So does anyone know if there is any noticeable difference between the Milteks and the scorpion versions? my guess is no - as a straight piece of pipe is surely a straight piece of pipe no matter who makes it, but I could be wrong

 

[MrAudi]

I have always been tempted by the secondary cat bypass pipes - for better noise only really, but I didn’t want the messing around with MOT's, however now it seems there is a decent chance of getting an MOT without changing I think I am sold on getting some. So does anyone know if there is any noticeable difference between the Milteks and the scorpion versions? my guess is no - as a straight piece of pipe is surely a straight piece of pipe no matter who makes it, but I could be wrong

YES.....a straight pipe, is a straight pipe BUT make sure you remove the little plate that says NOT FOR ROAD USE before fitting as that could cause you a problem MOT wise

 

[45bvtc]

Mine (Miltek) fell off... oops

You MUST take 'em off (Miltek pipes only) as it says "NOT FOR ROAD USE" and service personnel have refused to take the car onto the car where these have been found - so take 'em off before fitting.

 

[S3 AD]

Thanks for the confirmation and the extra advice , now just going off to search prices and I'll order who whichever can be ordered and delivered the cheapest.

 

[S3 AD]

Why is nothing ever quite as simple as it should be. Do the secondary cat bypass pipes come is 2 sizes? I have found Miltek ad saying the diameter is 2.5'' or 63.5mm (delivered for £178 - £190) and Scorpion 2.5'' or 63.5mm (£157 - £175). At this stage I was think easy go for the £157 Scorpion. I checked one last place and saw a Scorpion listed as 3'' or 76mm (£157.50).

All the above pages have said they are all compatable with standard systems, that cant be right can it? how can 2 different sizes both be compatable with standard systems? I think the last place must have the write up incorrect.