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After extensive development work with our own demo car MRC is proud to present its Stage 2 RS6 upgrade.



We are very pleased with the dyno results and quietly confident that actual road performance is quite possibly higher. This is due to better cooling on the road resulting in lower intake air temperatures.

Our tests show intake air temperatures hitting 60 degrees on the dyno dropping power off from 5000rpm however logs done on the road reveal intake temps a huge 20 degrees lower.

Parts needed for this upgrade:

Full exhaust system consisting of ‘no cat’ downpipes or 100cell high flow cats - From £1650+vat fitted

Uprated air filters – From £53+vat each

MRC stage 2 custom map incl the ‘plus’ gearbox map – From £800inc vat

Cheers Lucas I wanted to get to CC to see this!

I presume no cat down pipes are MOT friendly, could someone explain the difference between the two exhaust options? And is there a big volume increase? A sound file would be great at some point.

No cat downpipes are meant for race use only however we are MOT friendly and can fit cats at no extra cost on the day.

If it's possible to bring the car to us once a year then no cats is the best option in terms of performance and cost, they are significantly cheaper than going for the 100cell cats which would increase the cost of the full exhuast system by some way.

The DB meter reads 88db@4500rpm static

Please email us for firm pricing.

I remember being told that putting cats on for the MOT and then taking them off might be an issue. The scenario is that the insurance company might deem the car uninsured as it is "not roadworthy".

Have I been wrongly informed, or is it a risk that people are willing to take?

PhilT wrote:I remember being told that putting cats on for the MOT and then taking them off might be an issue. The scenario is that the insurance company might deem the car uninsured as it is "not roadworthy".

Have I been wrongly informed, or is it a risk that people are willing to take?

For the sake of a few ponies which are hardly going to be felt on the road anyway, is it worth all the hassle/risks?

I'd play it safe and leave em on and stick with a cat-back.

We like to offer our customers a choice to suit their requirements.

Those wanting more power above an MRC stage 1 and a catback exhaust need to address the flow of the stock downpipes. The following options are available:

'no cat' Downpipes - race use only

100cell high flow sports cats - road legal

Removing the precats from the stock downpipe - road legal.

We tailor any modification work to the customers needs so it's best to get in touch to let us know what you want and don't want.

Excellent results for a Stage 2 & unless i'm mistaken that takes the crown for best bang for your buck at Stage 2.

Nice job.

but isnt the MRC stage 2 the same as stage 3 at other tuners? Ie map+full exhaust?

Still, somewhat better value than MTM...

Removing the pre-cats from the downpipes also evacuates more heat from engine compartment/turbos.

bobjebb wrote:but isnt the MRC stage 2 the same as stage 3 at other tuners? Ie map+full exhaust?

Still, somewhat better value than MTM...

Kind of in materials, but defo not price. Although i've been out of the RS6 modifying scene for a few years, to get those kind of gains from a re-map & full Milltek were not really possible back then, 510-515 was pretty much the absolute max & even then you'd be looking at another £Grand to get it.

I think £3K for an 82BHP gain is pretty awesome.

I am having the engine and gearbox remapped and stripped pre-cats done just now by MRC - along with replacement gearbox.

It will be interesting to see how she runs. Car will be std apart from K&N replacement filters.

Milltek cat back is only half a job, but I would say that with a full Milltek and 100 cell sports cats!

The full system provides a much better sound and it leaves me ready to pop round to MRC for a remap, any day now!!

IMHO I'd leave the cats in, but must be 100 cell though

Gavc450 wrote: IMHO I'd leave the cats in, but must be 100 cell though

For those of us who haven't made that move yet, could someone take the time to explain the difference between the 100 and 200 cells both in terms of performance and noise.

NB: 'Noise' for me is best described as:

Current sound of V8 produced by the RS6 = perfect
Sound of popping corsas, scoobies and evos = nah.

Disclaimer: my opinions only etc etc

100 cells per square inch means less restriction than 200 cells, thus allowing the exhaust gases to flow by with less in the way. The cats do just enough.

Less restriction could allow more of that V8 sound, plus my centre box is non-resonated, which helps that V8 sound all the way through and some to be heard in the cabin. A description versus the stock exhaust may be.... imagine the stock sound amplified 3 times!

In terms of performance a free flowing sports exhaust helps the bhp gains but only by 10-15bhp, which to my mind is not that noticeable, that's what the remap is for. The free flowing exhaust definitely helps get the max from the remap..... as well as liberating the sound that most buy the V8 for.

Definitely no popping, bangs or silly dump valve noises.

Oh, by comparison its quieter than my TVR 4.5 V8 which just has one main cat in the way with the one silencer sleeved to provide a straight through exhaust. Taking the pre-cats out made a very noticeable difference to torque and allowed the motor to spin more freely. Same should apply to the RS, but the turbo's also help!

The RS6 remains family friendly with the sound and fantastic under torque load, addictive even. The main consideration after deciding to free up the exhaust with 100 cell cats, is whether you go resonated or non-resonated. This is a very key decision based on your sound requirement or tolerance.

I've no comparative idea of performance differences between 100 and 200 cells, but if 100 cells are available, why would anyone choose 200 cells which restrict gas flow?

NB: I heard several cat-backs but they just didn't do it for me, so waited and then went for the full system, on the basis that if you are going to do it, then do it!! Always had a remap in mind some day, but fear my license will vanish overnight

The 100 cell cats assist in providing a deeper note from up front and is noticeable if you stand next to the car while its running.

stock downpipes have 400 cell precats and 200 cell main cats.

if you remove the precats then you have a significantly better exhaust. It is not just restrictive but the heat and back pressure at the turbo is reduced significantly.

We have just had Milltek redesign their downpipes so they are proper 3" downpipes, before were restrictive with the 2.5" flexi joints when the rest of the downpipe and catback was 3".

Our car runs the new 3" downpipes with no cats and a non resonated catback. At castle combe at 4500rpm it registered 91dB. (My S4 on the limit for allowed on track is 99dB).

We have videos and noise levels available for stock, the differnet catbacks and the different downpipes.

If you are wanting a group buy on a remap/exhaust/suspension group buy then we can do something.