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Hi,

Road tested a new Audi RS 3 on Sunday and although it was raining I was not overly impressed.... Would of liked a longer test drive in the dry but could not get used to the no manual gear lever....

So after 6 months of ownership I have decided to hang onto the RS4 avant and modify a few things...

Remove pre-cat internals and fit Miltek resonated valued exhaust system. Re-map to cope with lambda sensor issue and new exhaust.

I may fit some of the KW lowering springs and set it up too.

Can't wait now.

Mike

Just curious, why were you thinking of selling it after only 6 months of owner ship?

Great choice of mods. The RS3 is a great car, but not so great in the wet with factory fitted tyres. Its great in the dry and with decent tyres I'm sure it will be great in the wet too.

Good decision on keeping the B7!

Have you considered a JCWF exhaust? Similar money to the milltek.

Neil will probably be along in a second to remind us all we have the wrong exhaust.

Just by me typing "JCWF" I'm now reminicing about how epic my passenger ride in Neils car was, because of the exhaust, and how I REALLY REALLY want one.

Yes JCWF is by far the best sounding exhaust for the B7 and much better hold quality than the milltek. And I think it is similar or cheaper on a like for like ie full jcwf compared to full milltek.

I was thinking about changing the car as it would need tyres, brakes and other items sorting out in next 6 months.... I love the car and I work in the motor trade on Porsche cars so it take quite a car to get me excited as the Porsche stuff is mental.

I have got it booked in at Awesome GTI tomorrow for an initial power run now I have sorted a coolant leak from one of the outer radiators.

Will post the results tomorrow evening and then at least I know when I have gutted the pre-cats and installed the Miltek I can see first hand where the power gains are coming from.

Millet should be here by Friday with some luck, if car is terrible tomorrow on Dyno then I may have to do the carbon clean first and re-test.

Mike

Milltek won't gain you much power though.

Why would it not..? Are the standard exhausts quite good in terms of back pressure and flow ?

They made a good 20BHP on 911 turbo models we installed them onto.

It's a normally aspirated car so exhaust gains are minimal anyway, and then the OEM is fairly good to start with.
The main cats are 200 cell so if you replace them with the milltek 200 cell cats yours not really gaining anything (other than losing the precats which I'll mention in a minute). Milltek also do 100 cell cats so these will give a slight gain.
However, the biggest gain to be had from the exhaust is to loose the 400 cell pre cats. 4 ways to do this, either replace the OEM cats with something like the milltek cats mentioned above, or gut the precats which is probably the cheaper option especially if you do it yourself, but be warned you might get an error without a remap. Some people have stated they've done this and had no errors but I don't think this is the case for everyone.
But if you are going for a cat back system then the gains are minimal, they might show a slight increase on a dyno but I doubt you'd notice it when driving. These exhaust are worth doing though as they are all about the noise.
The JHM exhaust I believe is the one that has shown the biggest gains so far.

I have had the rolling road test done today and it has made 385 BHP and 395 BHP on second run.

So no carbon clean required for me!

The carbon is what is stopping you making 414ish but those are strong numbers so I wouldn't bother with a clean.

sportsandclassic wrote:Why would it not..? Are the standard exhausts quite good in terms of back pressure and flow ?

They made a good 20BHP on 911 turbo models we installed them onto.

IIRC when people first started fitting Millteks to B7 back in 2008 they saw a power LOSS of around 4bhp - the slightly lower back pressure lead to more scavenging (when both inlet & exhaust valves are open) and actually sucked out some of the fuel before it could be burnt.

PetrolDave wrote:

sportsandclassic wrote:Why would it not..? Are the standard exhausts quite good in terms of back pressure and flow ?

They made a good 20BHP on 911 turbo models we installed them onto.

IIRC when people first started fitting Millteks to B7 back in 2008 they saw a power LOSS of around 4bhp - the slightly lower back pressure lead to more scavenging (when both inlet & exhaust valves are open) and actually sucked out some of the fuel before it could be burnt.

I am not massively educated about petrol direct fuel injection engines BUT I was under the impression that they actually injected the fuel into the cylinder after the valve overlap period,( both valves now closed) so you don't need the same scavangening like you do on a conventional fuel injection system. I stand to be corrected but thought this was how they worked.

IIRC some years ago on here ArthurPE gave an erudite explanation of the cause of the slight power loss with a Milltek, but it all boils down to the combination of reduced back pressure and valve overlap timings.

Ok.

On another note I see you have a resonated valved Miltek system... Are your pre cats still installed and how do,you find the noise ? Mine should be here tomorrow or Monday.

Mike