Page 1 of 2
Milltek vs stock
Posted: Mon Feb 20, 2012 10:27 pm
by RIV
Thinking about getting a milly fitted, I have heard about stories of losses of power rather than gains any thoughts on this before I take the plunge and buy one
Re: Milltek vs stock
Posted: Mon Feb 20, 2012 10:31 pm
by Pie
Negligable losses vs awesome soundtrack - its a no brainer unless you're a track fiend.
Before and After:
http://www.youtube.com/watch?v=nNllAuCBIw8
Re: Milltek vs stock
Posted: Mon Feb 20, 2012 10:56 pm
by RIV
Thanks for the info, they do sound the nuts, worth going for I guess + negligible losses, no track use for my car that's for sure
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 9:13 am
by DazN
I read that a Milltek would give a slight gain in power, something to do with back pressure?
I do know cheaper exhausts can give problems, I had a mate who fitted an aftermarket exhaust to his Ferrari 360, it sounded amazing but he lost around 60bhp when he had it on a dyno!
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 10:26 am
by gazzars4
i was told they give a gain in power as well when i had mine done a few weeks back .it does seem to pull better and less resticted so should be a better on power .
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 10:50 am
by adsgreen
On it's own, less power.
In conjunction with a remap more power.
Either way though isn't a huge amount
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 11:33 am
by RIV
Thanks for all the info, it's booked next week + map is going to be tweaked
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 11:38 am
by Brownies3
I originally went for the Milltek Non Res Valved and the Milltek 100 cell Cats, this combination was way too loud for me and I wasnt so keen on the tone either, I ended up putting the standard exhaust back on but kept the 100 cell cats, this with a sports filter produces a harder better sound louder than standard but quieter than Milltek but you also get extra power provided you get it remapped.
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 12:25 pm
by adsgreen
I went the other way... standard cats and non res valved miltek.
Apart from the drone between 1500-2000 rpm which you drive around it's just lurvely

Re: Milltek vs stock
Posted: Tue Feb 21, 2012 6:50 pm
by PetrolDave
Milltek without a remap gives about 4bhp loss due to the lower back pressure causing a very slightly weaker mixture due to the greater scavenging effect, but Milltek plus remap gives beeter sound and more power = win, win.
Re: Milltek vs stock
Posted: Tue Feb 21, 2012 8:09 pm
by RIV
Thanks for all the info, looks like its worth doing with the map and the savage exhaust note,I'm getting excited to get this done, and taking it out for a good thrashing!!!
Re: Milltek vs stock
Posted: Sat Feb 25, 2012 12:33 pm
by Shadow6ix
PetrolDave wrote:Milltek without a remap gives about 4bhp loss due to the lower back pressure causing a very slightly weaker mixture due to the greater scavenging effect, but Milltek plus remap gives beeter sound and more power = win, win.
Not wishing to be contrary, but simply trying to understand, why with such a small increase in airflow is the ECU not able to dial in more fuel to provide the correct mixture as per the table? If more air is being drawn into the cylinder, it must read this at the MAF?
Re: Milltek vs stock
Posted: Sat Feb 25, 2012 3:10 pm
by adsgreen
It's not thought.
There is an overlap in valve timing so that the exhaust gas exiting the cylinder helps draw in fresh air charge.
If the exhaust is 'free-er flowing' the more of the exhaust gas has already left the cylinder before the intake valve opens and so the scavenging effect is lower reducing the amount of air the cylinder draws in.
The ecu can't really adapt to this as it only sees the maf which is way up the intake system.
Re: Milltek vs stock
Posted: Sat Feb 25, 2012 6:41 pm
by P_G
A proper x- or h-pipe will help the scavenging effect and minimise power reduction
Re: Milltek vs stock
Posted: Sat Feb 25, 2012 6:58 pm
by RIV
Excuse my ignorance, but can explain in more detail about the x or h pipe?