Milltek vs stock

[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

[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

[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

[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!

[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 .

[adsgreen]

On it's own, less power.
In conjunction with a remap more power.

Either way though isn't a huge amount

[RIV]

Thanks for all the info, it's booked next week + map is going to be tweaked

[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.

[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

[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.

[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!!!

[Shadow6ix]

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?

[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.

[P_G]

A proper x- or h-pipe will help the scavenging effect and minimise power reduction

[RIV]

Excuse my ignorance, but can explain in more detail about the x or h pipe?