Whats next? only had s4 for 3 weeks now

[Doug_S2]

I have a stock exhaust with gutted precats and no main cats and it sounds awful! Gettting rid of the cats makes a big difference but the stock exhaust is still restrictive even for 300bhp cars - The sound is worth the money alone when you ditch the stock exhaust. Most stock exhausts on S4s are starting to break brackets off them these days. Millteks are still very subdued, even the cars with just a back box are not too loud inside the car (they are loud outside).

Exhaust first then! Then you are not going to get much more out the car without changing injectors - the FPR is modified on your car already to get more fuel. So injectors and fuel pump and a remap. Then you can get around 400bhp. ICs are the next limit. Source RS4 ICs, brackets, cowels, hoses and you are good for upto 450bhp (or get a FMIC on there) It is always cheaper in the long run if you can do everything in 1 go though!

Depending on how you drive it brakes should be upgraded.

[ZeroK66]

Okay I will shut up about the exhaust now.

[s4woody]

its a no brainer..

[KayGee]

I agree Miltek sounds better, not sure performance is that much different though. AMD claim +5 hp and +5ft/lbs. MTM claim +14 bhp. In my experience, closer to the first than the second.

[NeilMc]

I think there might be some confusion here regarding exhausts. Catback systems don't do much except make a nice noise. Gutting precats and getting a catback system will make a noticeable difference, especially in the higher revs, and a full system with no precats and race main cats can give anywhere up to 30-40bhp more with a remap.

[Doug_S2]

An exhaust can make no difference at all power wise - it all depends on how the car is mapped that will make the difference - if it is mapped on a stock exhaust but not pushing the back pressure limits, changing the exhaust will not make a difference or minimal - if it is mapped before beyond the stock back pressure limits changing the exhaust can make a really big difference.

[ZeroK66]

So moral of the story is only replace exhaust if you intend on getting a custom map... from MRC of course

[springfield]

Doug,
You have re-mapped my car Imola S4 Avant Cumbria,do i now need to bring it down once the pre-cats are gutted and a miltek fired on to release some more hp?
Or what would the approx cost be of gutting the pre-cats fitting a miltek and setting up ?
Cheers Jim.

[Doug_S2]

jim - you have a pm

[ZeroK66]

Surely it would make sense to hold out spending money on a remap till you have more bits isntalled... injectors/fuel pump? Then get the whole lot mapped as a whole and WHOLLOP - stacks of power.

[mikecmr]

yeah plan is to take it to mrc and get all engine bits done exhaust will have to wait till the end i think money wont stretch that far yet

[andy1234]

injectors,fuel pump and I/Cs mike. Dont worry bout the exhaust till a later date!