jeffwressell

Looking for advice on some of the best options to build horsepower on my son's B6 S4 without ripping the motor apart and breaking the bank. Can currently has a Stage 1 tune (but I believe it is from several years ago), Long tube headers and a Stage 2 clutch. thanks in advance.

Nerevar22g

Best way would be getting your exhaust done, get those cats out, straight through mufflers and a tune for it, Jackal is probably the best. But dont expect much difference, it is naturally aspirated after all

Scotty (UK)

Mine was running about 390/395bhp after full Milltek system and remap. Theres not many ponies available for low money on a n/a V8.

Nerevar22g

can we see a dyno sheet?

AudiAllTheWay

Inducted engines are the way to go if you want to build horsepower but of course there can be a trade off with longevity depending how far you go.

If you’re serious about exhaust then no need to run catless on a 4.2 street car as there are high flow cat options available, but unless you can find ways to significantly increase the 4.2 horsepower then it is a bit of a waste as the stock high quality cats are reasonably matched to the engine. Also catless car exhaust stinks to high heaven and some folks get pulled over for “fix it” tickets and have difficulty selling a catless car that fails inspection etc.

Could install a 2.7T and chip it up over 400HP. Need custom AC line as it does not reach the 2.7T compressor and a wire mod to the instrument cluster otherwise pretty much drops in 👍