Originally Posted by bcornwellatl
What is the opinion of the intake? In your opinion, do you think it was a good choice? (vs the 2 cone open system). I also unplugged that exaust port cable in the back of the car to make it sound better. Assuming that won't do anything to HP - I am not ready to get a new muffler yet... I don't see the gains that are worth the 1000 plus dollars to do that...
So what HP and TQ do you think I should expect with what I have on the stage 1 agressive? What do you need to go to stage 2? I think this 335 has the intercooler because of the sport package... just not sure how good the injectors and coils are since I purchased used.. plugs were changed at 46000 miles by BMW dealer with previous owner.
You'd be surprised with the intakes. Terry@BMS did a test of open vs. closed element filters and there was no significant difference in IATs. Chances are you'll trap a little more cold air with aFe since it's a closed filter & takes air directly from behind the kidneys.
For the exhaust, your real gains are gonna be from catless downpipes. DP back system are absurdly priced & will net you at most 10 HP (the OEM exhaust system is good until 500 WHP). Stage 1 Aggressive (no timing corrections & holding boost) will put you around 330 WHP / 340 WTQ (a 60 HP/70 TQ gain over stock); you'll be boosting ~4-6 psi over stock (from 8 to ~12 psi; OEM Turbos are fine up to 18 psi midrange). I would recommend that your next mod be a real FMIC upgrade (Helix, Active Autowerke, Evolution Racewerks, ETS; anything not OEM) and run the Stage 1+ Maps. The OEM intercooler (sport package or not) is the same & will heatsoak very quickly (thus, the DME starts pulling timing & reduces performance). To go Stage 2, all you need is Catless/Race Cat Downpipes. Shockingly enough, the Stage 1+ Maps are more powerful (which is why I recommend the FMIC upgrade 1st).
As of right now, the N54 does not have any aftermarket injector options (we're actually JUST
about to a fuel pump upgrade). Spark plugs are good for 20-25k tuned & the Ignition Coils last ~45k. The OEM Bosch Plugs/Coils are fine until you start making BIG power (talking aftermarket turbos HP).
Sadly enough, while the N54 is VERY responsive to aftermarket mods, it gets very expensive very quickly. Welcome to COBB though