Quote:
Originally Posted by CombatNinja
Gavin, what are the estimated gains of the 3-stage manifold, MMW headers, quality exhaust and a tune to bring it all together? I want to say around 280bhp and 250 ft-lbs. What do you think? I am scheming a way to build my wife's e91 into something I don't mind driving. Please post audio clips as soon as you have them installed in a car. If this is too loud it will never pass the wifey test. At any rate, good on you for being one of the few to support the naturally aspirated engines.  |
Assuming you have a 328 e91 - massive.
3 stage, 8-10whp
Headers - 15whp+
good exhaust system - 2-3whp in combo - but it will aid in efficiency of power which is crucial.
AA tune, about 15whp also.
All together that's about 40whp gained.
stock on motor a 328i is 230hp, so lets factor a huge loss of 20% from the drivetrain (it more like 18% in reality for an auto tranny, at least on all the dyno's i've done)
So that's about 50hp gained on motor - Puts you right at the 280hp mark your shooting for.
But with headers and the 3 stage, I would ask for AA to do the "off road" tune they offer... be up closer to 290-300 if Active works the magic i KNOW they can do.
the noise... well the wife will notice. Unless she is Hellen Keller.
I would honestly run it with the OEM exhaust but remove the 2nd cats from the OEM pipes to have the best sound to power gain/ and not make the wife mad.