[Dark_Knight_335]

+ BMS powerbox = LESS power on my 2009 328xi coupe? Can someone please tell me the skinny on this? If need be I'll remove one or more components.

[guerilla twang]

Where did you hear that? Are you feeling a loss? Are you on Map 3 for the PBX?

[c_jeong89]

i doubt bmw perf engineers would make 2 things for the bmw that causes u to lose power.

[Delta0311]

Originally Posted by SDeFranco1

+ BMS powerbox = LESS power on my 2009 328xi coupe? Can someone please tell me the skinny on this? If need be I'll remove one or more components.

That makes no sense. Why would BMW design a "PERFORMACE" part that will rob you of hp and torque and then charge you like a $1,000 for it?


If you can feels sluggish then reset the PBX and put it in MAP 3 again. The PBX in fact works better with a good intake and exhaust combo.

[wareagle900]

he is referring to another thread somewhere. the answer is no.
the thread our referring to was talking about a muffler delete.

technically, in a NA car, a muffler delete will hurt power.

[guerilla twang]

Originally Posted by wareagle900

he is referring to another thread somewhere. the answer is no.
the thread our referring to was talking about a muffler delete.

technically, in a NA car, a muffler delete will hurt power.

What about just the res then?

And is the loss off backpressure enough to offset the benefits of shedding 50+ lbs from the rear?

[wareagle900]

The res. doesn't really cause too much back pressure in the first place... and idk about the weight issue.

but a for actual hp tq. numbers they will theoretically decline because of the lack of back pressure.

[ska///235i]

isn't the res. just a silencer?
doubt it will gain/loss hp..the thing prbly only weight like 4 pounds

Originally Posted by wareagle900

The res. doesn't really cause too much back pressure in the first place... and idk about the weight issue.

but a for actual hp tq. numbers they will theoretically decline because of the lack of back pressure.

[Wlew]

res weighs about 10 pounds. the muffler about 50. give or take. so 10lbs is 1 hp. in weight loss ideally. However, lots have complained that removing the muffler lost too much low end tq, yet gained a few high end hp.

In our cars i think tq is more important since we dont have a lot to begin with. Deleting the res wont change anything except the exhaust note. and you lose about 10 lbs. aka 1hp.

And to answer the OP... all 3 of these things will make you gain power, not lose it. performance intake is just about the same as the stock intake... therefore not worth it in my opinion. its expensive as hell, for the same look, sound, and hardly gains worth the price. Go with an AFE.

[Juan.sidarta]

Yeap. It wont make it lose power. I just put on a BMW perf exhaust and it includes a resonator delete. It is definately much better than an Muffler Delete at low end. MUCH.. MD just made me lose so much torq+hp, nice loud sound, but too loud, and drone is horrible. As for intake, Im sure it wont make it lose hp, but if you wanna sell it, I'd buy it XD

[Dark_Knight_335]

Nope, car feels great! Thanks to everyone, as always!

[IancoleTX]

You know what, until I see it on a dyno, I absolutely DO NOT believe that a muffler delete decreases HP or TQ, especially by loss of backpressure. It comes AFTER two sets of cats, and furthermore, deleting the primary yields +15hp! Someone prove me wrong, please.

[bavarian19]

Originally Posted by IancoleTX

You know what, until I see it on a dyno, I absolutely DO NOT believe that a muffler delete decreases HP or TQ, especially by loss of backpressure. It comes AFTER two sets of cats, and furthermore, deleting the primary yields +15hp! Someone prove me wrong, please.

How about trying to prove yourself right about deleting cats adding over 15 hp on a NA engine?



The loss of power has been confirmed on dynos, but I am too lazy to look them up.

[Juan.sidarta]

Originally Posted by bavarian19

How about trying to prove yourself right about deleting cats adding over 15 hp on a NA engine?



The loss of power has been confirmed on dynos, but I am too lazy to look them up.

Yes!! Finally someone who supports me. Actually, look at cravens dyno. Although his dyno is stingy, it states that his car has 200ish hp after his tune which is suppsedly abt 15hp again. Without the tune hed be on 185, which is 15 less hp than normal 328i's. Maybe its abt 5 to 10 given the stingyness of his dynos.

[michaelthepsycho]

Loss of backpressure never hurts performance. It's loss of exhaust scavenging and exhaust velocity. Those things should not be used interchangeably. This is why header tuning is more important than whatever happens after the cats.

If you want acoustics, go for aftermarket. End of story.

Sure... If your butt dyno tells you that a new set-up sucks, by all means, go back to your previous gig because it's your money and your time.