[EDM92]

I'm probably going to do a muffler delete to my car and throw on some cyba tips at the same time. I've been reading tons of threads on the muffler delete (almost all seem to be 328s and 330s), and I read a few posts that said deleting the muffler reduces back pressure on the N54 which in turn reduces hp/tq. I'm assuming it's not true, but I just wanted to verify from someone who actually knows what they are talking about.

P.S. I don't care what your opinion is on the MD, I don't think it's ricey and I like the exhaust note it provides. I can handle the drone, it doesn't bother me all that much.

Thanks in advance for any help.

[Beemw335]

Sous ricey....but you should gain some power!

[ZTZ1010]

I was under the impression back pressure was less important on an FI motor than a NA motor, thus would yield gains from less restriction rather than losses.....

[EDM92]

Originally Posted by ZTZ1010

I was under the impression back pressure was less important on an FI motor than a NA motor, thus would yield gains from less restriction rather than losses.....

I honestly have no idea, that's why I came here to ask. lol I wish I understood more about engines and cars in general.

[dlbrooks18]

The ECU should adjust, less back pressure is good, best exhaust mod is aftermarket dp's..

[hipnotic]

less backpressure the better the car performs, do it

[prelude2perfect]

The less back pressure the better on a forced-induction engine

[EDM92]

Originally Posted by dlbrooks18

The ECU should adjust, less back pressure is good, best exhaust mod is aftermarket dp's..

I will certainly be getting some catless DPs in the future. Most likely when my CPO warranty expires, though.

[teek]

In a turbo car you want the least amount of back pressure possible. One thing you may want to consider is possible exhaust drone, especially since you have an auto.

[EDM92]

Originally Posted by teek

In a turbo car you want the least amount of back pressure possible. One thing you may want to consider is possible exhaust drone, especially since you have an auto.

Thanks for pointing the drone out to me, however I do know what I'm getting myself in to. I actually just rode in an auto 335i today that had the delete done. The drone is pretty loud, but honestly it doesn't bother me that much. Maybe it's because all my friends have loud ass Nissan 240s lol.

[4.8 E70]

Less back pressure + shave off some weight = WINNING! Those mufflers easily weigh about 50 - 55 lbs. Do it.

[raceyBMW]

In a turbo car, most of the back pressure happens in the manifold, caused by the turbo itself. For the turbo to run most efficiently with the least amount of pumping losses, you want as little back-pressure at the outlet side of the turbo as you can. It has been found that the cats in the stock DP's provide the most restriction in the exhaust system (especially when tuned), and eliminating them can be beneficial.

However it has also been found that past the catted DP's there isn't much restrictions in the remainder of the exhaust, and that eliminating the muffler is not going to make hardly any difference.

Do it for the sound if you like it (and maybe to drop some weight), but don't expecting to gain hp or change the torque band.

[EDM92]

Originally Posted by 4.8 E70

Less back pressure + shave off some weight = WINNING! Those mufflers easily weigh about 50 - 55 lbs. Do it.

Originally Posted by raceyBMW

In a turbo car, most of the back pressure happens in the manifold, caused by the turbo itself. For the turbo to run most efficiently with the least amount of pumping losses, you want as little back-pressure at the outlet side of the turbo as you can. It has been found that the cats in the stock DP's provide the most restriction in the exhaust system (especially when tuned), and eliminating them can be beneficial.

However it has also been found that past the catted DP's there isn't much restrictions in the remainder of the exhaust, and that eliminating the muffler is not going to make hardly any difference.

Do it for the sound if you like it (and maybe to drop some weight), but don't expecting to gain hp or change the torque band.

Thanks for the help guys. Seems like the general consensus is that it doesn't hurt at all, which is what I was looking to hear. If/When I do it, I'll definitely post up some videos, even though they don't really do any justice.

Can't wait to shed 50 pounds and make my car roar like a sports car should.

[jacky822]

honestly if you have an auto, u want it with mufflers, because it felt different when u dont have mufflers. feel losing alots of torque. if u want more torque on low end, keep it. After u removed it, it feels like the air wont build up in the exhaust to pull you car harder.

[ar design]

For the "backpressure" crowd... Some interesting reading and actual DATA instead of the usual internet forum butt dynos

http://www.modified.com/tech/modp-11...ech/index.html

[PKumarM3]

i like the sound my muffler delete makes, it the drone doesn't get annoying if you ride in the car 1 day. but if u drive it daily, it eventually becomes annoying as hell.

[raceyBMW]

Originally Posted by jacky822

honestly if you have an auto, u want it with mufflers, because it felt different when u dont have mufflers. feel losing alots of torque. if u want more torque on low end, keep it. After u removed it, it feels like the air wont build up in the exhaust to pull you car harder.

LOL, what? Do you have any proof besides your butt dyno cause I would be very curious? Less exhaust restriction means your turbos spool faster which technically means less lag which means more air into the cylinders quicker, increasing torque. Again, all the "backpressure" you need is created by the turbo itself, especially with the small restrictive turbos in the N54.

Yes there can be something said for backpressure and header design in an NA car for low end torque, but for turbo, you want that exhaust air post turbo to get out as fast as you can.

[momstmg78]

I just put aa exhuast on mine and noticed a huge loss in low end torque.

[Mr. Nice]

Originally Posted by momstmg78

I just put aa exhuast on mine and noticed a huge loss in low end torque.

Give it a few hundred miles to adjust, you shouldn't be losing any torque.

[BMW1986]

Originally Posted by PKumarM3

i like the sound my muffler delete makes, it the drone doesn't get annoying if you ride in the car 1 day. but if u drive it daily, it eventually becomes annoying as hell.

I have it my daily driver and I LOVE IT! Wakes me up in the morning!

[GQ335i]

As the guys have said, less back pressure is good for Turbo cars. I have a Muffler Delete on mine and love it! Do it man.

[Bakeme521]

nuff said