[DrRobert]

So I got my suspension dialed in and my car is handling great. Got a custom engine tune from Pro Tuning Freaks using a Cobb AP and got a nice boost of power over the BMW PPK I had before. Now I'm kinda hungry for even more power and starting to think about bolt-on engine mods. Thing is this is a street car and while I do have a long commute and enjoy spirited driving I don't want the car to get any louder in the exhaust department. So that leaves me with an FMIC and maybe a CP on my short list of bolt on mods that won't increase the exhaust volume.

Do you guys think I'll feel a noticeable increase in power from a FMIC and another round of tuning? I'm looking to get as much oomph as I can out of the N55 without making it sound like I have an after market exhaust.

TIA,
Robert

[Walker16]

You can do everything but a catless dp and the sound won't change. But the do will give you the most power after a tune.

[Johnny Boost]

The DP really isn't crazy loud when you have the stock exhaust. It's basically only loud when you want it to be aka when you're laying into the accelerator. Under normal, light throttle it is slightly louder than stock. Under light throttle, the sound is comparable to a stock N55 after a cold start.

[tkong]

Originally Posted by Johnny Boost

The DP really isn't crazy loud when you have the stock exhaust. It's basically only loud when you want it to be aka when you're laying into the accelerator. Under normal, light throttle it is slightly louder than stock. Under light throttle, the sound is comparable to a stock N55 after a cold start.

X2 but with the extra added smell of gasoline with the windows down

[junniior95]

I think you should pull the trigger on the FMIC....I'm FBO minus DP on my 11 e90, im xdrive so i removed my secondary cats / resonators, and added a BMW PE, as of now i love the sound but i may want more and get an Eisenmann Race....point being about the FMIC, im protuned from Brentuning (Local tuning shop in MA) my numbers on the dyno before and after my FMIC / CP were phenomenal, here are my dyno numbers (To The Wheels) throughout my performance upgrades:

Stock: 255hp / 255tq
Cobb S1 Tune, K&N Drop In, BMW PE, Alpina TCU: 263hp / 305tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU: 302hp /365tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU, Secondary Cat Removal, VRSF 5" Stepped FMIC, BMS CP: 325hp / 408tq

Future Mods: BMS Meth Kit

This car has drastically improved performance wise and would 100% change for the better if i put DP's but here in MA as my DD i want to pass my inspection w/out the hassle of removing my DP yearly....if i were you and wanting more power, i would def pull the trigger on the FMIC as well as Upper CP

[Sidewinderpb]

Originally Posted by junniior95

I think you should pull the trigger on the FMIC....I'm FBO minus DP on my 11 e90, im xdrive so i removed my secondary cats / resonators, and added a BMW PE, as of now i love the sound but i may want more and get an Eisenmann Race....point being about the FMIC, im protuned from Brentuning (Local tuning shop in MA) my numbers on the dyno before and after my FMIC / CP were phenomenal, here are my dyno numbers (To The Wheels) throughout my performance upgrades:

Stock: 255hp / 255tq
Cobb S1 Tune, K&N Drop In, BMW PE, Alpina TCU: 263hp / 305tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU: 302hp /365tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU, Secondary Cat Removal, VRSF 5" Stepped FMIC, BMS CP: 325hp / 408tq

Future Mods: BMS Meth Kit

This car has drastically improved performance wise and would 100% change for the better if i put DP's but here in MA as my DD i want to pass my inspection w/out the hassle of removing my DP yearly....if i were you and wanting more power, i would def pull the trigger on the FMIC as well as Upper CP

Cp doesn't do anything power-wise; just a safety mod. I agree that it is necessary though.

[junniior95]

Originally Posted by Sidewinderpb

Cp doesn't do anything power-wise; just a safety mod. I agree that it is necessary though.

Correct, CP was only added due to plastic CP about to break

[JETmn]

You can always do a stage 1 turbo too. It really helps the pull up top as it pulls nicely to 6500 now instead of 5500. I love being able to rev it out now when I want to!

[junniior95]

Originally Posted by JETmn

You can always do a stage 1 turbo too. It really helps the pull up top as it pulls nicely to 6500 now instead of 5500. I love being able to rev it out now when I want to!

what turbo kit did you go with, pureturbos?

[kevBquick]

Originally Posted by DrRobert

So I got my suspension dialed in and my car is handling great. Got a custom engine tune from Pro Tuning Freaks using a Cobb AP and got a nice boost of power over the BMW PPK I had before. Now I'm kinda hungry for even more power and starting to think about bolt-on engine mods. Thing is this is a street car and while I do have a long commute and enjoy spirited driving I don't want the car to get any louder in the exhaust department. So that leaves me with an FMIC and maybe a CP on my short list of bolt on mods that won't increase the exhaust volume.

Do you guys think I'll feel a noticeable increase in power from a FMIC and another round of tuning? I'm looking to get as much oomph as I can out of the N55 without making it sound like I have an after market exhaust.

TIA,
Robert

FMIC is not so much about gain power as it is to being able to keep power held. your rate of loss is after multiple runs will be far less of a drop with an FMIC than without.

I'm Full FBO N55. if you can get a catless dp at this point....one of the greatest mods you can do besides tuning. You wouldn't know if I had a DP or not. My start up is loud but I also have can flap set to open. IF they were set to close....you would never know. So noticeable increase from an FMIC....no way. but you won't lose so much doing multiple runs.

[DrRobert]

Thanks for the replies, guys. My indy mechanic said an aftermarket DP would be louder. Are there 2 different types of DP - cat and catless? What is the difference? I live in CA where emission standards are strict, don't want to have to undo anything every time DMV makes me get a smog check.

I understand about replacing the plastic OEM CP - what about the diverter valve? Does that need to be replaced on an N55 or can I keep the OEM DV?

[Sidewinderpb]

Catted has a catalytic converter, - necessary to pass emissions in most places - catless does not. By removing the catalytic converter, you free up the flow of air through the car, thus producing more power.
Generally, N55 owners do not replace the bypass valve. It is integrated into our turbos, whereas the N54's bpv is located on their chargepipe.

[DrRobert]

Got it, thanks. Is there any difference in volume between a catted and catless DP? Does anyone know if a N55 E90 w/ catted DP would pass a smog check in CA?

[Johnny Boost]

Originally Posted by DrRobert

Got it, thanks. Is there any difference in volume between a catted and catless DP? Does anyone know if a N55 E90 w/ catted DP would pass a smog check in CA?

I've read that some catted DPs do pass emissions but also that some do not. I've also heard that the high flow cats in catted downpipes deteriorate over time. Overall, catless will be better for performance because it's a straight pipe with no airflow being restricted. We have yearly inspections where I live and there are plenty of people that get away with not removing the DPs.

[DrRobert]

Will have to look into that, thanks. But I'm getting off-topic in my own thread! Thinking of starting w/ a black ano ER FMIC and CP + another round of tuning, for now at least.

[JETmn]

Originally Posted by junniior95

what turbo kit did you go with, pureturbos?

Yes, I have a Pure stage 1 with JB on E30. No FMIC or DP yet.

OP - you can also check out the Wagner catted DP. It looks like that will probably pass emissions. There is a nice review of it on here.

[snaimpally]

Originally Posted by DrRobert

So I got my suspension dialed in and my car is handling great. Got a custom engine tune from Pro Tuning Freaks using a Cobb AP and got a nice boost of power over the BMW PPK I had before. Now I'm kinda hungry for even more power and starting to think about bolt-on engine mods. Thing is this is a street car and while I do have a long commute and enjoy spirited driving I don't want the car to get any louder in the exhaust department. So that leaves me with an FMIC and maybe a CP on my short list of bolt on mods that won't increase the exhaust volume.

Do you guys think I'll feel a noticeable increase in power from a FMIC and another round of tuning? I'm looking to get as much oomph as I can out of the N55 without making it sound like I have an after market exhaust.

TIA,
Robert

FMIC is going to get you incremental hp gains. If you want "noticeable" gains, I suggest a turbo upgrade such as Pure Turbos stage 1

[e92proper]

Originally Posted by junniior95

I think you should pull the trigger on the FMIC....I'm FBO minus DP on my 11 e90, im xdrive so i removed my secondary cats / resonators, and added a BMW PE, as of now i love the sound but i may want more and get an Eisenmann Race....point being about the FMIC, im protuned from Brentuning (Local tuning shop in MA) my numbers on the dyno before and after my FMIC / CP were phenomenal, here are my dyno numbers (To The Wheels) throughout my performance upgrades:

Stock: 255hp / 255tq
Cobb S1 Tune, K&N Drop In, BMW PE, Alpina TCU: 263hp / 305tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU: 302hp /365tq
Brentuning Protune, K&N Drop In, BMW PE, Alpina TCU, Secondary Cat Removal, VRSF 5" Stepped FMIC, BMS CP: 325hp / 408tq

Future Mods: BMS Meth Kit

This car has drastically improved performance wise and would 100% change for the better if i put DP's but here in MA as my DD i want to pass my inspection w/out the hassle of removing my DP yearly....if i were you and wanting more power, i would def pull the trigger on the FMIC as well as Upper CP

I assume brenntuning is a shop that does COBB protune?

And what do you do for warranty work when you have to go to dealer? Do you remove DP?

[Jeef]

Originally Posted by e92proper

I assume brenntuning is a shop that does COBB protune?

And what do you do for warranty work when you have to go to dealer? Do you remove DP?

Depends on your dealer. Most of them are pretty lenient on mods from my experience. But not sure about your area!