[MAD335i]

Hey guy, I had an N54 for a long time and just got an N55.....don't know much about this engine/car. Can anyone hook me up with the good to know info on it? Does the N55 respond as well to performance mods as N54? Thanks

[MAD335i]

Sorry it's an E90 N55

[Akbubba47]

Search search search. There's a million threads

[Everfly]

http://www.1addicts.com/forums/showthread.php?t=344186

[snaimpally]

Originally Posted by MAD335i

Hey guy, I had an N54 for a long time and just got an N55.....don't know much about this engine/car. Can anyone hook me up with the good to know info on it? Does the N55 respond as well to performance mods as N54? Thanks

Check the marketplace. Dozens of forum sponsors are selling all kinds of N55 performance mods:
http://www.e90post.com/forums/forumdisplay.php?f=204

I have purchased from Mike at N54Tuning.com as he is very responsive. Despite the name, he carries a wide range of N55 mods. Also check Burger Motorsports - N55 JB4, N55 charge pipe, etc. Just exactly how much money do you have to spend?

[Sidewinderpb]

Modding is modding. There's always some gremlins that will come along with it. Well worth it though. Start with a JB4 ASAP!

[JETmn]

Turbo on the N55 is quite a bit smaller, so that is the limiting factor. Tune is still a huge jump in power (JB4 is the choice right now or AP protune) but after that you won't see as big of gains. Max on stock turbo seems to be 370-380whp. The pure stage 1 turbo has been showing very good gains and will probably get you close to N54 stock turbo levels.

[MAD335i]

Originally Posted by JETmn

Turbo on the N55 is quite a bit smaller, so that is the limiting factor. Tune is still a huge jump in power (JB4 is the choice right now or AP protune) but after that you won't see as big of gains. Max on stock turbo seems to be 370-380whp. The pure stage 1 turbo has been showing very good gains and will probably get you close to N54 stock turbo levels.

Thanks all! I had a few mods on my 08 and had done tons of research about N54s so I'm not completely new. I guess I should have been a little more specific in my question/post. Just heard that I wouldn't come close to the same power with the N55. I have a 5 day return and got worried so what better place to get quick, awesome, answers....
Not sure if there was plus side or neg side to N55 vs N54. Kinda was looking for the answer JETmn gave. Thank you again to everyone!

[Subaru335i]

Basically what JETmn said. Turbo is the limiting factor compared to N54. It is still a great engine imo.
If you are dead set on 400+whp then return it but I don't really understand all the shit-talk against the N55.
There is a lot of potential in the platform and the benefits of the new engine outweigh the drawbacks by far in my book.

Although I have a track car with a big turbo to satisfy my top end desires

[Knobi]

Although the N54 has more potential (power-wise) at the moment, the N55 is a more reliable engine with newer technology including Valvetronic and a state of the art transmission. The N55 is the current production engine in the 1, 2, 3, 4 & 5 series and has lots of potential. There's already a tested Stage 2 turbo upgrade showing 477whp, a Stage 1 showing great results up top in the rev line, and a couple more coming soon. I'm dying to make more power but i would never trade my N55 for a N54. My .02

[MAD335i]

Cool thanks guys! I guess I'll just wait it out for new toys(upgrades) that come out for the N55. I appreciate all the input/info

[Manoah]

N55 hasnt been out as long as N54 (obviously), thats why there isnt a huge aftermarket following for it. tuners have only recently started playing with the turbos to see what they can do. going FBO with JB4 is about the best you can do right now, without dropping 5K+ on new turbo upgrades. given enough time, ive read that the tuners expect as much HP out of the N55 as the N54. ( im not a tuner, thats just what ive read on here.)

[Knonsense]

The n54 has twin turbos; the n55 has a dual-turbine, single-compressor turbo, which rotates counter to the standard rotation - this is why the turbo is the primary limitation to power potential. it's a hybrid, which is fantastic for general driveability, but it runs out of steam ~6.5k RPMs. the counter-rotation, along with the turbine being integrated into the exhaust manifold, is why it's such a goddamn bitch to upgrade the forced induction. systems exist, they're expensive.

Cobb + ProTuningFreaks is easiest to reach maximum power, unless you're OK with ethanol, then JB4 is your ticket. I'm relatively sure the JB4 does better with ethanol/methanol, and Cobb does better with octane.

Cooling isn't as big an issue in the n55 and the n54; you won't NEED an oil cooler, but if you're going FBO, do include it in your FBO specs along with charge pipe, intercooler, intake (or at least drop-in filter), dp, and exhaust. there is a companion exhaust mod for the n55 (straight pipes w/in muffler instead of perforated pipes) - it is fucking jawdroppingly sexy sound w/o a catalytic converter.

if you have the 6at, get the Alpina TCU flash; this really isn't even worth discussing. it'll be ~$100 and i'd be fine paying 3-4x that much. makes slush box into zoom box.

also, the n55 doesn't have the carbon caking problem or oil getting everywhere inside the engine problem. walnut blasting is every 85k or so, not 50k. catch cans go 15k miles and catch nothing.

[MAD335i]

Is the tranny the same as the n54? I bought a nice race clutch that I never used...

[Dark_Knight_335]

No the transmissions are different- that's why you can't use the Alpina TCU flash with an N54.

[MAD335i]

Originally Posted by Dark_Knight_335

No the transmissions are different- that's why you can't use the Alpina TCU flash with an N54.

Ok cool thanks.

[mike@x-ph.com]

Originally Posted by MAD335i

Hey guy, I had an N54 for a long time and just got an N55.....don't know much about this engine/car. Can anyone hook me up with the good to know info on it? Does the N55 respond as well to performance mods as N54? Thanks

Its unfair to compare it to the N54 since the N54 is one of these rare cases where you can get couple hundreds Hp without much effort or money.
But to answer you question yes the N55 reacts good to modding and increased boost.

[JETmn]

Originally Posted by Dark_Knight_335

No the transmissions are different- that's why you can't use the Alpina TCU flash with an N54.

Where did you see that? Only the very early 2008's can't do the flash. Other N54's can do it just fine. 6AT N54 and N55 are the same, just a different control module on the early '08's.

[bk335ilci]

Originally Posted by Dark_Knight_335

No the transmissions are different- that's why you can't use the Alpina TCU flash with an N54.

The alpina flash works for both n54 and n55

[Dark_Knight_335]

Sorry MAD...I guess I was wrong - somebody done lied to me then, I was told it was incompatible with N54

[MAD335i]

Originally Posted by Dark_Knight_335

Sorry MAD...I guess I was wrong - somebody done lied to me then, I was told it was incompatible with N54

Cool, np... I have a 6sd manual. Hope I can use the clutch I bought for my n54. I'll have to try and call or look it up tomorrow. Thanks for the info guys.

[Knonsense]

Originally Posted by Dark_Knight_335

Sorry MAD...I guess I was wrong - somebody done lied to me then, I was told it was incompatible with N54

I think the B3 used the n54.
http://www.alpina-automobiles.com/en...e90919293.html