[Padfan9]

Does anyone know why it shows there are 2 BOV's for the N54....I may have read that wrong...when buying an aftermarket BOV, you only buy one, so the stock is just a wastegate right? or bypass valve?

[R1000K3]

There are two diverter valves on the N54 because it has twin turbos. There are also two wastegates by the same reason. BOV's are used to replace diverter valves if you prefer BOV's.

[spottedhyena]

very nice and informative

[SpeedRacer]

Great info. As a new owner of a 2007 335i Coupe with only 30,000 miles I really appreciate the date presented here. Thank you

[USAF Rick]

Love this post.

[hsantiago335]

great read very interesting to find out all the small little details with the turbocharging system

[V-Viper]

Some great infomation here, for anyone interested in learning about the N54/N55 or just a modern turbo charged engine. Far cry from the small block chevys/fords.

[OkashiiKen]

Thanks again for the great post - super informative for a newcomer like myself.

[Q8_TwinTurbo]

Ksfrogman,

Thanks for sharing this valuable information. Helps so much to know where everything is located inorder to install aftermarket parts in the likes of intercooler, blow off valves etc.

[muzzammil15]

Quick question, are the turbo inlet tube which hooks up to the intake box, 2.5 inches or 2 1/4 inches? Thanks!

[OEM99]

bump, thanks for the great info!

[USAF Rick]

That was a lot to read but man I understand my car so much better now.

[jdnguye90]

Great info. Thank you for this thread.

[scuber]

Thanks for great info~

[ksfrogman]

You're welcome.

[MGT81]

Bump!!

[amilo123]

does anyone have something similar for the N43 engine?

[fixedreality]

Very interesting read

[ZNITE]

Thanks for posting.....Great info

[x986]

FWIW
I'm the original owner of a 2007.5 coupe with the N54 that I picked up at the factory. (The mid year changes mainly consisted of extra colors and an I-Drive improvement that gives programable buttons.) I have 50K on it, and have NEVER had a problem with the engine (or anything). I got the Dinan tune (there was only one at that time, 400hp and 400 #/ft) when the car was about 4-6 months old. The car has the factory oil cooler and has been through all the factory recommended and mandatory updates for the HPFP problems. Only one of the reflashes wiped out the Dinan tune, and I had that re-installed for the cost of 45 min. labor for a Stage II tune.

The bottom line is that this is the greatest car ever made! I have NEVER kept a car for more than 2-3 years, and this one is 5 years old. I'm starting to get the new car itch, but other than a very few minor things, there is nothing out there better, and I will probably keep it.

My experience says: "If you're thinkiing of keeping your N54 beyond 30-40K, do it. If you're thinking of buying used, do it. Don't worry about the OLD bad rep."

YMMV

[dlbrooks18]

N54 is a marvel of an engine!

[GoRomeo]

Thanks for sharing great info like this...