Twin Turbos need advice

[Mekuf]

hello to everyoneI have a 2007 BMW E92 N54 335i coupe based on youtube, FAQ searches and looking at forums im pretty sure the twin turbos have gone in my car i have decided that if they have or not i am going to replace them anyway,
ive done a fair bit of window shopping and found what could be the best bang for my bucks but ive come across one or two snags I dont know much about cars. though i am learning every day and i know even less about turbos.
THE snags are A: I dont know if this is a good buy or not B:i know very little about turbos SO I NEED AN EDUCATION if someone has the time to explain what to look out for what to avoid that would br great
In the meantime this product has option to change the turbine wheel blades from 9 to 12 what is the better option and why? i also read that the fins can make a difference and that should focus on this rather than number of blades. tbh i do not know where the "fins are"
there has also been been discussions about the configuration TD04HL and why different markings denote better or worse. but i dont know why or what the codes mean

Any assistance or advice would be very much appreciated and if anyone has better product options please let me know ,,, my budget for this project is 3k

N54 335 TD04HL-19T TWIN TURBO W/ OIL FEED RETURN KIT

Arashi N54 335i Twin Turbo TD04HL-19T
Application:
● BMW 335i / 335xi (E90/E91/E92/E93) N54 3.0L Turbo, 2007 - 2010
● BMW 335is (E92/E93) N54 3.0L Turbo, 2011 - 2013
Compressor Wheel:
● 46 / 58mm (6+6 Blades Billet 19T)
Turbine Wheel:
● 45.6 / 50mm (9 Blades TD04HL) We also offer 12 blades. Please let us know if you need to change
Turbine Housing:
● 6cm^2 / 0.41 AR
Bearing:
● Journal Bearing
Includes:
● 1 x N54 twin turbo with manifold
● 1 x Oil feed line & return line kit

[Greydog]

Morning Gary

Welcome to the Forum

Everyday is a school day 

I guess that you are suffering a lack of performance, but what convinced you that the turbos have failed? 

Before shelling out your hard earned cash on new/refurbished Turbo's is the rest of the engine in good condition? Compression good on all 6 cylinders, injectors in good conditioThn, fuel pressure correct, Oil pump oil, feeds and returns clear, all vacuum lines in good condition. (Teaching Granny to Suck Eggs time) Assuming it is then the turbo chargers are designed to increase the amount of air/fuel mix by forcing it in (compressing it) beyond normal atmospheric pressure) more fuel/air = bigger bang = more power that;s the theory

There are two sides to the turbo Exhaust side has a number of Vanes/Fins hot gas from the exhaust manifold moves over them making them spin. More engine revs more gas the faster they go. The exhaust turbine is on a common shaft that at its other end has another turbine with a set of Vanes/Fins as these are being spun at the same speed as the exhaust turbine they draw air in through the air filter forcing it through the intercooler to reduce it's temperature (cooler air is denser a denser fuel/air mix = better performance.

Today we can get turbo's with refined Vane technology/design or increased turbine size or number of blades. The theory being they spin up faster and give better performance. There are also Turbo's with variable vane technology (the vane/blade angle can be changed) to give boost from lower revs spreading performance across the rev range.

Schools out

If you haven't already get a competent mechanic to check the Turbo's and their operation as turbo actuators and their associated pipework can often be the cause of folks thinking the Turbo is gone.

When your Googling check the Register of BMW Specialists these are Garages normally run by BMW trained technicians these guys will have the knowledge, tools and software to fix your car.

A few websites to help with School if you are not aware already (1) www.realoem.com this is a BMW online parts list, put the last 7 digits of your Vin into the search box it will bring up your model. Then search the sections for what you need, very useful when buying parts and making sure they fit.

(2) An American site so the steering wheel is on the wrong side 🤣 www.pelicanparts.com their articles section has comprehensive "How Too's" with pictures that will help understand what is involved in many tasks they also give indicative times for tasks that even if you are paying a garage for its helpful to know whats going on (well I like to know)

Hope this is helpful

Dave