N54 twin turbo question

[Wraith]

First of all apologies if this has been covered before anywhere else on the forum, if so I havn't seen it after searching a little...maybe I should search longer - but I'm taking the easy way out

It relates to the Top Gear/Clarkson 135i review and because that thread has been closed, I thought I'd ask the question here rather than in the dedicated N54 section - mainly for the reason I've outlined in my opening lines :smile:

Anyway Clarkson states that the 2 turbos on the N54 are of different sizes ??? a smaller one for low engine speeds and then bigger one for higher engine speeds - is this true ??? I've never heard of this before, I thought they were identicle units working together at all engine speeds ???

I find it hard to believe that Clarkson or a Top Gear review would get technical information like that wrong :iono: if it's correct - all's good and I've learned something new today :smile:

[Lester]

Originally Posted by Wraith

First of all apologies if this has been covered before anywhere else on the forum, if so I havn't seen it after searching a little...maybe I should search longer - but I'm taking the easy way out

It relates to the Top Gear/Clarkson 135i review and because that thread has been closed, I thought I'd ask the question here rather than in the dedicated N54 section - mainly for the reason I've outlined in my opening lines :smile:

Anyway Clarkson states that the 2 turbos on the N54 are of different sizes ??? a smaller one for low engine speeds and then bigger one for higher engine speeds - is this true ??? I've never heard of this before, I thought they were identicle units working together at all engine speeds ???

I find it hard to believe that Clarkson or a Top Gear review would get technical information like that wrong :iono: if it's correct - all's good and I've learned something new today :smile:

Yes it is true - hence the no turbo lag.

[Wraith]

Originally Posted by Lester

Yes it is true - hence the no turbo lag.

Thankyou Lester - I've indeed learned something new today - the N54 has 2 different sized turbos, not identicle - I'll have to remember that one :smile:

[135iPSU]

thats pretty crazy, i didnt know that either

[smarm]

Actually, that's erroneous from my reading.

I believe the N54 uses parallel (rather then sequential) identical units, each feeding 3 cylinders.

[smarm]

[smarm]

http://www.1addicts.com/forums/showthread.php?t=901 is worth the read.

[Wraith]

Oh nuts, so now we're back to square 1 :iono:

I've actually seen some of those pics and literature smarm - that's why I posted the question after my Top Gear read...

Can we please have a definitive answer on this :smile:

It would seem they are identicle units, running in parallel - as I initially thought - please someone clear it up 'good n proper' :smile:

[smarm]

That is a definitive answer.

That's directly from a BMW internal technical document regarding the N54.

Clarkson makes stuff up he's not sure about, it's not the first time, it won't be the last.

[Wraith]

Originally Posted by smarm

That is a definitive answer.

That's directly from a BMW internal technical document regarding the N54.

Clarkson makes stuff up he's not sure about, it's not the first time, it won't be the last.

Thankyou smarm - I am with you on this one after reading 'most' of that literature...

And I kinda feel good about Clarkson stuffing up

Do you think this needs to be pointed out on other parts of the forum ?? (say the N54 section) as maybe alot of other people may think otherwise, eg: Lester - no pun intended here...

[jcw2006aus]

I think the Diesel twin turbo engine for the X5 has one smaller than the other!

Maybe thats where he got it from...

[amk2912]

Methinks the 535d has two different sized turbos...Clarkson mentioned that in his review of the 535d a while back on TG (dunno which episode). Maybe he just ASSUMED the same for the N54.

[AussieRacer]

Yeah it is quite common in bi-turbo arrangements to have different size turbos. However all I've read suggests the N54 isn't one of them.

[Bim135AUS]

Yep, Smarm's right- they are two small turbos in parallel. Clarkson's good but not infallible.

[molar]

Smarm is correct. Two turbos in parallel, each one fed from 3 cylinders.

Even the great Jeremy gets it wrong. He is but a journalist, although I have a suspicion we would all like to be like him, even just for a day.

All those cars to test thrash (sorry drive). Life is tough but someone has to live it. Pity it is not me. :wink:

[2QIK4U]

Both are the same size. Fortunately Clarkson isn't a technical nut and like most Journalist he is time poor, sometimes the facts get screwed, that's what makes him interesting.

Mike...

[Wraith]

Thankyou all :smile:

It's definitely question resolved and case closed on this one :smile: