All 35i and 35iS Twin turbos or did change to twin scroll turbo

[2k35is]

As title says seems these changed over at different times for models within the other ranges from about 2011 to twin scroll turbos.
Info I've looked at says that the E89 was a twin turbo until it ceased production. Seems strange that that E89 didn't change at same time to twin scroll when all other models in BMW ranges changed.
Anyone got a definitive answer -Twin turbos or later changed to twin scroll turbo?
Thanks

 

[R.E92]

It wasn't just the turbo that changed, the whole engine changed from the N54 to the N55 in the 335i and 135i.

Luckily the Z4 kept the N54 with it's twin turbo setup until it finished production. The N55 was a step down in most respects.

 

[tiglon]

All the N54 twin turbo engine.

They sold in incredibly low numbers so BMW had absolutely zero motivation to "upgrade" the engine to the more efficient and lower emission but arguably less fun N55.

 

[2k35is]

Thanks for information and explanation of why it didn't change.
Got a whine at low revs which I suspect may be small turbo. Three friendly z4 members let me listen to theirs on startup(many thanks) at Zedfest. So its back to dealers for another check.
Counted four (including mine) 35i/S's at zedfest during time I was there so less than 2% -looked to be lots more Z4M's so yes could be a relatively rare beast.

 

[Chippie]

I’m sure there 2 turbos of the same size each feeding 3 cylinders each

 

[Anonymous]

The N20..little step daughter to the N55 fitted to the 18i 20i 28i was a single turbo which was twin scroll..called ‘twin power’ to confuse everyone..

 

[mcbutler]

It wasn't just the turbo that changed, the whole engine changed from the N54 to the N55 in the 335i and 135i.

Luckily the Z4 kept the N54 with it's twin turbo setup until it finished production. The N55 was a step down in most respects.

Agreed N54 is epic

 

[Silverstar]

The N55 was a step down in most respects.

Was the N55 more reliable than the N54?

 

[Marcoose]

Isn’t it a N54T on the 35is?

 

[Anonymous]

The consensus is that the N55 tidied up some of the issues that beset the N54, however many common issues continued..(and many are common to all BMW engines). …tuning wise the N54 seems to tolerate more tuning / abuse..

https://bmwtuning.co/n54-vs-n55-comparison/

This refers as an example..

The N20 was a further tidy up of the N55 being essentially a 2/3 N55…so improved matters but still subject to the same common threads..

 

[Anonymous]

Isn’t it a N54T on the 35is?

It’s the same engine ..just the ECU has been mapped for more power plus a short lived overboost function..again ECU controller..AFAIK..

 

[tiglon]

I think technically it's N54B30 in the 35i and N54B30TO in the 35is. The latter is just a different version of the same engine, probably with just ECU changes as Pbondar says - although depending on which forums you read you may come across rumours of various other alterations, most likely all bullsh1t.

BMW also produced a N54B30 with around 325bhp.

 

[R.E92]

35i and 35is have identical engines. The difference in power in stock form is just down to the 35is having an extra 4PSI of boost momentarily.

The N55 has crank bearing issues. I know someone who's on their 3rd engine already. The N54 may have issues but you rarely hear of anyone blowing them up.

 

[Anonymous]

I think technically it's N54B30 in the 35i and N54B30TO in the 35is. The latter is just a different version of the same engine, probably with just ECU changes as Pbondar says - although depending on which forums you read you may come across rumours of various other alterations, most likely all bullsh1t.

BMW also produced a N54B30 with around 325bhp.

Real OEM lists both short engines (35i and 35is) as N54B30A with identical part numbers..11002158617

So that just leaves the DME..

 

[tiglon]

Some might say that the DME are part of the engine. Semantics...

 

[Anonymous]

Some might say that the DME are part of the engine. Semantics...

That's why I quoted 'short engine' as BMW don't include the DME in that! :rofl:

 

[tiglon]

Some might say that the DME are part of the engine. Semantics...

That's why I quoted 'short engine' as BMW don't include the DME in that! :rofl:

Yes, I understand that, but the question was just about the "engine". My point is that your interpretation of that was to look at the short engine, others might look at a broader meaning and include DME.

 

[Anonymous]

The DME does obviously defines the personality of the engine..however BMWs naming convention is relatively uniform , so the E89 20i and 28i both have N20B20A engines..the DME changes the power rating..

Pedantically the DME is more associated with the car and the CAS system and are wedded together..

You can change the motor and keep the DME without any coding..you can’t change the DME without re-coding for another body ..

So you cant’t easily change the 35i DME for a 35is DME to get the power boost as it’s coded to the relevant body shell…AFAIK..

Of course you can change the number and size of radiators , coolers, external fuel pumps etc but that’s just the same as discs brakes etc…all non related directly to the power rating..

 

[R.E92]

They have the same DME too. The only difference is the boost targets.

If you are proposing that different DME calibrations count as the engine being different then you are also suggesting that a car with cruise control has a different engine than one without because to enable cruise control within the DME you have to change 1 hex byte.

 

[Anonymous]

They have the same DME too. The only difference is the boost targets.

If you are proposing that different DME calibrations count as the engine being different then you are also suggesting that a car with cruise control has a different engine than one without because to enable cruise control within the DME you have to change 1 hex byte.

That’s good to know..so the 35is is a marketing man’s dream..

A quick tweak on the s/w and charge yet another premium over the 35i.. :rofl: :tumbleweed:

No other changes in Europe save a few bits of plastic ?