Smoothness of the N52 engine compared to others?

[chris82]

In the great scheme of things, how smooth of an engine do you think it is compared to others old and new that BMW offers? Name specific engines please! (like S54, etc.)

I wish I had an answer myself for this, but I have not been in enough other BMWs than my 1!

thanks for your opinions!

[Zeros and ones]

telling you from having an e39 Dinan 5 that has the M52 engine in it, the n52 engine is just as smooth.

You really can not compare old with new for the old BMW just have a different feel/vibe.

My e39 although a sedan, has much more of a raw feeling than me e82. I get really excited when I get into my e39 cause it communicates with me so very well.

But my e82 on the other hand, I get a nice smile on my face when I open her up cause she just wants to be driving like she is stolen.

[TheSt|G]

Smoothest engine they have made outside of the 7er V12.

My fiance thought it was broken the first time she drove it after driving her E46 ZHP.

[flinchy]

The thing stopping the n52 from perfection smoothness wise is the DISA intake

You feel a shudder when it engages, it sucks

See a dip on a dyno too

[TheSt|G]

Originally Posted by flinchy

The thing stopping the n52 from perfection smoothness wise is the DISA intake

You feel a shudder when it engages, it sucks

See a dip on a dyno too

Seeing as the US 128i doesn't have one stock, it is very smooth.

Evolve also can fix it a great deal.

[flinchy]

Originally Posted by TheSt|G

Seeing as the US 128i doesn't have one stock, it is very smooth.

Evolve also can fix it a great deal.

the downside of having almost 40hp more :P

[TheSt|G]

Originally Posted by flinchy

the downside of having almost 40hp more :P

Hence the easy retrofit I did. Now significantly faster than either.

[flinchy]

Originally Posted by TheSt|G

Hence the easy retrofit I did. Now significantly faster than either.

howso?

[TheSt|G]

Originally Posted by flinchy

howso?

DISA+SS Headers+Tune for both/93>None or just DISA.

[Kgolf31]

Originally Posted by TheSt|G

Seeing as the US 128i doesn't have one stock, it is very smooth.

Evolve also can fix it a great deal.

I have the N51N with the 3 stage DISA, as it came with in stock trim.

you can clearly feel a pick up in power after 3k, probably as the DISA valve fluctuates. The feeling is almost identical to my S54 after 4k where it gains its torque and becomes a beast.

does evolve tune n51s? I thought they never touched my engine before, yet can theoretically tune the DISA which doesn't make sense to me

[Zeros and ones]

Originally Posted by Kgolf31

I have the N51N with the 3 stage DISA, as it came with in stock trim.

I wasn't aware that you can fit a 3 stage disa on a N51 engine. Of course my only source for this is turner Motorsports as they sell the N52 disa intake manifold but they clearly state that it is not for n51 engines.

Can you clarify?

[Suprgnat]

Originally Posted by Zeros and ones

I wasn't aware that you can fit a 3 stage disa on a N51 engine. Of course my only source for this is turner Motorsports as they sell the N52 disa intake manifold but they clearly state that it is not for n51 engines.

Can you clarify?

N51 comes from the factory with the DISA manifold.

[Kgolf31]

Originally Posted by Zeros and ones

I wasn't aware that you can fit a 3 stage disa on a N51 engine. Of course my only source for this is turner Motorsports as they sell the N52 disa intake manifold but they clearly state that it is not for n51 engines.

Can you clarify?

Originally Posted by Suprgnat

N51 comes from the factory with the DISA manifold.

Bingo.

In order to make up for the lower compression, the N51 has a DISA manifold already on the car, in stock trim

[Zeros and ones]

Originally Posted by Kgolf31

Bingo.

In order to make up for the lower compression, the N51 has a DISA manifold already on the car, in stock trim

So if we already have the 3 stage Disa Manifold, were can we make up that loss of performance? besides for a tune?

Correct me if I am wrong, but you can take a n52 engine with 230hp put the 3 stage intake manifold on and a tune get you to ~255 hp with roughly everything else being stock

And if we have the 3 stage Disa manifold, would it be safe to assume you can get the stage 2 evolve tune for our cars?

[Kgolf31]

Originally Posted by Zeros and ones

So if we already have the 3 stage Disa Manifold, were can we make up that loss of performance? besides for a tune?

Correct me if I am wrong, but you can take a n52 engine with 230hp put the 3 stage intake manifold on and a tune get you to ~255 hp with roughly everything else being stock

And if we have the 3 stage Disa manifold, would it be safe to assume you can get the stage 2 evolve tune for our cars?

that is a base assumption.

I've tried talking to evolve, and it seems they've never tuned a n51. so potential gains are out in the air.

I'm in contact with AA now to see what they say. I'm interested on evolve's answer. If it is as simple as taking their tune and throwing it on our car for that type of gain, then it really is a no-question what to do

[chris82]

The 3 stage manifold on the N51 (SULEV engine) is identical to the one found on the US 330i. however, the reason you cannot simply tune the N51 to get that extra 30 hp is because the software will not comply with the engine's DME. There does not seem to be a way around this. . . .

[Obioban]

More to the point, the n51 is already using the DISA to get equal power to the n52 without DISA (because of the lower compression on the n51). It comes from the factory much closer to its stock potential... Sucks for the n51 owners big time.

The n52 is both smoother and jerkier than the M54 and s54. When it's not at a DISA actuation point, it's SMOOTH. Only thing smoother is a v12. When it's at a DISA actuation point... Not smooth. Still, worth it. Only way I see to smooth that over would be artificially curtailing the power to make a more gentle transition. So... smooth engine rotations, not smooth power delivery.

The s54... Not that smooth of an engine. Kind of part of what makes it awesome-- always feels like its on the edge of blowing up (It isn't-- 135,000 miles on mine including 4000 track miles, no issues). Though, while it's not particularly rotationally smooth, it has VERY smooth power delivery. Kind of the opposite of the N52.

[631twentyeighteye]

By far the smoothest motor i've ever driven in, granted i haven't been in many luxurious cars. But i guess ill find out if the DISA really is as noticeable as you say.

[TheSt|G]

Yeah the DISA definitely adds some bumps in the power band of the N52:





Much better than this turd though:

[ulrichd]

After 5 years of ownership I still love the combo of my N52 with a manual. Oh, and the BMW Performance exhaust helps with a slightly too docile stock exhaust note.

[TheSt|G]

Originally Posted by ulrichd

After 5 years of ownership I still love the combo of my N52 with a manual. Oh, and the BMW Performance exhaust helps with a slightly too docile stock exhaust note.

Yeah, the engine is definitely crippled with the auto.

You should join us in header/DISA valve world, makes it have even more character.

[Kgolf31]

Originally Posted by Chrisar82

The 3 stage manifold on the N51 (SULEV engine) is identical to the one found on the US 330i. however, the reason you cannot simply tune the N51 to get that extra 30 hp is because the software will not comply with the engine's DME. There does not seem to be a way around this. . . .

Interesting. Active Autowerke told me this:

As far as hp is concerned 40 crank hp with a tune and manifold is very realistic but since you already have a 3 stage the difference may be less. We have seen more gains with the severely detuned 325 models with the same engine. Unfortuantly we have not had a n51 on our dyno to get a before and after baseline comparison.

and this

BMW has very similar calibrations in the N51 and N52 SW, they calibrations are extremely close even though the compression ratios are different, but not that different, you will be surprised how good the DME can adapt and how fast it can with ignition timing, the main difference in the engine is the hardware, we have tuned both N51 and N52 with great success. The valvetronic engine has great potential.

Seems like we need to get to the end of this.

Originally Posted by Obioban

More to the point, the n51 is already using the DISA to get equal power to the n52 without DISA (because of the lower compression on the n51). It comes from the factory much closer to its stock potential... Sucks for the n51 owners big time.

The n52 is both smoother and jerkier than the M54 and s54. When it's not at a DISA actuation point, it's SMOOTH. Only thing smoother is a v12. When it's at a DISA actuation point... Not smooth. Still, worth it. Only way I see to smooth that over would be artificially curtailing the power to make a more gentle transition. So... smooth engine rotations, not smooth power delivery.

The s54... Not that smooth of an engine. Kind of part of what makes it awesome-- always feels like its on the edge of blowing up (It isn't-- 135,000 miles on mine including 4000 track miles, no issues). Though, while it's not particularly rotationally smooth, it has VERY smooth power delivery. Kind of the opposite of the N52.

With 0.7 compression difference, you're not talking about a huge HP swing here. Maybe 5-10 HP at most.

With that being said, I still think there are huge gains out there for a properly tuned N51. Just gotta find them (gotta talk to Evolve and see if they have tested a N51 yet)