BMW Valvetronic and TwinPower Turbo Overview

[AlexanderR]

Originally Posted by mkoesel

What don't you believe?

That the S65 does not employ Valvetronic throttle technology is a well known fact. Most naturally aspirated BMW engines do not (or did not).

Regarding FWD applications for the N2hat has not been announced but is all but certain at this point. We know that FWD BMW's are coming in the 1 Series product range, and the N20 will naturally find its way into these models (though it is possible that they will give the transverse version of the engine a different name).

I don't believe the fwd applications until I see one in person, I guess im just in denial that bmw would actually water themselves down to that level, if they do actually make a fwd bmw I hope it never comes to our shores.

[Evice]

Originally Posted by csween86

...I could be way off...

Oh yes, you are.

[mkoesel]

Originally Posted by AlexanderR

I don't believe the fwd applications until I see one in person, I guess im just in denial that bmw would actually water themselves down to that level, if they do actually make a fwd bmw I hope it never comes to our shores.

In case you are ready to come out of the denial phase of grieving

http://www.e90post.com/forums/showthread.php?t=363146

[AlexanderR]

Originally Posted by mkoesel

In case you are ready to come out of the denial phase of grieving

http://www.e90post.com/forums/showthread.php?t=363146

Im still gonna deny it just because hahah but I can't see a fwd bmw ever coming to the us.

[csween86]

I never said my theory was fact. I just figured I'd throw my opinion out there for ideas. I did agree with Gnip Gnop that since it is a twin scroll turbo, that could be a very good reason why it is called "twin power turbo." I just took it as: twin power turbo=turbo w/ power of 2, and figured because a lot of people think 1 turbo compared to 2 is bad...... Anyway, exactly what is a twin scroll turbo? For example the n55, it is my understanding that the exhaust manifold has the cylinders hooked up in 2 pairs of 3 going to a split wall turbine housing, instead of all 6 cylinders going to 1, preventing certain cylinders exhaust back-flows and pressure from affecting another's when they fire? I see some people saying there are two turbine blades, one for high revs and the other for low(wasn't that the function of having 2 turbos in the n54)???

[AlexanderR]

Originally Posted by csween86

I never said my theory was fact. I just figured I'd throw my opinion out there for ideas. I did agree with Gnip Gnop that since it is a twin scroll turbo, that could be a very good reason why it is called "twin power turbo." I just took it as: twin power turbo=turbo w/ power of 2, and figured because a lot of people think 1 turbo compared to 2 is bad...... Anyway, exactly what is a twin scroll turbo? For example the n55, it is my understanding that the exhaust manifold has the cylinders hooked up in 2 pairs of 3, instead of all 6 cylinders in 1, preventing certain cylinders exhaust back-flows from affecting another's when they fire? I see some people saying there are two turbine blades, one for high revs and the other for low(wasn't that the function of having 2 turbos in the n54)???

On a twin scroll turbo, the turbine side of the turbo(exhaust) is split into two channels to turn one turbine. The two channels are coupled with 3 cylinders to each channel. Having it split allows the turbo to spool up quicker are reach peak torque at a very low RPM, due to the exhaust gasses having a higher velocity.

[csween86]

Ah I see thank you for clearing that up, I was kind of on the right track, I went back and edited my post realizing I left some out while you posted yours.... Seriously though thats a nice and simple explanation that makes sense! Finally!

[AlexanderR]

Originally Posted by csween86

Ah I see thank you for clearing that up, I was kind of on the right track.... Seriously a nice and simple explanation that makes sense!

No problem, its kinda complicating at first but thats the best way to describe it.

[csween86]

Lol I did it again... I'm always trying to edit my post and make it nicer before someone writes back lol, I'm OCD haha. Thanks again.

[Ben_XI]

BMW is applying "TwinPower Turbo" broadly. It can mean a single twin-scroll turbo for the N55 engine or twin turbos for the N63. Yes, can be confusing unless you look at the specs.

[e90pilot]

I just wanted to interject here about some observations I've made regarding valvetronic. I'm not sure why BMW keeps saying the the throttle plate remains in the full open position one the engine is warmed up, because it's simply not true. I hooked up a data logger to my car (2006 325i sedan N52) and logged throttle plate position, pedal position, and valvetronic angle. I drove the car for 45 min and observed the movement of each variable. I noticed that the throttle acts just like a normal throttle plate in any car. If you give it gas, it opens. If you take lift, it closes. If you don't move your foot it stays the same. It doesn't matter weather you're driving on the street or freeway, or just revving while stopped. Valvetronic also increases and decreases with pedal position. When you start the car, the throttle angle is about 10-13 degrees and then CLOSES to about 4-5 degrees for normal idle. Max angle is 81 degrees.

I also noticed something else that's interesting. The throttle plate action is heavily dampened. If you lift suddenly, the throttle and valvetronic will not close immediately, especially while cornering. When increasing the throttle quickly, there is less damping and the response is better.

I'm not sure if there have been updates to the way the system functions since it the generation they installed in my car, but the way it works in my car is contrary to the way everyone has portrayed it.

[mkoesel]

^^^

Interesting. Perhaps the implementation is different for TwinPower, HPI applications like the N20, N55, N63tu, and N74 than it is for naturally aspirated, port injection engines such as the N42, N52, and N62.

[e90pilot]

Or maybe mine's broken lol. But seriously, that may be true but BMW said almost the same thing hen they advertised my car's engine. It just seems strange maybe someone else should take a look at thier car. If you have a turbo car with valvetronic and BT tool you can pull up the actual values and log them.

[SilverII]

nice

[vase330]

Originally Posted by csween86

I am a big skeptic of this issue my friend. I made a post on this issue at one point. I brought my 135i in for it's first service a while back, and the service rep told me they had to do an update to the DME but never gave me a straight answer why.... I will admit afterwards my car did not feel less powerful in the long run, but my throttle response became weaker on the low end and my exhaust note completely changed... It used to growl (burble), especially when the revs would fall(decompression) ... I might be crazy but to this day I'm convinced that BMW might have accidentally added the ppk to some factory cars and then realized it, and inconspicuously removed it.....

Wouldn't surprise me. They detuned our N54s way back when after we had them for a few months. eventually they admitted it, but claimed it was to reduce rattle which it ofcourse never did. Now that we have tunes around, who gives a rat's ass what they do, I have been getting all the juice I can handle out of mine for the last couple years.