2014 z4 - eps? n54?

[Guynamedsean]

does the 2014 z4 have hydraulic or electric power steering?
does the 2014 35i and the 201435is still use the N54?

the lease is up on my 335is coupe. I'm trying to decide what to go to next.

[Gpwheels]

eps and the 35is uses the n55 twin scroll single turbo engine. I think the 35i uses a version of the same engine, but I am not sure

[Beryl]

If you are talking about the Z4 35i/is motor, it's still the N54. Never the N55.

[jeffp1105]

+1
Z4 never switched to N55 on any version / year

[ManiacGT]

It's amazing how many people think the iS has the n55. The 35i and 35iS are both n54 as they're essentially the same car with a slightly different tune. And yes electric power steering on all models and years .

[Guynamedsean]

thanks guys
looking for the purest bmw experience
had a 135i
traded it for a 650i and hated it. it drove like a boat.
traded that for a 335is and put Dinan stage 2 on it. love it!

i thought the z was still n54

big question?

will the 2014 car accept the Dinan tune or does it have the new 128 bit encryption? I called Dinan and they don't even know.

also, how is the EPS in the Z? vs a the older hydrolic systems. The 650i sucked.

[jparnes1]

Some people complain about the lack of road-feel with EPS. I would agree that there's less feedback then before, but it depends on how picky you are. But what's your alternative? Even Porsche has gone to EPS.

[nicknaz]

Originally Posted by Guynamedsean

thanks guys
looking for the purest bmw experience
had a 135i
traded it for a 650i and hated it. it drove like a boat.
traded that for a 335is and put Dinan stage 2 on it. love it!

i thought the z was still n54

big question?

will the 2014 car accept the Dinan tune or does it have the new 128 bit encryption? I called Dinan and they don't even know.

also, how is the EPS in the Z? vs a the older hydrolic systems. The 650i sucked.

Another forum member recently posted about problems with a Cobb tune on his 2014 Z4, and Cobb mentioned there were changes to the ECU, so I would GUESS the same issue would come up for the Dinan tune and it will be some time before there is a tune for the 2014.

"purest BMW experience"... I would say you have to go M3 (wait for F80 or get E9X ?). Your 335is with a tune is pretty solid as well with the hydraulic steering, N54 and DCT

You aren't going to see a performance gain since the Z4 weighs the same as 335is, and 335is has better engine cooling. Also the Z435is has the same brakes as 335is but Z435i has smaller brakes than 335is

IMHO, you need to take a LONG test drive with the Z4 and be really clear going in that it is a "lifestyle car" and not a "sports/track car", as well as love the folding roof and styling, since those are the key advantages of the car.

(full disclosure... I am planning to switch to F80 M3, Porsche or C7 vette when my lease is up next year since I want a car that doesn't overheat during HPDE)

EDIT: The EPS on the Z4 is ok. I personally define "good" steering as 987.2 Cayman S and 997.2 C4S hydraulic steering, so "ok" means I can live with it, but it isn't the best I've driven

[Guynamedsean]

I also come from several Porsches in a row before the bmw's. I agree I owned boxsters, caymans and 911s before eps.
I have done real bad injury mobility issues now and the slightly higher ride height and more compliant suspension on a bmw help. I thought I would drive porsche forever but I honestly feel best up now when I just ride in one.
I loved bmw's hydrolic steering it wasn't nearly as good as Porsche is very light with lots of feedback. My 335is is good but it's like drawing with a fat market vs a pen.

[CeEl]

Mobility issues? It may take some practice (and pain) to get in and out of a Z4. Some use the memory seat as an in/out aid (one position to enter and exit the car, another for driving). Make sure that's not an issue before you even drive the car and fall in love with it.

[Asbjorn]

If you want comfort combined with more steering feel, then driving with DSC=off is a great option. It has the steering feel of sport+ but not the hardest suspension setting. I use it all the time because I do not like how the steering feels in sport (which I claim is different from sport+, but in sport+ the throttle is too boosted when combined with ESS).

But don't get the Z4 because of steering feel. It is clearly filtered by the electronics to make the ride more comfortable. Get the Z4 because of drifting feel, the fact that is the lightest and most beautiful BMW convertible and because of the N54. You sit very near the rear tires and all the feel you do not have of what the front end is doing, you get back when the rear end looses grip. It is such a wonderful feeling. But you have to really know the car to get such pleasures out of it.

[jeffp1105]

Originally Posted by Asbjorn

But don't get the Z4 because of steering feel. It is clearly filtered by the electronics to make the ride more comfortable. Get the Z4 because of drifting feel, the fact that is the lightest and most beautiful BMW convertible and because of the N54. You sit very near the rear tires and all the feel you do not have of what the front end is doing, you get back when the rear end looses grip. It is such a wonderful feeling. But you have to really know the car to get such pleasures out of it.

+1

[nicknaz]

Originally Posted by Guynamedsean

I also come from several Porsches in a row before the bmw's. I agree I owned boxsters, caymans and 911s before eps.
I have done real bad injury mobility issues now and the slightly higher ride height and more compliant suspension on a bmw help. I thought I would drive porsche forever but I honestly feel best up now when I just ride in one.
I loved bmw's hydrolic steering it wasn't nearly as good as Porsche is very light with lots of feedback. My 335is is good but it's like drawing with a fat market vs a pen.

BMW vs. Porsche is always a tough comparison to make. I'm always on the fence about driving friend or family's Porsche at the track because I know I'm going to want one more!

Have you looked at Macan S ? Its got a tall ride height and will likely have great "Feel" like all of the Porsche products.

Current gen Cayenne is fun to track even though its a tank so Macan should be even better

[Hujan]

Originally Posted by jparnes1

Some people complain about the lack of road-feel with EPS. I would agree that there's less feedback then before, but it depends on how picky you are. But what's your alternative? Even Porsche has gone to EPS.

All the new ///M cars are/will be EPS as well. It's already in the M5/6 and will be heading to the M3/4 too. I believe the E9x M3 was the last BMW to have hydraulic steering.

For what it's worth, I switch back and forth between my M3 and Z4 quite often and really enjoy both cars quite a bit. And the M3 is FBO (downpipes, pulley, intake, tune) whereas the Z4 is bone stock. I'm half afraid that once I tune the Z4, I won't want to drive the M3 as much on the street.

[Guynamedsean]

Originally Posted by CeEl

Mobility issues? It may take some practice (and pain) to get in and out of a Z4. Some use the memory seat as an in/out aid (one position to enter and exit the car, another for driving). Make sure that's not an issue before you even drive the car and fall in love with it.

is it that low? I can get into an e92 easy. will this be harder? a 997 Porsche is more difficult for me to get into to.

I am going to go sit in one tomorrow.

A black z4 with black grills is starting to look really good.

[Asbjorn]

Originally Posted by Hujan

All the new ///M cars are/will be EPS as well. It's already in the M5/6

No, M5/6 are still not EPS!

The new M3/4 will have EPS but with different software which allows more feedback but less comfort compared to the Z4. The M software does not compensate for over and understeer like the system in the Z4, and does not help returning the wheel to center in the same way either. You just can't get comfortable/intelligent steering AND unfiltered steering at the same time it seems.

[pete_z89]

Originally Posted by Guynamedsean

A black z4 with black grills is starting to look really good.

Yes it does just a little convincing for you to jump into the e89:

[Gpwheels]

Are those wheels new for 2014? I asked at BMW and they said there was no factory option for dark (black or gunmetal grey) wheels for the e89

[nicknaz]

Originally Posted by Asbjorn

The new M3/4 will have EPS but with different software which allows more feedback but less comfort compared to the Z4. The M software does not compensate for over and understeer like the system in the Z4, and does not help returning the wheel to center in the same way either. You just can't get comfortable/intelligent steering AND unfiltered steering at the same time it seems.

I think you might be confusing "active steering" (which E89 does not have) with "electronic power steering"

http://www.bimmerfest.com/forums/att...3&d=1371458966

Check out page 79 in that attachment which explains the difference, as well as all the other stuff about EPS in our cars.

Long story short, the EPS does not super-impose a steering angle other than what the driver has specified (i.e. the E89 EPS does not provide any compensation (i.e. change in steering angle) for over or understeer)

another interesting tidbit in that attachment is explanation of how EPS doesn't provide as much feedback as compared to hydraulic steering because of "dampening effect of electric motor" and also there is "road feel data" added to the steering, so the computers use the electric motor to simulate the feedback of a hydraulic steering rack. This is where the programming skill of the engineers and the decision of how much to filter for comfort or pass on to user for "feedback"

I think the key reason for EPS switch is outlined pretty clearly there too. 0.2L/100km fuel savings and easier to manufacture and install....

[Asbjorn]

Originally Posted by nicknaz

I think you might be confusing "active steering" (which E89 does not have) with "electronic power steering"

Long story short, the EPS does not super-impose a steering angle other than what the driver has specified (i.e. the E89 EPS does not provide any compensation (i.e. change in steering angle) for over or understeer)

I am not talking about active steering. Ie I was not talking about steering angle, but only about steering force. The document also clearly states the the EPS can superimpose a steering force, but not a steering angle.

So I was referring to the EPS actively pushing the wheel back to center as well as pushing it to the left or right to compensate for over and over steer.

The new EPS in the M3/4 does not do this.

In a Z4, if you are coming out of a turn, and let go of the wheel, it will return fairly quickly to center even at very low speeds. Of course this would also happen with no power-steering at all, but it would happen much more slowly, solely depending on the speed and front suspension setup. As I understand it, the new M3/4 will behave more like a car with no power-steering in this regard.

Also, in a normal car, and with DSC=off, if the car starts to under-steer, the wheel will become much lighter as the load eases of the front wheels. In the Z4 there will still be an artificial push towards correcting the problem. Something similar happens on over-steer, making it easier to correct it. This has all been disabled in the new M3/4 as I understand it, hence providing more realistic feedback and of course less comfort.

[Asbjorn]

BTW the document also says on page 93 that one of the inputs of the EPS is the DSC sensor. And why would you use the DSC sensor as input if the EPS only had to do active return to center and speed-sensitive stuff?

The function that has the DSC sensor as input is described as "Steering power assistance" and "active roadwheel feedback". A subfunction hereof is "Active Damping" which includes "Damping Steering Input from Driver". An example is given that roughly translates into "we help you so that you do not loose control of your car by selectively reducing/increasing power assistance". Over- and understeer is not mentioned directly, but I believe it is fair to assume that the DSC sensor knows exactly what the car is doing and tells the EPS about it.

The fact that it was mentioned specifically about the M3/4s EPS that it does not compensate for over- and understeer, nor provides active return to center, would support that these functions exist.

[nicknaz]

Yes, I get what you are saying about the difference in steering force providing some form of "assistance" in some cases.

I think the best example of this is in the comfort mode, it takes a bit more effort to turn the wheel away from the straight ahead position, to help keep the car going straight.

What you are saying about the change in the self centering force when the car is over/under steering is interesting. I never thought of that as "assistance" since I still have to turn the steering wheel in the appropriate way to get back under control.

I wonder if we can get the moderators to bring that Scott26 BMW employee to answer these types of detailed questions (along with whether the traction control in sport+ is the same as DTC mode )