Z4M coupe v Porsche 911 997.1 C2S comparison.

[BMWZ4MC]

Out of sport mode, the first centimetre of throttle pedal travel does little. It's improved with sports mode, but overall the fly-by-wire throttle is a poor substitute for a throttle cable. I'd love to find someone who could write a different map for the throttle to more closely match the behaviour of a cable set up, specifically removing the initial dead pedal travel.
I'd quite like to programme out the preemptive boost in brake servo pressure that occurs in response to rapid throttle closure too. It's supposed to be a safety feature for an impending emergency stop, but I find it can interfere with modulating the brakes on the track.
That's a nice choice if cars for the daily commute Nick. I ran an S2000 as my daily driver for a while next to my Zed and every journey was a pleasure

 

[abar121]

I'd love to also be able to convert the Z4M pedal to cable and remove some of the over-servo'd sensation from the brakes. I still think the DBW throttle is one of the better installations, but it still has the odd flatspot / hiccup. The delay is there whether you use the sport button or not. It's just a question of if you want to be able to use the full throttle travel, or just the first 2/3ds.

It's a bit like comparing the throttle on an N52 equipped 330i vs a Z4 3.0si. In the Z4 you get a really slack throttle with quite a delay in normal mode, or the same delay but over what feels like half the travel in sport mode. The 330i does without the sport button, yet the throttle feels slightly better everywhere and was more natural to heel and toe for me. Nothing like as responsive as the M though.

It can be done much better though. I was riding a Yamaha MT10 with DBW the other day. The electronic throttle is very sensitive and quick to react compared to any car I've driven. It has to be though, throttle response is much more critical on a bike, even just balancing a bike when manoeuvring. Also ND MX5s and GT86s have much less delay and more natural feeling throttles and even pretty good EPAS systems.

A nice 997.1 review released today:

https://www.youtube.com/watch?v=L6vlVdY2Fr8

I have to echo his comments at 11:30 re: PASM. A complete waste of time really, stock it's fine, but the sport mode just leaves it over-damped, without any handling benefit. Another placebo type feature with no real benefit

 

[Viren]

I find at low speed or city driving the throttle is quite frustrating, however at medium to high speed the throttle is fine, anything above 2.5krpm is sweet. Every car has its character this is the zeds, it sulks at low speed and sings at high speed.

 

[petrolhead88]

I don't believe the Z4M throttle is difficult to modulate in non-sport setting.

The throttle response is amazing from the engine and the pedal well matched against that.

I think the issue is the first 2cm of pedal travel does next to nothing. This makes rev matching and heel & toe difficult in normal mode. It's easier in sport mode, but then it's jerky when pulling away.

Aside from that, it's the feel of the throttle pedal that I have issue with. It just feels very light and offers little feedback.

 

[TomK]

I don't believe the Z4M throttle is difficult to modulate in non-sport setting.

The throttle response is amazing from the engine and the pedal well matched against that.

I think the issue is the first 2cm of pedal travel does next to nothing. This makes rev matching and heel & toe difficult in normal mode. It's easier in sport mode, but then it's jerky when pulling away.

Aside from that, it's the feel of the throttle pedal that I have issue with. It just feels very light and offers little feedback.

I think I've commented on your throttle thoughts before, but in case not I will reiterate that I think you really ought to get yours checked out. I drive mine exclusively in non sports mode and have immediate pickup from the throttle (if anything I would prefer something very slightly less aggressive to modulate better). I have also driven my friend's z4M quite a bit and found the throttle behavior to be pretty much identical.
Throttle lightness/heaviness I can't really comment on as I don't know what you're comparing it to, however I found it not to be much difference to my old 968. The throttle map in my e46 M3 is non sports mode was horrible and had the feeling you describe of no power for the first few cm of travel. With that car I did have to use the sport mode which was annoying as it's so much more binary.

ETA: maybe try and compare with a local member?

 

[pHilli0]

I think I've commented on your throttle thoughts before, but in case not I will reiterate that I think you really ought to get yours checked out. I drive mine exclusively in non sports mode and have immediate pickup from the throttle (if anything I would prefer something very slightly less aggressive to modulate better). I have also driven my friend's z4M quite a bit and found the throttle behavior to be pretty much identical.
Throttle lightness/heaviness I can't really comment on as I don't know what you're comparing it to, however I found it not to be much difference to my old 968. The throttle map in my e46 M3 is non sports mode was horrible and had the feeling you describe of no power for the first few cm of travel. With that car I did have to use the sport mode which was annoying as it's so much more binary.

ETA: maybe try and compare with a local member?

Same as Tom. Throttle is very sensitive and immediate, a few cms of travel is more revs than I would like even in non sport mode, makes it quite hard to modulate super accurately. Absolutely no lag and no dead spots. Above 3000rpm its perfect to the red line and pretty easy to balance.

 

[Beedub]

I don't believe the Z4M throttle is difficult to modulate in non-sport setting.

The throttle response is amazing from the engine and the pedal well matched against that.

I think the issue is the first 2cm of pedal travel does next to nothing. This makes rev matching and heel & toe difficult in normal mode. It's easier in sport mode, but then it's jerky when pulling away.

Aside from that, it's the feel of the throttle pedal that I have issue with. It just feels very light and offers little feedback.

I think I've commented on your throttle thoughts before, but in case not I will reiterate that I think you really ought to get yours checked out. I drive mine exclusively in non sports mode and have immediate pickup from the throttle (if anything I would prefer something very slightly less aggressive to modulate better). I have also driven my friend's z4M quite a bit and found the throttle behavior to be pretty much identical.
Throttle lightness/heaviness I can't really comment on as I don't know what you're comparing it to, however I found it not to be much difference to my old 968. The throttle map in my e46 M3 is non sports mode was horrible and had the feeling you describe of no power for the first few cm of travel. With that car I did have to use the sport mode which was annoying as it's so much more binary.

ETA: maybe try and compare with a local member?

yes... totally agree.

i dont think I've clicked the sport button more than 4 times in my complete decade of ownership :|

 

[Babw]

The guys stating immediate throttle response all seem to have one thing in common - remap of some sort.

My stock Z4M throttle map seems very similar to my old E46 M3, a little laggy in normal and a little too sensitive in sport.

 

[TomK]

The guys stating immediate throttle response all seem to have one thing in common - remap of some sort.

My stock Z4M throttle map seems very similar to my old E46 M3, a little laggy in normal and a little too sensitive in sport.

I don't remember the throttle being any different before my alpha-n map and anyway a remap has no effect on a throttle map, they are entirely different things. My friend's car I spoke of, that hasn't been mapped.

That said there does seem to be 2 types of Z4M out there :?

 

[Argenta]

By the sounds of it you never tried reset the throttle?
Big difference I think. No remap on my car and never had any real problem with the response (its immense) other than it can go out of tune on rare occasions. Gets a bit edgy but a quick reset fixes that.

 

[Jaw]

I love the sport button on the M, that little extra bit of sharpness makes it that teeny bit more wild. Suited my driving style in it well. At the same point where my foot would be with it off it's at an extra couple of hundred revs which did make a difference before and after a reset

 

[BMWZ4MC]

The first centimetre of throttle pedal travel produced little change in engine rpm in every Z4M I've driven. Thereafter, there was the expected progressive change in rpm with increasing pedal travel. I think it's a characteristic of the standard fly-by-wire software. This magnitude of the lag is reduced in sports mode.
I suspect that those who've not experienced this are thinking that those who have are describing a more dramatic lag than is actually present.
I expect if a 'believer' and a 'non-believer' shared a ride in each other's ///Ms then mutual understanding would result!!

 

[Babw]

The guys stating immediate throttle response all seem to have one thing in common - remap of some sort.

My stock Z4M throttle map seems very similar to my old E46 M3, a little laggy in normal and a little too sensitive in sport.

I don't remember the throttle being any different before my alpha-n map and anyway a remap has no effect on a throttle map, they are entirely different things. My friend's car I spoke of, that hasn't been mapped.

Likes of Evolve definitely modify the throttle map when doing an engine map recalibration.

– full throttle fuel
– full throttle ignition aim
– part throttle ignition aim
– minimum ignition set
– torque calculation
– speed limiter of 250km/h removed
– dyno rpm limiter removed (normally set to 6300rpm)
– sport button memory function enabled (sport button remains on permanent if set to on even after ignition is switched off)
– normal and sport throttle maps modified for smoother driving
– vanos intake and exhaust
– throttle opening maps (to achieve 100% opening)

I don't necessarily think a more sensitive throttle is a good thing. One of the things I like in something like a Lotus Exige Cup compared to a Cayman GT4 is the longer throttle pedal in the Lotus. Same with brakes, it give you a bigger spread to tweak your input.

 

[TomK]

They can of course but it is an entirely different part of the electronics, ring them up and ask them.
The throttle map and other fancy things like shift lights, sports memory on etc are adjusted using something like this http://www.ecuworx.co.uk/2015/05/19/mss5x-binary-modification-tool-faqs/
The actual engine map is far more involved.
I had my m3 alpha-n mapped by them and I was asked whether I would like the throttle maps adjusted.

Similarly with my Z4M, the throttle map was not touched as the tuner did not know how to achieve that on our dme.
I wish somebody did as I would love to make the map slightly less sensitive.

 

[Babw]

Good info Tom

I was basing my opinion on my old M3 which I owned pre and post Evolve map. I really disliked the throttle map and eventually had the whole remap taken off.

 

[Beedub]

mine may have been tweaked tbh.... the map has been changed by ess a few times now.

Also my sport button definitely functions differently.... if i switch it on.... it will remain on when i restart the car, the stock car used to reset back and needed to be turned on again.

i feel no lag in my throttle.

 

[MrTops]

What a great article! (sorry for being several years late). I have a 2007 ZMC and I love that my 911 owning friends don’t have a clue.

 

[R60BBA]

The guys stating immediate throttle response all seem to have one thing in common - remap of some sort.

My stock Z4M throttle map seems very similar to my old E46 M3, a little laggy in normal and a little too sensitive in sport.

Don’t think it’s map related.

Sport mode on the E46 M3, Z4C and Z4M (I’m talking cars which have not been mapped here) is too sensitive imo.

It does make the car ‘feel’ more urgent and perhaps heel and toe is slightly easier, but this is where the benefits stop for me.

Driving smoothly is a lot easier in non-Sport mode (whether cruising on the motorway or pushing out of a corner on track). The throttle is longer and so modulation of it is much better imo.

 

[BMWZ4MC]

It’s very much each to their own preference, but in 13 years I’ve not intentionally driven out of sport mode in any circumstance. I tried non-sport mode when I first bought the car and found the first centimetre of dead travel of the pedal very frustrating for throttle modulation, especially when pulling away gently or during heel-and-toe at normal road speeds. I’m sure that not using sport mode contributes to the “kangarooing” often demonstrated by inexperienced Z4M drivers when pulling away with a cold engine - engaging sport mode gives them a throttle that reacts when pressed and often solves the problem.
At road speeds when decelerating gently, brake pedal travel might be considerably less than a centimetre and braking sustained for reasonably long periods. In such circumstances, progressively shifting down the box using heel-and-toe is unnecessarily difficult with an insensitive throttle. On the track where the brake pedal is depressed much further and for very short periods, and the requested throttle openings are much bigger (using the full rev range of the engine), the insensitive throttle in non-sport mode is much less of an issue for heel-and-toe during aggressive deceleration.
With sport mode engaged, the throttle response to initial pedal application is more akin to a cable-controlled throttle. It allows for predictable and precise throttle modulation throughout the pedal travel, which in turns assists with both gentle and aggressive driving.
Many other BMWs of the early 2000s have the same frustrating throttle map characteristic with very little throttle opening during early pedal travel. It seems to be a consequence of early BMW fly-by-wire throttle design since it is absent from their earlier cars with cable driven throttles and from their later cars with more considered throttle maps.

Edit to add: looking back through this thread, I’ve posted a few times over the years. Each time I’ve said essentially the same thing, so at least I’m consistent even if the throttle response in non-sport mode is not

 

[beanie]

I find mine to be very inconsistent with throttle pedal response/travel. Sometimes it’s incredibly sharp, others it feels flat and ‘dead’ like others have mentioned. It makes shifting an issue that I’ve never encountered in any other car. Heel and toe is also a bit hit and miss at lower revs and in normal driving, though like most aspects of this car, it seems to work best when giving it death! Unfortunately the police don’t seem to sympathize with this issue, nit-picking gits that they are!

I’ve changed both of the engine tps and have cleaned the linkage for the itbs several times, perhaps it’s time for a new pedal and tps? Then again, maybe it’s cable throttle time, at least it’ll be consistent.