Anyone here have an Z4MC/Z4MR that brakes like a Porsche?

[donoman]

My OLD dinosaur Porsche 964 brakes are phenomenal. You brake, they engage, then you press harder and they feel like braking power increases linearly.

I have owned many BMWs, and have never really liked the brakes. But these take the cake for the worst, most grabby, unpredictable ///M brakes I've ever had. I think my E36 M3 had better brakes than this. They are very poor on modulation although they have good stopping power. They are grabby.

The 964 has 4 pot calipers. I might be wrong but these BMW brakes look like single-pots. But the rotors are huge. They look like they should be able to brake alright. I mean, my Z4 2.5i brakes alright and it's just a smaller version of the Z4MC, right? What makes the 911s brake so nice? and this so bad?

Aside from a big brake kit, what can I do? I'd rather buy a dirt bike than spend $4000 on brakes.

I think this is the only disappointment for me, having purchased my Z4MC recently. The motor and the handling are all really nice and it's a great GT car to complement my 911. The brakes... Brakes are for wussies... and I'm a wussy.

[KevinC]

That's how I've felt about my brakes since buying the car new 7 years ago - grabby as hell! My other (2) previous BMWs have both had awesome brakes - nice and linear, with plenty of stopping power. My Z4MC brakes are "on/off" and could throw an inexperienced driver through the windshield if not warned in advance. Curious to hear what kind of responses you get with suggestions for a cure that doesn't cost an arm and a leg. I don't track my car so I don't need anything with more stopping power, but would love some linearity.

[Finnegan]

Swapping out stock for Stoptech performance pads helps, but doesn't cure this. Yes, my E36 has better "feel" with braking. Linear and hell of a lot easier to trail brake. The stock Z4M brakes have good stopping power but are too grabby and non-linear, and feel compared to a Porsche or my E36 leaves something to be desired.

[Vanne]

s'funny, mine are fine, and they are linear.. that said, i havent had t do an emergency stop in a portcha (intended) , but compared to the GSXR750RR i used to have , my M brakes pretty much on par.. obviously not in the same distance, but has the same progressive feel.. only thing i think is different to stock is i have steel braided brake lines.

[Beedub]

drove a carrera GTS on track with PCCB and my AP setups feels as strong and every bit as linear, easy to modulate, still right up their with one of the best mods I've ever done to a car.

[ga41]

You can only do so much to improve the feel of single pot calipers... Even with stainless steel braided brake lines and different pads and fluids it's still a huge single piston.

I've got Stoptech's six piston front and four piston rear big brake kit and while they improve the feel a lot your braking experience really depends on the pad that's used. With the supplied Stoptech Street Performance pads they were pretty linear. With the Pagid RS29's i replaced them with street driving is quite "exciting"! Press gently, no power, a bit more, no power again, a tad more and BOOM you headbutt the windscreen! :P

What i still wish for though is for an even firmer pedal. The Stoptechs are pretty much as stock but when i drove my buddy's M3 CSL with AP Racings it was very stiff and firm from the get-go. Much better than mine....

[angelr]

Yep, my 6 piston calipers front and and 4 piston rear helped immensely with feel. Power has increased as well along with thermal capacity but feel was the most rewarding aspect because that you enjoy on every drive.

[The HACK]

A friend of mine and a long time Porsche owner explained to me as to why Porsche brakes are so damn good...

It's a front wheel drive car trying to drive backwards. Meaning the weight is concentrated on the DRIVE axle like a FWD, but the drive axle is in the @ss end of the car. So naturally the front end of the car isn't asked to do as much as what a typical 50/50 weight distribution car like a BMW would under braking. Therefore a Porsche is more naturally balanced under braking than any BMW would ever be.

You add that to the fact that even ancient Porsches have heavy under car ducting redirecting air into both the front AND the rear brakes, it means you can brake harder, brake more often, and brake with confidence time and time again even on inferior hardware.

And Porsche does not come with inferior hardware.

I will tell you this now. You will never be able to make enough modifications to the MZ4 Coupe's brakes to make it brake better than a Porsche. Not until you step way the heck up to a high end race system. And even then, a couple of simple modifications on a Porsche will still out-brake ya. The Porsche is engineered to take FULL advantage of the fact that their engine is on the wrong side of the rear axle.

I remember taking a ride with another friend in his Cayman R at Auto Club Speedway, and although technically the Cayman R doesn't share the front wheel drive going the wrong way problem the regular 911s have, it does share the fact that there isn't significant amount of weight and hardware up front and it has all the ducting to keep the rotor cool...And my friend was braking from near triple digit speeds at the last second before a decreasing radius, off camber hair pin...while he's half way into his turn-in. I asked him what sort of pads he was running, Hawk DTC series, PFC-whatevers, or one of the Pagid colored series for track use.

He looked at me, gave me a huge grin (it must have been a huge grin, since I can't see his face behind the helmet and head sock) and said they're bone stock.

There are inherent mechanical advantages to how Porsches are designed that a BMW will never be able to overcome when it comes to the brakes.

[donoman]

Originally Posted by The HACK

You add that to the fact that even ancient Porsches have heavy under car ducting redirecting air into both the front AND the rear brakes, it means you can brake harder, brake more often, and brake with confidence time and time again even on inferior hardware.

I agree with this, but our cars ducting isn't bad, and I'm talking about grabby and non-linear on the STREET, where I haven't touched the braked for maybe MINUTES at a time exiting the freeway. The rotors should be cold. I don't think this is the root cause of the day to day crappy brakes that we experience... I think you are right that the hardware is the key.

There are inherent mechanical advantages to how Porsches are designed that a BMW will never be able to overcome when it comes to the brakes.

Do the M3 guys complain about the brakes too? Boy, BMW really skimped on these things. Like I said, this Z4MC is a street car for me and I really don't want to drop next month's rent on a Stoptech kit.

Can we solve this problem with different pads with different bite characteristics? My pads are OEM.

[Beedub]

Originally Posted by ga41

You can only do so much to improve the feel of single pot calipers... Even with stainless steel braided brake lines and different pads and fluids it's still a huge single piston.

I've got Stoptech's six piston front and four piston rear big brake kit and while they improve the feel a lot your braking experience really depends on the pad that's used. With the supplied Stoptech Street Performance pads they were pretty linear. With the Pagid RS29's i replaced them with street driving is quite "exciting"! Press gently, no power, a bit more, no power again, a tad more and BOOM you headbutt the windscreen! :P

What i still wish for though is for an even firmer pedal. The Stoptechs are pretty much as stock but when i drove my buddy's M3 CSL with AP Racings it was very stiff and firm from the get-go. Much better than mine....

yes.... the pedal is very firm from the top of the pedal.... really nice feeling.

[donoman]

Originally Posted by Vanne

s'funny, mine are fine, and they are linear.. that said, i havent had t do an emergency stop in a portcha (intended) , but compared to the GSXR750RR i used to have , my M brakes pretty much on par.. obviously not in the same distance, but has the same progressive feel.. only thing i think is different to stock is i have steel braided brake lines.

This is encouraging... do you own a Porsche or Big brake kit? I feel that only people who drive them regularly could really understand what I mean by good braking feel.

In my opinion, this thing is nothing like any motorcycle I've ridden (and I've ridden a few in my day ... mostly Italian garbage recently). If I had brakes like this on my bike, I would probably be doing stoppies every time a squirrel scared me or I sneezed...

Maybe you're talking about stopping power... I'm not talking about stopping power here but braking FEEL and linearity.

[Finnegan]

Originally Posted by donoman

This is encouraging... do you own a Porsche or Big brake kit? I feel that only people who drive them regularly could really understand what I mean by good braking feel.

In my opinion, this thing is nothing like any motorcycle I've ridden (and I've ridden a few in my day ... mostly Italian garbage recently). If I had brakes like this on my bike, I would probably be doing stoppies every time a squirrel scared me or I sneezed...

Maybe you're talking about stopping power... I'm not talking about stopping power here but braking FEEL and linearity.

Feel. Stock pads are grabby. Stoptech Street are more linear. Even so, pedal feel isn't like my Cayman was or friend's 07 STI with stock Brembos, nor is it as linear.

Why not give pads a try and see if that's enough of an improvement?

[The HACK]

Originally Posted by donoman

Do the M3 guys complain about the brakes too? Boy, BMW really skimped on these things. Like I said, this Z4MC is a street car for me and I really don't want to drop next month's rent on a Stoptech kit.

Can we solve this problem with different pads with different bite characteristics? My pads are OEM.

What came on the MZ4 Coupe is the most advanced brake system BMW has developed (at the time). It's the same brake rotor, caliper, and master cylinder as what was on the E46 M3 CSL (as in Competition Sports Line, or whatever the acronym means). Compared to the later BMW models, including the Ms, it's still the most advanced brake system made up to the current generation of BMWs (and the MZ4 Coupe is 2 generations old).

In particular the 2 piece rotor design that is standard on the basic car is far more advanced than even the 135i's brakes, which came with fixed 6 piston calipers front, 4 piston rear.

What you are experiencing, is BMW put on this car a set of brakes designed to slow down and stop a car that's 300 lbs heavier (the E46 M3 ZCP) and/or the last "mass" produced BMW designed to live its useful life on track (E46 M3 CSL).

And since the MZ4 Coupe has 50% of its weight on the front axle, that means when braking (and braking HARD) there's more mass transferred up front, therefore the front brakes do far more work than the rear brakes, therefore the front brake rotors are MASSIVE 13.5" units for a car this size and weight, therefore car has more of a tendency to pitch and dive due to the discrepancy in brake torque supplied by the front and rear brakes (the E46 M3 non ZCP, by comparison, has relatively the same size rotors front and rear) thus leading to a significant change in the sensation of weight shift and a "grabby brake" feel. It's by nature, how this car was designed using left over parts from the E46 M3 ZCP/CSL. Porsches on the other hand, having more of its weight in the rear, under braking actually NEUTRALIZES the weight distribution, therefore they do not need significant bias changes to shift more of the work up front, leading to a more balanced brake feel.

It's inherent in the way the chassis is designed and laid out.

[Finnegan]

So we "just" need to move the engine to the hatch!

[donoman]

Originally Posted by Finnegan

Feel. Stock pads are grabby. Stoptech Street are more linear. Even so, pedal feel isn't like my Cayman was or friend's 07 STI with stock Brembos, nor is it as linear.

Why not give pads a try and see if that's enough of an improvement?

I think you're absolutely right. I'm going to give the Stoptech Street pads a shot, with a fresh bleed. Maybe I should get SS lines at the same time, too... since I will need to bleed it out anyway. More money, more time, oh well!!!

[yousefnjr]

I sort of like how rough the brakes and other controls on the car are. It fits in with the overall character. Steering is heavy, shifting is notchy, and sport-mode throttle demands some respect. It's not a friendly car, and I love it for that. A lot of the appeal for me is in taming the beast, and that's how a proper mans car should be

[sixspeed]

APs here also. Pretty much what has already been said. A very solid, firm pedal that just increases bite the harder you press.

Disagree with the poster above who commented about the RS29s though. I find they have plenty of bite from cold and initial application.

[Walkurie]

Originally Posted by yousefnjr

I sort of like how rough the brakes and other controls on the car are. It fits in with the overall character. Steering is heavy, shifting is notchy, and sport-mode throttle demands some respect. It's not a friendly car, and I love it for that. A lot of the appeal for me is in taming the beast, and that's how a proper mans car should be

Good characterization of the car. Love it!

[PLCZ4MC]

my breaks pretty nice on the streets. even from high speeds. Not so much like a Porsche but I don't fell them grabby. On the track sometimes a little from breaking to often. Was thinking in switching after my free break changes is over to a BBK but do not found it that necessary for the rode.

[angelr]

I think he was speaking more of feel and take up of the brakes not chassis dynamics so much. I think most enthusiasts are aware of the inherent advantages and disadvantages of a given chassis layout. FR, MR, RR, FF etc.

Originally Posted by The HACK

A friend of mine and a long time Porsche owner explained to me as to why Porsche brakes are so damn good...

It's a front wheel drive car trying to drive backwards. Meaning the weight is concentrated on the DRIVE axle like a FWD, but the drive axle is in the @ss end of the car. So naturally the front end of the car isn't asked to do as much as what a typical 50/50 weight distribution car like a BMW would under braking. Therefore a Porsche is more naturally balanced under braking than any BMW would ever be.

You add that to the fact that even ancient Porsches have heavy under car ducting redirecting air into both the front AND the rear brakes, it means you can brake harder, brake more often, and brake with confidence time and time again even on inferior hardware.

And Porsche does not come with inferior hardware.

I will tell you this now. You will never be able to make enough modifications to the MZ4 Coupe's brakes to make it brake better than a Porsche. Not until you step way the heck up to a high end race system. And even then, a couple of simple modifications on a Porsche will still out-brake ya. The Porsche is engineered to take FULL advantage of the fact that their engine is on the wrong side of the rear axle.

I remember taking a ride with another friend in his Cayman R at Auto Club Speedway, and although technically the Cayman R doesn't share the front wheel drive going the wrong way problem the regular 911s have, it does share the fact that there isn't significant amount of weight and hardware up front and it has all the ducting to keep the rotor cool...And my friend was braking from near triple digit speeds at the last second before a decreasing radius, off camber hair pin...while he's half way into his turn-in. I asked him what sort of pads he was running, Hawk DTC series, PFC-whatevers, or one of the Pagid colored series for track use.

He looked at me, gave me a huge grin (it must have been a huge grin, since I can't see his face behind the helmet and head sock) and said they're bone stock.

There are inherent mechanical advantages to how Porsches are designed that a BMW will never be able to overcome when it comes to the brakes.

[Beedub]

Originally Posted by angel@forgemotorsport.com

I think he was speaking more of feel and take up of the brakes not chassis dynamics so much. I think most enthusiasts are aware of the inherent advantages and disadvantages of a given chassis layout. FR, MR, RR, FF etc.

exactly how i read it.....

[ga41]

Originally Posted by sixspeed

APs here also. Pretty much what has already been said. A very solid, firm pedal that just increases bite the harder you press.

Disagree with the poster above who commented about the RS29s though. I find they have plenty of bite from cold and initial application.

They do have bit from cold but it sometimes hard to modulate them, say leaving a car-park after it's been sat there for an evening.

Do your AP's offer a stiffer pedal than the stock brakes?