A few years ago I sold the Z3 M and bought a Z4 M.
I bought the Z3 with 90k miles and sold it with more than160k miles. I was amazed at how many people wanted that car!

You might think that the Z4 M would be just like the Z3 M only faster. The Z4 has 330 hp compared to the Z3s 240. But, they are very different cars and it's just not that simple.

Z3 design was based on the third generation 3 series (E36) which started development in 1981 and began sales in 1991.

Development began on the Z3 in 1991 with production starting in 1995.

 Z4 development began in 1998. The car went into production in 2003.

In many ways these two cars could be a case study on the changes in the automobile industry from both a technology and style perspective.

For me the bottom line is that both of these cars are great fun to drive. They have distinct personalities that go beyond which one is fastest.

A Short 1998 M Roadster Tour

On my youtube channel someone asked for a tour video of the Roadster.

Never had a request before and it seemed like a good idea so here it is.
Tour Video
For some reason BlogSpot is not letting me insert the video so a link is all we get.

Cool Carbon Brake Pads - 20,000 mile update

They are not the bomb.
Reduced dust - not so much. I think I get as much dust as the stock pads.
Improved braking - I suppose it depends on what you mean by improved. It takes less force on the brake pedal than it did before, so that's a kind of improvement. At the same time the brakes are twitchier or more touchy than before which you may or may not like - I've gotten use to it.

I guess it's all about your expectations.

Rotor Replacement Challenge

Usually, replacing the brake pads and rotors an any late 90s BMW 3 or 5 series is pretty easy.

1. Remove the wheel - 5 bolts
2. Remove a spring clip
3. Remove 2 7mm bolts holding the caliper
4. Remove the 6mm rotor retention screw.

That's about it
Unless the rotor retention screw won't come out.

These screws get stuck more often than anyone likes. Here are some links to some videos on the topic:
How to Remove a Stripped Rotor Locator Bolt
Drilling Out Stripped Brake Rotor Screws
Removing Brake Rotor Screws That Won't Come Out

While replacing the front pads and rotors on the 98 M Roadster I found a rotor retention screw that had been badly mauled. My best guess is that someone had trouble removing the screw and then re-installed it for me to learn from - how nice.

I didn't remove the screw. Here's what I did:

You may wonder why I didn't use an "easy out". My experience with using an easy out has been all bad. I broke an easy out in a drilled out bolt and found myself in worse shape than when I started.

It does bother me that I left that screw in the hub, with a little work I'll get over it.

Cool Carbon Brake Pads

Yes, they really are good. There is a dramatic difference in braking between these and the metallic pads I was using before.
The metalic pads had a grinding feel to them, these are smooth. The metalic pads took more foot preasure to engage than the Cool Carbon pads.

the box came with four pads, the instructions and a sticker.
The bedding instructions that came with the pads were crazy - at least they seemed crazy to me.

From the instructions

• Perform a series of 10 to 12 partial stops from 70 to 20 mph with the first 3 under moderat braking, increasing to 75% to 90% of full braking during the series of stops"
• Performance should increase somewhat during this process and fall off toward the end of this cycle.
• Do not come to a complete stop during this cycle, if at all possible, as this may interrupt the material transfer proces to the rotor surface; Note: material transfer process will take longer with new rotors.

There is more but you get the idea.
So what is crazy about this?

• Finding a road where you can do 10 to 12 accellerate to 70 and then brake down to 20 mph is not easy
• The instructions go on to recommend "Repeat the above sequence, including the cooling section" so I'm suppose to go through the cycle twice.
• When you are trying to find a stretch of highway deserted enough to do 10 to 12 runs to 70, brake to 20 and then cool down it's easy to lose count - was that 8 or 9?

I should have checked the website they have new instructions that indicate a long term break in method along with a modified fast break in.

All that aside, I like them.

How Does an M Roadster Sound?

I think it sounds better at idle than at high RPM
About half way through I experiment with picture in a picture mode on my video editor

The Brake Rotor Controversy

Plain, slotted or cross drilled?
In 1998 BMW M models came with plain rotors.
In 2010 the M3 comes with drilled rotors.

Do slots or holes or both actually help?
After much searching I didn't find anything I'd call authoritative on the subject. I chose to go stock solid rotors. The information from brembo at tirerack.com helped make my decision. (the brembo logo uses a lower case "b"). I ordered stock rotors and ceramic pads - rotor and pad replacement video to follow.

The bottom line is that in their advertising brembo appears to emphasize the appearance aspect of the slots or holes rather than the performance aspect. They indicate that drilled rotors should not be used with racing brake pads at all.

Here is the actual verbiage -

brembo Sport Slotted Rotors
On the "Product Description" tab is the following disclaimer:

"Brembo Sport slotted brake rotors are designed to meet the challenges of high performance street driving while adding an authentic, race-ready look.

NOTE: Brembo Sport slotted brake rotors can be used in conjunction with race compound brake pads on the track for drivers’ schools and lapping days.

IMPORTANT REMINDER: Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable"

brembo Sport Drilled Rotors 
On the "Product Description" tab is a similar but slightly different disclaimer:

"NOTE: Brembo Sport drilled brake rotors are not recommended by The Tire Rack for track use or intended to be used in conjunction with race compound brake pads on the street. For severe duty brake demands see Brembo Sport slotted brake rotors.

 IMPORTANT REMINDER: Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable."

brembo Replacement Rotors have no disclaimer. Maybe it's because they don't think people will track plain rotors and so they don't need a warning.

brembo has it's own website. The advertising there indicates benifits in water, to dissipate heat and eliminate brake dust and gases.