4 Inch Rear Speakers

In the continuing quest for better sound in a Z3, I decided to replace the stock rear 3″ speakers in my 99 2.3 with 4″ speakers, or possibly 4×6″. Model year 2000 and newer have 4″ speakers, so I knew that in theory at least, I should be able to fit a decent set of 4″ co-ax’s back there. The stock 3″ speakers are pitiful single paper cone drivers, “designed” for “filtered” midrange sound from the factory amp. I found their sound lacking, even annoying. They did not add anything to my audio experience. I am cheap, …..let’s say cost conscience,…… so I am always looking for more bang for the buck and aftermarket speakers have always provided more satisfying sound over stock OEM drivers. The first step was to see what kind of volume and interferences I had to work with. I popped out the little hatch, shown in first photo, but even with a flashlight it was difficult to get a clear view. The 3″ speakers are held in place by a threaded collar, essentially a giant knurled nut. If you take a large screwdriver and tap the knurls through the little hatch counter clockwise with a rubber mallet to start, it then unscrews easily. The speaker pulls out to reveal a circular hole with a chord (flat spot), that is supposed to prevent the speaker from spinning. This allowed a better view and some discouraging news as well.

There’s a bunch of stuff in there…the seat belt retractor, the structural steel for the roll hoop and the re-enforcing cross member that goes across the vehicle. The steel is a problem because it is so close to the plastic trim housing. This limits where the speaker can be placed, because either the driver basket or magnet will hit something. Depth is about 2 ½”, but variable because the housing slopes. In addition, the 3″ speaker opening is located far to the outside, because the tiny magnet does not interfere with anything. It is actually easier to install a new speaker if you have NO rear speakers; ie. you can cut a new hole farther inboard without worrying about the existing hole showing beyond the coverage of the speaker trim/grill.

Luckily, 4″ speakers are strange creatures, many appear to have grills with trim that increases the coverage area. This was critical in this case; if the trim were any smaller, it would not have been possible to mount the speakers and avoid interference, and still cover the existing opening. The last photo shows the grill coverage outline (courtesy of dirt sticking to Armorall……will stop using that stuff!). I looked at installing a 4×6 speaker, but quickly found that only Blaupunkt 4×6 seemed to come with grills! The other manufacturers assume you are replacing an OEM installation and do not include them. I was not impressed with the Blau 4×6 specs, so I decided to go 4″.. Based on listening and a car audio store recommendation, the speakers I installed were Pioneer TS-A1086. They had nice plain black grills, and once I dremeled off the Pioneer name and made a P-touch label that spelled “BMW” to put in its place, it really looked stock. They have a cut out requirement of 4 1/16″, and a magnet diameter of 2 3/4″ . The trim and grill actually covers a diameter of about 6″.. I also looked into installing Infinity 452i speakers which are a “plus one” 4 inch size; ie the cone is 30% larger for the same cutout. It has a magnet that is ½” larger in diameter and ½” deeper, so it would be trickier to fit, but has a rubber surround, silk tweeter, and higher power handling capability. It would be easier to install the 452i, if there had not been any rear speakers. And since they were out of stock at the time, I went with the Pioneers. My cutout (from the outside edge of the hole, closest to the measuring point) ended up being 3/8″ vertical down from the upper trim piece end that starts the groove (leaves about 1/8″ left in bottom trim piece TO the groove) and 1 5/8″ horizontal from the center trim piece. This allowed the magnet to clear (actually JUSTS touches the carpet over the cross member), the speaker trim to cover the old opening, and still contain the plastic cut within the lower trim piece. I was afraid that cutting into the upper trim piece would cause the assembly to be too flimsy and buzz or rattle. There are also some interference issues, if you feel up under and into that area. The upper and lower trim pieces snap together, and I wanted to try to avoid breaking that connection for aesthetic and structural reasons. The plastic is thick, about 1/8 to 3/16″ and is ribbed on the backside for more support. I used a Dremel tool with a cutting blade that resembles a tiny circular saw. It cut through the plastic like butter, but it is CRITICAL that you tape the surrounding area, as it is VERY easy for the saw to jump and instantly mar the surface for good. It is easier to work the saw with the seats removed but I actually only removed the driver side; once I had my measurements I did the passenger side with the seat moved all the way forward, but then I also have a flexible extension that really helps…YMMV.

The pictures are pretty self- explanatory. There was a very noticeable increase in clarity and volume with the new speakers, even hooked up to the stock amp. I ended up running dedicated, unfiltered speaker wires directly from my Toronto head unit under the center console to get full range (for a 4″, anyway) sound, which sounded MUCH better than the stock amp connection. Even firing into the back of the seats, they are so close to you that they provide significant “top down” midrange and high sound. I find the stereo sound similar to that of wearing headphones; it is as if you are “in” the sound, not “in front” of it. Some people don’t care for that…I like it. Another idea to try instead of the Infinity co-ax’s, would be to use a 4″ component set and locate the tweeters up and outboard in the upper trim unit for better separation and directionality. I found the Pioneers to be a significant upgrade to the sound system for very few dollars. Now if I can just find a way to put in a powered subwoofer and lose no legroom or storage space……..

2.8 SuperTrapp Exhaust

Subject: Muffler system upgrade for a 2000 2.8 Z3 Roadster
Cost: $150 for the exhaust plus installation (approx $75), I just checked the website and the price increased to $160.
Good: Customizable sound & performance, low cost AND lightweight
Bad: Non-that I am aware of at this time.

Why do this: As the immortal Tim Allen said “MORE POWER”. One of the first things I did to get more power out of my 2.8 was to Fogg the cold air intake (CAI). Even though Shawn never did a 2000 2.8, I took his ideas and suggestions from both his instruction on the 1.9 and from communications with the immortal himself and I was able to modify my CAI to work similar to his.

Of course this was not enough. So the hunt was on for a more affordable power upgrades. So I started looking into exhaust system replacements. I looked at every type possible, even asking about replacing the exhaust manifold and/or catalytic converter, not without screwing up my emissions & computer. So I concentrated my search to muffler replacement only. I looked at Bola, Dinan, Supersprint, etc. I searched for all types of information (horsepower increase, cost, material type, etc.) that would help me decide what muffler to purchase. I read all the articles from the MZ3 website on exhaust/muffler systems.

To my surprise, I found that all the stainless steel mufflers’ costs were in excess of $300 to $600!!!! Not including installation. Plus I was not convinced that the performance versus cost ratio was worth the money spent. I then remembered about the SuperTrapp system. They were primary an aftermarket motorcycle muffler. But, I saw them on cars in the past, about the late 70s. Plus I knew that they made systems that were stainless steel and lightweight. So the hunt was on.

First: I found their limited website http://www.supertrapp.com/default/atv_splash.htm not a great site to see what was available. But it did explain on how their system works.

Second: I found a supplier (there were not many in my area): http://www.racesearch.com, Part number: 543-2519, http://www.racesearch.com/CGI/mhp?mode=sbpn&pn=543-2519

Third: I found the one I wanted Stainless steel 5″, now granted if you called SuperTrapp & view the Z3 Coupe message board, they recommend that I use a 4″ system for horsepower up to 250 Hp. The 5″ system is rated up to 400 Hp. The reasons for the 5″ is simple with the wider inner diameter, the exhaust gasses would flow easier, less noisy and the 5″ outer diameter fills the factory muffler exhaust cutout nicer.

Arrow points to the location where the stock exhaust tube was cutWhen I had my muffler installed I had the installer hack off the original muffler and it’s supply piping back to the rear axle. If you look at the picture, you will see that the bend to the muffler has been reduced. He then made some custom hangers to hang the muffler at the stock points. Due to the heat generated from the exhaust gasses and the many discussions on the message board on melted bumper fascias due to the muffler. I instructed the installer to have the muffler hang a little lower and poke out more than normal. Giving it less of a chance of the muffler from melting the bumper fascia.

What is with the metal disks and cover???? The SuperTrapp muffler is basically a “glass pack”, where you have an inner tube that has holes and an outer tube that has insulation between the two tubes. Since there is no bends or baffles within the muffler, the gasses are unrestricted to flow toward the end of the pipe. Now the glass pack system has been around for a long time, if you had a hotrod or muscle car, you will know what I mean. Now for the metal disks and cover. The disks that you see on the side of the muffler are really spacers that have been stamped to allow the exhaust gasses to pass between two spacers. The metal cap is to help tune the performance of the muffler and car. Now the easiest way to explain this is to imagine that you have a large bucket with some holes in it. Now fill the bucket up with water, you will see that the water takes a long time to empty out. Now add more holes to the bucket and add water, you will now see that the water will empty out quicker than before. So the more holes you add the faster the water exits. Now there is more to the SuperTrapp system, which deals with vanturies that help pull the exhaust gases from the car. View the SuperTrapp website for more information.

Basically this is how this works with the car: The less spacers you install on the muffler, will produce more backpressure on to the system. Thus, increasing your torque, decreasing overall horsepower and a more quiet sound. With (6) spacers, the noise was a similar to my stock system. The more spacers you install on the muffler, it will reduce backpressure. Thus, decreasing your torque, increasing overall horsepower and a more robust sound. I ran both (12), (18) & (24-max) spacers. I normally run (24) spacers as a daily driver. Which is has a nice growl during idle and a cool roar during hard acceleration plus, I have had no complaints from my neighbors. I did try the system with NO spacers and it was too loud for normal driving.

I have raced my new exhaust with only (12) and no spacers, only to find that no spacers worked best. I will try my (24) spacer setup to see how it fares. Since the installation, I have not conducted a horsepower comparison, my fault. It will be hard to see if my new muffler has done anything, because I have done a ton of things to get this car quicker than stock. Check out my website for details: http://www.z3power.net

Summery: I am happy with the purchase of this muffler and I would do it again. In addition, if I did not have any performance gains in torque or horsepower, I have reduced the overall weight of the car. Which is always a good thing for our heavy cars.

Hartage Classic Wheels

19″ Hartage Classic’s Wheels

19″x8″ (front)

with 235/35/19 Yokahama AVS Sport

19″x”9.5 (rear)

with 265/30/19 Yokahama AVS Sport

Zeemax Body Kit

The Car is a 1998 Mroadster. I found the car 1 year ago at a local (orlando) Mercedes/Porsche dealer. As the story I was told goes, It was owned by the guy who trucked the ring around for the WWF. He never drove the car due to the fact that he was on the road all of the time. One night his wife told him she wanted a boxster instead of the M. They got in a big fight and surprise, she won. The car was on the lot 1 day when I saw it, I immediately put down a deposit and drove it home the next day with 950 miles on the clock.

The very next week I ordered the H&R lowering springs from RacingZone Auto House and had them installed (thanks Brian). From there it went a little nuts. All of the orange in the lights HAD to go. I ordered the front headlights, side markers, and bumper light from Circle BMW (found through MZ3.net). I ordered my controversial Taillights from Racing Zone Autohouse in Orlando Fl. They are from Inpro but have since been discontinued and are very hard to find. People either love them or hate them.

Next I started on the interior, the pedals are from AJUSA.com and are a good set of pedals that look right at home in the retro interior. The carbon fiber kit is from Joshua Tree and I think it gives the cars interior a racy look. I also have a ///M Hood emblem and Chrome door handles from a website that I can’t quite remember.

For the exterior I went to my friends over at RacingZone Autohouse again. The rims are 19″ Hartage Classic’s, 19×8 (front) with 235/35/19 Yokahama AVS Sport Tires and 19×9.5 (rear) with 265/30/19 With Yokahama AVS Sport Tires.

The Body Kit is Zeemax and was ordered through Eric at Supreme Power Parts (www.supremepowerparts.com). It was done after all of that Zeemax stuff with SMS and Eric is now able to order Kits Directly from Zeemax. The cost was right around $1,920 shipped to my door. The fit was great, some minor mods had to be done by the body shop to make it PERFECT. All of the paint and body work was done by Moores Precision Collision in Orlando Fl. (www.precisioncollisioninc.com). The wing is from Veilside and was ordered from RacingZone Auto house also. The shipping company cracked 2 of them before I finally got one that wasn’t damaged.

All and all the car has taken a year to get to its current state. Now I am going to focus on performance, not that the car really needs it, I am looking into the forced induction options available and am leaning towards the Mech-Tech turbo system, that big mouth up front is just screaming for a huge intercooler.

I would like to thank everyone who has helped me out in this last year:

Thanks to Everyone at Jade Motorsports

Brian at RacingZone Auto House

513 N.Semoran Blvrd.

Orlando Florida 32807

(407) 273-0099

Eric at Supreme Power Parts

1025-B Ortega Way, Placentia, CA 92870.

www.supremepowerparts.com

(714) 632-1951

Edward Hickman at Moores Precision Collision

420 N. Kirkman Road

Orlando, Fl 32835

(407) 294-0100

Dinan ///M Air Intake

The ///M engine can benefit from additional air (mass) intake, however the Dinan design (specifically for the M roadster and M coupe) concerns me. Look at the picture below, the air filter is exposed in the lower air intake (front bumper). While this may provide additional performance I really question the long term effects. The K&N filter is rather durable, but what happens when it gets wet. I’ve heard a report of a check engine light coming on after a car wash. I also look at the amount of rock chips this section of my bumper has picked up and wonder how long a paper filter could last against this kind of impact abuse.

For these reasons I would not recommend the Dinan intake unless it was only for Autocrossing or Track use, even under those circumstances I question if the Dinan design has any advantage over the ECIS or Jim C design.

Update: I have been informed “Dinan is now shipping (for free) filter covers, a la K&N condoms, which are supposed to solve these issues”. I think this shows great customer service and reminds everyone why Dinan is such a popular company to do business with.

BMW Chrome Door Handles

Pros: Looks good, matches other chrome trim
Cons: Expensive BMW part, difficult installation.
Cost: Roughly $400 retail*

# Chrome Exterior door handles: Left: 51 21 8 401 625 (BMW Part) $184.00 retail*

# Right: 51 21 8 401 626 (BMW Part) $184.00 retail*

# Chrome Exterior door handle surrounds: Left: 51 21 8 399 239 (BMW Part) $17.90 retail*

# Right: 51 21 8 399 240 (BMW Part) $17.90 retail*

* BMW Retail price at the time this article was written. Using discounts, online vendors or a BMW parts department that doesn’t charge full retail can save 10 to 20 percent.

Hamann Gas Tank Lid

Pros: Looks Really Good
Cons: Difficult installation, Painting Required
Cost: $490

There is an re-emerging trend, the Audi TT and a few other sports cars are starting to bring attention to, rather than hide the gas cap. If you’re looking to draw a little more attention to your Z3 gas cap, then Hamann has what you’re wanting.

This Aluminum performance gas tank cap kit from Hamann Motorsport contains everything you need to install it yourself, however one of the parts needs to be painted (body color). The installation sounds a little scary, but you can install it yourself in a little over an hour. The included instructions are in German the following is an English translation.

1. Take off right rear wheel and inner fender lining.

2. Take off tank flap with assembly. Take off tank cap.

3. Take off rubber lining around tank filler opening (will not be needed any more).

4. Install new HM tankcover insert and rotate into correct position (it will only fit in one position).

5. Drill insert at marked place with 2mm drill (picture).

6. Take off insert and enlarge drill hole to 3.5mm.

7. After painting of tankcover insert apply a thick coat of P1 adhesive to frontal area of tankfiller opening.

8. Attach HM tankcover insert using supplied 4×15 screws. Smooth out any excess adhesive.

9. After adhesive had hardened attach the HM-tankcover and gasket, align and mark drill hole point.

10. Take off HM tankcover and drill marked spot with 6mm drill.

11. Attach HM tankcover,gasket and some gasket material (?) with provided Senkimbus screws.

12. Reattach inner fender material and wheel.

There is some debate if you really have to take off the right rear wheel, one owner reported to me that he successfully installed the kit without removing the rear wheel. Not sure if he cut the rubber lining out or was able to just man-handle it out of there. If you’re going to tackle a project like this use your own best judgement. The “scary” part of the installation (in my opinion) is step 7. Your gluing the painted fiberglass sleeve onto your gas tank filler opening, better get this done right the first time.

Everytime you start your Z3, the gas tank is “tested” by car. If you listen close you can hear an air pump pressurizing your gas tank. The system then monitors that pressure, if the pressure drops too quickly it triggers a check engine light because it thinks there is a leak in your gas tank. If you don’t get an air-tight seal while cementing this part in place you’re going to have check engine lights haunting you.

Dinan ///M Exhaust

LeatherZ Shift Knob

LeatherZ just keeps coming out with new ideas and products for the Z3. When I first heard that LeatherZ could recover the stock BMW shift knob with their higher quality leather, I knew I would want to have one. After thinking over the additional color options LeatherZ offered I decided to try something different and go with a two-tone dark gray and black. LeatherZ’s dark gray is an almost perfect match to the dark gray on the seats in my 1998 M roadster, and it’s also a great complement to my LeatherZ covered armrest.

Removing the stock Z3 shift knob is fairly easy, the M series has one additional step due to the lighted face. Basically all you have to do is pull it off. With the M series you’ll want to get under the shift boot first and disconnect the two wire plug. Once I removed my shift knob I mailed it to LeatherZ and waited for its return. I went about a week without a shift knob, surprisingly it wasn’t that big a hindrance to shift without the knob in place.

LeatherZ provided a couple interesting pictures (1, 2) of the shift knob during the recovering process. You can see how the lighted knob is internally wired in these pictures. Once LeatherZ completed the upgrade they mailed the shift knob back to me. Reinstallation was fairly easy, I threaded the 2 wire connector plug through the shift boot and plugged it in. Then noted the “U” shaped pattern to the receiving end of the shift lever, aligned the shift knob and pushed it back down (adding a whack with the heal of my hand for good measure).

I’ve heard of some Z3 owners having shift knobs come off while driving. I wouldn’t recommend using glue but maybe some lock-tight inside the “U” indentation would provide some additional holding strength for those that require it.

LeatherZ Pricing Options:

If LeatherZ provides the shift knob (new):

1. Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather Shift Knob – $100.00.

2. Illuminated M-style Leather Shift Knob in Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather – $135.00

3. Illuminated M-style Leather Shift Knob in Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather with Corrected Amber (not red) LEDs – $165.00

If customer provides shift knob:

1. Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather Shift Knob – $40.00.

2. Illuminated M-style Leather Shift Knob in Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather – $75.00

3. Illuminated M-style Leather Shift Knob in Black, Beige, Dark Gray, or Tanin Red monochromatic or 2-tone Leather with Corrected Amber (not red) LEDs – $105.00

In most cases the customer can specifiy a different shift pattern insert at no additional charge.

LeatherZ is also planning to carry BMW brushed and matte chrome (real metal) shift knobs that also illuminate. These knobs are shorter than stock and should be similar to the one in this article.