Pricing:

1. FVD / M&M headers with 200cell "HF" cats: $ 2,995.00

Current retail is $ 3,788.80, that's a savings of $ 793.80!!

2. FVD / M&M headers with Cat Bypass: $ 1,995.00

Current retail is $ 2,768.37, that's a savings of $ 773.37!!

The latest "HD" cats will be more expensive but if enough people show interest we will also create special pricing.

A few months ago, I decided to take my next step towards Boxster bliss. My focus was exhaust, more specifically headers and cats. Many of my friends have said, “the car sounds great, just leave it alone.” But, as many of you can relate to, I am on a mission to make my boxster sound and perform exactly how I think it should have left the factory. Many forum members are aware of the vast amount of exhaust offerings for our cars. In fact making a decision can be a little overwhelming. This post is intended to help those who already have or are considering an FVD / M&M exhaust, headers and cats.

I own a 2006 987.1 Boxster S (3.2L, 6 speed) and have the added the following modifications in the order that they are listed:

1. FVD Software & BMC Sport filter

2. FVD Sound Version Sport Muffler

3. H&R Lowering Springs

4. OZ Ultraleggera HLT 19” Wheels with 7mm FVD spacers (front) & 18 mm FVD spacers (rear).

5. 75mm throttle body with 75 mm IPD Plenum

As many of you know, the vast majority of FVD exhaust systems (about 85% of our entire Porsche line up) are made by M&M exhaust, GmBH in germany. M&M actually stands for Motorsport and Marine by the way, they also make racing exhausts for boats!

Here is a little more background on M&M.[/url]

FVD sound version muffler background:

In order for me to expand on the headers and cats, a little background is necessary on our sport mufflers. I purchased the FVD Sound Version muffler. I have had it for nearly a year now and couldn’t be happier with its performance and sound. When driven softly and it is extremely docile, and parallels the stock sound and interior noise level, drone is non-existant. With a slight increase of rpm’s this system teases you with what is to come. You find yourself trying to sneak out of the neighborhood on an early morning a little quicker, dying hit wide open throttle. When you open it above 2,800 – 3,000 rpms the sound is absolute bliss. To me the Boxster’s and Caymans have much more of a mechanical sound than a 911 and the sound version muffler highlights this extremely well. It adds a lower, deeper horizontally opposed flat six tone at lower rpms and then changes pitch at higher tones like a GT3 Cup Car. M&M is spot on with this muffler and I am extremely finicky about a Porsche sounding like a Porsche. It must be the years of following ALMS and the Grand-Am series.

Logical Progression, FVD /M&M sport muffler to complete system:

Up to this point, M&M was only making a complete system with headers, cats, muffler and tips OR a sport muffler option that I mentioned above. They didn’t have a modular system. Most of us want to start with the M&M muffler and eventually acquire the headers and cats, depending on how mod crazy we are of course . So about 4 months ago I asked M&M to put modular headers and cats into action to cater to those who want to take their cars to the extreme on the tracks or on the streets.

M&M Headers:

Once I received my headers and cat’s I knew that M&M had delivered on all the points we had discussed.







When I inspected the headers I noticed how beautifully manufactured they were. M&M builds these systems by hand and they are magnificent. Let me start with the flanges that meet the engine block. Most aftermarket flanges for the boxster and caymans are a thick single plates. M&M uses a double flange, which is welded together to dissipate thermal stress.



Thick single plates tend to warp over time which will eventually lead to exhaust leaks. M&M cannot take this risk as the vast majority of their systems are used on racetracks all over the world. The double flange is more time consuming to make but it M&M does not sacrifice when it comes to their systems.

From the flange the primary tubing widens then smoothly narrows back down. Interestingly enough M&M does not mandrel bend the primary tubing. Contrary to what many of us think about mandrel bending being a superior way to get around a corner. M&M’s stance is that mandrel bent headers have been proven to crack under the severe stresses found on the race track. The mandrel bending process actually stresses and thins the material, which leads to cracking. M&M segment the primarys and actually welds them together by filling the sections with forming gas. Forming gas actually pressurizes the area being welded to create a smooth inner surface. Once this is completed then they pass a tool inside the header, which will actually grind away any left over slag. This process produces extremely durable headers with a superior straight through design that ensures higher gas velocity and less exhaust gas restriction.

The long tube design utilizes all of the space that the stock header and cat took up. M&M extended the header out away from the block as far as they could for smoother more laminar flow. They took the path of least resistance and then gradually smoothed it back towards the flange. Look at the pictures below for reference.







Note the picture below, the stock headers come off of the block smoothly on 2 banks but note the hard near 45 degree angle of the third? Then note the short 4.5 – 5” (estimate as I did not actually measure) travel until they meet the “collector”. The stock headers and many of our competitors systems suffer from extremely short primary tubing, which robs power. M&M thinks outside of the box, they would rather extend the length of the primaries and moved the cats all the way back towards the muffler.



Stock Porsche headers tend to end with simply cut tubes that merge together. As you can imagine, 3 exhaust paths slammed together so abruptly tend to cause turbulence. Turbulence equates to reduction in velocity and an increase of heat. The M&M set up incorporates a collector that smoothes out exhaust flow, creating more velocity and reducing backpressure. But, this isn’t your ordinary collector, they take it to another level. Many of our competitors use “pyramid style collector” which is manufactured from the center of the merging tubing outward to the flange in a pyramid shape. M&M’s collector gently guides exhaust gases from the walls of the merging piping towards the center creating a “singular” exhaust stream through the center of the flange. See the pictures below of the M&M merge collector, this picture is actually taken of a turbo header as I couldn’t get proper pictures of the boxster collector with the flash.





M&M Cat’s:

M&M’s design sets the cats all the way back to allow for maximum exhaust velocity and the ability to build up good back pressure for low end and mid range torque. These systems can be ordered with HJS “HF” (High Flow) cats or HJS “HD” (High Durability) cats. I chose 200 cell HJS HD cats. They are the latest HJS cats, and are nicknamed “HD” for high durability matrix design catalytic converters. They have a SM-matrix (winding of three flat and corrugated foils) and a special connection to the matrix sheath, which equates to extremely high durability for track and street use. The added benefit is that they DO NOT generate catalytic efficiency codes (CHECK ENGINE LIGHT) that most OEM Porsche programs (EU 5 software) generate. HD cats are perfect for those who are consistently tracking their cars or want to run sport cats without a software program. The cats are secured to the M&M muffler using the sleeves that came with the muffler.









The sound:

Obviously the muffler is dictating most of the sound with this set up so the deep, rich flat 6 tonal quality is enhanced. Personally I enjoy louder exhaust systems that enrich the sound that Porsche intended these cars to have. In my opinion many systems on the market are lacking a true Porsche tonal quality. After living with this set up for a few weeks I have decided that it is exactly what I was looking for.

With the HJS “HD” cats the sound has a little more rasp than with the muffler alone particularly when cold. I think that the rasp is due to the sheathing of the cats, which I explained above. I have heard a few of these M&M systems with normal “HF” cats and they don’t exhibit that raspy tonal quality at all. When the system warms up the rasp is noticeable between 3,800 and 4,000 rpms and then goes away as quickly as it comes in. I don’t enjoy raspy systems at all but this set up just hints rasp and settles back in to deep, rich tones. It seems to add another auditory dimension that adds to it’s exotic sound.

While this configuration sounds more aggressive it still lacks that over the top aggressive sound found with many other systems. This is a more refined aggressive if you will, more of an exotic Porsche aggressive. In the lower to mid range rpms this system has the deep, low aggressive tones of a 997 RSR. When you approach the 3,800 – 4,000 rpms you hear shades of a more exotic Ferrari with the additional rasp. The sound then builds to a higher Cup Car pitch and then lessens in volume at the very top end. The sound at the top end is quieter and somewhat similar to what you experience up to 2,800 rpms. The decibels taper off at the top and bottom of the rpm spectrum. You can still modulate this system with the right foot just like you did with the muffler. The fact that you can still make this system sound like a stock system below 2,800 - 3,000 rpms is unbelievable!! I never imagined that would be possible but it’s a fact and it is a testament to just how good this system is.

Internally there is a small amount of resonance in the cabin and frankly I expected it. Peoples opinions on resonance and drone differ. To me resonance is when you have a loud exhaust system that penetrates the cabin. Drone is when that resonance becomes uncomfortable. This system has resonance, a small amount but it is there. Remember, I wanted more power and more sound and the drawback was some resonance. This system’s resonance does not escalate to annoying drone by any stretch of the imagination. It is simply just louder in the cabin, which I completely accept. I am sure some can find some drone if you drive at about 45 mph in 6th gear, but how many of us really do that?? :crazy:

My Boxster S Video (I am working on an extended video as well):

http://www.youtube.com/watch?v=liGB2TD_6aY

Boxster S Video with M&M headers, 200 Cell HD cats and the TUV (quiet) muffler:

http://www.youtube.com/watch?v=rJqSNs6v-70

http://www.youtube.com/watch?v=RM7gX5yauhw

The weight savings:

Another benefit of this system is the weight savings. Simply put…

Stock Mufflers ( 18.25 lbs x 2 = 36.5 lbs )
+ Stock Headers ( 8.35 lbs x 2 = 16.7 lbs )
+ Stock Tips ( 8.40 lbs )
= 61.6 lbs.







FVD / M&M Muffler with tips ( 25 lbs )
+ FVD / M&M Headers & Cats ( 12.6 x 2 = 25.2 )
= 50.2 lbs.

So the total weight savings is 11.4 lbs.





The power:

Finally I am at the business end of my findings. Since I have had this car and settled in to it’s power I have always yearned for even more. With this header and cat set up I can officially say that this car has now reached it’s peak. I was impressed by the addition of software, then the sport muffler. When I added the throttle body and the IPD Plenum I thought that I was getting close to reaching this car’s potential. But with the addition of the headers and cats all of my previous upgrades have simultaneously come together to make this little car downright evil. I really didn’t think it was possible for a Boxster S to be scary fast but it is! Ok, ok I know some of you turbo guys are saying scary fast? You don’t know what that is. To be quite frank I was a little bit worried about losing to much backpressure with this set up. Loose to much backpressure and you loose your low end and mid range torque. To my surprise this set up is not lacking anywhere!! With the stock system I was unimpressed with the flat spot between 4,000 and 5,000 rpms. Those days are simply a memory now. My car pulls hard through every gear. The real power comes in between 3,000 and 6,000 rpms. All that I can say is that the respect that I have for M&M has grown tremendously. They are the business, no questions asked.

In tuning any of the cars that I have owned over the years I have always relied on the seat of your pant’s test and real world take it to the track attitude. Personally I don’t have much faith in dyno tests and most of them around here are run by our competition. So, I would rather share verified Performance Box data with video. I will be doing these tests within the next week or so. I will keep you posted.

Header and Cat Facts from our website:
- + 20 crank hp & + 19 crank torque
- 2" tubing (50 mm) straight through design for max. power
- 200 Cell HJS Tri Metal High Flow Cats (“HF” Cats)**
- Weighs 12.6 lbs. (5.7 Kg)
- 26 lb weight savings over complete OEM exhaust system!!!
- T 316 stainless steel for improved durability over T 304
- Made in Germany by M&M Exhaust GmbH
- Intoxicating Cup Car like growl above 2,800 rpms.
- 8 on a scale of 1-10 in volume (1 being stock) above 2,800 rpms.
- 4 on a scale of 1-10 in volume (1 being stock) below 2,800 rpms
- Additional hardware is not necessary, headers and cats reuse the M&M muffler sleeves.
- No DME programming necessary with HJS HD Cats**

Link to the website for the 200 cell "HF" cat version.

Please Note we also have a new cat bypass version of these headers. I will be posting on that very shortly as well. Link for the cat bypass.

Thanks in advance for your time,
Rhonda