The RSR Muffler

For 993 NA and Twin Turbo

The name RSR Muffler is something my friends made up for me for my modified 993 factory exhaust.  Since my name is Robin Sun, the initials were perfect for what everyone calls it. The RSR moniker was originally used by Porsche to designate the factory lightweight 911, which is still one of the best horsepower to weight ratio cars ever made by Porsche. 

Enough talk about the RSR name, I really came out with the RSR Muffler to satisfy my own needs.  After months of searching for a perfect exhaust for my 911s (a 1996 993), and trying out several different solutions I came to the conclusion that in order for me to have what I wanted I needed to build one for myself.   What I was looking for in a 993 exhaust in particular was the extra 911 muscular growl that was missing since the introduction of the 993, as you may or may not know Porsche tried really hard to lower the noise level of their cars with the introduction of the 993 model in order to meet strict European "drive by" standards.  Although this is perfect for most Yuppies, but for an old fashion 911 enthusiast like me this is a nightmare.  But in the same time I didn't want to deal with too much resonance and didn't want my car to sound like a modified "Rice Burner" (Japanese cars with big exhaust tips).  I wanted a sophisticated mechanical sound and a muscular sounding idle....... 

So, the experiment started. I began with a stock 993 exhaust to maintain the factory look.  Personally I didn't want to make my 993 look boy racer; they are such elegant 911s that it deserves the classy factory look  (personal opinion).  After several revisions and months of road test I finally stumbled on the perfect exhaust for the 993, perfect in the sense that it is what I wanted it to be.

In September, 2002 I started to cut the 993 muffler open on top of the original factory welded seam, so once the mufflers are welded back together there is little evidence that the muffler is ever modified. (Perfect for those who wants to keep their car in original concour condition)  Here is a picture of the RSR 993 muffler weld.   Just as a reference I have had the 993 RSR Muffler on my own car for more than  nine years now, there are no signs of cracking or bursting at the welds.  With that said, I will gladly replace any muffler free of charge due to any defective welding on my part for the life time you own your 993

I also want to make it perfectly clear to everyone that I am offering the RSR muffler not as profit based business, but as a service option to other 911 enthusiast out there who just wanted more sound from their 993 mufflers. 
 

Below are some click able links to help you answer any questions you may have about the RSR mufflers. 

Testimonials

FAQ

Installation

Read the most comprehensive review of the RSR muffler by Jim Calder
 

The current core exchange price for the RSR N/A 993 muffler is $450 plus freight, $550 plus freight for the 993 twin turbo mufflers.  if you are interested in obtaining the RSR Muffler for your 1995-1998 993 please click on the FAQ section for detail ordering information and then send me an e-mail to webmaster@p-car.com

993 owners outside of the N. America continent, the RSR muffler solution is also available through a fabricator in Belgium.
Please contact Gert Carnewal in Belgium for more information. 

There is absolutely no obligation with this, if you don't like the way it sounds you can always ship it back to me and there will be no charge.  The only expense to you would be the freight charge to ship the RSR mufflers back to me and the labor charges to have the muffler installed and removed. (If you have someone else install the muffler) 

A word of caution, the RSR 993 Muffler is not going to be very loud.  Upon start up there is a little more rumble, and there is a gradual increase of  mechanical sound through out the RPM range.  The top end sounds even better.  And don't expect any big horse power gains either, this exhaust mod will definitely help your engine rev a little faster through all the gears, but I refuse to believe changing out the muffler will give you 15-20 more horse power.   The RSR Muffler in my opinion is a nice sound you just grow to love.  But if you want something to terrorize your neighbors with the RSR Muffler is not loud enough for that. 

 If you are interested and want to give it a try please let me know right away so I can put you on the waiting list.  Please check the FAQ section for detail ordering information.
 
 

Below are some brief explanation of the RSR muffler modification process 

The process to make a RSR Muffler unit from a factory stock unit takes about 5 hours for the pair.  The first process is to clean and polish the outside surface of the muffler, the outer surface must be clean of any debris or contaminates before it can be cut open with a plasma cutter, the surface also needs to be clean in order for the welds to be strong.  The plasma cutter method of cutting metal provides one of the cleanest cut possible on the stainless steel metal, short of cutting the muffler with a laser gun it is by far the most high tech method of cutting any metal.  The learn more about the plasma cutting process click here

A diagram of how the plasma cutter works 
 
 


This picture shows the clean cut line done with a plasma cutter.

The next step is to split the muffler open, I fabricated a special tool to ease the splitting process.  Once the muffler is opened I go to work on modifying the pipes inside.  Once the pipe modification is complete I grind up the edges of both open surface with an angle grinder to make sure there are no contaminates on the surfaces to be welded.  (The rule about welding preparation is that you only use brushes and grinding pads specifically for one type of metal, can't use the same pad to grind steel and then grind stainless steel, because of the cross contamination) 


This picture shows the differences in the metal surface after a light surface grind.

What makes stainless steel difficult to weld is that stainless steel are a much poorer conductor of heat and so the temperature of the welding spot can grow hot much faster since the heat is not carried away.  As the temperature gets higher you obviously get more expansion, per unit of energy injected say that is injected into the weld. This is what makes it awkward to weld, the conduction properties not the coefficient of expansion which is in general about 6 parts per million per degree C.  Which means in order to weld the muffler halves back together I must strategically position the tack weld around the two halves of the muffler before I can start the actual welding process.  The tack welds must be welded on in balance, in other words a tack weld would need to be welded on right after a tack weld in the opposite side of the muffler.  This is the process where you wished you have 3 hands.....

http://p-car.com/ferrari/diy/clutch/album/
 

Again because of the property of stainless alloys, the only right choice of welding method to use is a "Gas Tungsten Arc Welder" (GTAW), I call it TIG (Tungsten Insert Gas) welder for short.  TIG welding is a commonly used high quality welding process.  TIG welding has become a popular choice of welding processes when high quality, precision welding is required. 
In TIG welding an arc is formed between a non consumable tungsten electrode and the metal being welded. Gas is fed through the torch to shield the electrode and molten filler rod.  A TIG welder's main benefits are superior quality welds, welds can be made with or without filler metal, precise control of welding variables (heat), free of spatter, low distortion. 


To learn more about the TIG welding process click here

The final process is to complete the welding around the two halves of the muffler canister one bead at a time, and each canister takes approximately 1 hour to weld back together.  And because the TIG welding process is a very clean welding process and free of spatter only a light stroke with a stainless steel brush is required at the end to complete the welding process.


This picture was taken during the welding process


Here is a picture of some completed RSR mufflers


This is the same exhaust system that was mentioned on John Stewart's running report in the August issue if 911 & Porsche World magazine


 
 


 
 

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