RSR muffler FAQ

Here are some Frequent Asked Questions about the RSR mufflers, hopefully they should answer all of your questions regarding this exhaust modification.  Please feel free to contact me at my e-mail address if you have any additional concerns or questions.

Q: - Hi Robin, Well, after considering all my muffler options for my 1995 993, I'm ready to purchase your RSR muffler for my car. Please let me know what I need to do regarding ordering?
A: - Please e-mail me your ship to address, day time phone number, year model of your car, VIN number and the current mileage.  993 owners please also take a look under the muffler to see what brand of stock muffler you have, the brand is stamped on the muffler canister it is either a Bischoff or a Gillett brand.  Starting July, 2006 I have decided to discontinue the "try first pay later" policy as the number of dead beats are increasing.  So I will accept paypal as the only method of payment for all future transactions.  Please paypal me the correct amount according to the below payment schedule prior to me shipping out the muffler.  Once I have received the core muffler return the core deposit will be refunded via paypal.  Please also take a moment and read through the rest of the FAQs.

Here is the payment schedule:
993NA - $450
993Turbo - $550

The core charge is $300 for the 993 muffler, the 993 turbo is $500.  Your core deposit minus the shipping charge will be refunded back to your paypal account once I have received the core muffler return from you.

Here is an example of how it works (shipping charge is an estimate)
Say you want to try out a set of 993 NA RSR muffler.  First e-mail me the information on your car, once I have confirmed back to you that the muffler is ready to ship then you will need to paypal me $750.  If you decide to keep the RSR muffler then go ahead and ship the old core muffler back to me.  Once I have received your core return I will refund you the core deposit of $300 minus the freight charge for me to ship you the RSR muffler.  For example if the freight charge was $45 then you will receive a refund of $255 ($300 - $45 freight) back to your paypal account.

You have 60 days to return the core muffler once you have sent me the paypal payment, as that's the number of days I can send a partial refund payment without a penalty.  So any core muffler that's received after 60 days is subjected to a handling fee.

If you are not familiar with the paypal system please visit their web site at

Q: - What is the cost of the RSR muffler?
A: - The core exchange cost for a set of RSR muffler for a 993 is $450 + freight (freight cost to ship the muffler to you)  The core exchange cost for a set of RSR muffler for the 993 twin turbo car is $550 + freight (freight cost to ship the muffler to you).  You will also be responsible for cost of shipping your core muffler back to me.

Q: - What is the best way to ship my original mufflers cores back to you?
A: - UPS(Ground) Insure the package for at least $499.

Q: - What is your shipping address?
A: - 1142 S. Diamond bar blvd #808 Diamond bar CA 91765

Q: - If I don't like your mufflers, can I get a full refund, once I return your unit?
A: - Yes, I will fully refund your paypal account once the muffler is received by me.  Your only out of pocket expense will be the cost to ship the muffler back to me.

Q: - I spent $xxx amount of money to have your RSR muffler installed on my car and I don't like the sound.  Will you compensate me for the labor charges to have them installed and removed and will you reimburse me the freight charge for shipping the RSR mufflers back to you?
A: - That's the only other out of pocket risk you'll have for trying the RSR mufflers if you pay someone to install it.   I will not reimburse any labor charges or freight charges for the RSR muffler to be taken off the car.   However I would be happy to make arrangements for someone in your area to meet up with you for a RSR muffler sound test prior to you placing your order to eliminate that risk.  And if your are located in the Los Angeles area I would be glad to install the muffler for you free of charge.

Q: - What if I want to keep my original mufflers
A: - You can pay an additional $300 core charge for the 993 muffler and $500 for the 993 turbo mufflers.

Q: - Can I still use my original exhaust tips?
A: - Yes, as long as they are original Porsche part that will fit on a stock muffler.

Q: - What kind of warranty do you offer for your RSR muffler?
A: - 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.

Q: - Are you going to do anything for the 964 cars beside the 993?
A: - I originally came out with the RSR mufflers for my own 993, it was friends that I made the RSRs for asked me to market this product.  So at this moment I will not be doing anything else other than the 993 mufflers.

Q: - My car was stored for 3 years before I bought it, and only has 13K miles on it.  Is it possible to get a set of modified mufflers with approximately the same mileage on them?
A: - Yes, that's why one of the questions I ask during the ordering process is the mileage on your 993.  I have a variety of different mileage cores on hand which I use to match up the mileage of your current muffler when I do the RSR muffler conversion.  So that the RSR muffler you will be getting from me will have very similar mileage on it.

Q: - Will I have any problems with my yearly emission test?
A: - No, the exhaust on the 993does not provide any emission control devices.  It only muffles the exhaust sound.  Click here to see the emission test result after having the RSR muffler on my own car after 3 years.

Q: - I have read that there are failed mufflers all over the country from "backyard hackers" which causes melted bumper and fire to the car is that true?
A: - Since 1998 the only returns from dissatisfied customers have been because the muffler was not loud enough.  Recently I have discovered that there are other individuals around the country who tried to modify stock mufflers to achieve the same result as the RSR muffler, but without any luck.  Most of these modification were done with a MIG welder, which will not produce good quality welding with stainless material.  Below is a picture that shows the difference in welding.  (The below picture is a modified stock muffler done by someone else which I had to turn into a RSR muffler).  All the welding for the RSR muffler is done on a TIG (Heliarc) welder, which is the only correct method to weld stainless steel, the results is self evident.

(click on the above picture to view a higher res picture)

Q: - How strong is the welding on the RSR muffler?
A: - Below are two pictures that will show you how well the welds held up even when the muffler was crushed.  This muffler came off a RSR muffler customer's 993 that was involved in an accident.  The muffler was crushed on both sides.  And not a single bead of the welding broke loose.

Q: - Are the mufflers "back purged" during the welding process?
A: - "Back purge" is a method used during welding where the opposite side of the welding area is also filled with argon to replace the oxygen.  The argon is kept at a constant flow rate to create an absolutely shielded environment for the melted metal on both sides.  It is a time consuming method of welding, but I do back purge the RSR muffler while they are being welded.  Below is a picture that shows the method that I use to back purge the mufflers.  The tube is capped off with two rubber caps, one cap is fitted with a argon supply line and the flow rate is kept constant at 10-15 CFH, all the open seams of the mufflers that needs to be welded is taped up with masking tape, leaving only a small area opening waiting to be welded.   I would peal back the masking tape one inch at a time as move forward with the welds.

Q:- What grade of stainless steel do you use to weld back the muffler?
A:- All the RSR muffler are welded back together with 316L stainless filler rod compared to 304 stainless that everyone else uses.  316L stainless is more expensive, but it is also a much higher grade of stainless steel.  Although one might not eat off their muffler, but is good to know that  food grade quality stainless steel were used.  (Meaning that this is the grade of stainless steel required to be used on manufacturing of any food processing machines, and it is more corrosion resistance than the 304 stainless)

Q: - What other benefits would I get besides sound from my RSR muffler upgrade?
A: - Besides making the modification to make it sound better, I also go through the original factory muffler and make necessary repairs and touch up where the factory had missed.   Since the mufflers are welded up with automated welding machines by the muffler manufacturer there are a lot of  "missed" welds on the muffler.  I make a practice of making touch up to these "missed' spots during the RSR muffler making process.

From the below pictures you can see the picture on the left shows that the factory left out a 1/2" of seams on the welding.  The picture on the right shows the repair I made to make it complete.

Missed weld spot from factory
After repair

Q: - Will I get a ticket for too loud of an exhaust sound?
A: - I can't guarantee what excuses our friendly local officer may want to use to pull us over, but one thing I know for sure is that the RSR muffler sounds exact what our car should sound like from the factory.

Q: - I just read your testimonials for your RSR creation.  I like what I read and wondered if your RSR Special will work for my car.  Has anyone replaced their mufflers on a '98 993?  I have a '98 993S and would like your honest opinion your RSR Special exhaust will fit.  I've always enjoyed the raw throaty sound of a 911 and it seems that the 993 has lost that sound
A: - All the 993 mufflers are identical for the wide body and narrow body 993 cars, the only difference is in the exhaust tip off-set for the wide body cars, and the integration of the biscuits on the exhaust pipe of the muffler.  On later 96+ 993s Porsche integrated the separate biscuit mating piece as one unit with the muffler, below is a picture that shows the difference.  Either with or without the biscuit the fitment would be the same for all 993s.  (none turbo model only)

Porsche have a patented design for connecting the mufflers pipes together, which in eliminated the use of any gaskets.  The way the muffler is connected to the CAT. or the exhaust tip is through mating the pipes with a biscuit design and the flanges tights down the connection between them.  Sometime in 1996 Porsche integrated the biscuit into their muffler pipes to save weight and cost.

Q:- What's the different between the Gillet core and the Bischoff core?
A:- Besides the brand and quality difference, they are dimensionally and functionally identical.  The Gillets cores integrated the biscuit piece in to the muffler itself as part of the pipe, and the Bischoff uses a separate biscuit system.  (Biscuits are used in between the muffler tips to the muffler)

Q:- What's the new "RSR stealth mod"?
A:- Some people wanted the extra sound for their 993 but was afraid that they would loose points at a concour for having a modified muffler.  So the "RSR stealth mod" basically is a modification method that I used to cut open and weld up the RSR muffler at the original factory welded seam where it is visually very difficult to identify that the muffler was ever modified.  The idea of "RSR stealth method" originally came from Gert in Belgium, this is the same exact method Gert uses to modify the RSR mufflers for all the European customers.


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