http://www.fordracingparts.com/parts...KeyField=10563

Ford racing now has these mufflers listed on their site as the FR500S mufflers.
P/N: M-5230-S
Does anyone have any info on these or know what they may sound like?

 

Wow, neat design. They're going to drone badly and will be loud overall.

 

They're only there to keep the race car legal at tracks that have a volume limitation... The FR500S is NOT a street car, and the guys that run them could care less about exhaust tone...

 

Are these the mufflers on the KR?

 

Nope, those are listed as FR500S-specific parts. The exhaust is all FR500S-specific:

Headers and X-pipe: M-9430-MC
Mufflers: M-5230-GTA

MANY of the parts on the FR500S are listed as Mustang GT, Mustang GT/CS, or Shelby GT500 factory parts. The balance are parts specifically developed for the FR500S.

 

After doing some research before the hack, I do think these are the same as he KR mufflers.

 

M-5230-S are KR's.

GTA's are shaped like GTB's (Bullitt)

 

so the GTA's are different than the bullitt mufflers? Is the sound different?

 

Before the crash, it was mentioned that the KR/FR500S mufflers do not drone.
Here is a video that someone made of the exhaust.
http://www.youtube.com/watch?v=YBXw5s6G46c

 

Could not be farther from the truth. There is no drone what so ever I have had them on my car for abotu 5k miles and have loved every mile. they are no where as loud as Boom tubes or anything of the such and even slightly quiter then the FRPP/Borla "Stingers".

True the exhaust tone is not an issue on the track but the people who use them on the street do care and it happens to be a great exhaust note, IMHO. I think they sound great, loud on acceleration and a nice pop on a down shift but whisper quiet on the highway. Until you get into it again


Yes they are the same ones on the KR.

There is also a new pair offered for the 2010+ (M 5230-SA) because of the different rear facia. The tips need tips need be longer

 

You drone guys- lol. What they're referring to is the resonating sound that occurs at certain engine speeds. This occurs with EVERY type of exhaust, just more or less with different systems. Those FR500 mufflers are a glasspack, straight through style with resonating tips. They will be nice and deep, loud with a moderate amount of resonating sound.

 

The aftermarket mufflers all drone, some worse than others. Looking at the FR500S mufflers, I expect massive drone over stock due to the shorter resonant length. My stock mufflers drone, but it's low enough that it won't cause permanent hearing loss.

 

A number of Bullitt owners have reported no noticeable drone with the KR's and the stock H-pipe. A few have said they pop a little too much on let off. They have the same packed tips as the Bullitt mufflers.

My stock Bullitt mufflers have some pop and I can hear a very slight drone at about 1980 rpm/62 mph if I have the back seats down.

 

I agree that all mufflers will drone it is just if that sound is at a level that yours ears can hear it.

Maybe I should put it this way, there is no noticeable or audible drone from these mufflers. The stingers and others are quite different in that respect.

Until you have these mufflers on your car and try them you will not understand what I am talking about. It does not matter how they "look" but how they sound/perform. No one expected these mufflers to eliminate all audible drone from the exhaust system but in fact they have. I invite you to drop by my place and come for a ride, I think you would be quite surprised.

 

Roger that! I read your description again and it seems these mufflers should have been my first choice.

 

GTA's are a bit louder than Bullits.They have the same double wall type stainless tip but the GTA's are an angle cut verses the straight cut Bullitt type tip.

 

Those FR500S mufflers sound pretty darn good, very aggressive tone.

 

3-4 years later, I bought the FR500S/GT500KR mufflers and installed them on my 07 GT. I took a test drive today and noticed right away that there was more power available. The engine felt much more responsive at lower RPMs, and it seemed like there was more low end torque. I was getting the rear end to slide around in 1st and 2nd gear without using much throttle at all in slow turns. It surprised me because it never used to do this.

The FR500S mufflers are basically a non-perforated straight tube that breaks inside the muffler body to flow sound into resonant chambers. The tips are 08-09 Bullitt glasspack tips.

The only drone is at high load / low RPM, like pushing the engine a bit in 5th gear at 1000-1200 RPM. I get into this range if I do the 1-3-5 skip shift to save gas in the commute, but if you shift "normally" there is no drone. I am very drone sensitive and at 50-60 MPH, I didn't hear anything obnoxious. There is a significant difference from the stock exhaust.

My complaints are that the weld splatter is everywhere on the joints and even inside the resonator. I can hear some weld splatter rolling around inside the muffler body. The mufflers don't come centered properly, so there is some adjustment to be made using the intermediate/mid-pipes unless you want to heat and bend the brackets. The tips actually look very good but I still prefer the slash cut tips from the stock mufflers, as they match the GT and GT500 bumpers a lot better - but the straight cut Bullitt tips look very good.

I had Pypes Violators 5 years ago, and the exhaust note is *similar* to the FR500S, but the Violators were much deeper and had obnoxious drone. The FR500S has a higher pitch exhaust note (which I like).

 

I know this is way way way late but I waited, let's see, nearly 9 years to put these on my car and all I can say is I should have done it long ago. They are absolutely perfect. My son has a '97 Cobra with Flowmasters that's constantly "on", and by that I mean that the car's constantly screaming and announcing itself at any speed/rpm, and when he accelerates even easily the car is way too loud and it's constantly there even when cruising steady state on the highway. I suppose 4.30 gears in his car don't help matters but that's that. These FR500S mufflers in comparison are a louder than stock when accelerating moderately or hard, but are nice and subdued when cruising easily. Aside from a really nice cold start bark (which I absolutely love), the mufflers aren't offensive to the neighbors at all, and the burble and pop when downshifting is awesome. I don't particularly like the plain-ish tips (my car was ordered with the new-for-2007 appearance package that included straight cut rolled exhaust tips), but the way these sound and perform is exactly what I wanted. If you're considering them now for an S197, I highly recommend them.