Dave what I found (and everyone hears it different) is that right around 3/4 you get a balanced sound. That is the exhaust is not too loud that it drowns out the engine noise, you hear both equally from outside the car. When you run the 7/8 or larger the exhaust is louder then the sound the engine puts out and smaller is the opposite.

What I was looking for in doing this was cutting down the Jake Brake sound more then toning down the sound level. As S197 said just a small difference in size makes a big difference in the sound. I made these in 1/8 size increments but I would bet that you could hear a distinct sound difference in 1/16 size differences.

Give them a try but leave them in for a few days, it is hard to get an idea after only a day or two, especially since that is a 1/4 inch.

 

What about the ability to hear the radio with 3/4" vs 1/2"?

 

I've run wih stock restrictors, 3/4", and wide open. At cruising speed even wide open (no restrictor) is not much louder than the stock plates. The real difference is at idle and when you are are on the throttle IMO. I dont think you will have any trouble hearing the rafdo with 1/2 or 3/4.

 

Thanks, I'll put them in next week.

 

I have almost never used the radio but like Patrick says I doubt that will be a problem. 3/4 plates are not that loud, it is more about a tuned sound.

 

I am going to try the GT500 axlebacks and reinstall the 3/4" restrictors. Then I will see how my "rafdo" sounds. (Stupid iPhone & fat fingers)

 

I hear ya about the radio. One of the tracks I frequent is a 3 hour drive and I like to listen to my iPod.

 

I've got 1/2, 5/8, and 3/4" plates.
Put the 3/4 in, and haven't found a reason to take them out yet.
I'll most likely do it after I return from Sturgis Mustang Rally, and give the other sizes a try.
Cruising down the interstate is very reasonable. The harder the acceleration, the more the sound picks up.
Overall a great product, and Scott mailed them out fast.

 

Scott, interested in getting some 1/2 or 3/4 disks from you. Can't decide which one. Pls PM. Thx

 

I have 1/2, 3/4, and 7/8. I'd start with 3/4 or 7/8. The 1/2 are nice but moving up to the larger sizes gives the car a nice growl without being too loud. I'm currently using the 7/8 and they are fine around town and just a touch loud while talking on my phone at fwy speed.

 

It is very hard for me to recommend what size since everyone is different and eceryone thinks the size they have is the best sound. I do not know exactly what you are looking for sound wise or I could help a lilttle more. In any case I am doing these as cheap as I can and will not charge extra shipping if you want to try the second set. Just let me know a little more of what you are looking for and I will help you best I can.

 

Off to Miller so if you don't hear back from me right away that is why. I will reply to everyone on Thurs or Fri.

 

....

 

Scott, I took my discs out last April and really like the exhaust note. Been thinking of putting in something other than the full open pipes I have now but not sure how it may sound with some restriction. Has a "most popular sounding disc" set been decided by those that have bought them? Thanks for any feedback.

 

Charlie, I started with 1/2" and moved to 7/8" and like it a lot. It's a touch loud while talking on my cell at fwy speeds but other than that it sounds fantastic. I don't want mine any louder and I believe Scott also runs the 7/8".

 

Yep, what Rick said. 3/4 is a good sound and has been the most popular. Sent you an email

 

It is a personal preference. I tried with the discs removed & didn't run that very long. Opened mine to 1/2", still too quite, then to 3/4" & it suits me well.
Considering the GT-500 mufflers as well, but mainly for appearance, as I don't like the 'double' piped tips that come stock on the Boss.

 

I'm with you on the look of the stock muffler tips.

 

Rick, Scott and Aircare84, thanks for the feedback.

 

I finished up adding a complete quad exhaust system to my GT500 last week. I left the "attenuation discs" out for initial fire up. I couldn't believe how little flow actually makes its way out or how quiet the system is. I am not into overly loud, blaring, exhaust noise. A simple, light burble is all I'm after.

I'm now considering redoing another set of factory quads with the factory resonators either completely removed or changed to a larger size. The quad pipes neck down to 13/16" approximately mid-pipe. That would allow the QTP valves to really make a difference.

I thought that the blown 5.4 would have had fairly substantial flow as well as a bit more growl via the quad pipe exit point but it doesn't. Both engines use similar sized cats with a similar location of their respective engine. Maybe the Coyote has a larger tone for some other reason?

As for the Boss' mufflers, I noticed the "pipe within a pipe" instantly. It looks like Ford simply slipped their fart pipe tip over the stock pipe. Look closely and you can see that the weld for the tip (the weld closest to you) doesn't burn through.





Just cut the tip off at the weld (fart pipe to stock pipe), drive out the smaller diameter pipe, and then weld it back on. If you aren't equipped to do it at home just unbolt each one and drop them off at your favorite muffler shop and have them do it.