Ford racing touring axle back sound - 50 state

[twistedneck]

Vector just put on my new axle back mufflers..

FORD RACING TOURING MUFFLER KIT (50 STATE) -- M-5230-MGTCA

I got these because I felt the factory GT mufflers were causing HP loss due to back pressure. They sound a lot better than the factory GT axle backs however they are quieter than the Ford Racing Sport mufflers.

I'll post another video once the bullets go on - hopefully all the tin can noise will be gone. These sound several octaves deeper than the factory mufflers, they are 10lbs lighter per pair and look cool. Right now the tips stick out too far but that will be addressed.

Ford Racing Mufflers without Resonators - YouTube

FYI - car has 1-3/4" kooks headers, kooks off road x pipe, lethal 2.75" over axle pipes, and E85. E85 made the car noticeably quieter.

Thoughts appreciated.

 

[Coyote 2F2F]

I never understood, but aren't bullets resonators? Why replace stock? Someone explain please:??:

 

[twistedneck]

The factory resonators have a 2 1/4" diameter. Aftermarket resonators are usually 3" ID - although to match the lethal pipes i'm going with 2.75". that half inch improves flow significantly. Also, the factory resonators are short, longer resonators promote a deeper sound. A friend of mine runs 24" - i'm planning on 18".

On the Burns Stainless resonators you can replace the sound material when it wears out, that will quiet it down again after a few years.

 

[manolith]

I don't believe that the factory mufflers/resonators affect hp in an n/a application.

 

[twistedneck]

I don't believe that the factory mufflers/resonators affect hp in an n/a application.

I hear what you are saying monolith. however I checked and there is a back pressure increase with the stock GT muffler even compared to the GT500. When clawing for every last ounce of HP from NA, every little bit helps.

 

[Sick_Mustang]

I don't believe that the factory mufflers/resonators affect hp in an n/a application.

Agreed.

 

[twistedneck]

Agreed.

when you have a stock system they don't.. but when you have a fully opened up, headers, catless, x pipe, larger over axle pipes they absolutely do make a difference.. especially if you are running a big fat exhaust cam, bigger exhaust valves, etc..

Edit, FI guys can see up to 80HP difference..

 

[manolith]

when you have a stock system they don't.. but when you have a fully opened up, headers, catless, x pipe, larger over axle pipes they absolutely do make a difference.. especially if you are running a big fat exhaust cam, bigger exhaust valves, etc..

Edit, FI guys can see up to 80HP difference..

No. You are completely throwing numbers out there. The only fi people that could benefit from ditching the stock mufflers and deleting the entire exhaust are turbo guys. But blown cars don't gain 80hp from swaping mufflers. My car put down 620 rwhp on the stock paxton pulley and I had stock mufflers and resonators. I can guaranteed you that there is no way that my car would put 700rwhp even now with a smaller pulley and no mufflers. As for headers. Long tubes don't magically make your exhaust gases multiply. They simply help scavenging and don't let the exhaust gases from one cylinder creep to another cylinder. Maybe the stock mufflers on anything other than a turbo car would be worth 2 or 4 hp but not 80. Not even on a turbo car. Now if we are talking about cars pushing over 700-800rwhp then yes the couldnstart to become an issue but again for stock or n/a setups it won't make a noticeable difference.

And I am talking about the 2011-14 s197 cars.

 

[twistedneck]

I didn't specify turbo vs. FI - intentionally..

I've seen the flow numbers from the Ford mufflers and they had to decrease the pressure drop on the GT500 by a few Pa in order to hit the targets needed.

I'll agree the gains are small, but they do exist.

Edit: the 80HP is a confirmed number form a member on this site - yes, it was a Turbo.

 

[Sick_Mustang]

when you have a stock system they don't.. but when you have a fully opened up, headers, catless, x pipe, larger over axle pipes they absolutely do make a difference.. especially if you are running a big fat exhaust cam, bigger exhaust valves, etc..

Edit, FI guys can see up to 80HP difference..

Turbo cars sure, in higher HP applications it will make a difference for obvious reasons.

Your N/A combo, not so much. After the headers you're not going to gain much if anything......throttle response maybe, horsepower no.