Stock muffler question

[PaxtonShelby]

Does anyone know if the stock 2011+ GT mufflers are the same as the Boss 302 mufflers?

[scorpio333]

I don't think so. I recall reading awhile back that the OEM Boss mufflers are actually the same as the V6 mufflers.

[PaxtonShelby]

Thanks for the info. That really surprises me...since the Boss, even with the side-exit restrictor plates installed, has a really nice rumble.

[jaa55]

I think they are the same except for the tip size on the end of the muffler. I remember when they had the special on the boss on speed they said the exhaust was largely the same from the GT with the exception of the H-pipe

[PaxtonShelby]

Thanks Jim! By the way - I told a buddy about your car. He sounded interested. He installed the Paxton on my '66 and is a lifetime Ford nut. His name is Joe - great guy.

[jaa55]

Point him my way!

[03 OW SVT]

Ron, the stock mufflers don't provide much sound if thats what your looking for. It was the first mod I did to my car. I put Stainless Works on mine and it still wasn't loud enough so I removed the cats. Now it sounds great but its getting Headers next.

[gmslayer]

I think they are the same except for the tip size on the end of the muffler. I remember when they had the special on the boss on speed they said the exhaust was largely the same from the GT with the exception of the H-pipe

Correct. Let me know if you need a photo.

[PaxtonShelby]

Ron, the stock mufflers don't provide much sound if thats what your looking for. It was the first mod I did to my car. I put Stainless Works on mine and it still wasn't loud enough so I removed the cats. Now it sounds great but its getting Headers next.

After hearing Jim's ( jaa55 ) supercharged GT with the Boss side-exit exhaust and stock Mustang axle-backs ( awesome!! ), I'm seriously considering going with the same setup when I get my car.

[Seer]

They're similar to stock mufflers, just a larger tip.

The only V8 car that has different mufflers is the GT500.

The GT does in fact have two different sets, one for auto and one for manual though.

[PaxtonShelby]

They're similar to stock mufflers, just a larger tip.

The only V8 car that has different mufflers is the GT500.

The GT does in fact have two different sets, one for auto and one for manual though.

That is good info. Thanks!

In a perfect world ( one with unlimited funds ) I would go with the Boss 302 side-exit exhaust AND a Borla ATAK axle-back. But for starters, the Boss 302 side-exit with the stock axle back really does sound great.

I have heard that header swaps on these cars don't yield much in the way of horsepower gains. I'm sure it changes the exhaust note - but for that much money I'm not sure I'd go that route unless I was making so much power that the stock headers were a bottleneck.

[GOT SVT]

ron

you should consider just adding gt500 mufflers from the get go

they sound awesome, i did that with my 12 gt and i will be putting them on the boss as well

[Wolfpack Speed]

ron

you should consider just adding gt500 mufflers from the get go

they sound awesome, i did that with my 12 gt and i will be putting them on the boss as well

X2 Ron, you are welcome to stop down the shop and listen to mine if you like

[PaxtonShelby]

Thanks guys!!

Mike - I will definitely stop down sometime. I know the GT500 axle-backs sound great - but the Boss 302 side-exits really sound good as well, and are "different".

[GOT SVT]

i am saying add the gt500 mufflers first as they are like $300 then add the boss side pipes when $ available

[PaxtonShelby]

choices choices choices...

[Seer]

That is good info. Thanks!

In a perfect world ( one with unlimited funds ) I would go with the Boss 302 side-exit exhaust AND a Borla ATAK axle-back. But for starters, the Boss 302 side-exit with the stock axle back really does sound great.

I have heard that header swaps on these cars don't yield much in the way of horsepower gains. I'm sure it changes the exhaust note - but for that much money I'm not sure I'd go that route unless I was making so much power that the stock headers were a bottleneck.

If going catless I have seen 18-25r whp gains with headers. So there are nice gains to be made. There is no real tuning to be involved if the maf curve is already correct on a previously tuned car, just need cat overtemp turned off. The trick is to buy a header where the primaries match the firing order properly. Plenty of designs out there still using thr mod motor primary design. Doesnt hurt the car but doesnt give the best results.

[PaxtonShelby]

If going catless I have seen 18-25r whp gains with headers. So there are nice gains to be made. There is no real tuning to be involved if the maf curve is already correct on a previously tuned car, just need cat overtemp turned off.

I'm definitely not going catless. Would be nice to be able to put more than 5k miles a year on it, in which case I wouldn't be emissions exempt. The 20 added hp isn't worth the catless stink to me.

[Seer]

I'm definitely not going catless. Would be nice to be able to put more than 5k miles a year on it, in which case I wouldn't be emissions exempt. The 20 added hp isn't worth the catless stink to me.

I don't notice it :)

[PaxtonShelby]

That's good to know - I guess going catless with the coyote isn't as smelly as it used to be on the older 5.0s. But I have to keep the cats for inspection purposes. I think the performance and sound will be good enough for me even with the cats on the car.

My '94 Cobra didn't have cats...but I had it registered with Classic PA Plates, so it was emissions exempt.