Lost power to muffler swap

[Bctexascrazy1]

Hey guys I have had 3 different exhaust on my truck and finally happy with the sound now. I've had the exhaust delete, which was loud but no sound it was blahh but lost all low end torque, then I got the mufflex 14 put on sound great and ran amazing, but wasn't loud enough for me, so I bought a flowmaster super 10 3" in 2.5 dual out and welded it in the magnaflow place. Sounds amazing just a little bit drone but not to terrible, but I feel like I almost got to floor my truck to move. Still have resonators in place on all the. I guess there's always something u got to give

 

[Bctexascrazy1]

I will also mention that for some reason my truck runs higher rpm maybe like 200 at 75mph. The magnaflow really does outperform the flowmaster. But whenever I put my headers on I'm running true duals with no cats to the magnaflow tru x muffler. I hear a few say it's night n day difference!!

 

[clh1220]

I didn't loose any low end at all with my flowmaster 50 hd. These hemi do like some back pressure. My muffler it's designed for our hemi. I won't say it gives it more low end but I will say I didn't loose any.

 

[Jimmy68]

you probably do not have enough back pressure.

 

[Hemi450hp]

The fastest hemi trucks out there do not run any exhaust at all...the more free flowing, the better.

The 10 series Flowmaster mufflers are just not good performing mufflers. I ran 1 on my 03 hemi, and felt an immediate loss of power. If you want loud, I would just go back to that Magnaflow muffler for the street, and throw a cutout in front of it...best of both worlds.

 

[Limeybastard]

Not sure if it was my imagination or not, but now I can certaily hear and see the truck downshifting, meaning the RPMS go way up than before, then again it could be my imagination like most things LOL

 

[Jimmy68]

The fastest hemi trucks out there do not run any exhaust at all...the more free flowing, the better..

Sure. For built, high RPM, racing.
But in a stock daily driver? Sorry man. I have to disagree.
I had an early 70's Plymouth Cricket that sounded great with a hole in the muffler but it lost any power it thought it had. Fix the muffler and it was a freakin race car compared.

 

[Hemi450hp]

I'm not talking about all out drag trucks. Even my bone stock 03 hemi went from a 15.6 to a 15.2 in the 1/4 mile by simply opening an exhaust cutout in front of that Flowmaster 10 series muffler. I had no tuning and was shifting at the stock shift points of 5700 rpms.

This is why I say to run a muffler on the street, and then have a cutout for when you want to play. The open exhaust is without question going to make more power at WOT. It may feel a bit more sluggish at part throttle, but it will without a doubt make more peak hp and tq with the open exhaust/open cutout.

I've been working on these Hemi trucks for 12 years now since they first came out, and every single truck we have tested this on has had the exact same results.

 

[Bctexascrazy1]

I love the sound of the flow 10, and I loved the magnaflow. I just want a muffler that's good on low end torque. I'm gonna weld the magnaflow 14 back on. The flow feels like I lost 2 cylinders which is crazy cause I also had the full delete and the 10 is worse than the delete, so it's not a back pressure issue. The magnaflow sounds great just wish it was a tad louder

 

[Jimmy68]

I'm not talking about all out drag trucks. Even my bone stock 03 hemi went from a 15.6 to a 15.2 in the 1/4 mile by simply opening an exhaust cutout in front of that Flowmaster 10 series muffler. I had no tuning and was shifting at the stock shift points of 5700 rpms.

This is why I say to run a muffler on the street, and then have a cutout for when you want to play. The open exhaust is without question going to make more power at WOT. It may feel a bit more sluggish at part throttle, but it will without a doubt make more peak hp and tq with the open exhaust/open cutout.

I've been working on these Hemi trucks for 12 years now since they first came out, and every single truck we have tested this on has had the exact same results.

I should have clarified. I meant Built OR high rpm OR racing. Two of which cover what you say. 5700rpm WOT racing.