been running no muffler forever... its causes a loss in HP and low end trq. Putting a new system on soon.. shoul dhave my power n milege back.... a NA engine needs backpressure.... guess these guys dont know that

 

why is it some say they do lose HP and some dont?

 

Some people really know their trucks, others dont, exhaust vibration & drone can trick you into thinking you gained o lost nothing either, its just when you measure times such as low rpm climbs and 0 - 60s and even better a dyno, you notice the loss.

 

I had mine off for about 2 weeks and with 4 cats it is quiet at idle, but a little raspy and pops ocassionally on startup. WOT at top RPMS goes not make the engine sound happy either. That is my take on a mufferless 5.4 anyways with 4 cats.

 

a stock 5.4 with all four cats sounds really good its kinda loud it doesnt make a nasty poping sound like chevys do that dont have mufflers.....ive had mine off for like a weed i just got a magnaflow with dual turn downs on mine i love it!

 

With my big and heavy truck, a gain or loss of 10-15 hp is not noticeable. I still question whether I've actually lost any power. I'd like to see the dyno results for two identical vehicles...one with full factory exhaust and one with cats only.

 

how could you loose power??? all your doing is freeing up your exhaust leting your motor breath better... u still have plenty of back pressure from your cats. you will only gain from cutting your muffler off cuz

 

I'd like to think I got a bit of a gain out of it...and as a free mod that made my truck sound great, I couldn't be happier.

 

did u really call him CUZ?

 

wtf?

 

I actually just had mine off for a few days- it was LOUD. Mind you I left the first piece of the catback on which goes to 3" but it was pretty loud. It sounded great at some rpm's, stupid at 4-5k and seems to have less power. I was glad to put the system back on and fixed my rattle problem (reason it was off in the first place).

 

looks like he did broski

 

aight bra

 

running no muffler you will get alot of popping on deceleration due to lack of back pressure. it sounds good but i would run it out the rear or dump it atleast.

i ran no muffler on my first ford (02 4.6) sounded pretty good but had a bad drone in the cab because i cut it right in the middle of the cab. on my old 07 f150 4.6 i ran a flowmaster super 44 dumped at the rear of the cab and it sounded much better IMO and still pleanty loud. was planning on deleting cats before i sold it.

we cut the muffler off a 08 f150 5.4 and it had the same popping as my 1st 4.6 did, and had an odd sound to it IMO, but it wasn't ridiculously loud

 

If back pressure is such a great thing how come I run door to door with my buddies 03 hemi ram which runs in the 14's.