Open Pipe Guys...

[00SVTStrike]

So I put my 5" Straight-Pipe kit on my truck today (4" dp), and I wanted to ask your opinion. Should I be hearing a constant fluttering out of the exhaust, or should it be a smooth roar with whistle backing it up?

I have plenty of whistle, but it flutters so much it makes me question if something is blocking the exhaust or something. Maybe its how it is supposed to sound?... No other trucks around my town to compare it to..

[chappy]

My guess would be that it is your ebpv making the noise.I think the only way to get rid of it is to gut it.I'm sure others will be along that know for sure.I plan to gut mine.

[00SVTStrike]

Yea, I wondered about the ebpv too. Though its not a hiss sound at all. Just a ton of fluttering

[RockinJW]

That sounds about normal for 5" straight. Every straight piped 5" 7.3L I've heard almost sounds like it gargling under water. I didn't like the sound.

I just put a 5" on my 99' but left the muffler in it. Has a really deep deep tone to it and none of that weird flutter.

[NCHornet]

Perfectly normal, you will hear it more at different speeds!! EBPV wouldn't be closing at current temps, unless you were way up North I wouldn't have done the 4" dp as you loose low end torque, but many do. Actually a 4" system isn't even needed as the restriction is in the muffler not the size of the plumbing. I know this goes against popular opinion of bigger is always better!! But don't worry all is well!!

NCH

[TxPSD9673]

well im not sure about the "fluttering" sound your talking about but heres a clip of my straight 4'' system with 3'' dp

YouTube - 96' 7.3 Powerstroke straight pipe

[00SVTStrike]

Ok thanks guys

[binder man]

if the 3.5 is big enough and the restriction is in the muff. then how come so many people get rid of some EGT's with bigger exhaust. Wouldn't that tell you that there are restrictions still in the system?

[chappy]

I have never heard of losing low end torque because of a bigger down pipe on a diesel.If it was a gasser ,then yeah it would ,but I don't think so on a diesel.

[ford99PSD]

Originally Posted by chappy

I have never heard of losing low end torque because of a bigger down pipe on a diesel.If it was a gasser ,then yeah it would ,but I don't think so on a diesel.

i have heard of it but not first hand.