Sounds like crap lol - To much cab noise, - gets old.

The set up I have now sounds great! It took awhile for the muffler to break in, but it sounds awesome now IMO.

Do what you want to do, but now your truck runs like crap from choice, -Yours.

 

hey no one EVER told me I'd lose power from hacking the muffler off when I made the thread, oh, back in 04 with the 4six!!!

Truck is just the way I want it sounding. I've made this IN-CT trip plenty of times, I never get tired of hearing that my motor is alive... I hope a muffler doesn't kill the sound too much... I'ma keep it dumped before axle though, tell ya that....

Can you actually get a good video brew? Like say a 45 MPH driveby?

 

I hate to bring this up again but a muffler doesn't make or break hp. No offence to experienced people on here but scavenging effect has more to do with exhaust pipe engineering and size....mufflers have very little affect. Exhaust gases need to stay hot to exit the exhaust system quickly before cooling and the way achieve that is the exhaust pulses need to help pull one another without restriction. Too small or too big piping will hurt power more than a muffler ever will.

 

I dunno what your problem is... i drop out of OD for hills, let her wind and look at people's jaws drop when the truck, camper, and trailer blows them away up hill.

I'm going to stage a run one of these days with the "in laws to be" who has a tuned duramax. see if i can tow my load easier up hill than he can. im sure i can since i can blow my dads 00 PSD away with those 4.10 gears and 37" tires he loves, which was just barely keeping up with the duramax in front.

 

Yea, you can run straight pipes -duals and you won't drop in numbers without computer management in the older vehicles. But with computer management you have to be tuned. Sucks, but that's the way it is. You can only modify scavenging, flow or back-pressure (if you call it that) so much (within set parameters) before the computer needs to be dialed back in or tuned to reset margins for the set up your running. If you want to make good use of it anyway.

The factory set is fairly broad, so you can take away quite a bit performance before the computer will start spitting DTC's. Usually what happens is you move the powerband/torque up high and loose down low. That's because of the tune. Yea, you can gain up high in the RPMS, but as far as usuable HP/Torque that's needed in normal driving conditions down low, you'll be hurting.

You can do anything you want with the exhaust, but with computer management, you SHOULD hop on the Dyno after.

 

What numbers are you putting to the ground now lol. That things a beast!

 

well I want to do the hedman headers with two high flows and a Hooker out the rear....

 

a 99 with a metal fan? I thought they went to plastic fans in 98?

I usually see less downshifts with the truck cruising 60-65 then 65-70+

 

I used the fan from the 5.4. but that was still a 98 navi... my stock 4.6 was plastic

 

use the plastic fan until you can do efans

 

Yea, both 98's and the 01 had plastic fans. The trucks we had at one time anyway.

Not sure in which trucks/when or even why the metal fans were used..?

 

I run fairly fast 76-79 mph w/3.55's @ 2100 RPM in OD with the 1900 lb trailer and she rarely downshifts, if at all any more. In a head wind she might.

She sucks more fuel tho w/trailer - even empty lol. It's a fully enclosed box trailer, runs about 10 - 12 mpg. The truck by itself gets about 16 mpg at the speed.

 

maybe its your check engine light on causing the power losses.
why does your 5.4 shift out at only 4200rpm?

 

that video was when I was running the 5.4 with the 4.6 ECU.... since than it has been tuned and CEL is off


and I should be getting E-fans shortly

 

Wrong. It is all about maintaining proper flow and velocity.