Thanks for the info J & F,

I'll have to go with shorties myself as long tubes and a new Y pipe could get even more spendy.

 

And neither will make as much torque as your factory exhaust set-up...

When it comes to performance mods, headers should be WAY down the list - until you seriously change how much air and fuel can get INTO the engine, there's no reason to alter the exhaust system.

If the Lightning can put down 380 HP and 450 TQ through exhaust manifolds, you aren't going to exceed their flow potential naturally aspirated until you make a LOT of huge intake modifications.

Ask Mike T or any other knowledgeable builder / tuner - besides the sound, there are much better performance mods to be had before you turn to replacing the exhaust system on these trucks - especially headers. If anything, start with a cat-back (but be prepared to lose torque...

 

I agree - the stock manifolds are fine for 99% of the people here.

However, you can build a system that will improve torque in the low and mid-rpm ranges. Look for posts from openclasspro11 - he installed a dual 2 1/4" system and he reports much better low rpm power when he is towing. Also, the Magnaflow system reportedly does not cause a drop in torque.

 

No disrespect, but I do not believe SOTP dynos - only measured gains (or losses) on dyno runs operated by competent personnel.

I added a Magnaflow cat-back to my Lightning - I lost torque.

I added a Gibson cat-back to my SuperCrew - I lost torque.

Art-Man added long tube headers, full Magnaflow exhaust and a ported blower - he lost torque (but picked up 32 HP or so).

A "true dual" system is THE WORST for torque - the X-pipe greatly enhances the low end power of these motors.

Just what I have personally witnessed and what I have read MANY folks post about, albeit mostly in the Lightning forum. I know forced induction changes some things, but I challenge anyone to make dyno pulls and then swap the exhaust and make another pull - that is how you get meaningful data.

Big exhaust typically only improves power output in the higher RPMs, unless you are running big boost...

 

I don't believe in SOTP dynos either - they are too easily swayed by the $$ spent on the parts you are testing. The more you spend (or the louder it is), the bigger the reading on the butt-dyno!! The reference to the Magnaflow is based on info that Troyer is reporting (I am one of the few that doesn't take what he says as gospel, which is why I said it was "reported").

I don't understand this part - A "true dual" system is THE WORST for torque - the X-pipe greatly enhances the low end power of these motors. The dual system that I mentioned does have an "x" installed. A "true-dual" can have an "x" or "h" installed. A dual, with "x", properly sized, will increase torque as you will increase the scavenging effect of the exhaust at low speed. The system in question used 2 1/4" pipes, which a lot of people said was too small. That is actually a very good size for a stock or mildly modded (tuner, intake, etc..) 5.4. Now, the guys that are going with dual pipes, no muffler, 2 1/2" or bigger...well, we'll let them brag about their high rpm HP while the rest of us enjoy the added power in the rpm range that we use 99.99% of the time.

I like your post - nice to finally see someone here that is thinking for themselves and not taking advertising hype as real world results.

 

So what you guys are saying If I add headers and 2 1/2 pipes out the back I'll loose TQ? cause I have a set of pacesetter longtubes Magnaflow Xpipe high flow cats and Magnaflow 11" muffler coming to my house.

 

Thanks - I like it when folks think for themselves as well.

I'm sorry I misunderstood your post - I've always heard "True Duals" referred to as straight from each head to the tailpipe without any interaction between the sides.

The X pipe is a great idea, especially for low end torque...

Thanks for the open-minded post - I like learning from everyone elses experiences as well.

 

You will make good power up high, but your low and mid range will suffer.

 

Yeah, that is what most of the people here are talking about whey they say "true dual". Usually because they are too cheap to do it right, or they had a buddy with a Camaro and that is how they did his exhaust! Do a search on true dual and you will find lots of humorous posts - lots of guys that want to run headers into big pipes and run them straight out with no cats or mufflers.

 

Who cares about torque when you are going to be making all that horsepower? I did the same but without the cats and I used Aeroturbines. I didn't use the x-pipe either, I just ran the pipes to the back and into the mufflers. You won't even notice the loss of torque because it will sound so good that you will just be on the gas all the time.

 

Torque is what I need, Ive always been under the impression that headers were great. I guess the loss in backpressure makes the loss in torque. Heres my list: Homemade ram air, chip, 4.10s, port and polish and cams
My truck is a 94 f250 with a rebuilt 351
I have flex-a-lite e-fans, K&n airfilter (my airbox is ram-air stock from factory but is placed in a bad spot), 6 in lift, and 35s

I would like to see pictures of ram air that anyone has of a truck like mine. Also I would like to hear what yall say about head work and cams.

 

I have the long tubes x-pipe and magnaflow 11" muffler and I have not lost the low end torque in fact my truck willl stay with the flow of traffic now and I am not getting passed when I tow a 6000lb boat around. All of this was before my tuner and intake.

 

Head work and cams can do wonderful things for torque, but they can also kill it if you are not careful. For head work, mostly cleaning the bowl area and smoothing the radius on the floor will help nicely. For cams, keep the duration (@ .050) below 210*.

 

I have a 5.4 with the Roush Charger and MagnaFlow Cat back. It's at the dealership right now getting the Roush Intercooler upgrade as well as Dynatech LT's installed. After I get the Troyer Tune emailed to me, I will try to get it to a dyno. Anyone know of any in Tucson??

 

I have always figured headers do amazing things to these trucks. I guess I was wrong, the marketing hype is huge.