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View Full Version : dumb question about headers/exhaust



traksta15
10-29-2009, 01:56 AM
I have an 03 silverado ex cab with the 5.3 in it. Im thinking about adding long tube headers to it, but my only worries are:

1. Will it hurt my mileage (assuming I don't change my driving habits)

2. How much louder will it make my truck sound? I like a quiet ride and don't really like a loud rumble, I just want better mileage and maybe a few more ponies for when I get on it (rarely, but it does happen.)

Ray21
10-29-2009, 02:02 AM
What mods do you have on the truck now?

bigbirney420
10-29-2009, 02:07 AM
Exhaust will add a little rumble, but headers will make it pretty loud. If you add intake and proper tune, you will get more power, and typically a little better mileage with same driving habits. With that being said, anytime you mod, the driving habits usually change

traksta15
10-29-2009, 02:09 AM
all stock (except for aesthetics) no performance or exhaust mods have been done....yet lol

TnT_Sounds
10-29-2009, 02:10 AM
Since you'd be freeing up from restrictive manifolds, yes it should improve exhaust release therefore more HP and a little bit louder. Look into ceramic coated ones and personaly I'd go with shorty headers. I ran long tubes on my 5.0 and 5.7 and they don't quite have the low-end like shorty style headers. Also I'd probably run a 2.5" pipe at most if you do long tubes, that way you still retain some backpressure.

TnT_Sounds
10-29-2009, 02:12 AM
Not to mention if you want true duals it will be a little bit more costly to do since you have a saddle gas tank in there. At least I think you do.

Ray21
10-29-2009, 02:15 AM
With long tubes you'll have to do a full custom exhaust... won't necessarily be loud, that depends on the mufflers you use. I suppose you can tie it back into the stock exhaust but that would be a waste of money IMO.

If you simply want performance I would just get a programmer first (best performance increase per/$) and then an intake and exhaust later if you want more.

TnT_Sounds
10-29-2009, 02:16 AM
Do you know by chance how many O2 sensors are on it? Sometimes with newer ones it may throw a code and would probably be logical to throw the truck on a OBDII computer to re-adjust some things.

TnT_Sounds
10-29-2009, 02:19 AM
Motervation computer chips are really good. That's what I would do instead of a plug-in and play type deal.

Motervation actually sets the chips for the computer to truthfuly realize the performance mods. IE; cams, headers, intake, ignition, etc..

Ray21
10-29-2009, 02:21 AM
I would recommend a custom tuned SCT programmer but they don't work on '03 Chevies... :/

TnT_Sounds
10-29-2009, 02:28 AM
Do all your 'bolt on' performance mods then chip it.
That's if you want any more. Lol. I was pretty content with just intake and headers back on my 5.7l

stangman67
10-29-2009, 02:36 AM
Since you'd be freeing up from restrictive manifolds, yes it should improve exhaust release therefore more HP and a little bit louder. Look into ceramic coated ones and personaly I'd go with shorty headers. I ran long tubes on my 5.0 and 5.7 and they don't quite have the low-end like shorty style headers. Also I'd probably run a 2.5" pipe at most if you do long tubes, that way you still retain some backpressure.

That is actually opposite of how is usually happens. Long tube headers tend to give you much better long end grunt while shorties are just more convenient on newer vehicles because of the restricted engine bay space. You sacrifice a bit of performance with shorties but will be much easier to install.

traksta15
10-29-2009, 02:51 AM
im on fullsizechevy.com and from what i've read, longtube headers are better, If I got longtube headers, would it be possible to have a dual in/single out muffler? (to save on noise) Or do I have to go with a true dual exhaust setup?

Ray21
10-29-2009, 02:55 AM
You can go with a DI/SO... sure. 3" should be plenty, I like Magnaflow mufflers.

traksta15
10-29-2009, 03:00 AM
so it'll go something like this:

longtube headers--->to dual in/single out muffler---> dumped

Do I need anything to convert the headers to run into 1 muffler? Or will they connect right up? Sorry for all the dumb questions, im an exhaust newb

TnT_Sounds
10-29-2009, 03:18 AM
That is actually opposite of how is usually happens. Long tube headers tend to give you much better long end grunt while shorties are just more convenient on newer vehicles because of the restricted engine bay space. You sacrifice a bit of performance with shorties but will be much easier to install.

not on a 5.7L, could be all dependent to tubing and cross-sections, h-pipe, mufflers etc... To many variables, and from just swapping to shortys and 2.5" pipe, y-pipe, on the same muffler I gained about 8% ftlb torque. And shaved a little of my 1/4 ET runs. Granted it was only ran on the Dynojet.

TnT_Sounds
10-29-2009, 03:20 AM
so it'll go something like this:

longtube headers--->to dual in/single out muffler---> dumped

Do I need anything to convert the headers to run into 1 muffler? Or will they connect right up? Sorry for all the dumb questions, im an exhaust newb

should work.. look into some flowmaster super 40's. They have the deep tone thats quite suttle at idle.

traksta15
10-29-2009, 03:24 AM
this is another dumb question, when the headers run into the muffler, do the headers run along the same side of the truck?

TnT_Sounds
10-29-2009, 03:29 AM
this is another dumb question, when the headers run into the muffler, do the headers run along the same side of the truck?

what do you mean? you will most likely have to get some new motor mounts since you will more than likely have to move your engine from side to side to get them in. from there, you can tow it to a muffler shop and have them bend and weld you up some pipe and dump it after the axle.

Each header will be on its own side and the tubing will then need to be bent into place. Make sure you get good gaskets and header bolts.

Upgrayedd
10-29-2009, 03:32 AM
I havent seen a truck lately but on the 4th gen f bodies after the collector, the exhaust routes the same as stock. Noise will depend on things like cats, resonators and mufflers. All and all with a cat in place and a quality muffler you can have a great growl without being annoying.

prophecy
11-23-2009, 11:32 PM
you'll need a y-pipe to be made. im sure they sell kits. The best thing to do is intake exhaust and have a ls1 shop tune it. Your motor is almost the same concept as mine. and ive been working on them for years.

mlstrass
11-23-2009, 11:41 PM
not on a 5.7L, could be all dependent to tubing and cross-sections, h-pipe, mufflers etc... To many variables, and from just swapping to shortys and 2.5" pipe, y-pipe, on the same muffler I gained about 8% ftlb torque. And shaved a little of my 1/4 ET runs. Granted it was only ran on the Dynojet.

shorties gained more HP and helped your ET. Long tubes will increase torque down low compared to a shorty and will make the motor more efficient for everyday driving.

Also going with too big of a tube size (headers and exhaust/muffler) can kill bottom end torque, but gain HP on the top end. I'd look to increase torque for a stock style daily driver...

JBGabriel
11-24-2009, 02:31 PM
I would look into a performance tune for your 5.3, it will make a HUGE difference on a stock truck. I would go with a Westers or Nelson tune, they are very popular on fullsizechevy, there may be a few other options for mail-in tunes as well. I havent been on that site in awhile, since I own a ford lol

DSGBazemore
11-25-2009, 09:08 PM
im not sure if anyones mentioned this but when you free up an exhaust system on anything, you need to open up the intake also.. whats a nice open exhaust system gonna help when the intake is still restrictive?? i always do intake first then exhaust.. ok done lol

Ceebes
11-25-2009, 11:06 PM
I've heard headers are a pain. that the gaskets leak. Baze, should I get a intake before exhaust?

DSGBazemore
11-25-2009, 11:29 PM
we'll just modify yours c-boy hit me up..

tinctorus
12-04-2009, 01:02 AM
Do they make a diablo sport predator for that truck?
If so that would be the way to go for better gas mileage and much more power
I know with my srt-4 people have seen gains of as much as 45 horsepower with just adding that to the mods they already had on the car
Here you go man you can thank me later

http://www.diablosport.com/index.php?module=htmlpages&func=display&pid=65

walterGT67
12-04-2009, 05:28 PM
all stock (except for aesthetics) no performance or exhaust (http://allexhaust.com) mods have been done....yet lol

intake and a magnaflow and you should be all set