If I replace my exhaust manifolds, should I stay with manifolds. I want headers for performance, but I have heard that headers will rot off easier and produce a lot of heat. I want to replace my manifold with something that will last a very long time, and ment for a daily driver.

TIPS & THINGS I SHOULD WATCH OUT FOR>

 

ideally, you want stainless steel longtube headers. they are not cheap, either. dynatech and kooks make the best ones for our trucks. obx makes knockoffs of the dynatechs. generally, expect an increase of 30 hp and 30 ft lbs. exhaust modifications are required to make them work, however. the oxygen sensor wiring has to be extended as well.

personally, i am running the dynatechs with a true dual exhaust system, 2.5'' piping, high flow cats, x pipe, magnaflow DIDO muffler. the power and exhaust note are awesome on my 2v 5.4. i have faced no reliability issues/codes with the stock tuning, either. if you do decide to install the longtubes, install them up from the bottom. there is no need to jack up engine/trans for install.

shorties will net you 0hp and 0ft/lbs. they will give you a better exhaust sound, and stainless steel ones are better in quality than the POS oem manifolds. if money is tight, and Longtubes are outside the price range, i would still go w/ stainless shorties over the stockers. don't expect any performance gains, though.

 

Don't forget to add a Tornado to pick up another 30HP...

Of all the places for upgrades, exhaust is one that is done more for sound than anything else - unless you upgrade intake, heads, cams, etc.

Bolting headers on a stock engine will cause you to lose torque. Lost torque on your truck will be more noticeable than the 1.3 HP you pick up at 5400 RPM.

Headers are best installed as part of a total performance upgrade. If you improve the intake side of the engine, the exhaust side will need improving too.

You state you want something that will last a very long time. The OEM manifolds will last as long as the truck will last - even longer.

BTW - Those "POS" OEM manifolds are good for ~ 500HP on a modded Lightning...

You might want to add the truck info in your profile so everyone knows what year and size engine you are asking about.

 

If it where me and I was looking at the expense of removing the manifolds ANYWAY I would replace them with ceramic coated long tube headers. The header kits are pretty expensive at around a grand but you would have to buy manifolds anyway so it would wash some. I have cramic coated headers on my Mach I and they look great after about 5 years. Long tubes are dyno proven to give 30 hp so thats really a cheap 30 hp gain. Guys spend 500 to gain 20 from tuner. Hundreds on cold air intakes etc. They make your engine look better they make it sound better and they make it run better.

 

Please post a dyno sheet for a stock engine making 30 more HP by just adding headers.

I've witnessed plenty of dyno tunes after adding long tubes and full exhaust on modular motor Fords and NONE of them netted 30 HP.

I know Built5.4 says he got that, but his engine is HEAVILY modded and could actually put the headers to use. I would still like to see a back to back comparison with his truck - manifolds on, 3 dyno runs. Headers on, 3 dyno runs.

JoryWLU has a 2000 4.6 - a 30HP increase would be way over 10%.

 

Well if I going through the trouble with replacing the manifolds aren't ceramic coated shorties better then the stock manifolds I fold a set for around $550 after the stock replacement. plus I want new stainless cats. Does this truck have 4 cats or 2?

 

Built5.4 had those gains long before he swapped to this supercharged engine he's running and those were his max gains not his peak gains

long tube headers do cost low end torque on the lightnings and harley trucks due to the loss of boost (around 2#) but with a pulley swap to come back to 8# yields huge gains

as far as long tube headers on the non supercharged trucks the low end torque is always increased and the torque curve broadens making for better driveability.

JORYWLU look into teh OBX headers off of ebay (I'm not sure if they will fit the 4.6 though) a lot of people have had decent results with the PaceSetter long tubes on the 4.6 trucks

 

280 for pacesetter longtubes they are just steel they will rust but i had shortys before longtubes and they were on for 2 years never leaked or rusted threw. that includes 2 michigan winters lots mudding and other stuff. i dynoed before with my shortys i havnt had a chance to go back with longtubes if i get 400+ for X-mas ill head back there. but i deff felt a power increase in seat of the pants and my truck from a dead stop on dry pavment would burn the tires for a few feet. with shortys it never did that

 

have them coated, local shop quoted me 300 about a year ago when i was looking into it.

 

you can buy them jet-coated for your truck right from the website for 420 bucks i belive with that you get jet coated headers bolts gaskets and o2 wire exenter crimps and a lil bit of wire to make your own extentions.

i just got a few cans of VHT header paint and painted um. still rusted but parts are still patined prob hit it with another coat after winter

 

If you were to measure the diameter of the exhaust just after the bend where it connects to the exhaust manifold you would see that it measures 2 1/4 inches. The rest of the system is 2 1/2. That is the reason why there is little gain with shorties. Long tubes remove this restriction so their potential to create more power is greater. If you don't plan on any further mods then stick with what works and is the cheapest. If you plan on mods further down the road then if you can afford it get long tube headers. Stainless will last longer. One thing to do while you have it all apart is to upgrade to the stainless steel studs if you use OEM manifolds or Stainless bolts if you get headers.

 

What if I get 4 stainless highflow cats? what do you recommend then, I also already have a 3 inche mandel bent vortext exhaust, and K&N cold air. Was thinking of getting a bbk throtle body, but worried if the throttle body should require other mods.

 

You might want to take a peak at this - instead of anecdotal evidence, it actually has measurements taken on a vehicle with both shorties and long tubes.

What they tell you will not ring well with the folks here, but I trust a dyno sheet way more than a SOTP measurement.

My personal experiences follow this article's summation as well...

Good luck.

Real World Dyno Measurements

 

Thats really not applicable to our engines. A 5.0 isnt the same as a Modular.

 

After reading that article, I don't want to be the 4.6 long tube guinea pig anymore. They do need to do that test on a 4.6 mustang as well.