Differences with headers

I have talked to many guys with lots of different experiences with headers they all say they are good but how much they do depends on the application.

I've heard the "you'll get a little better mpg's and a little better power" story but usually this is on a 4L ranger if its a ranger at all. I'm wondering how a 3L responds to them particularly a newer (05+) truck with the less restrictive 2 cat factory exh.

I'm looking at jba's probably ceramic coated stainless ones, I'm interested in opinions on that decision as well. I don't plan on adding an after market exh (factory is 2.25" SS on my truck) or any major intake work (I have a kn panel filter and plan to do some intake mani port matching).

Yeah, headers are a good start to an N/A build, but other things will need to be opened up too, in order to see increases. The intake side, and no not a "cold air intake". I mean the manifolds, heads, etc.

A good port and polish or the heads will help. You have the composite intake, which is a pretty good intake performance wise vs. the old aluminum ones.

If you go for any headers, get quality. JBA's are known for their quality.

dont expect a huge kick in the pants increase in power...but a good set of headers will show a definite pep increase over the stock log manifolds.

ceramic coated is a good idea...it will increase the headers longevity, decrease engine compartment temps, and will actually perform slightly better than non-coated headers (keeping the heat in the exhaust keeps exhaust gas velocity up).

Thanks for the info. An older (50 years experience) mechanic at work said to expect 10-25% increase going from logs mani's to headers. His experience was mostly 60's-70's mopar applications but he thought I might see similar results just a little less dramatic.

I plan on port matching the intakes but I dunno about the heads, I don't want to take them off (warranty), I've done this to my turbo mazda 323 and it makes a difference for sure. After 9psi felt like 13 psi (it makes ~ 10hp per additional psi).

I know an NA 3L won't make crazy torque and hp that my car but I just wanted a little more zip. I bought the new truck cause its 3L was way faster revving and felt alot more powerful when driving than older ones,. I don't need a tire burner just something that keeps a little smile on my face when I can't drive my little rocket.

I am another old guy that worked on 60's mopar.. I gotta tell you a 10% increase because of headers in the 60's is a total fabrication!! And a 25% increase is so far out of the question it is hard to consider without a huge belly laugh.

What you got there is a header FAN.. not a mechanic! In normal driving the 3.0 will NOT be able to use headers.. True with headers and a glasspac the thing will SOUND fast.. but don't expect anything except PRIDE of ownership.

BTW my first, very own, vehicle was a 50 mercury.. Right away I installed headers, glasspacs and duals.. The guys driving stock Fords were just as fast as my car with the money spent on it. Mine sounded better but that was all. That was 1954. That car was my last experiment with headers without also doing a cam, intake, and head modification.
Big JIm

If you want an increase in get-up, a gear change is a good investment.

Maybe bump up to 4.10's. Your mileage may increase, and the lower gearing will help keep the 3.0 in it's high powerband.

Years ago hearders were a slippery thing because in the 60's muscle-car
era many people thought (wrongly) that bigger was better.

and frankly going too large in the header primary pipes was actually worse than the stock manifolds.

"Traditional" headers for a Small block chevy have 1-5/8" primary pipes,
this is for a reason, but years ago people made 1-3/4 and 1-7/8" tube
headers that many big blocks would suffer reversion blowing into them.


I agree that a 25% gain is rediculous but I disagree that a 10% gain
is "a total fabrication".

I have personally witnessed a back to back dyno test with and without
the headers on a 4.0 engine. the test article was a 1994 4.0 engine
and the headers were JBA's and it was on an engine dyno the engine
showed gains of 12-14hp on an entire day of "runs" on the dyno with
chances for the engine to cool down, there was one run that showed
16hp but that one was disregarded.

That's a 7.5-9% gain, that makes 10% not so far fetched.

For the Baseline he ran the engine with a complete (factory) explorer exhaust system
Manifolds, Y-pipe, Cat, extension pipe, muffler, resonator and tailpipe attached

Then progressively installed stuff working front to back

the 3.0 is a bit revvier and it's manifolds a bit more restrictive.
So I'd really expect headers to work better

On the 3.0 I'd also expect removing the cat to hurt a bunch more
because the 3.0 is equipped with EXACTLY the same cat as the 4.0
so it'll have to rev more to get past the reversion point.

but back to the 4.0, with a cat test pipe installed in place of the cat power jumped
up 17hp (3hp over the headers)
(he claims his dyno's margin of error is 1%)

He installed the headers with that engine in his explorer and did
install the cat. his logic (that I completely agree with) was that
the minor gain (argeuably within the margin of error on the dyno)
from the test pipe wasn't worth the perpetual exhaust leaks from
the less precise gasket flanges on the cheap test pipe.

Not to mention that the test pipe reduced torque at lower rpms
over the cat.
According to him the test pipe hurt torque below 2200rpm
(where the 4.0 engine lives most of it's life)
was an "even up" proposition from 2200-3000 and helped (slightly)
progressively as rpm increased... to rpms where nobody actually
operates the 4.0 for more than a few seconds.

Maximum torque gain from the Headers?
from 225ft/lb up to 261ft/lb That's a 16% gain over stock!
That was with the headers, but I'm not sure what the rest of the combo
that produced that result was, nor do I know at what RPM
and I can't ask him, cancer cures smoking.

I do know that while my 4.0 feels stronger down low than my brother's did
I also notice that mine doesn't start feeling so "Flat" at the 4200rpm factory
power peak, but as I've never dyno'ed my truck I can't quantify it other than
as a subjective perception (Read: Butt-O-Meter)

I feel confident in saying that unlike FIPK and other such intake systems
headers will produce SOMETHING for your money.

If nothing else on average they will lighten your engine by ~10lbs per manifold

While they lighten your wallet by ~$500 for any of the "good" headers
(JBA, because the Borla's are discontinued)

AD

Isn't the main choke point of the 3.0 exhaust system the Y-pipe and not really the mainfolds?

Am I thinking of the 4.6 instead?

Ranger44 said:

If you want an increase in get-up, a gear change is a good investment.

Maybe bump up to 4.10's. Your mileage may increase, and the lower gearing will help keep the 3.0 in it's high powerband.

Click to expand...

I already have 4.10 gears

I figured there would be more gain % wise than a 4L as the vulcan mani's are obviously designed with using minimal material as the goal (ie log style). I am unsure the gain in hp and possibly mpg would be worth the $$ but I guess a little more research might help.

I've heard there is more effect from headers in areas under the power curve other than peak, ie average gains over the rev range greater than peak gains.

Anyone know of dyno sheets / reviews with any headers on any 3L vulcan?

To correct myself the mechanic I was talking to actually said 10-25hp I was mistaken when I typed the 10-25% gain part.

I agree with Big J and AllanD on headers. The old rule of thumb is 1" dia exhaust for every 100 hp, everything else is just sound.

Good Luck