PDA

View Full Version : Long tube headers?



NEPatsFan
06-05-2003, 09:17 AM
Would someone tell me what tube headers are and how they will effect the performance of my MM. I saw some long tube headers for a little over 1K and someone else wrote something about shorties? What is the diff and what do they do?

merc406
06-05-2003, 09:25 AM
Long tube header's provide more torque if built right with equall length tubes.

RF Overlord
06-05-2003, 12:14 PM
^^^what he said^^^

Please excuse it if I misread your question, but if you're asking what headers ARE, they are just fancy exhaust manifolds, only instead of dumping all the cylinders into a common space, there is a separate tube for each cylinder. Each of these tubes should ideally be the same length, then they are brought together under the car into a common "collector", which then bolts to conventional pipes and mufflers...this allows for better scavenging of exhaust gasses from the cylinders, and lower back-pressure as well.

The problem with long-tube headers is getting them to fit.

ghost
06-05-2003, 12:24 PM
Originally posted by NEPatsFan
Would someone tell me what tube headers are and how they will effect the performance of my MM. I saw some long tube headers for a little over 1K and someone else wrote something about shorties? What is the diff and what do they do?

Headers help your engine "breathe" by effectively allowing exhaust gasses to be pumped from the cylinders during the exhaust stroke. Better breathing means more horsepower and torque.

Headers come in all varieties, such as Tri-Y, long-tube, shorties, equal length and any combination of these that are not mutually exclusive (like long tube vs. shorties).

Tri-Y headers start with 4 tubes that merge into 2 which then merge into 1, thus giving them a "Y" appearance in three places and hence it's name. Tri-Ys are effective in increasing horsepower high in the powerband while increasing torque down low where you need it. Traditional headers, which start with 4 tubes and merge into 1, are effective at increasing horsepower but often move the torque peak higher in the powerband. This effect causes some guys to think that they lost torque with the addition of the headers when in actuality they increased available torque but the peak was moved up higher in the RPM range. You guys with MMs need the torque down low, so Tri-Ys would be more effective with your platform.

Shorties are just that, short tube headers. Sometimes space in the engine compartment is at a premium and these come in handy. Accepted knowledge is that shorties are not as effective as long-tube or Try-Y headers, but certainly better than factory cast-iron exhaust manifolds.

Equal-length headers have the tubes designed so that they are all of, well, equal length, which is supposed to help "scavenging," i.e., the momentum of escaping exhaust gasses helping to draw in a fresh air/fuel charge into the cylinder during valve timing overlap. Often you will see the word "tuned" in conjunction with equal-length headers. For example I have equal-length, tuned shorties on my Caprice (Hooker Super Competition).

Hope this answers your questions.

Eric

(edited for spelling. -Eric)

MAD-3R
06-05-2003, 12:28 PM
Well I learned something new there... :)

Hmm Almost need a "Performance 101" link in the FAQ...

studio460
06-06-2003, 12:27 AM
Great post, Ghost! Thanks!

Now . . . do long tube headers, by definition, mean no cats? Does the installation of long tube headers make California smog tests impassable?

ghost
06-06-2003, 01:13 AM
Originally posted by NBC Shooter
Great post, Ghost! Thanks!

Now . . . do long tube headers, by definition, mean no cats? Does the installation of long tube headers make California smog tests impassable?

:) Glad to help.

Long tube headers does NOT mean no cats and there is no reason whatsoever for the addition of headers to compromise emissions, provided you retain all factory emissions parts. To be safe, look for a CARB number for the headers in question. This will typically mean that they accept EGR hookups from the stock setup. If a part doesn't have a CARB number, ask if it has smog hookups on it. As long as you retain your emissions parts you should be okay.

Some long tube headers require "fabrication" in order for them to fit. That usually means that you'll have to have someone move your exhaust around a bit so your cats will line up with the headers. This can be a real PITA if you don't have muffler shop tools like a welder and pipe bender, etc.

You will want these to keep your headers bolted to the block using the bolts attached to this post. They are available from Stage 8 (http://www.stage8.com/AutomotiveStart.htm) and they WILL NOT loosen until YOU want them to. (Header bolts loosening on their own is a typical problem, regardless of manufacturer.)