Low End Question

Get a long tube header and stay with 2" pipe then.

long tube headers rob low end torque because the exhaust pulses are very long... short headers keep low end torque but dont gain as much high end hp as a long tube... you could put a ranger header on there with 2" or 2 1/4" piping to the muffler(s)... I currently have a longtube header to 2 1/2" pipe to a y-pipe to 2" pipe, then to 2 spintech mufflers.



my car at idle:
http://www.j0o.com/ka0tyk.mp3

"long tube headers rob low end torque because the exhaust pulses are very long"

Where did you get that info?

Long primaries = torque

Short = higher rpm power

you HAVE to be kidding me... look under ANY 5.0 car thats pulling the wheels off the ground, and what do you see? LONGTUBES. because they launch at high rpm... so they see higher benefits at high rpms due to the long primaries which carry the exhaust pulse further to the collector...

at any rate I've had both the ranger header and the longtube pacesetter header is currently on the car... ive felt the difference. go ranger for low end... longtube for high end...

It's true mang. Short for mid range and longs for high rpm. Just read a Summit catalog for that info.

Kaotyk your car would look bad ass on some 28" M/T's and frontrunners on welds.

I have a long tube with a full 2.5" exhaust, and performance cam, which should all hurt low end torque and my 60' times didn't change. (with an auto, never exceeding 3000rpm in the 60')
If you want more torque, mill the head for more compression. I think Dan'l milled his head .060 for nearly 11:1 compression, but occasionally has to run mid grade. If you were just to go a mild .050, you could bump up the compression to 10.5:1 and still run low grade. You will also see better gas milage.

Well maybe you need to dyno your car and then change back to the Ranger header and see the difference on paper cause your long tube will produce more torque at any rpm.
The reason Ford made a shorty was because of the O2 sensor location.
They wanted the sensor close to all primaries and close to the manifold heat.

here ya go
http://www.dynomax.com/headers.stm

From the above website:

Primary Tube Length
Determines torque above or below the peak horsepower RPM point. Shorter tubes add torque above the peak RPM point and reduce torque below. Longer tubes add torque below the peak RPM point and reduce torque above it.

Primary Tube Diameter
Determines peak horsepower RPM point. Use small diameter tubes on small CID engines to produce mid-to-high-RPM torque. Use large diameter on large CID engines to produce mid-to-high-RPM torque. If in doubt, use smaller diameter tubes

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You have to keep in mind that every single aftermarket header is going to have a larger diameter tube than the stock cast iron piece. I wish I had a ranger header, or cast iron header to measure, but the difference between the stock diamater, and even the small 1.5" tubes of the long tube pacesetter header is substantial. Because both change, it is impossible to say which will produce more low end torque.

James Duff have a 4cyl truck header and I believe Hooker did too. All long tube.
The Ford Ranger header is SS tube and a compromise but better than the old csat iron manifold.

Shorty headers have always been a compromise...mainly just for easy installation without having to modify exhaust. Long tubes have been known for years for the increased low end torque (from runner length) and increased high end HP (increased flow over stock). Basically an all around benifit...gas mileage even improves on most cars. The only downsides are the fact most V8's require lifting the motor out a few inches to get the headers in, the extra noise from the thin tube walls, and the age old habit of header bolts backing out (fixable).

Also, a daily driven car that never sees over 4000rpm has more to do with the fact the engine currently runs best at the lower rpms. If you modify the engine so it likes to run in the 3000 - 6000rpm range, you'll modify your driving style to always be in that range. When I used to daily drive my 2.3L Turbo, it rarely ever saw less than 2500rpm and usually was ran to at least 4500rpm for each shift. My Eclipse is an automatic and on an easy take-off, it shifts at 4500-5K rpm...it only drops below 3000rpm for freeway cruising. When I drive a V8 like my 351W, It'll never see over 2500rpm unless I want a little adrenaline rush.

a351Must2 said:

Also, a daily driven car that never sees over 4000rpm has more to do with the fact the engine currently runs best at the lower rpms. If you modify the engine so it likes to run in the 3000 - 6000rpm range, you'll modify your driving style to always be in that range. When I used to daily drive my 2.3L Turbo, it rarely ever saw less than 2500rpm and usually was ran to at least 4500rpm for each shift. My Eclipse is an automatic and on an easy take-off, it shifts at 4500-5K rpm...it only drops below 3000rpm for freeway cruising. When I drive a V8 like my 351W, It'll never see over 2500rpm unless I want a little adrenaline rush.

Click to expand...

Great philosophy

Its funny how that works but your right My turbo cuts on at 3k and thats is a min of where I shift gears at.