Header design
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JerryMopar (Talk | contribs) |
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Now we get to the collector - ever see a header with 1 5/8" primaries that had a 2 1/2" collector? No, me neither. But that is the optimum diameter for most street headers. Run that right into a 2 1/2" exhaust and you have a sweet system, lots of torque where you need it and better fuel economy. The collector should have a gentle smooth shape from the four tube area down to the final diameter as well to keep things moving smoothly. | Now we get to the collector - ever see a header with 1 5/8" primaries that had a 2 1/2" collector? No, me neither. But that is the optimum diameter for most street headers. Run that right into a 2 1/2" exhaust and you have a sweet system, lots of torque where you need it and better fuel economy. The collector should have a gentle smooth shape from the four tube area down to the final diameter as well to keep things moving smoothly. | ||
| − | While we are on the subject, I see the proliferation of 3" exhaust systems out there. If you have very healthy big block | + | While we are on the subject, I see the proliferation of 3" exhaust systems out there. If you have very healthy big block,running a blower,some turbo, or have even a ton of nitrous, you go boyee! About the only street application of the monster 3" diameter pipe is when you count on having a engine with large gobs of top-end power. Otherwise, velocity is king in exhaust and 3" is probably too big to keep the speed of the gasses up in the exhaust, and there goes that bottom end torque again! Many reccomend either 2 1/4" or 2 1/2" diameter pipe for street V-8's. |
Summary: | Summary: | ||
| − | 1. "shortie" - not a header | + | 1. "shortie" or a "block hugger" - is ''not'' a header |
| − | 2. Bigger diameter | + | 2. Bigger diameter primary tubes are NOT better in most street applications |
| − | 3. Longer tubes are better | + | 3. Longer tubes are better for torque |
| − | 4. Equal length is important for tuning and power output | + | 4. Equal primary tube length is very important for tuning and power output |
| − | 5. | + | 5. A long and smooth collector is a good thing |
| − | 6. | + | 6. Just like header tube size, be reasonable with the size of your exhaust system |
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