Originally Posted by
Superwes98
and does the size of the collector on equal length make a difference or no?
Originally Posted by
Hurstmeister
With long tube headers the size, shape, length of the collectors can make or break an NA power band. Custom long tubes will be made to optimize the exhaust stroke and the cam. The size and length of the collector can actually be tuned move the torq curve of a power band.
Originally Posted by
Superwes98
and curious, is there a difference between equal length and shorties?
i would think equal lenth would be better but iv read and heard that shorties r better
Equal length OR shorties?
What are you asking?
You can have equal length shorties AND you can have equal length long tubes. Equal length headers means that all primary pipes from each cylinder have the exact same length to the collector. With most average headers the front primary pipes are longer and the rear pipes closer to the collector are shorter. These are called UN-equal length headers. And again,.. can be short or long tube.
Shorty headers have almost no collector and compared to long tubes will come up short on low end torque when looking at a dyno graph. Long tubes can gain low end torque by adding 6 - 8 inches of pipe the same diameter as the collector before the mid pipe. This is called 'tuning' the collector. By changing where the torque comes in at on the RPM band at almost no cost to HP. The size and length of the primary pipes is what generally effects HP. Bigger is not always better with primary pipes. This is where backflow comes in to play. When primary pipes are increased in size this will force the HP farther and farther up into the RPM band until it exceeds the cam specs or efficiency of the engine size and will fall and lose HP once that threshold is passed.
Here are a couple articles to read that explain more.
Header Basics - How Headers Contribute to Horsepower - Car Craft Magazine
Header - Exhaust Manifold - Tech - Jack Burns - Popular Hot Rodding
Hurst