plenum size.....
Burning Brakes
Joined: Oct 2003
Posts: 779
Likes: 1
From: Buffalo, NY
Headers wether intake or exhust are tuned to a specific frequency. Regardless of physical restrictions the device will always operate most efficiently at the resonant frequency. Pulse width is another contributer to the flow, or how much volume is considered in one cylinder, another reason bigger cylinder, more torque. Where do you want your max power/torque? Shorter runners generally contribute to peaks in the higher RPM's. longer in the lower. Headers are very complex systems one small change here can effect results in other places. Companies spend tons of money trying to tune and get the best results they can out of a piece of pipe simply because its a simple component and inexpensive to manufacture. Like many things in life it's a matter of balancing the variables to get to where you want to be.
Thread Starter
Instructor
Joined: Jan 2003
Posts: 131
Likes: 0
From: Winston Salem
I would think max torque low on the band would be best. I used to always build street V-8s with low end torque in mind rather than high rpm hp. They were always quicker off the line and accelerated well through mid range. Usually for street driving that was best. Made more than a few high rpm motors look bad. I realize this is not an 'off the line' car but a 'driver'. Still, it would seem if you moved the torque curve up in the rpms, you would loose some street ability in every day driving. What would you think the optimum runner length for high rpm hp and again for low end torque would be assuming the cross sectional area of the runner is 'stock' and plenum size is the same (stock)? Factory had to make a 'best of both worlds' intake so I wonder if there is a more efficient length for each? A reasonable 'ball park' figure should be obtainable mathmatically without the need for extensive testing for the peak performance 'sweet spot'.
Last edited by 944JM; Dec 23, 2004 at 06:09 PM. Reason: change wording
