Exhaust System Tips

By Mike Palermo Jr.

There is alot of horsepower wasted on bad exhaust systems. As an engine builder, this really chaffs my hide. You bust your butt for every ounce of power that you can squeeze out of these pups, and then watch it go to waste because of a bad system.

Basically,a what makes the difference between a good system and a bad one is attention to detail, and having the proper equipment to get the job done right.

First off, all of the primary pipes need to be of equal length. Secondly, it is important that the bends be done on a mandrel bender which insures that they are smooth and constant. Also important is the collector. It acts as a gathering for the charges expelled thru the four primaries and influences the "scavenging" that be accomplished in a system. Scavenging is the phenomenon where each exiting charge actually helps pull the following charge along through its pipe, thereby allowing that cylinder to except a slightly larger charge. At this time, there are basically two different styles of collectors: The "square four," and the "flat four." There are theories that support the use of either, but if done right, they both work quite well, and the flat one has the advantage of also lending itself to fitting under the tranny.

The length of the primaries strongly influences where the engine is going to make its power. Most of the systems are in a range of 38 to 42 inches long from flange to collector. You need to determine what tracks you will be running on, and what rev band you will be operating in to know which system you will benefit the most from. The lower that you need the power-band to be, the longer the primaries. If you are constantly under 6000 RPM, you are best off with 42 inch tubes. If you are spending alot of time on the super-speedways and see alot of 6500 plus action, you need to consider the 38 inchers. Otherwise, it is my feeling a good 40 inch system is the best system for you, as it does it all well. Peak Performance is now stocking all of the above systems, and will be happy to answer any additional questions you may have.

Lastly, it is a shame to see systems rusting away on some of the cars. The hi-temp paints work for a very short time, and chrome gets quite pricey. I have found that if I wipe the system down with Redline Synthetic Oil, (your old drainings will do), the unit takes on a burnished appearance that eventually prevents rust, even in a rainstorm!

Good Racing!!

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