Branching Out
- HEADER COLLECTION AGENCY
As you are probably aware, header collector length can be varied. This was never going to be a walk in the park; any job is a job worth doing well, so, by varying the length of the header collector, you can also adjust the basic power curve of any engine. Basically, if you want to improve low-end torque, you should increase the header collector length. On the flipside of the coin, if you want to decrease low-end torque, you would need to shorten the length of the collector pipes. That’s great, yes, except how do you know what length is just right for your combo when the time comes?
Simply draw a thick line down the length of the collector using a crayon or similar marking pen. Make a normal hard pass with your car and examine your crayon mark you made. The temperature of the exhaust gasses within the collector will cause the mark to discolor or burn at a specific location on each collector showing a distinct area of discoloration. You can shorten the collector at this point. Just be certain to leave an inch or two of added material for further fine-tuning. It’s tough to add material to the collector once it’s been cut, so take your time and check, check and check again. Don’t rush this type of work, it’s tedious and can be very unrewarding if you don’t get it right first time!
- EXHAUST EQUALS
If you’re building something out of this world, and we all know the feeling, you want to build the best set of headers around town, and to make your drag machine not only sound good, but the pipes must do exactly what your demands were set out to be.
Flowmaster Exhaust Systems offer these recommendations: You can use 3-inch diameter tubing from the front to the rear. Install a balance tube between the header collector and the mufflers. The correct location for this balance tube can be found by spraying a light coat of lacquer paint on the system-beginning in an area approximately eight inches ahead of the collector flange and ending approximately 30 inches rearward of the header collector flange. Drive the vehicle around the block, but be careful to have the engine within the torque band (an area between 2500-3500 rpm should prove suitable). Return the vehicle to the hoist and inspect the paint markings. A “hot spot” will be indicated in the lacquer paint. At this point, the exhaust crossover or balance tube can be marked out and your new balancer tube can be tacked and then welded into position.
Generally speaking, a balancer tube should be at least 2-3/4 inches in outside diameter readings with a maximum performance 3-inch street system. Better still; make the balance tube out of 3.0-inch material. If the balance tube comes close to an oil pan or transmission pan, don’t get too worried. The crossover tubes purpose is to balance the resonance between the two exhaust pipes. Most builders fit flanges to accommodate quick removal and fitment of the balancer pipe. Heat generated will proceed through the normal “channels” out of the exhaust pipes.
Balancer tubes will increase horsepower in any V8 engine. They keep the exhaust gasses from building up more pressure in one exhaust tube than in the other, they help dissipate heat and decrease the sound levels generated by the engine. Remember one thing, There is no replacement for displacement, but every modification helps to win tenths at the end of the day.
