The individual flanges shown...
The individual flanges shown here were machined out of stainless bar stock on a CNC mill.
SCR: What about mufflers-good or bad? Is a header with a different design required to make allowances for the muffler?
Boat: Mufflers present a different set of problems. Many headers were not designed for the extra weight of the mufflers, and they can cause some issues with cracked tubes and broken collectors even if the muffler is properly supported. If the muffler is a small, lightweight unit like the Schoenfeld units, there is not really an issue. But if you have to run a muffler that is much heavier, there can be some issues.
Stahl: We should have been running mufflers from day one. We don't need the extra noise. The circle track guys could learn a lot from the road racing guys. They have a really well-defined system for mounting the exhaust systems on their cars. The tailpipes are isolated from the headers through well-designed brackets and flex joints. We need to remember that the addition of mufflers is going to require some re-engineering of the exhaust system.
Notice the thickness of the...
Notice the thickness of the flanges.
SCR: What about collector lengths? Is this something the racer should use as a tuning tool?
Boat: Yes. Many headers have adjustable collectors, and this is another tuning tool you can use to adjust the powerband of the engine to match the track.
SCR: What should a racer expect to pay for real racing headers, not a convenience header or a header that was designed for a street car?
The finished product will...
The finished product will be welded onto the primary tubes.
Boat: This is a difficult question. A set of mild steel headers with a non-merged collector can range in price from $250 to $500 a set. The difference in price will be based on how well the header is made. The price will be higher if it is TIG welded, and the flange thickness will also command a higher price if it is a thicker model. The racers have to ask themselves what they are willing to pay. If you look at some of the Outlaw teams, they replace their headers every six or so races. Most of those guys are getting their headers for free, so it is not really an issue for those teams. The Saturday night racer has to look into his own pocket to finance the cost of headers. A set of stainless headers is more expensive. The costs can range from $2,500 to $4,000. So if it is a part that gets damaged a good bit, the mild steel may be the only real option. It depends on the level you are racing.
Stahl: At the Cup, Busch, and Craftsman Truck levels, they all use stainless headers-at least the teams that are winning. They cannot afford a cracked header to cost them a win. The cost of the header at that level is not really an issue. I may not be the best guy to ask that question [because] I do not pay attention to what the other guys are charging for their products.
The flange is an area of much...
The flange is an area of much debate. Some builders feel that the flange should be at least 1/4 inch thick. Thicker is better, but you may pay a penalty with a bit more weight. Make sure you use a quality header gasket and quality hardware to mount the headers.
SCR: What about the material the header is manufactured from? What works the best when considering durability, performance, and cost? How should the racer make this decision?
Boat: The mild steel headers simply do not last as long as a stainless header. From a durability aspect, the stainless steel header is the hands-down winner. If you consider two headers that are exactly the same, except one is made from mild steel and the other from stainless, the power they make is the same. The racer has to look into his own resources and how he spends his money. Over time, the mild steel header will have to be replaced several times (excluding crash damage) while the stainless header will still be working just fine.
Stahl: Stainless steel is more durable than mild steel. But if you consider that the cost is as much as three to four times more than mild steel, you have to ask what will a header failure cost the Saturday night racer and if that failure justifies the cost differential. At the Nextel Cup, Busch, and Craftsman Truck levels, the cost of a header failure could be millions of dollars. At that level, the difference in cost between stainless and mild steel is insignificant. We have documented that headers we have built out of mild steel last for years. It is a matter of care.
Although financially out of...
Although financially out of reach for most Saturday night racers, stainless steel is the preferred material for headers.
The information presented in this discourse is to help the Saturday night racer make better decisions. These experts make their living developing, manufacturing, and selling headers. It is in both their best interests for the consumer-the racer-to make informed decisions.
What did we learn? The short track racer has different needs from those of racers at the highest levels of the sport. The engines used by the Saturday night racers develop less power, and they develop peak power at much lower rpm levels. Some Saturday night racers are forced to use engines that have some type of restrictor that is there for various reasons. Headers and the entire exhaust system help the savvy racer regain a level of control that many are not utilizing.
Headers simply offer a greater level of adjustability than most racers realize. With some experimentation and improved driveability, you can drive right into the winner's circle.