"What are hedders?"
Hedders are specially designed tubular steel exhaust manifolds which replace the inefficient and heavy factory cast iron manifolds.
"What do Hedman Hedders do?"
Hedman Hedders increase performance and economy by improving the efficiency of a car's engine. They do this by removing exhaust gases faster and more efficiently than stock manifolds. Stock manifolds are designed for low cost, and have a short cramped design which causes some exhaust gas to get bottled up in the cylinder. Because of these residual exhaust gases in the cylinder, the size of the new fuel charge is limited and engine temperature is increased.
Hedman Hedders have smoothly contoured individual pipes for each cylinder. These primary pipes create a suction effect, called scavenging, which pulls the exhaust gases out. This creates additional velocity in the cylinder and helps to pull in the fresh fuel charge.
"Do Hedman Hedders provide more power?"
You bet! Hedders were originally developed for racing applications and Hedman Hedders are carefully designed to provide the maximum increase in power for passing, hauling loads, towing, etc. In some cases this extra power contributes to improved economy because the engine does not have to work as hard to pull a heavy load or conquer a steep grade.
"Are all Hedman Hedders the same?"
No, definitely not. Each Hedman Hedder is designed for a specific application. The length and diameter of the primary tubes and the collector size vary according to the size, weight, transmission type, gear ratio, and intended usage of the vehicle. A hedder for a RV or camper will have relatively long, small diameter primary tubes and a modest sized collector. On the other hand, a race car hedder will often have large primaries and a much larger collector. Applications and useage are different, so each hedder must be designed differently to provide maximum efficiency and best results.
"Why should Hedman Hedders be the first performance product installed on your vehicle?"
Cost is of great concern! Why not get the most performance for your dollar? The highest gain in performance is simply done by installing a quality set of Hedman Hedders. Hedman Hedders allow an engine to breathe more efficiently, to produce more horsepower, allowing cooler engine temperatures and better derivability.
"How do hedders lower temperatures?"
Hedders reduce engine temperatures in two ways. By increasing the speed with which the superheated exhaust gases are drawn out of the cylinder, hedders reduce heat buildup. In addition, the increased volume of the fresh fuel charge due to scavenging, acts as a further cooling agent. A cooler combustion chamber and cylinder provide for a denser fuel charge which in turn creates more power. Lower temperatures also reduce the chance of pre-ignition or "knock".
"Heat Wrap Products?"
Hedman does not recommend these products to be used on our hedders because they are designed to hold extreme engine temperatures inside the hedder. By doing so, cool air is not allowed to circulate around the external surface of the tubular construction. Thus the internal temperatures reach almost molten stages causing the hedder to become highly fatigued which will cause hedder failure. This will void your guarantee!
"Is there any special coating available?"
Hedman offers the most significant improvement since the creation of performance hedders - HTC, Hedman Hi Tech Coating. This revolutionary finish is guaranteed a full 5 years to protect your Hedman Hedders from external rust-through for the entire life of the hedder and its hi-lustre finish gives you a quality appearance.
"What about installation?"
Hedman Hedders are designed for the easiest possible installation. Almost any muffler shop can do the job, or you can do it yourself using only a few simple hand tools, a jack, and some car stands. To make it easy, Hedman includes detailed, easy to follow step-by-step installation instructions with each hedder set.
"What about convertibles?"
Unfortunately, due to vast differences in construction of convertible frames, x-members, boxed chassis, heavy duty suspension, etc., Hedman cannot guarantee a perfect fit on these applications.
"What about durability?"
Hedman Hedders are built using the finest materials and manufacturing procedures. That's why each new Hedman Hedder is covered by a LIFETIME GUARANTEE against defects in workmanship or materials.