Stainless Steel 944 Header

Now made from 304 stainless steel, our headers have been designed to provide a very significant power increase over a broad RPM band. Click here for a detailed dyno graph of modification results.

The header's effectiveness can really be felt when additional changes are made to the rest of the exhaust as seen in Run 95. Run 35 has a modified exhaust that provided the maximum power we could extract from that engine with the restrictive factory manifold. The header lets the engine breath and then remodifying the exhaust to make use of the new header's capabilities really made power. This was only attainable due to the header's long tube 4-into-1 merge-style collector design. The graph shows power at the wheels. In order to calculate power at the crank you can divide by .85 to get a good approximation.

Note: All dyno figures are shown with DIN correction applied. In order, the dyno sheet shows:

It is worth noting here that, although adding the right parts to your car will certainly improve its power, it takes time to adjust any given engine to extract the absolute most power possible from that particular engine. And, even if you have spent a lot of time maximizing one setup, as soon as you change another component in the system, the system then needs to be readjusted because even a single item can affect more than you think. You can see exactly this happening in the dyno chart.

For instance, the length of the hose after your air filter can significantly change the air/fuel curve, which can and does affect the power produced. Every engine is a bit different and each may have slightly different "add-ons." Even stock-class cars can legally have differences in air filters, exhausts, etc., so not only does it take time to optimize everything, it takes experience and knowledge, too.

In the dyno examples shown here, on run #35 (the first one shown) we built a custom-tuned exhaust specifically for that engine. Run #35 was the best of many different pipe lengths and configurations tested and let the engine make the most power it was capable of making with that particular setup.

An engine is nothing more than a big air pump, and the more air you can move through it, the more power you can theoretically extract. At any given volume of air, you can tune the intake and exhaust to get the maximum power, which is what we did with run #35 using what we had, the comparatively-restrictive Porsche Factory exhaust manifold.

Rebuilding the engine (as shown in the second figure, run #57) gave another 10 bhp or so, still with the factory exhaust manifold.

Adding the header to the rebuilt engine (run #66) immediately added power (another 7 bhp) when we bolted it on. Although most people would stop there thinking they had already tuned the exhaust back in run 35, we went back and re-tuned the exhaust, in the process going through half a dozen different mufflers, different diameter pipes, different pipe lengths and configurations, etc. Unfortunately there are few shortcuts to be taken here but Run 95 shows that we were able to find yet another 5 horsepower over that we got by adding the header without adjustments.

What you should take away from this is the understanding that while bolting on a new performance part may give you some kind of improvement, in most cases you will not be getting the full potential that part may offer unless you play with other things, too. At Racer's Edge, we have spent years doing this for ourselves and others. We would be very happy to do it for you, too. While you can certainly go through the same learning curves we have, why bother?

Our extensive experience means we won't be fumbling around trying to reinvent the wheel. While there will, of course, be a cost for this service, by knowing what to try and how to "tweak" components with each other we will be starting with a great deal of the work already done, minimizing your ultimate cost. For more information about what we can do to help optimize your car, please call us at 865-862-5262.