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The X-ram was never intended to be a production type manifold.
Originally, it was intended only as a demonstration unit to prove once and for all that the Crossfire's could make horsepower that would make most tuned ports look for a place to park.
Because of the interest in the X-Ram, a few extra units were built and sold to handful of selected customers for evaluation reasons. But everyone else still wanted one. So the quest for production continued. |
The final Prototype was completed in the late summer of 1998. It took over a year and seven other designs to get to that point. A few of the designs worked very well, but would not fit under the hood of the 84 Corvette. The 82 Corvette’s, Camaro Z-28’s and Firebird T/A’s all had plenty of room to work with. However, the 84 Corvette proved to be very limited.
Over 170 base intakes where checked and measured for runner lengths, port sizes, overall height. Out of them all, only one fit all the requirements.
After the first model of the eighth design was completed and tested it was time to build the first prototype. After the many long hours of CAD work, it then had be programmed into a "G" Code machine language to work with a CNC Milling Machine for the final process. |
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The next step was to build the X-Ram Plates using 6061T billet aluminum, and then remove all the unwanted material.
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After the top plates were completed the base manifold still required extensive modification to qualify for the X-Ram plates to be matched and mounted to the corrected height requirements. Then a mounting bracket was designed for the fresh air pump used on the serpentine belt drive engines. The end results were that the first X-Ram was ready to be mounted and tested for the first time. And the first time was a time that will be long remembered.
Standing Quarter Mile
Class D Stock / Automatic
From 15.6 second @ 86 mph
To 14.3 seconds @ 97 mph
And no one could figure out what was different!
Since the first 4 years, there have been a few changes in the X-Ram, but the basic design has stayed the same. The latest change is helicoiled threads in the base manifold to insure precise alignments of the base and top plates.
But that was not the end of the X-Ram or the search for more power and better performance.
To date, X-Ram has sold over a thousand units world wide. In the United States as well as in Europe, England, Greenland, Australia, and Canada. Customers from all over the world continue to let us know what they are doing with their X-Ram engines and the performance increases that they have found. |
Many X-Ram’s today are producing over 320 rear wheel hp. And, on this end, we still continue to listen and test new ideas to make the X-Ram (Crossfire) known for it performance instead of the lack of.
What it takes to build a Performance Intake There is a magic number (something like PIE) that is used to figure performance, fuel mixtures, emissions and many other things in this strange world. That number is: 14.7.
14.7 is the number used by the computer in your Corvette (or any car for that matter), and most all other engines to control the performance and insure that the fuel delivery system has the right ratio of air and fuel, or 14.7:1, 14.7 parts of air to 1 part of fuel.
This calculation is derived at sea level where (guess what) the atmospheric air pressure is 14.7 psi. Now when you here people talking about boost from turbo's and superchargers, the odds are they don't realize that all engines work with boost, and that boost starts with 14.7 psi of air pressure that is around everyone on the planet (at sea level). So the boost that Pumps make is over, or plus the atmospheric air pressure. Now if that sounds crazy, think about placing the engine in a vacuum chamber and removing all the pressure, now that engine won't run at all. Now atmospheric air pressure will decrease approximately .5 psi per 1000 above sea level or 14.2 psi. This is a fact that can not be changed, and even supercharging can not get that lost pressure back because no matter how much boost is increased at 1000 feet, it will always be .5 psi less then it would be at sea level. Because this can not be changed, engines with carburetors must be re-jetted to establish proper performances. Less pressure, or leaner air, requires less gas or smaller jets to create a leaner mixture, because you can't get proper performance at 14.2 psi while feeding a fuel mixture for 14.7 psi.
But your Corvette has a computer that watches things like this using a sensor called an altitude sensor that in conjunction with a map sensor draws the correct mixture map for the present altitude and changes the injector pulse to maintain the proper mixture and keep the performance level as close to normal as possible.
But things are not always the same, and there are other forces that are at work keeping your engine from performing the way it could. These forces are known as VE or Volumetric Efficiency.
Runners to "Ram" VE is a measure of an engine's ability to use or "pull in" all 14.7 psi of the atmosphere's weight. Street engines are typically 75%VE or .75 x 14.7 =11 psi. They are utilizing 11 psi of the atmosphere's 14.7 psi, and to make matters even worse, the Crossfire intake drops that figure even further to 66%VE or .66 x 14.7 = 9.7 psi. Some racing engines are 100%VE and others are 110% because they use the intake runners to RAM in more air and good headers to "scavenge" or suck out more exhaust. The X-Ram's VE is 96% with stock exhaust headers, and as much as 106% with Racing Headers.
This among many other factors are the reasons that the X-Ram is known for it excellent performance increases of 50+ hp at the rear wheels with out any other modification to the engine. Many people ask how can you get a 50 hp increase by just changing the manifold? The answer is not all that hard to figure out.
If you took a well designed intake and you wanted to limit its performance, all you would really have to do is restrict the amount of air flow or "VE" to the engine. Now you have an engine with 50 or so hp less. We didn't build that much more hp, we just gave back what was taken away when it was built. |
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Now that you have a little better view of the X-Ram, we'll ponder the effects of the EGR very shortly. The EGR is an emission reducer. They do this at an rpm range be 1100 and 1900 rpm's, or normal street driving range. The EGR is opened by the computer during this rpm range and allows about 20% inert gasses (burned gasses) to enter the intake and mix with the air and fuel. Because these gasses are inert (or already burned) they can't be burned again. Thus, the mixture enters the compression chamber and you have 20% less emission in the exhaust cycle. This works well, but also has 20% less performance. By removing the EGR we don't have the inert gasses to take up the space in the cylinders which increase the emissions slightly and cause a slight lean effect in the mixture. Because of the oxygen sensor, the lean mixture is detected by increased heat in the exhaust and the computer compensates with a slightly longer injection pulse to bring the mixture back into specs. Thus, there is no loss or no gain; just good clean performance, better mileage, more hp, and even more strange, less emission at the tail pipe.
Because there are a few other states that now have adopted California’s Clean Air Resources Board or C.A.R.B. Laws, we have designed an adaptor that will allow the use of the stock EGR in close to the same area of the original Crossfire intake.
The kits can be ordered with the X-Ram as user installable, or pre installed. The Kit can also be ordered separately to install on existing X-Ram systems. |
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