Lets just say I live in a small town where you never have to go to emissions. And there is hot rods all over the place. You know if they built their hot rods from the ground up, they don't have any emissions on their cars...right? My guess is, if you were to take a 1993 Jaguar XJS 4.0 convertible and took all 400 lbs. of emissions off of it, it wouldn't run. The ECU would probably throw a fix as well as many other items. Right?

 

Back in the old Days of the 70's and 80's, emission compliance took a lot of power from the motor. It had to be tuned to meet standards and hopefully run well enough. In 1975 most cars got catalytic converters and they could be tuned to get some power back. Then came ECMs which could control spark and other things that was followed by port fuel injection, then crank fired ignition then direct injection all these made it possible to get more power from the engine. Modern high performance motors don't really give up much power for emission and noise controls. Many times removing factory mufflers and air boxes just results in more noise and often a reduction in power. A tunable ECM can increase power, other changes have to be made in a systematic manner so that the mods build on each other. Forced induction via a supercharger is often the best power adder. My Dad's advice to me was; if you want a faster car, then buy a faster car. I think that a supercharged XJR six would be perfect for an XJS. If you mess around too much in Calif. you might not be able to register your car, so you've got to proceed with care.

 

For me, I think this car is fast enough. What I don't like is how hard all those extra hoses make to work on it. They block too much.