I've seen a few ads for performace chips for the XK8. I have a '97 with 95,000 miles on it. The engine runs very well so I'm a little hesitant to take any chances that might booger things up.
Do any of you have experience with a performance chip? If so, what was your experience - would you recommend installing one, and if so, which one?

 

Gimmick.

On vehicles that are designed and optimized for fuel efficiency, you might get a nice boost in performance at a cost of fuel economy, but our cars are already optimized for performance and not fuel economy. Put it in sport mode and you're good.

 

Ditto. They're an abject waste of money, especially for the earlier cars. No telling what the cheaper ones really do anyway. I'd avoid them.

 

For the past 20 years or so automotive engines have been engineered to their optimum operating parameters. Any change in one element is pretty much guaranteed to effect other elements. For example, you may be able to squeeze out more low end torque but it will come at the price of top end horsepower, etc. Mechanical and electronic engineering has moved well beyond the point at which there was untapped, free, horsepower to be easily found.

Still, on the mechanical side, you can always enhance what is economically prudent to do in a large scale production environment. Blueprinting, porting, and opening up intake and exhaust are proven methods but come at a price both in terms of dollars and sometimes reliability as you move closer to, and beyond, design tolerances.

On the electronic side, automobiles and motorcycles are subject to many regulations concerning emissions and typically run very lean as dictated by their EFI "maps". Most consumer installed "power chips" are simple remaps of the EFI commands designed to enrichen the fuel delivery at various points. The key to their efficacy is how well they meet the needs of the particular engine they are going into (and whatever modifications it may have seen) and at what level of granularity they make changes. (A simple motorcycle EFI map can have thousands of individual AFR cells to map or remap)

One size fits all does not apply here! There are many very sophisticated EFI remapping tools and an expert tuner can make changes throughout the TPS/RPM range for smooth, linear power delivery and good street manners.

Neither of these approaches are inexpensive when done correctly and the change in power/performance is incremental, especially for a car that is already pretty high on the performance scale like the XKR.

For the most part, an average driver in common situations will never get to that part of the performance envelope where the changes will be noticed. If you are, however, in that 1% an internet-sourced chip won't get you what you are likely looking for.