|
i agree with most of what's been said here, but there is more to the story on all of the mods - it's not as simple as "this does that"
airbox mods - reducing negative pressure is the key - whether or not a mod to the airbox increases power is entirely dependent on that - on the 968, using a K&N filter, the mod makes 11.8hp (about half that with the oem filter) - other cars may not see that much
removing the cat - a few things happen here that generally make for more problems than anything else - the emissions systems are tuned to the cat being there - removal may increase upper end power, but will cost low end torque and can ultimately cause other problems as it messes with the mixture
throttle cam - if the cable already allows your throttle body to open and close fully, the only difference would be geometry of the foot position - it won't add any power
chips - this is VERY car specific - chips are tuned to a particular car and condition when they are designed - different chips make different power, and get that power differently - one might do it with timing - one might do it with fuel - one might use a bit of both - you would have to know how they did it, and then try to determine if your other mods help or hurt that method - i did a chip shootout test on all of the 968 chips, and you would be amazed at the different results and why they were different
cat-back - again, this one is very car specific - a cat back could do one thing on one car, and something totally different on another, depending on what else is going on with that car - too big and you lose torque - too small and you lose horsepower - even the resonator placement affect things - so does the muffler design
the single best thing you can do for power is to make sure that your engine is in top condition - check your compression - there is a direct relationship between power and percentage of compression - you can bet that an engine with 100k on it is down at least 10% - that as much power as you would get from all the above mods combined
|