Nope. Compression is not affected by intake or exhaust mods. Ang mawawala lang kung sobrang laki yung exhaust system ay ang backpressure, which help keep torque up.

A simple way of putting it: (HINDI ITO ACCURATE, GUESSTIMATE LANG!)

hypothetical 1.6 liter engine, 116hp, redline at 6500rpm

stock exhaust: 116 hp * 6000rpm / 110 ft-lbs torque 4000rpm
stock+muffler: 118 hp * 6000rpm / 108 ft-lbs 4000rpm
muffler+(1.75" inch)midpipe: 122 hp * 6200rpm / 107 ft-lbs 4200rpm
muffler+1.75"mid+headers: 125 hp * 6500rpm / 106 ft-lbs 4500rpm
muffler+2"mid+headers: 128 hp * 6800rpm / 100 ft-lbs 4800rpm
muffler+2.5"mid+headers: 130 hp * 7200rpm / 100 ft-lbs 5000rpm

Basically, the more horsepower you get out of the exhaust, the less torque. If you change your pipes to extremely large ones, the horsepower you gain will be beyond the usual rev range of your engine and will be mostly useless. Plus you shift your torque curve higher, meaning your engine actually feels weaker at low revs.

The generally accepted rule is 1.6 = 1.75 - 2" pipes, 1.6 SiR = 2 - 2.25" pipes, 2.0 = 2 - 2.25" pipes for best usable power. Not exactly sure on header measurements, but 4-2-1 headers give you less hp gain but less torque loss, while 4-1 headers are more preferred for dragsters. Original headers (DCX, Spoon, etc) will give you either more hp or the same hp as 4-1s and less torque loss, because they're usually dyno tuned.