Loud is a relative term, I have full cats and headers and most folks say my car is too loud - which I almost agree with. In reality if you have any emission testing in your state I wouldn't sacrifice a few extra horses for not having cats and possibly messing with your chance to drive a great car. I'm with Mac on this one. Unless you race a car often the difference in 10 - 15hp is so insignificant that it really only matters if you want bragging rights. Any given day, temperature, traction, air density, brains, all affect the performance of the car. 99% of us our NOT tuning the car at the track competing in an NHRA event trying to squeeze the last thousand of a second out of our cars.
Steven
2004 Marauder Black, loaded
Vortec S/C
4.10s
3500 PI Stall
Kook's headers
476.9 rwhp 385 lbs/tq
KVR's, QA1's, M&Z control arms, rear sway bar
Lidio tune
2004 Suburban Dark Charcoal
1970 W-30 442 convertible twilight Blue