its actually not an engine, its called x-pipes which are different exhaust pipes and change the pitch of the sound drastically. look it up, its really cool!
All these cars also use stepped headers! Your boom tube build isn't going to sound this good unless you also have stepped headers! It's not just the collector!
Wow, finally a video that shows the speed/sound comparison perfectly. Thanks so much! My family from Ukraine (lady and 2 boys) love the sound of NASCAR (like I do) but nothing compares to the speed of an Indy car.
