Chuck S

Modern cars with ECUs don't have static "tunes" so even without altering the internal firmware in the ECU the computer is constantly making fuel, air, timing changes and will react to something as simple as a less restrictive air cleaner or less restrictive exhaust. We can see this in hundreds of YouTube videos where someone slaps a K&N air filter on the car and runs before and after dyno tests. But I've not seen any creditable dyno tests just changing the cat-back exhaust and to pickup small changes the tests need to be run within minutes of each other on the same dyno and the same car.

Got a dyno handy? You can swap the exhaust in half an hour on a lift is the OE exhaust hasn't rust-welded itself to the car.

-- Chuck

usafstud

My s2000 is right at the threshold limit of NASA TT5. Too much top end power or drop in weight would put me into TT4 (which I don't want for 2019). Look of the stock exhaust is lame. I don't want loud since AMP (even though nasa doesn't run there) has a db limit of 98.

yeah, my oem cat bolts were rusted on to the oem exhaust. had to cut it off when installing a test pipe.