3" certainly wont hurt it. why buy parts twice?
i have a very good friend that bought a 93 cobra new. to this day it has 24K miles on it, but i digress. a month after he bought it we put an a trim on it. that became an s trim in '96. the car ended up making 434rwhp with the s trim pullied to 12lbs with a stock engine from tb to pan. it had bolt ons. 3.55s, tuning, injectors, suspension, powerpipe, 1 5/8" shorties, 2.5" off road H pipe and 2.5" flowmaster catback.
it was a consistent 11.40@122mph car running high 1.5 second 60' times.
we put a set of 1 3/4" to 3" collector accufab longtubes on it, a 3" H pipe and 3" flowmasters dumped at the rear axle. after the exhaust swap it only made 10lbs of boost and we only got 8rwhp out of it for a total of 442rwhp. this was after we added more fuel to the tune to get the a/f back to where it was pre exhaust swap.
even though it only made 8rwhp with the exhaust, the car consistently went 11.0s-11.1@124 after the exhaust swap. still running high 1.5 second 60' times. the engine just accelerated harder.
this was an untouched 302 with a vortech, not some 700hp combination. yet the larger exhaust was worth a consistent .3-.4 in the 1/4 mile and 2mph at a 3300lb race weight. there is absolutely nothing wrong with running a 3" exhaust on a supercharged 302.
i have a very good friend that bought a 93 cobra new. to this day it has 24K miles on it, but i digress. a month after he bought it we put an a trim on it. that became an s trim in '96. the car ended up making 434rwhp with the s trim pullied to 12lbs with a stock engine from tb to pan. it had bolt ons. 3.55s, tuning, injectors, suspension, powerpipe, 1 5/8" shorties, 2.5" off road H pipe and 2.5" flowmaster catback.
it was a consistent 11.40@122mph car running high 1.5 second 60' times.
we put a set of 1 3/4" to 3" collector accufab longtubes on it, a 3" H pipe and 3" flowmasters dumped at the rear axle. after the exhaust swap it only made 10lbs of boost and we only got 8rwhp out of it for a total of 442rwhp. this was after we added more fuel to the tune to get the a/f back to where it was pre exhaust swap.
even though it only made 8rwhp with the exhaust, the car consistently went 11.0s-11.1@124 after the exhaust swap. still running high 1.5 second 60' times. the engine just accelerated harder.
this was an untouched 302 with a vortech, not some 700hp combination. yet the larger exhaust was worth a consistent .3-.4 in the 1/4 mile and 2mph at a 3300lb race weight. there is absolutely nothing wrong with running a 3" exhaust on a supercharged 302.