I just bought a 81 GSL from a friend of mine for 300.00 I really like it but the thing is eardrum exploding loud. It has a racing beat header and 3" exhaust all the way back to the gutted muffler that has been filled with something other than what came in it. Just wondering if anyone else has this setup and if there a recommended mild exhaust and exhaust sizing for the 12a or does the 3" exhaust really help it that much? Also does anyone have a radiator w/ the temp sender for an 81 manual rex?

 

The only way to quiet it down is to purchase racing beats presilencer, as far as more horsepower with a gutted muffler, no. The muffler available thru racing beat actually makes more hp. 3 inch exhausts are good for turbo motors or high hp motors. rx7doctor