Originally Posted by former NXMX5
you'll get more hp out of a K&N than you would out of a muffler. there are chips and intake airbox setups you can try. do a search --
I can't say for sure which would actually give you the greatest H.P. increase, better breathing intake, or a decrease in back pressure. I suppose it would probably depend on which "stock" system was the least effective to start with. Has anybody ever seen any "dyno" tests on either swap?
I know from drag racing my '69 AMX, that my 1/4 mile times never improved after I installed the functional 1970 hood scoop. But I never noticed any improvement after I installed the free flowing side pipes either.
I do know one thing, it sure "sounded" like it was going faster!
So unless you're actually going to race it, maybe the exhaust would supply the greatest "phycological" benefit, and the most satisfaction.
Of course the "chip" is without a doubt the best improvement you can make for real performance.