thedarkie Posted July 19, 2014 Share Posted July 19, 2014 Does anyone have data or knowledge about the effects of changing the size of exhaust tubing towards the back of the car? My 302 V8 currently has dual 2.5" tubing merging into a single 2.5" to the muffler. This merge is located roughly by the nose of the diff. I'm wondering if this is a choke-point, or if by then the exhaust has slowed and cooled enough that the loss in cross-sectional area isn't something terribly important. (is this even correct?) Would $1200 on fabbing up a true dual 2.5" exhaust with an x-pipe net me any appreciable gains? I estimate the engine is putting out about 300hp. 9:1 comp, aluminum heads, 262/270 cam, edelbrock alu. intake. Thanks Quote Link to comment Share on other sites More sharing options...
G-E Posted July 20, 2014 Share Posted July 20, 2014 In my experience, keeping the diameter changes small and consistent over the length of the whole system, ie. stepping up 1/8" or so every couple feet, will help reduce backpressure, and lower the tendency to resonation.... oh and it lowers the pitch of the exiting sound If you're considering using it to "tune" the power band, keep in mind that there's a narrow sweet spot for every diameter and shape, so you might gain a few hp at say 3000-3500 rpm with one size, whereas another would gain you a few more only above 4000... This is also true for a straight diameter the whole length, it will operate most effectively at a given engine rpm/load, above or below that will be less efficient. Pro tip: don't cut your tips at an angle, it makes them much louder Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.