We compare the exhaust sound on two muscle cars that have the same 2 1/2" exhaust, the same Flowtech Terminator mufflers, full length headers, and very similar engines. One has a H-pipe and the other does not have a H-pipe. This direct comparison will show how much difference there is in rapping blap sound. We show how the exhaust H-pipe, or X-pipe will mellow out the sound of the exhaust.
The two vehicles are a 1965 Impala SS and a 1967 GMC C15 pickup. The GMC has a 450 HP 383 with 9:1 compression, BluePrint heads, and a Comp Hyd roller, 450 HP/450 TQ. The Impala has a BluePrint 400 that has 9.5:1 compression, BluePrint heads, and a Comp Cams Hydraulic roller camshaft, 508 HP/500 TQ.
Below is the description of the FlowTech Terminator Mufflers from Holley's website:
The Terminator™ is constructed entirely of super thick, fully-welded aluminized steel, with huge 3" inner pass tubes that reduce backpressure and increase horsepower like no other muffler can. Put a couple of Terminators behind your powerplant and you'll hear a bark that will scare the meanest junk yard dog in town!
Features:
Aluminized Steel Construction
3" Inner Pass Tubes
Reduced Backpressure
Increase Horsepower
No Glass To Burn Or Blow Out
Will Flow In Either Direction
Fully Welded For Strength/Durability
![](https://s2.save4k.ru/pic/9IqjRO1-oTw/maxresdefault.jpg)