Recently we ended up going back to back on the dyno with two different headers on a mild k24 build. One header was a classic traditional big tube style 4-1 with no megaphone built by DTR(later known as SSR). The other was a Sheepey hood exit which is also a 4-1 style and incorporates a megaphone.
I guess it comes down to how you like to party.......and how loud you want that party to be.
The basics of this setup are as follows
- 12.5:1 compression 88x99 on e85
- Ported head on Cartel Elite 3.5's
- Skunk2 Ultra (4.5L)
Testing was done with the dump attached to the DTR unit. The hood exit was run as shown. You know, out the hood.
Blue line - Sheepey Hood exit
Red line - DTR 4-1
Some might speculate that the gains and shift in powerband can be attributed to the megaphone being part of the equation. Either way, it gained power.