American Racing 1 7/8" headers, tune add 50rwhp to 2009 G8 GT
Very impressive results from just adding headers. For those who have a hard time reading the results, here's how it went:
Baseline with Vararam CAI, muffler delete, stock tune: 320rwhp/341rwtq See the bottom curve in the graph comparison for baseline numbers.
Added ARH 1 7/8" long tube headers, stock tune: 354rwhp/363rwtq (a gain of 34/22 from headers alone). The bottom curve is the graph with headers and no tune. The top graph is after the tune.
Added EFI Live dyno tune: 370rwhp/383rwtq (a gain from tune of 16/20 from the tune)
Total gain for headers and dyno tune: 50rwhp/42rwtq
Hats off to American Racing Headers for making an outstanding product. The 1 7/8" headers lose nothing to 1 3/4" headers down low, but gain at higher rpm. On a hotter 6.2L G8 GXP, the gains would be even larger.
hell yeah! bad ***, but man i would hate to drive that thing with all that rasp withnot having any mufflers
yeah xXxmotorsport has a stingy dyno so dosnt dyno high but gains are gains. it had a 56whp gain on GT and 50 on GXP with same parts. Both a6, They had tune, rotofab intake/AR LT no cats mid pipe on stock catback/muffler. . Customer had everything installed on G8 GT then had it put back to stock and got a GXP and had it all put on GXP. The GXP mufflers are louder and raspy and dont sound to good with not cats.
Went from 319 to 369 with GXP and the GT G8 went from 279whp 335whp so only had 34 more whp