Originally Posted by b4z
No way it's just the octane rating. Sounds like some of these cars are putting out about 350hp at the crank the way they are running and dynoing.
That's LS1 power in a '04 GTO.
My '87 IROC advanced the timing when 91 octane or over was put in. It gained 10hp. I believe the 215hp rating was with the 91.
We're talking automatic (not 6 speed manuals). The L99 Camaro's that dynoed around 305 rwhp are off by about 20rwhp.
But the majority of the L99s are dynoing around 320 rwhp (on average).
On average, this is what most GTO's dyno. I owned two GTO's and I've seen more than my share of them dynoed.
04 GTO's (Automatics) dyno in the 280s rwhp.
04 GTO's (Manuals) dyno around 305 -310 rwhp.
05/06 GTO's (Automatics) dyno in the 320s rwhp.
05/06 GTOs (Manuals) dyno in the 330-340 rwhp range.