Yes, kind of...
There was a local modded 997.1 TT 6speed with 516whp/536wtq SAE on a dynojet that I ran multiple times... My 997.2 GT3 (2950 lbs) was making 411 whp/300wtq SAE on the same dynojet at the time...
From 30mph to 170mph, I would be ahead by 1 car length...
From 50mph to 170mph, he would be ahead by 1 car length...
Gearing, weight (600+lbs car weight difference, and he also weight 250lbs), N/A Vs FI(Throttle response), redline difference, powerband, play big part...
He ran 11.5 at a drag strip without launching...
After that, he went catless and retuned (535-540whp), he would pull away from my on a straight at a rate of about 1 foot per second. Still, at PBIR (2.2 mile road course), he would disappear immediately from my rear view mirror within the first half of the first lap.
My point is, it would take serious upgrades ($15K+ on engine mods) to really destroy a (Exhaust/tune/high octane) 997.2 GT3...and as you now know, to get power from exhaust for the 997.2 GT3 can be done real cheap
This is with the 997.2 GT3... the 997.1 GT3 cannot compare... The 997.2 GT3 puts down 40whp more (stock for stock) than the 997.1 GT3, although the 997.2 GT3 supposedly only got 20 crank hp increase. I
I know the OP is talking about a 997.1 GT3, but I thought these real world results with the 997.2 GT3 should be noted.