Thoughts on the "928GT"
#31
Captain Obvious
Super User
Super User
I was able to get 1.8 sec in the 60' so the manual 928 can jump off the line regardless what the differential ratio is. It doesn't feel slow during any part of a quarter mile run either. 105mph was my trap speed when the car was stock so 104 looks good to me. Most N/A same displacement and hp cars run about the same trap speeds too.
#33
Rennlist Member
It's pretty likely that Porsche under-rates all of their numbers as a rule of thumb. The car magazines consistently crack off 0-60s that are a half-second faster than Porsche's claims.
#34
Rennlist Member
BTW - this dyno run was at the manufacturer's headquarters during the 2009 928 Owners Club International Convention (OCIC.) We ran a bunch of cars through that day and the runs seemed accurate and reliable. Ed Scherer's well maintained S4 put down 282 if I'm not mistaken, right where you'd expect a properly tuned S4 to be.
I've since added a Motorsport SLC x-pipe and Bosch/Ford Racing Type III 24lb injectors. Additionally, I had the good fortune of having Colin ride shotgun at 3rd Coast a few years ago - he did several hours of real world sharktuning during the Saturday fun run. You could really tell the difference after tuning it optimally. I recall some 5th gear pulls from low rpm - after tuning the smoothness and rate of acceleration was very noticeably improved.
I haven't been back to the dyno since the sharktuning but I'd expect 335-340 rwhp. Jim Corenman's 90GT was dyno'd the same day as mine. IIRC, he had Devek Level II headers going into a x-pipe, probably by Louie. Put down 335 with the A/C mistakenly left on! I recall him saying he'd seen 345 on his Mustang dyno back home with the A/C off.
I believe this was the video proof of the dyno runs
https://www.youtube.com/watch?v=th4zUCNHG5k
https://www.youtube.com/watch?v=th4zUCNHG5k