Quote:
Originally Posted by MARINE1991
Why are the dealerships or GM not taking care of this problem....   |
Maybe they have not figured out what is wrong yet. Like HPTuners says, the engines are supposed to adapt to knock conditions over time, but that does not appear to be happening with the problem cars. Thus, the fuse fix does not really solve the problem as someone already noted.
I do know that no one at the G8 board is complaining about the 361 hp L76, and with only 800 miles, my car definitely feels like it can do 0-60 in 5.3 as claimed by Pontiac. The L76 is similar to the L99 but does not have variable valve timing. It does, however, have the same 10.4:1 compression ratio.
I note from the spread sheets at the GM powertrain site that both the L99 and the LS3 are premium fuel recommended engines, so my guess is they both use high and low octane fuel tables (click on the "SS" for each engine at this site:
http://media.gm.com/us/powertrain/en...a/10car_us.htm)
All that being said, it seems extreme that using 87 octane gas would increase the 0-60 time by a second or more, which is literally like taking on the order of 100 flywheel hp away. Most times I have seen actual comparisons between hp on high and low octane fuels, the differences have only been a few percent.