Knock?

Discussion in '2005 Saleen S7 Twin Turbo' started by enfiniRx788, Apr 3, 2006.

  1. The thing I’m curious about is how is it possible to run 11.0:1 compression and it be bi-turbocharged and not have it pinging like crazy running on pump gas? (Considering that it’s a street car, Race gas is out of the question) I'm estimating that the compression ratio after bi-turbo charging is anywhere from 13.5:1 to 15:1, (again I’m estimating) in that case octane levels would have to be at least 110 to 115 R+M/2. The only thing that I can think of is that its 11.0:1 after the turbocharging. Any input would be appreciated.
     
  2. The 03,04 NA s7 had a compression in the 13s, this engine has a VERY efficent combustion chamber, and does not need alot of timing. Also we are only running 5 psi so we are just a little over a NA engine anyway.
     
  3. Bill, the only "flaw" I've heard about in this car is the noted engine surge circa 1800-2000 rpm because of emission regs. Can this be fixed oe improved?
     
  4. The surge is due to really light parts combined with a lean calibration in the very low off idle range for emissions, the easist way to fix it is dont drive there! (it is only 200 rpm) The aftermarket 1000 & 850 kits are richer there and dont have the same issue. 1 day in the car and you know how and when to shift to stay out of there. It does not do it if you drive through that range only if you try to drive and stay there.
     
  5. and by the way, when will the 06 S7 be unveiled? and will it have a power hike? say to 850?
     
  6. With efficient cooling and slightly retarded timing, an engine can run high compression w/o knocking. Any c-average engineer can tell you that...
     
  7. yep, this site requires an engineering degree to join, im disapointed TipoO52 doesnt have one, he must have slipped through the sscreening process without a degree
     

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