Thread: compression ?
View Single Post
fredmeister fredmeister is offline
Smart quod bastardus
fredmeister's Avatar
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,235
I figure shouldn't the values be roughly compression ratio times 14.7psi plus 1 times 14.7psi.
For example at 7 to 1 compression 7x14.7 = 102.9 plus 14.7 or 117.6psi.
This assume 100% VE or Volumetric efficiency. In reality it must be less because 100%VE is not attainable at low rpm speeds especially with our manifold design.
This is alot lower number than 120 or 130psi that most guys are quoting. Just theoretically what I suspect to be the case.
Someone else chime in please.....sanity check needed.
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 02-08-2009, 04:58 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)