View Single Post
Old 10-20-2013, 07:15 PM   #51 (permalink)
Sean.Heihn
EcoModding Lurker
 
Join Date: Apr 2013
Location: Nowhere
Posts: 53

Land Shark - '11 Toyota Yaris 3dr Hatchback
Team Toyota
90 day: 36.68 mpg (US)
Thanks: 0
Thanked 5 Times in 4 Posts
Quote:
Originally Posted by vskid3 View Post
One question, how do you figure that the Atkinson valve timing makes it 750cc and 6:1 compression? I've never seen any numbers for the effective compression ratio and I just didn't expect it to be so extreme.
Using the valve timing numbers:
http://www.mr2.com/files/mr2/techinf...ata/1nzfxe.pdf

I think he means effective intake draw volume, since the displacement is always 1497cc. The 1NZ-FXE varies intake draw from 898cc down to 539cc. And since you're compressing less volume, your effective compression ratio is lower than your physical. Something like 7.8-4.68:1 vs 13:1.


Last edited by Sean.Heihn; 10-20-2013 at 07:29 PM..
  Reply With Quote