View Single Post
Old 02-28-2012, 10:24 PM   #28 (permalink)
oil pan 4
Corporate imperialist
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,267

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 273
Thanked 3,569 Times in 2,833 Posts
Quote:
Originally Posted by rmay635703 View Post
The reason is typically reliability but also the fact that your engine is not going to automatically increase in efficiency as compression ratio goes up, in fact it can go down because of the massive dynamic frictional losses, egr and blowby
The highest production compression ratio I could find was 22.5:1, so I find no reason to try and reinvent the wheel. I am sure the OEMs found good reason not to go to say 27:1 or higher.

After every one went NOx crazy that was one of the reasons C/R stayed low.

I have no EGR.
EGR = BAD

The dragster and pulling tractor diesels run C/R as low as 14.5:1 but take over 100lb of boost. Not built for fuel economy.

My water injection pump and pressure control system is all ready to go, just waiting for warmer weather.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote