Welcome to the North American Subaru Impreza Owners Club Wednesday July 30, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 11-09-2003, 07:36 PM   #1
PeterJ
Scooby Newbie
 
Member#: 14727
Join Date: Jan 2002
Vehicle:
2002 impreza RS

Default Can octane requirement be calculated?

If one was "building up" a NA 2.5 motor and wanted a higher compression ratio, would there be a way of calculating the octane level of the fuel required to run the engine without damage? Or to word it another way, knowing that 11:1 is good for 87 octane, how hight of a compression ratio could one go using 93 octane as the minimum?
* Registered users of the site do not see these ads.
PeterJ is offline   Reply With Quote
Old 11-09-2003, 08:59 PM   #2
orndog
Scooby Specialist
 
Member#: 34670
Join Date: Mar 2003
Chapter/Region: South East
Location: Atlanta
Vehicle:
2013 No gears!
Saltine American

Default


11:1 and 87 octane? Are you nutz?
orndog is offline   Reply With Quote
Old 11-09-2003, 10:48 PM   #3
PeterJ
Scooby Newbie
 
Member#: 14727
Join Date: Jan 2002
Vehicle:
2002 impreza RS

OMGHi2U

Isn't that what a 2.5RS is at? Or did I mean 10:1... oops.
PeterJ is offline   Reply With Quote
Old 11-14-2003, 08:45 AM   #4
Section 8
Scooby Specialist
 
Member#: 821
Join Date: Jan 2000
Chapter/Region: MWSOC
Location: "Like a hyena you are..."
Default

you cannot calculate octane requirements. You can calculate compression ration before hand though. Most people will not run more than 11:1 on 93 octane, others even less.

Other things come into play for detonation resistance of an engine, such as quench, timing, anything not quite right in the cylinder/combustion chamber ect. You can play with timing, but eventualy you run into a point where you can raise the comprssion, but you loose timing so you gain nothing.

cheeRS,

Greg
Section 8 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
What octane would be safe to run? chico_kj_23 Subaru Conversions 20 07-16-2006 11:34 PM
I know beautiful woman can be unattractive but can ugly ones be attractive? Undepelo Off-Topic 27 06-23-2005 04:47 PM
Minimum Octane Requirements For FXT N10S Factory 2.5L Turbo Powertrain 8 12-24-2004 07:48 PM
Cobb & Vishnu Octane requirements allythom Engine Management & Tuning 5 04-29-2003 12:36 AM
Unichip Octane Requirements/Octane Boosters? 2002wrx1 Factory 2.0L Turbo Powertrain 12 08-18-2001 12:42 PM


All times are GMT -4. The time now is 07:31 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.