VVT @cruise for MPG - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


ECUs and Tuning Discuss Engine Management, Tuning, & Programming

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 10-02-2013, 05:23 PM   #1
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default VVT @cruise for MPG

Has anyone figured out if you want minimum or maximum overlap?
JasonC SBB is offline   Reply With Quote
Old 10-02-2013, 06:07 PM   #2
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,202
Total Cats: 2,584
Default

Relevant to my interests.

Hopefully someone has some good info for us. I plan to experiment with it later, but for now its minimal advance in cruise cells for the next few tanks. Tuned on the lean side and hoping to achieve decent mileage on e85.

Last edited by 18psi; 10-03-2013 at 10:23 AM.
18psi is offline   Reply With Quote
Old 10-02-2013, 06:14 PM   #3
Junior Member
iTrader: (6)
 
Join Date: Feb 2012
Location: Phoenix, AZ
Posts: 143
Total Cats: 4
Default

I might have some relevant info from a toyota engine I can post when I get home. The pdf is on my home computer.
300zxrb26dett is offline   Reply With Quote
Old 10-02-2013, 07:35 PM   #4
Junior Member
iTrader: (6)
 
Join Date: Feb 2012
Location: Phoenix, AZ
Posts: 143
Total Cats: 4
Default

Since I cant seem to upload the file here is the link:
http://rav4world.com/pdf/2009/2009_R...w_Features.pdf
Pg 73 should have the relevant information.
300zxrb26dett is offline   Reply With Quote
Old 10-03-2013, 08:04 PM   #5
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

That suggests big overlap to get EGR effects.
JasonC SBB is offline   Reply With Quote
Old 10-03-2013, 08:36 PM   #6
Junior Member
iTrader: (6)
 
Join Date: Feb 2012
Location: Phoenix, AZ
Posts: 143
Total Cats: 4
Default

Quote:
Increasing overlap to
increase internal EGR
to reduce pumping loss

 Better fuel economy
 Improved emission control
These 2 things go hand in hand though. Another thing I would suggest is go digging through the Ecomodder forum and see if you can find more information about cam timing in relation to improving MPG.
300zxrb26dett is offline   Reply With Quote
Old 10-08-2013, 03:56 PM   #7
Elite Member
iTrader: (24)
 
Join Date: Jul 2007
Location: Cypress, TX
Posts: 3,778
Total Cats: 35
Default

I havent passed the sniffer test here with my 04 motor due to high NOx. I need to get the car back on the road within a few days. This would be much easier than plumbing and controlling a stock egr valve.
Bryce is offline   Reply With Quote
Old 10-08-2013, 04:59 PM   #8
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Excessive overlap can increase HC too because of fuel going straight out the exhaust.
JasonC SBB is offline   Reply With Quote
Old 10-08-2013, 06:59 PM   #9
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by JasonC SBB View Post
Excessive overlap can increase HC too because of fuel going straight out the exhaust.
When does overlap occur on a stock VVT engine?
hustler is offline   Reply With Quote
Old 10-10-2013, 04:52 PM   #10
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

You mean in the stock mapping? Midrange RPMs, dunno how it changes with throttle position / load though.
JasonC SBB is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
1991 special edition with hard top full part out JC, NJ russian Miata parts for sale/trade 6 10-08-2015 04:01 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
Got bad Crank Angle Sensor and Random Misfire codes, but runs fine. Greasyman General Miata Chat 2 09-28-2015 11:44 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:30 PM.