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-   -   VVT @cruise for MPG (https://www.miataturbo.net/ecus-tuning-54/vvt-%40cruise-mpg-75316/)

JasonC SBB 10-02-2013 04:23 PM

VVT @cruise for MPG
 
Has anyone figured out if you want minimum or maximum overlap?

18psi 10-02-2013 05:07 PM

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.

300zxrb26dett 10-02-2013 05:14 PM

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 10-02-2013 06:35 PM

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.

JasonC SBB 10-03-2013 07:04 PM

That suggests big overlap to get EGR effects.

300zxrb26dett 10-03-2013 07:36 PM


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.

Bryce 10-08-2013 02:56 PM

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.

JasonC SBB 10-08-2013 03:59 PM

Excessive overlap can increase HC too because of fuel going straight out the exhaust.

hustler 10-08-2013 05:59 PM


Originally Posted by JasonC SBB (Post 1060903)
Excessive overlap can increase HC too because of fuel going straight out the exhaust.

When does overlap occur on a stock VVT engine?

JasonC SBB 10-10-2013 03:52 PM

You mean in the stock mapping? Midrange RPMs, dunno how it changes with throttle position / load though.


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