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Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
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 Post subject: Table Sizes
PostPosted: Fri Dec 30, 2016 10:59 pm 
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Joined: Sun Oct 11, 2015 2:07 pm
Posts: 122
All,

What are your opinions on the ideal size of major speed/load indexed engine tables (like VE, spark maps, etc.)?

I have used 17x17 tables, with variable axis points, for no particular reason. I have never felt a need for more points, but I do adjust the RPM breakpoints to match the shapes of the torque curve. I have also always shared RPM and load axis points for major tables, this hasn't been a problem yet.

What are your thoughts?

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 Post subject: Re: Table Sizes
PostPosted: Sat Dec 31, 2016 7:22 am 
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Joined: Thu Jan 01, 2015 6:47 pm
Posts: 2183
I think it depends a lot on the application.

You need enough rpm points to approximate the shape of the torque curve as a minimum, then points around cranking, idle cold/hot and off idle can be very helpful. So for a lawnmower 8 is plenty, but on an engine with hot cams that you want you drive on the street 16-32.

The number for load depends on the load sense method and range you need to cover. With MAF you can get by with 1 row, 8 is way plenty. With MAP 8-16 should do it but with a lot of boost up to 24 maybe. With TPS you need to approximate the flow curve at all the MAP values....16-32

That is for VE. Other tables like a target lambda if you use it can be much smaller.

Spark again depends a bit on the application. 8x8 will do, 16x16 (or 17x17) is probably plenty for most things unless you want every bit of fuel mileage, perfect idle/off-idle and every bit of power on a high-boosted application.

When I have the option I start small and add points as needed while tuning.


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