Table Sizes
Page 1 of 1

Author:  apalrd [ Fri Dec 30, 2016 10:59 pm ]
Post subject:  Table Sizes


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?

Author:  mk e [ Sat Dec 31, 2016 7:22 am ]
Post subject:  Re: Table Sizes

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.

Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group