gemellocattivo.com

Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
It is currently Thu Mar 28, 2024 12:07 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: Table Sizes
PostPosted: Fri Dec 30, 2016 10:59 pm 
Offline

Joined: Sun Oct 11, 2015 2:07 pm
Posts: 134
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?

_________________
"Sometimes, the elegant implementation is a function. Not a method. Not a class. Not a framework. Just a function." ~ John Carmack

"Any sufficiently advanced technology is indistinguishable from magic" ~Arthur C. Clarke


Top
 Profile Send private message  
 
 Post subject: Re: Table Sizes
PostPosted: Sat Dec 31, 2016 7:22 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4251
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.


Top
 Profile Send private message  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group