how is load calculated

crans · Post by **crans** » Wed Oct 24, 2007 1:27 am

Just working some thing out so i have a full understanding of everything needed for tuning.

How is load calculated. is it purly based on the afm voltage scaled to something?

Matt · Post by **Matt** » Wed Oct 24, 2007 10:42 am

The ECU uses a forumla to work out TP (Theoretical Pulsewidth) which is used to index the fuel/timing maps

The formula is based from the AFM voltage after it gets recalibrated from the VQ map curve and then gets adjusted based on temperatiure and minor adjustment from other factors. There are some patent sheets which have the forumla on there if you want me to chase it down... its on my laptop somewhere...

NIStune pulls the value from the ECU divides by 256 (16 bit -> 8 bit) value for maptracing purposes

crans · Post by **crans** » Wed Oct 24, 2007 10:56 am

Yeah that would be really good thanks

Matt · Post by **Matt** » Thu Oct 25, 2007 2:30 am

heres the patent
http://www.freepatentsonline.com/4787358.html

and a thread discussing TP
http://ecu2.forumwise.com/ecu2-thread725.html

I've tried attaching but this forum keeps timing out so I'll have to email the docs

JCD · Post by **JCD** » Sat Nov 17, 2007 9:07 pm

Some very nice ones here:
http://www.uspto.gov/patft/index.html ('snot very user-friendly...)

Use this search engine:
http://patft.uspto.gov/netahtml/PTO/srchnum.htm

Input these pat nrs:
4509331
4787358
7127344

once you see the text, hit the red "Images" button.
Happy reading

LMQT · Post by **LMQT** » Sat Nov 24, 2007 7:12 am

Big big big thanks for this link to the patent

At least I've got all of the explication clearly detailed to understand how TP is calculated