Information: MAFT Pro v4.80 Terms/Definitions/Info

drjonez

Supramania Contributor
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
3,061
Location
the motor city
Obviously this will be in progress for a long time....but here we go. This info if a conglomerate of stuff printed in manuals, found on the internet and pulled from my own head. Enjoy!

Part Throttle AFR Tracking
The idea behind Part Throttle AFR Tracking (PTT) is wide ranging. It allows you to disconnect the O2 sensor connection to the ECU and let the MAFT pro trim your AFM input accordingly during idle and closed loop. Note that PTT idle correction is only +/- 10% and cruise/lean is +10/-25%.

There are three parts to PTT- Idle, Cruise and Lean: Idle is meant for idle conditions, Cruise is meant for steady-state cruising conditions, Lean is an additional level of adjustment allowing for a time delay before engaging.

In order to make proper use of this, I HIGHLY recommend you start off tuning the MAFT Pro with the O2 sensor connected. This will enable the Vf function and allow you to trim the low/mid throttle maps according to what the ECU wants. Once you've properly tuned your car, you can switch over to using PTT and ditch the ECU O2 sensor.

Here's a breakdown of the parameters of PTT:

Afterstart (in the System Settings panel)- the duration of time before PTT kicks on (?, perhaps there's a base 5 min there?)

Idle
  • Idle TPS- the TPS V below which idle PTT is active
  • Idle RPM- the RPM level below which idle PTT is active
  • Idle A/F Ratio- the desired idle AFR

In short once the engine has been running for 5+ minutes AND the TPS is below Idle TPS AND the RPM is below Idle RPM, the MAFT pro will begin to scale the AFM input to achieve Idle A/F Ratio.

Cruise
  • Cruise TPS- the TPS V below which cruise PTT is active
  • Cruise RPM- the RPM level below which cruise PTT is active
  • Cruise Load- the load level (KPa) below which cruise PTT is active
  • Cruise A/F- the desired AFR

In short once the engine has been running for 5+ minutes AND the TPS is above Idle TPS AND the TPS is below Cruise TPS AND the RPM is below Cruise RPM AND the load is below Cruise Load, the MAFT pro will begin to scale the AFM input to achieve Cruise A/F Ratio.

Lean
  • Lean Load- the load level (KPa) below which Lean PTT is active
  • Lean Delay- the time (in seconds) before PTT Lean is activated AFTER all other parameters have been met
  • Lean A/F Ratio- the desired AFR

In short once the engine has been running for 5+ minutes AND the TPS is above Idle TPS AND the TPS is below Cruise TPS AND the RPM is below Cruise RPM AND the load is below Lean Load AND Lean Delay has passed, the MAFT pro will begin to scale the AFM input to achieve Lean A/F Ratio.

Gain- Applies to all PTT, this is the speed at which PTT will attempt to maintain XX A/F Ratio. (units?)
 

CRE

7M-GE + MAFT Pro + T = :D
Authorized Seller
Joined
Oct 24, 2005
Messages
3,485
Location
Denver, CO
Thanks! It's still nowhere near finished. I've got a lot of plans as far as an online guide/worksheet goes. It'll be some time before I'm even ready to put up a beta of the interactive version, until then I'm planning on trying to keep this one at least up to date... besides, it's a good place to keep my notes.

Also, if anyone has any additional info or corrections concerning any of the listed parameters feel free to shoot me a PM.
 

turbobob

New Member
Authorized Seller
Joined
Aug 15, 2005
Messages
196
Location
Near Detroit
that site seems to be down, is it someplace else? If someone has the files I will host it.

Bob
 

CRE

7M-GE + MAFT Pro + T = :D
Authorized Seller
Joined
Oct 24, 2005
Messages
3,485
Location
Denver, CO
Hey Bob,

That's my website and guide. Hosting's not a problem; I pulled it and my Supra related info pending a rebuild of the site, more complete information and the filling in of some major gaps. If you can make some time to help me go through the worksheet/guide (I'll be removing the worksheet part, most likely) then shoot me an email and let's get this thing corrected and up to date.

I'll send you an email with the URL the guide is parked at and we can start going through it... I've got some questions from other people which I've got saved somewhere that involve various settings in the Pro which don't have labels in its menu and I'd like to at least document them in my guide.

Generally, I prefer that my articles not be mirrored as it makes for a great source of headache when 20 people start calling because they've got questions about an inaccurate diagram that was fixed months ago... I'm sure you understand.
 

turbobob

New Member
Authorized Seller
Joined
Aug 15, 2005
Messages
196
Location
Near Detroit
I am familiar with out of date mirrors..... :)

Version 5.2x is done (we are even up to 5.22) but the documentation is lagging somewhat. A friend has helped update the manual some, its almost done. Your guide should help a lot, lets get it up to 5.2x.

drop me an email so we can take it offline.

One of the Pro guys installed one on a 2007 Suburban, talk about diverse applications....

Bob
 

CRE

7M-GE + MAFT Pro + T = :D
Authorized Seller
Joined
Oct 24, 2005
Messages
3,485
Location
Denver, CO
I'm putting my electrical references back up 'as-is' for now... I'll update them as I have time and will eventually continue with my plans to actually build a site up around it. You'll find the guide and my wiring diagrams on this page.

http://www.fadingworld.com/CRE/Automotive/Supra/Electrical/

It's probably best you bookmark this post and not the URL above as it may change... I will update here if I move things around again.