Speed Density on the BA/BF Australian Ford Turbo 6

[DarrylC]

This was one of the things I kept trying to find on the net but no one seems to have written it up so I have done a write up on Ford Speed Density. It is probably too long and wordy and I would appreciate feedback (particularly by tuners who have worked in this area) but hope it gives some information to other people trying to understand how it works.

It is for the BA/BF turbo 6 but you can use the concepts on other Falcons. I have not included the correction factors that get applied as it complicates the description and I am not sure all the tables are available in HP Tuners.

At this stage I have left it as a pdf attachment but once it has had some feedback I can put it in the post. I had to take the tables out because you are only allowed to upload ~195kb for a pdf (yet you can upload tune files much bigger).

Feedback welcome, especially where there is further information/corrections.

Darryl.

[IH8TOADS]

My BA runs off a 14 breakpoint table for SD.

P.s, well done.

[JVK]

Great write up DarrylC.

[mycomputeratesme]

Awesome, about to have a read.

[JETURBO]

Very good write up daz

The basics REALLY need to be understood FIRST as many will find this helpful but for reasons they cant really understand, many "think" they know how an internal combustion engine works but when they start digging realise they actually do not

Many books/internet forums can help people understand what VE is first .....and why and no its not a commodore lol

[mycomputeratesme]

Thank you for that. Nice logical explanations and easy to understand. Appreciate your effort.

[mycomputeratesme]

The HP scanner does appear to have "air load" , seems to line up with your spread sheet.

[Eric@HPTuners]

Gonna read this when I come back from vacation. I hope it is good, and am sure it is. Takes one of my projects off the table if so.

[DarrylC]

The HP scanner does appear to have "air load" , seems to line up with your spread sheet.

People do use Air Load as an indicator of Load, have logged the values and they are close but different. Load is from the SD tables whereas Air Load can be calculated from the MAP and temp. Paul Yaw's article actually uses Air Load to get to VE.

[DarrylC]

Gonna read this when I come back from vacation. I hope it is good, and am sure it is. Takes one of my projects off the table if so.

Eric, your feedback would be greatly appreciated Have a great vacation.

[DarrylC]

Very good write up daz

The basics REALLY need to be understood FIRST as many will find this helpful but for reasons they cant really understand, many "think" they know how an internal combustion engine works but when they start digging realise they actually do not

Many books/internet forums can help people understand what VE is first .....and why and no its not a commodore lol

Jet, thanks. I particularly liked "and why and no its not a commodore". I think that while the Ford system is more complex than the GM VE system it may be a better system and did not seem to need a complete rewrite in order to add extra diagnostics for OBD and emissions. The outcry over the virtual VE table and how tuners have worked out how to put it back to the old system worried me.

[hiddeous]

Awesome Effort Darryl.

[JETURBO]

Very correct "LOAD" is extremely similar and can help beginners for sure

Daz i think people expect to think its all the same and freak out when its changed, then the smart reverse engineer to see what they want it to be, and at the end of the day we really cant advance past physics base

[45T-XR]

Well done Darryl, Great write up mate. Clarified a few things for myself also. Eric...doesn't forum posting classify as work? If so get off the computer, enjoy your holiday so you are all fresh to bash out the Ford scanner when you return

[bugsy]

Awesome write up Darryl,
It cleared up a few things for me.

[hiddeous]

Darryl,
I'm very keen to build and excel workbook that would allow a tuner to enter a Lambda Error for a particular RPM/CAM ANGLE and have the sheet provide the correction required to the AIR MASS Table. At first glance it looks like we would need to enter the follow
Desired Lambda
Actual Lambda
RPM
CAM Angle
IAT
LOAD (Calculated)

I'm keen to hear your thoughts and for any input into how to structure the calculations

[DarrylC]

Darryl,
I'm very keen to build and excel workbook that would allow a tuner to enter a Lambda Error for a particular RPM/CAM ANGLE and have the sheet provide the correction required to the AIR MASS Table. At first glance it looks like we would need to enter the follow
Desired Lambda
Actual Lambda
RPM
CAM Angle
IAT
LOAD (Calculated)

I'm keen to hear your thoughts and for any input into how to structure the calculations

hiddeous,
I was just reading about your excellent spreadsheet for tackling the ZF shift points

For full throttle runs I have found that you can basically ignore most of the stuff and just multiply the "MAP per Airmass" table by the (desired lambda)/(actual lambda). I know it may sound a bit crude but effectively you put in all the corrections to get the new AirMass, correct it and take out all the corrections. So you just need to RPM, Desired Lambda,actual lambda and cam angle (which you can derive for the BA as the load will be about 1).

For low throttle work then that is a different game as I believe you need to collect a a fair bit of data to work out the new tables (with SCT you can log cam angle, and the two table values but not with HP tuners just yet). I will PM you with contact details. I know we are not SCT but I would love to see the "Jerry" speed density spreadsheet that toads referred to.

Very good project and I have a lot of scripts I used to do this stuff so I can provide details of what I did. They even started to work after Eric found the table that worked on my tune (the high res tables)

Darryl.

[Eric@HPTuners]

I just read the PDFs, and I would like thank you again for doing this. Excellent job.

Engine Displacement is the dry air mass to displace the volume of one cylinder. Ford uses to different conditions, depending if the car is N/A or Boosted. The N/A cars use 60°F and 29.95 inHG BP, the Boosted cars use 100°F and 29.95 inHG BP.

[DarrylC]

Everyone,
Thanks for the great feedback I really appreciate it I am thinking of doing a few more of these on:

1. Speed Density corrections
2. Injector pulse width, duty cycle and horsepower
3. Tables - breakpoints, interpolation and boundary conditions

My motivation two fold. First, to explain the tables and allow tuners of differing skills levels to make alterations with confidence. Second, when you start there seems to be a huge lack of information on Fords (but not the GM side). I suspect this is something to do with the culture and may stem from the SCT side (pure speculation).

I am not a tuner and my background is Computer Science, Maths and Physics so that is how I am approaching tuning. I have written a small simulator so that I can work out the affects of changing the LPG injector parameters (calibrator size and pressure) in order to get a good match for a petrol injector.

I don't think it is possible to do (1) yet as I have not been able to get the logged values (SCT LiveLink) to align up with the tables supplied by HP tuners (something/tables missing?). This could just be my lack of understanding but you can get really close by using the tables without corrections

Desperately waiting for the new Scanner. I hope it is as good as SCT LiveLink.

[turbotrana]

Does anyone know how accelerator pump enrichment is done. Does SCT have anything that does it. I would like to enrichen fuel on Tip In (if that makes sense) Basically when you jab the accelerator from idle. I notice that with the way I have tuned my injectors it jumps to 17+:1 FOR A MOMENt on sudden take off and that there can be a slight hesitation. However it could easily be rectified if there was an accelerator pump table.