RomRaider

Recently new to RomRaider but have everything setup and good but where I am trying to figure out something and I'm not sure if its a limitation of RomRaider or something I'm missing, is change values by a percent.

I am working through this for a 2002 WRX Base map

As an example in the Tuning Guide by Bad Noodle it says in the "Timing Table" decrease by 4% for WOT values.

What I am finding is that "coarse increment" is only allowed a .2 value minimum and the "fine adjustment" also only allows a minimum of .2 values.

So for example if I have a value of 21.84 in a cell and I want to reduce it by 4% that would put my new value 20.9664 and if we change that to a 2 decimal place number that would put us at 20.97.

Now if I change that cell from 21.84 to 20.97 the value ends up being 21.13 which is a -3.2% change.

If I manually adjust the value using ctrl+down arrow the values I get are -1.6, -3.2 and -4.8.

So I'm not able to actually set it to 4% but instead only -3.2 or -4.8 so is it actually possible to do whole numbers? Or is RomRaider limited to decimai placements like this because of the formulas in use?

I'm sure in the real world for a rom there isn't much of a difference between -4 and -4.8 but was something I was noticing.

To change by percent:
add 10%, multiply by 1.1
reduce by 10%, multiply by .9

Not all tables are based on float data type values. Some are byte, some are word. When converting the human readable 21.84 to the underlying data type of the table it may be rounded by that data type and convert to a value not exactly the percent you changed it by.

Check the table properties for the data type and conversion formula.

Hmm I'm not sure if I'm grasping this program right for example.

Working in Base Timing table and value is 10.94

In the Absolute Value box I enter 0.9 and hit the "Mul" button which you say should reduce the value by 10% but it drops it to 7.84 which is 33%.

So I'm going to assume based off the data you said and formulas in place that either I don't understand as well as I did or that you can't apply the same principles of adding/subtracting values from tables.

** EDIT **

After a bit of digging around I think I have figured out how things work but values still don't make sense to me.

The value that is displayed in a cell can be considered 100%.

So if you have a value of 10.94 and I wan't to subtract 10% that means:

In the box I put .9 (100-10 = 90) and I should have a reduction in value by 1.094 and if I subtract 10.94 from 1.04 my new value for that cell should be 9.846 but instead I get 7.84

This is why I'm getting confused.

1 * 1.1 = 1.1
1 / 1.1 = 0.909090~

10.94 / 1.1 = 9.454545~
10.94 * 0.9090909~ = 9.454545~

0.9 times whatever is not a reduction of ten percent.

1 / 0.9 = 1.111111~

0.9 times something is a reduction of 11.11 (eleven repeating) percent

10.94 / 1.111111 = 9.846

try looking at the cell value as it's raw format and use the multiplier function then.

So I still don't quite get all this because well math is not a strong suit of mine but I try to figure it out.

Switching the values to Raw allows this all to make more sense because in Raw format the 10.94 equals 88 and if MUL 0.9 from the 88 number I get 79.2 which isn't exactly 10% but its a lot closer than using the default rules. And even when I go into compare mode I can now see the -10% value in the cell.

Then by switching between the Default and Raw values I had a better understanding of the formula in place.

So this is definitely confusing because in Default view it shows a change of -28.3 but in Raw view it shows the change of -10%

So I guess this leaves the questions.. Is it better to work in Default or Raw mode?
Is Default mode a Human Readable format? And Raw what the ECU says?

My concern is that if I work in Default mode and apply the 10% but it shows the -28.3 change compared to the Raw of -10% am I making a -28% change or -10% change.

sometimes you just have to do the math in a calculator and manually enter the value you want

sometimes the scale of how RAW is interpreted into a 'standard unit type' is absolute and not relative, but the standard unit type is relative, so when you multiply against the absolute sort of based value, you get a different change than how it should look.

So in other words.. stick to Default, use a calculator and work from 1 cell to another

or learn to use excel

copy from RR, paste the table contents (from the value type you want) into excel

put the factor change number you want in an unused cell

copy that cell

select a rectangular portion of cells you want to adjust

paste special, mutliply (or divide, depends on how you calculated your factor)

then select a the whole table including the table identifer and probably offset axis

paste into romraider

Yeah was about to look into doing that as well

** EDIT **

So using a spreadsheet is definitely easier, but its still interesting because of the formulas how things round up or down.

In a spread 4% of 10.94 is 10.50 but in the table it comes out as a 3.2% change.

Even though there is this variance it makes me feel a lot more at ease.

Assuming the conversion between the table's data storage type (a byte value) and the display value in RomRaider is (x*.3515625)-20, see the Table Properties for these details.

Your 10.94 in raw format is 88
The smallest change that the table can accommodate is +/- 1 of the raw value, i.e.: 87 or 89
Which equates to 10.59 or 11.29. Therefore the smallest change you can make is 3.21% of the display value.

Since 3.21% does not divide evenly into 10%, you will never get an exact 10% reduction or increase to the original value. That's why is a close approximation that works in most cases.

When I do that, 10.94 changes to 9.88 (9.6%).


What is the formula in the Table properties for this table?

Appreciate all the feedback on this.. And wasn't aware a local Canadian was a developer

Expression: (x*.3515625)-20
Byte: (x+20)/.3515625

Screenshots posted for before and after results.

because you're multiplying 0.9 against the RAW value

RAW value is 0 @ -20 BTDC on your timing table

so 30.94 * 0.9 = 27.846, minus 20 offset, 7.846 degrees BTDC

dschultz check your RAW value at lowest timing possible in the table, in his case, it's 0 and -20 respectively.

Interesting and makes sense.

So the 0.9 is being applied to the raw value not the absolute value.

So is there a way to actually do a 10% reduction with the tools in Romraider? Or is it better to work from an excel sheet and update the values that way?

Agreed...

The RAW value is the absolute value since that is the only value the ECU understands. The values you seen in the Default view are the human readable values. The formula converts them.

Here, I did 90% of the displayed value (notice other 10.94s unchanged around it). Seems to works for me ...

As I explained, you can't get an exact 10% reduction due to the underlying byte data type.
If you wish a specific value you can enter that and press the Set button. But it to will be converted to the closest RAW value when the ROM is saved.

So you must have something changed or done differently somewhere.

I grabbed that base map and did the same thing and still get a 7.84 value.

I assume your using the latest romraider and defs? Care to share your map?