UDC Timing Calculator

AH64ID

AH64ID

New member
Here is a timing calculator I created for use with Smarty's UDC.

The file is not designed by, nor endorsed, by MADS. It's use is purely at your own risk. I assume no responsibility for its use.

Okay, onto the file. I built this over the last 6-8 months and have refined it, and checked it's accuracy enough to share. I have had several people test it and all appears good.

This is a good tool for tuning, and may not be the final answer for your tune, but is certainly a good start. It's data is only good as the data you feed it, so be accurate.

Please let me know if you have any issues with it. I tried to include some instructions to help out.

Enjoy!!
 

Attachments

  • UDC Timing Calculator v1.3.zip
    219 KB · Views: 0
A tremendous amount of work must have went into this. Thanks for sharing such a useful tool.


AH64ID said:
Here is a timing calculator I created for use with Smarty's UDC.

The file is not designed by, nor endorsed, by MADS. It's use is purely at your own risk. I assume no responsibility for its use.

Okay, onto the file. I built this over the last 6-8 months and have refined it, and checked it's accuracy enough to share. I have had several people test it and all appears good.

This is a good tool for tuning, and may not be the final answer for your tune, but is certainly a good start. It's data is only good as the data you feed it, so be accurate.

Please let me know if you have any issues with it. I tried to include some instructions to help out.

Enjoy!!
Click to expand...
 
AH64ID said:
Here is a timing calculator I created for use with Smarty's UDC.

The file is not designed by, nor endorsed, by MADS. It's use is purely at your own risk. I assume no responsibility for its use.

Okay, onto the file. I built this over the last 6-8 months and have refined it, and checked it's accuracy enough to share. I have had several people test it and all appears good.

This is a good tool for tuning, and may not be the final answer for your tune, but is certainly a good start. It's data is only good as the data you feed it, so be accurate.

Please let me know if you have any issues with it. I tried to include some instructions to help out.

Enjoy!!
Click to expand...
What a nice job! I have saved this calc in my Smarty file, Thanks so much.
 
not that I doubt your handy work, but I would like to see Marco comment on this, and ask that he give it a try.
 
I haven't sent it to him directly, but BrianatSmarty has a copy and said he was going to fwd it up the chain.

I'm hoping it will reinforce our request for the copy/paste function.
 
AH64ID said:
I haven't sent it to him directly, but BrianatSmarty has a copy and said he was going to fwd it up the chain.

I'm hoping it will reinforce our request for the copy/paste function.
Click to expand...

And it was sent John. Now I will wait for comment and email it back to you. And I would like to also say thank you for taking the time to help members out and sharing your knowledge.
 
John
I was playing around with the calculator you created and thank you so much for sharing it. You have a tremendous amount of time in this I can see.

One question though, when I use the PSI to MPA converter then take the converted spreadsheet and copy it over to the pressure tab the PSI numbers are slightly off from what I input in the converter tab. I input 24240 PSi in the converter and when I take the converted MPA and put it in the pressure tab I get 24221 in the output table...

Have you seen this in your use of the spreadsheet?
 
I had to build it that way. The calculator needs whole MPa numbers, so it rounds the direct conversion. 24240 is 167.12 MPa, which rounds down to 167 MPa or 24221 PSI.

It would be advisable to copy the PSI table at the bottom of the Pressure sheet back into UDC to clean up any changes like that. The difference between 167 and 168 MPa is only 6us at WOT (stock duration table), so even if you don't change it nothing will be effected by a difference of .12 MPa.
 
Last edited:
lets say you have a good timing table, and you know where your pressure should be, if you input these two into the calculator is there a way to get the duration calculated? I only looked quickly at the work you did, in no way am I able to wrap my head around it yet.
 
ok thanks I figured it was something like that but wanted to make sure. Another question, How do you decide on what percentage of fuel you want BTDC and ATDC? I ran my timing map through and I have some numbers much higher than 50 in the upper reaches of the map. My timing is a smoothing of SW5 in TNTr which ran good in my truck before UDC
 
mikmaze said:
lets say you have a good timing table, and you know where your pressure should be, if you input these two into the calculator is there a way to get the duration calculated? I only looked quickly at the work you did, in no way am I able to wrap my head around it yet.
Click to expand...

I didn't put a duration calculator into the mix. It can be done, but that's a lot more work that I feel is necessary.

But how do you know the timing table is good if you aren't sure what duration it's setup for? Looks aren't everything.

Building a timing table off desired duration is much easier than going the other way. If it's too much fuel then add some duration where you need it, if the fuel split was good then don't change that, and the calculator will give you the timing needed for the same relative (BTDC:ATDC) timing.

RAB 38 said:
ok thanks I figured it was something like that but wanted to make sure. Another question, How do you decide on what percentage of fuel you want BTDC and ATDC? I ran my timing map through and I have some numbers much higher than 50 in the upper reaches of the map. My timing is a smoothing of SW5 in TNTr which ran good in my truck before UDC
Click to expand...

Trial and error, but you want to avoid as much combustion pressure as possible BTDC, the higher the rpms and fuel split the more likely you are to create too much pressure BTDC, especially with more than 52% BTDC at upper loads/rpms. This is the reason I say use caution without a dyno. Say you go from 52 to 55% BTDC and rwhp drops, then that's too much. With a dyno you may find 60 or more works, but without a dyno you are just asking for trouble.

Remember it's a tool for getting close, or a good starting point. It's probably not going to be the direct answer.
 
John can you give us a lesson on fuel split in the spool and cruising area's? For instance @ 200RPM in the 6.4/12.5 eng % area you have 190. What are you telling ECM to do? You want 90% of the fuel BTDC but stop at TDC? So you get higher engine combustion with less spool. The 03 stock first cell in the 400 rpm range is 215 according the Calc reverse. Why would you need that? The 05's are -170... This baffles me..So does this mean the 03's need a lot more compression to start? Thx
 
190% means that the injection starts at 190% of the commanded pulse width. So if it was a 1000us pulse it would start 1900us before TDC, and end 900us BTDC.

That's a no load cruise region and as you increase load you have to back the timing off, then when you get out of cruise you want some additional fuel ATDC to get the turbo spooling.

Also remember that the 03 piston design in much different and they don't like as much fuel BTDC as the 04.5-07's do.

The difference at idle is probably related to the quantity of the pilot injection, which I believe is smaller on an 03/04.
 
You must log in or register to reply here.
Back
Top