I was out tuning for a while today and got some weird results from the sharkplotter.

One cell, 1700 RPMs and load value of 60 had an AFR of 15.1. The map targets a 14.7 AFR. So adjusting that cell should've resulted in a positive number. Instead, when I updated the map, it suggested reducing the fuel in that particular cell.

There were several lean cells, and in each case, the recommended adjustment was less fuel, not more.

Not sure what I am doing wrong or what might be causing the problem? Thoughts?

 

Brian, Sounds odd all right-- but hard to say without seeing the log files, and the LH map. Can you send them via email? (support at siriuscyber dot net). I'll dig into it and post back here.

Thanks, Jim

 

Hi Jim,

My battery was dying on the laptop so I shut everything down in a hurry and just threw out the files that were producing the odd results. I'll do some more logging over the weekend and see if I can get it to reappear. Thanks for the offer to review.

Here's my quck and dirty procedure. I know I'm not using all the functionality, but maybe I'm skipping something:

Load the log files into the SP
Copy and paste the LH map from the ST to the SP
Run the adjustment function
Check the adjustment amount and look at the updated cells,
copy the updated map from the SP and paste over/replace the ST map

 

Mystery solved.

Oh, so you mean you actually have to SAVE THE LOG FILES from the sharktuner before loading them into the sharkplotter?? Duh. What a maroon I am.

So I was reloading the same logs and, consequently, adjusting the maps leaner and leaner. No wonder it didn't look like I was improving anything.

In case anyone wonders, you only have to do this a couple times before (1) your AFRs go above 14.7 and (2) you start running out of adjustment room past -127.

 

It's always the details that get you!!

An "autosave" option is pretty high on my wishlist for Niklas to add to the ST software, along with remembering data-log settings.

 

I also am very puzzled by acceleration enrichment--how much of a change is needed to activate it, and how long it lasts. The ST manual is fuzzy in the description.

It would probably be neat to be able to log when acceleration enrichment is triggered, and when it decays away, so we could see the effects of making changes...

 

I'll add...

on the data log screen it would be nice when you scroll down the rows, the titles of the columns would be fixed at the top.

AS for the Sharkplotter, my ST-2 is in the mail..and Im ready for the next level of tuning with the Sharkplotter!

 

I'll raise you:

Once you decide to log, it would be nice if it would log in the background while you could switch back to the fuel maps or other tabs. I can definitely find/feel lean cells using the throttle and tach, and it would be nice to see in real time which cells those were while logging. They become revealed during the SP session, but it would be nice to follow along in real time while logging.

 

Since we are talking about improvements, how about to add a parameter to the fuel parameters dialog to manually turn on/off the enhanced pulse width? The reason for this is that someone could be running a different fuel pressure, which would mean that the injector size would be off since for S4 it is expecting an S4 regulator. The way it is currently set I believe is that any setting above 31.9lb turns on enhanced pulse width at idle/low loads.

Dan
'91 928GT S/C 475hp/460lb.ft

 

John is going to kill me for mentioning my "wishlist"

I agree, the ability to access the other ST pages while logging would be terrific but I think it would be a pretty big change to how ST works. What might be more practical would be to update the log file in real-time so that SP can "paint" its plot as your drive. But the reality is that development work for a specialized low-volume product is always difficult. Personally, I feel lucky to have what we have, thank you John and Niklas!

 

Dan,

OK, you got me-- what's "enhanced pulse width"? Do you mean the double-pulse-width-ever-second-revolution that happens above 5000 RPM? Or something different?

 

Hi Dan
The reason for this automatic parameter is to prevent the pulse width at idle/low loads becoming too short for reliable operation i.e when the injector opening time is too close to the programmed injector pulse width.

The changeover point assumes that poundage injector running at its rated fuel pressure. If you lower the fuel pressure the atomisation of fuel suffers, raising fuel pressure will force Tinj lower but in the "enhanced mode" the system will cope with that.

As there is no diadvantge of enhanced mode that we are aware of, what is the problem you wish to address ?

 

The acceleration enrichment is too complicated for a simple explanation. It is a very dynamic operator.

Enrichment depends on rate of throttle opening and it also detects how long since the last enrichment and changes the characteristics of the next required enrichment accordingly.

Try making some data logs at fastest logging speed to give you clues as to what is going on. Cruise along, then stamp on the throttle and check out the resulting datalog.

Repeat at various rpm and starting throttle openings.

Clearly this is an entirely different method to making the datalogs required when using the Sharkplotter :-)

 

Congratulations, Tony ! Archive your ST1 bin files as when you load them into ST2 the format is changed slightly and they are no backward compatable after that point.

I agree with your comment column headers..... will pass onto Niklas.

 

The K dataline is running at full capacity when datalogging so that option is not possible......