Carpokes Porsche Forum

I have the Focus 9 DME and OBD+ software as well as other modifications and I have noticed that my car's seat of the pants power level and responsiveness does not feel like it should. So, I have been checking many things associated with electronics, etc. that could lead to this "feeling", such as my MSD 6A digital ignition, Blaster 2 coil, new cap and rotor, new MSD 8.5mm spark plugs, new speed and reference sensors last May. I also have the Rogue A-Tune. Which has now led me to trying to understand ignition advance and timing.

I read an old post on the other forum about advanced timing via chips and tuning and his timing value at 2500 rpm was in the 40s. After reviewing my recent data log, my ignition advance is much lower. I attached a pdf with some sample values from a recent drive.

So my questions are, are my values out of spec? What would cause them to not be where they should be (timing belts,etc.)?

Thanks in advance!

Hi Spencer (I think that is your name based on past experience),

The big problem is the data presented in the attached PDF is erratic----the most consistent inconsistency is in the AFM readings. There are some huge outliers there! You should try another AFM to see if things change. I can send the original AFM from my 951 for the cost of shipping if that helps, it is sitting under my desk at my shop.

Ah, I see. I literally just sorted the data by ignition advance and then copy and pasted the different readings based on Advance and RPM. I am really new to this and trying to understand what exactly I’m looking at. I’ll repost it based on the actual time/chronological order.

Thanks,

Spencer

Here is log of it during initial start up/idling; a short log.

Here's the log that I initially pulled the data from. It's MUCH longer and it covers idling, driving and some high psi pulls.

Hi Spencer,

Is there any way you could convert the spreadsheet data into a graph? That would be much more usable.

Also, post your timing table here if you can. It is difficult to compare the timing tables of two different engines without knowing individual details, fuel type, etc, but I assume your engine is stock internally. Some of the chips from the late 1980s and early 1990s were too aggressive with the timing maps, which is a death sentence for a turbocharged engine, especially one limited to CA-spec 91-octane gasoline.

The best method of tuning ignition timing is dyno testing using a load-bearing dyno and portable knock detection equipment, but that is not possible or practical for everyone.

Two schools of thought on low RPM timing for turbos - more timing equals faster initial response but retarded timing creates more heat in the exhaust to get the turbo spooling better. getting the balance right is very turbo dependent and also application dependent. (street vs track, drivability vs ultimate power)

I’m using the Rogue A-Tune chip as far as which map I’m using. My turbo is the Evergreen Hybrid K27/8.

I’m still trying to figure out if I can record the data as a graph….

CDA951: I'm looking at converting the spreadsheet into a chart/graph using Google sheets. Which columns should I use/compare? Also, after taking a look at the complete log, do you still think that my AFM is faulty?

Also, here's the link to the Rogue Tuning Map: https://www.roguetuning.com/multi-dimensional_mapping

Thanks again

Hey Spencer, I think cda951 was thrown off by your data sorted out of order like that. That first chart makes it look like the AFM signal is jumping all over the place, but that's because you sorted the data and presented it out of chronological order. I peeked at the very long pdf and admit it was too long to review fully in any meaningful way, but the few pages I looked at showed AFM data moving up and down as expected. I doubt your AFM is bad, or if it is, it's just a coincidence. cda951 can correct me if he saw something I missed. If still suspect your AFM, we have a good/easy test DIY here:

viewtopic.php?t=561

For a sense of low power, unless you modified the A-tune maps, I would not think ignition timing is the culprit. Does the motor run smooth and normally, just less power than you'd expect, or is is it sputtering/missing, etc.?