Ignition Advance/Timing Help

[Tom]

I went through the big logs and cannot find the 3:10 -- 3:12 data shown in the subsequent shorter log. Those entries in the shorter log are curious. The car goes way rich at 3:10 with nearly 17psi boost, then the AFR's recover as the RPMS climb, but you've lost all boost. Maybe still just a data jumble issue. If you want, do this: fully warm up the car and post of short log showing a full throttle run from idle to redline (at least 6k) in first and second gear. Post a log for just that 1st/2nd run as collected (no sorting or time-jumbling) so we can see all the data as the RPMs climb. Be sure to floor it (somewhere safe and legal of course). That will go a long way in helping to see what's going on.

[Spencan]

Tom,

Good to know about the AFM. I was not sure how to present the data since there is so much of it and I am definitely not sure of what I am looking at or what I am looking for at times; like which type of data goes with another in terms of cause and effect.

My car is smooth in terms of how it runs and drives. However, I have noticed that the responsiveness is not quite right at times. I first noticed it when I changed the speed and reference sensors last May. As you may recall, the connectors got burnt when I put the larger diameter down tube on my turbo without your modified shield (thanks again for that and the AOS!). Once replaced, my car fired up immediately and was nice and responsive to throttle inputs again. Then slowly, it started taking more than one crank to start some times. Months later I replaced the cap and rotor and the same thing happened over the next two to three times that I started the car. Then I replaced the battery and experienced the same thing. Most recently, I replaced my spark plug wires with MSD 8.5 super street wires because I have the MSD 6A digital box and MSD blaster 2 coil and I have experienced the same thing. So, it's been this pattern of changing/fixing some problems, experiencing both the instant startup and more responsiveness and then eventually going back to this generally less responsive state.

So now I am trying find out why.

[Tom]

Hmmm... odd. Are you saying the slow starting and low power go hand-in-hand?

If you have a chance to do logs the way I mentioned above, they would give us lots of diagnostic info.

p.s. the 6A box is great when it is working right, but failures are pretty common. I have one in my car, but the car started missing under boost and I traced it back to the 6A and MSD coil. I reverted to stock for now, and the missing is entirely gone.

[Spencan]

They kind of do go hand-in-hand...

I should be able to do a run as you described on Wednesday.

I have checked both of the MSD box and coil within the past 12 months, but if the log from Wednesday does not show anything then I will check them again.

Thanks for your help!

[danmartinic]

For a few years I felt the response was not up to par... tried a bunch of things incl. A-Tune chip... turned out to be a bad recirculation valve (aka "dump valve")

Be sure to check that

I also hear the 2 or 4 deg cam gear offset key is a good mod for better low-end response

[Spencan]

I have the newer APR1 valve that I got 2 years ago. It’s worth checking, so I’ll check that too.

I know that I need to replace my belts and all other associated hardware, the PO did them about 8 years ago (but less than 20k miles ago) and my plan was to do them June. So I looked at 928 Motorsport’s website but it looked like that offset key page was dead. Is there another source for them?

[danmartinic]

I am able to put one into the shopping cart (?)

https://928motorsports.com/product/4-degree-offset-key/

Not sure what other mods you have but a ball & spring type boost control placed in-line with the hose that feeds the stock control (off the banjo bolt behind air cleaner) noticeably improves response. Lindsay sells a version called 'Boost Enhancer'.. mine is just a cheap Amazon find but I found this to be perhaps the most dramatic improvement to "response".. more so than changing chip or increasing total boost

If you install the key, I'd be curious what you find

[SirLapsalot]

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!

The timing map you saw with 40deg advance, that must have been in the high vacuum area?

When I calibrated my 951 engine (all stock internals, intake, intercooler, downpipe, etc.) on a dynapack I found MBT at 2500rpm to be ~20deg at 140kpa (WOT), and ~ 25deg at 60kpa (part throttle). If you extrapolate that out to the high vacuum area that's still only ~30deg...

Methodically tuning an engine to MBT takes a decent amount of time and effort. Dyno time is expensive and there are a lot of unqualified and/or lazy "tuners" out there. If you take the time to hold conditions as constant as possible and perform steady state calibration on a dyno capable of accurately displaying torque, you can find where MBT actually is quite well. As I said, in my case that was ~20deg at WOT. Meaning I could keep adding all the advance I want past that value, but no torque increase would result. In fact, I bet at 40deg torque would have started decreasing...

[Spencan]

Dan: Thanks for the link! I do have an electronic boost control, the Go Fast Bits III https://gofastbits.com/product/3005-g-f ... ontroller/, which I really like. I have had for over a year now and I really like the ease of use and functionality. I'll post a picture of it installed later. Of course, I paid $300 for it back then...

As far as mods go, I have a good amount of bolt-ons. My first 951 that I bought in 2007 was totaled in an engine fire in 2020. I used the money to find a near identical completely stock 1989 Glacier Metallic 951 from the east coast; the only difference was the interior color. So I used my knowledge over the years of what worked and what didn't for this car: custom Bell intercooler that fits in the stock location, APR R1 Diverter valve, Evergreen Raptor stage II k27/8 turbo, 3" exhaust from the turbo back, PLX WBO2, Reconditioned and flow matched stock injectors, MSD 6A digital/Blaster 2 Coil/MSD 8.5mm spark plug wires, F9 Tech DME and OBD+, Oil catch can. The fuel lines were done by the previous owner within the last 5 years. The suspension and brakes have also been updated and upgraded where needed.

[Spencan]

Sirlapsalot: Thanks for the information on timing. There was no timing map, just a mention of the values that the person was seeing while doing his tuning. The only map that I have seen was the one on the Rogue website after I initially started this thread.

The more that I read/watch videos on timing, the more that I realize that I am not ready to do any tuning. But I am trying to understand what I am looking at when I look at my data logs to see if there is something there telling me why my car does not feel the way I think it should at this point.

I am going to record a run today the way that Tom described and I'll post it. Hopefully that will shed some more light on if there is something or I am just being too optimistic with my expectations.