SIXSTRINGHAMER

I notice there is very little, if any discussion on tuning the MA1 engines here and I'm thirsty for knowledge. Im not lookoing to do my own tuning or anything but more so to understand these motors better and be able to identify an issue with my tune as seasons or octane changes. Perhaps we could establish a "baseline" of targets and safe ranges for various channels (AFR, IGN advance, Timing pull, Corrections) in our datalogs that indicate a happy engine and tune. With other platforms there was always a "range" or "threshold" that folks much smarter than me established as safe for the datalog channels listed above.

So I'm asking for logs and general info for the greater good of the 981 community. Input from those professional's who are RL members would be agreat bonus.
For example:
"inevitably when IAT's (intake air temp) rises above X the ECU will begin to pull timing to prevent knock or predetonation"
"AFR | Lambda in the 12.0-12.9 range is ideal for a street tune on 93 pump gas under full load WOT (wide open throttle)",
"timing corrections of less than 1 degree on non adjacent cylinders is considered accetable during WOT and not something to worry about as the stock ECU pulls timing during regular street driving all the time",
THESE ARE EXAPMPLES FROM ME AND WERE THE TYPES OF GUIDANCE I RECEIVED ON OTHER PLATFORMS IN THE PAST, IM NOT A TUNER. THESE COULD BE GOOD RULES OF THUMB OR A DANGEROUS ASSUMPTION ON MY PART? THATS WHY IM ASKING) Perhaps a "Guidance on how to read your logs" post form a reptuable tuner would be best.

I would appreciate it if anyone could share datalogs, details of the car | mods, ambient temp when data logged, and fuel used for the comunnity to digest. Maybe, just maybe, we could even entice some of the protuners to eloborate on these engines and their thoughts on what constitutes a good log | happy motor.

Hope we can get a dialog going and I will upload some of my COBB OTS logs in the coming days for a 981 CS with headers on 93 octane.

absoluteczech

I would assume that's because there's very little to extract from the engine with tuning.

SIXSTRINGHAMER

Absolutley, there is little gian to be had, but most tune these cars anyway right?? I certianly did and enjoy the change!

To me, if the car is tuned and Im going to push it hard during both cold and hot seasons, its beneficial to know what a happy motor looks like in my logs, and to log often. Further more I need to understand what to look for and identify as being out of line vs a clean log. Thats all Im going for here and hopefully discussion that will help others understand these engines better.

okie981

If you already have a GTS, that is a more accurate statement. For a non-GTS 981 3.4L, there are noticeable gains to be had with tuning, and overall improved power delivery with some of the dips in torque through the RPM range being smoothed out.

jscott82

I'm not familier with the data logger you are using, but does it let you see the full map? Does it show all of ECU parameters to understand what part of it is being referenced?

Again not families with the Cobb stuff, but I've never heard of anything that captures the full detail of a 3D (or is it 4D or 5D now?) ECU map that is availibe e outside of the tuning shop.

Without understanding the full map and all the parameters at play, I'm not sure that capturing a few pieces of info without full context does you much good

okie981

I've seen John Tecce (BGB) make some posts here on RL stating things about intake air temperature being critical on the 981 cars. Seems like I recall reading that at any IAT above 75 degrees, the ECU is susceptible to pulling timing. The location of the air intakes aft of the doors is also breathing in some of the air that just exited the radiators and front wheel well. This is why on John's Cayman race car this year in IMSA he introduced a revised air intake location up higher on the side of the car and also routes air to the throttle body in such a way it picks up less heat soak from the engine bay.

Forgot to mention, my BGB Pro Tune had a WOT AFR target of 12.79 if I recall correctly. That was due to the hot weather I typically saw in South Texas (COTA, etc.). For cooler climates, I believe the baseline target AFR for John's Pro Tune is 13.0, but don't quote me on that.

absoluteczech

I respectfully disagree that you wont notice or feel 10-15hp

okie981

I respectfully reply that you will notice it on the three long straightaways at COTA when instead of the 981 GTS pulling away from you you will stay even with them or pull away from them. Ask me how I know.

absoluteczech

well for one a base w/ a tune is nowhere near going to stay even with an S or GTS , perhaps an S w/ tune might be even to a stock GTS. but i suppose if youre WOT on a race track then sure. However not everyone lives at the track and for those that don't I'd say spend that $1000 on better tires or something else before getting a tune which is negligible difference on these cars

okie981

If you will read my post above in this thread, post #4, you will see I was referring to a 3.4L non-GTS getting a tune, not a base model. Who was talking about a base model? And I’m giving you real world results with an S having a tune not giving an armchair analysis “perhaps” as you stated in your reply. A 981 S with a tune can not only be even with a stock GTS on a WOT pull, it can have more power, albeit only a small amount. I’ve seen it through my windshield and through my rear view mirror in my car on track on many occasions. Everyone spends their $$ how they want. A tune can also give you a smoother power delivery that around town can make many people believe that’s more important than tires or whatever. To each their own.