Discussion and questions related to the course Reflashing
Hi HPA members,
Our project is to tune GT86, with ecutek (proECU) to produce 10-15 whp more with better torque curve.
We buy ecutek GT86/BRZ tuning suite, i read all instructions about proECU, i watch course "practical reflash Tuning" and i feel ready to do this tune. My main problem is the access to dyno, is far from us and when i go, i will not have a lot of time to make lot of runs, so i must to prepare very good my tuning steps.
Step One: MAF rescaling (I will follow Andre's instructions)
Step Two: Fuel Map (mode 1)
I edit the fuel map with theory information about AFR.
At Low load with low RPM set 14.7:1 stoichiometric value.
At Low load with high RPM set 14.1:1 (a little bit richer than stoichiometric , my choice)
At High load with low RPM set 13.3:1 (13.3:1 because is Lean Best Torque, info from books)
At High load with High RPM set 12.2:1 (12.2:1 because is Safe Best Power at Wide Open Throttle, info from books)
From test run, i saw the maximum MAF sensor value [email protected] = 139g/s = 1.127s/rev.
I decide to have 12.2:1 minimum AFR for two reason, first is rich enough to keep exhaust gas temperature in limit and second the stock O2 sensor reads minimum 12.17:1. You can see the map. I use interpolated fill selection function to complete the table.
In this point i make a run with dyno to see the results. If i have good result, i will continue with ignition table.
First i increase Ignition multiplier from 0.5 to 1.0 then make a dyno run with Live Data Log. If "ignition correction value" parameter don't drop minus, i will continue to increase 2 degree the ignition base map from 0.8 g/rev and above. All those are theoretically so i need Andre's opinion and advice about my steps.
Your approach is sensible. From my own experience with various FA20 engines in N/A form I haven't seen any reason to run as rich as 12.2:1. I also find that the factory wideband isn't 100% accurate down at these sort of air fuel ratios so I always use a professional wideband for my open loop tuning.
For tuning it's a good idea to set the IAM to a starting value of 1.0 and then once tuning is complete I'd recommend lowering this to 0.7 to allow the closed loop knock system to work as intended. Yes you can advance the timing in the full load areas provided no knock is being logged. I still use audio knock detection to confirm the logged knock events.
This is the first dyno run. The result is +6.5whp. My goal is +10whp. I believe the solution is CAM timing. You can see the changes in bin & log file files.
From dyno graph, between 3250 and 4500 rpm, i see torque drops. i found in CAM maps the same drop so i will increase the intake cam timing and exhaust by 12 degree total. First, Andre, please confirm that, FA20 has mechanical stops in CAMs for protection? I want your opinion about max ignition timing at high rpm too.
I need 3.5 whp to complete my NA1 stage. Thanks
Firstly with an N/A FA20 engine you will not be able to eliminate the torque drop off. You can reduce it but it is a fundamental aspect of the engine design and short of forced induction it can't be totally eliminated. I know that the cam timing maps drop off in that area but holding a consistent cam timing doesn't fix the torque hole. By all means test this for yourself though. The FA20 engine does have mechanical cam timing stops so there is no danger of valve to piston contact.
The amount of timing the engine will take is dependent on your fuel quality and the level of other modifications so quoting what works on our local fuel may be misleading. You need to base your decision on the dyno results along with knock feedback in your logs. I will have a look at your logs tomorrow when I have access to my tuning laptop.
Andre, could you sent me an example from your NA gt86 stage 1 ecutek? The dyno is 300Km far from me, so i must to prepare a setup very close to ideal.
I will have only 2hr on dyno. 25 November is dead end date. I really appreciate any help from you about 3.5 extra whp.
Here is an example ROM from an N/A car with headers, exhaust and intake running on our local 98 octane fuel. Use at your own risk.
Thanks you very much Andre. I will follow your instructions from lessons, step by step.
Good luck and let us know how you get on. Keep in mind that these engines are pretty close to optimal in stock form and getting worthwhile gains is challenging and time consuming.
I have problem with one of three GT86. 2012 model with HKS air filter. I tried to did the same tuning with 2015 model with K&N filter which gain +7WHP, but when i increase 4 degree base ignition advance gained only 2WHP (2015 gain 4WHP) an finally when i tried to give 6 degree intake cam timinig, the AFR drop to 10.5:1 !!! Looks like save mode.. Andre do you have any event like that?
Attached file show GT86 2013 Dyno graph, with K&N air filter, exhaust and second cat removed.
There are quite likely to be small differences in power between different filters so your results aren't necessarily surprising. You can also see differences in power and torque based on the ROM ID used in the base car. Basically every engine is slightly different and what we see on one example doesn't necessarily transfer to another one exactly. Just adding timing to the base advance table isn't necessarily telling you the full story. You'd also need to check the actual final delivered timing. Aspects such as the IAM and the knock feedback can affect the final timing and hence the power and torque.
I've never come across the issue you're seeing with the cam timing. I'll assume you're targeting a cam advance that you can actually achieve? If you try and target a cam angle that mechanically the engine can't achieve this could result in a fault code but you should also be able to see/read that code.