similar WOT AFR/Timing but different Acceleration?!!

[Toyota86.ir]

you can see two log files of my car:
Mod: EL Header + Front pipe + catback
fuel: pump gas

first log file is 3 hours after ecu flash :
http://datazap.me/u/toyota86ir/amir-...data=6-8-12-30


second log file is after 600 miles driving :
http://datazap.me/u/toyota86ir/amir-...data=6-8-12-30

in both log files all parameters like WOT timing WOT afr are similar (minor difference) but the car acceleration and feeling in the first run is far better than second run.

why acceleration is different when all parameters are similar?

[sw20kosh]

Butt dyno

[Toyota86.ir]

Originally Posted by sw20kosh

Butt dyno

No dyno

[KoolBRZ]

It is because of something your logs don't show. The throttle sensitivity. It starts off mushy and slow, but tightens up over time. The difference in throttle application gives a different acceleration profile.

[Toyota86.ir]

Originally Posted by KoolBRZ

It is because of something your logs don't show. The throttle sensitivity. It starts off mushy and slow, but tightens up over time. The difference in throttle application gives a different acceleration profile.

The First log is after ecu flash , the throttle is better than second run.
I know after ecu flash there is alittle mushy throttle .

In both log files iam is 1 and IAT is similar .
The only difference is the fuel and air pollution.
Fuel in both log files is crappy and there is little difference.

[DarkSunrise]

You might be surprised to learn your first pull was actually slower than your second. The butt dyno can be deceptive

If you look at your "time" variable, it takes 14.758 seconds to go from 2779-7231 RPM in the first log, and 13.322 seconds to go from 2786-7229 RPM in the second log. So your first run took about 1.3 seconds longer. Did you test in the exact same location?

There are also significant differences in ignition timing. For example, in the second run you hold ~25.5 degrees advance from 3000-3500 RPM, but in the first run, you don't even reach 25.5 degrees until 3400 RPM. In the second run, your ignition advance tapers off after 6400 RPM from 28.5 degrees to 25 degrees by 6700 RPM, but in the first run, your ignition advance roughly holds at 28.5 degrees up to redline. Etc., etc.

And then there are differences in AFR.

You can see some of the differences in ignition timing (pink) and AFR (green) in this comparison shot, but you really need to do a close detailed analysis to figure out what's going on:

[Toyota86.ir]

Originally Posted by DarkSunrise

You might be surprised to learn your first pull was actually slower than your second. The butt dyno can be deceptive

If you look at your "time" variable, it takes 14.758 seconds to go from 2779-7231 RPM in the first log, and 13.322 seconds to go from 2786-7229 RPM in the second log. So your first run took about 1.3 seconds longer. Did you test in the exact same location?

There are also significant differences in ignition timing. For example, in the second run you hold ~25.5 degrees advance from 3000-3500 RPM, but in the first run, you don't even reach 25.5 degrees until 3400 RPM. In the second run, your ignition advance tapers off after 6400 RPM from 28.5 degrees to 25 degrees by 6700 RPM, but in the first run, your ignition advance roughly holds at 28.5 degrees up to redline. Etc., etc.

And then there are differences in AFR.

You can see some of the differences in ignition timing (pink) and AFR (green) in this comparison shot, but you really need to do a close detailed analysis to figure out what's going on:

Thank you for deeper look at my logs.
the overall acceleration in second run is better not for better engine performance, because in second run i swapped FD to 4.88

the engine performance of first run is far better than second.

second test was in uphill road .
timing in second log drop to 25 after 6k rpm but afr in both is similar

[Toyota86.ir]

ignition timing comparison :
green is first run
red is second run

[KoolBRZ]

Originally Posted by Toyota86.ir

Thank you for deeper look at my logs.
the overall acceleration in second run is better not for better engine performance, because in second run i swapped FD to 4.88

the engine performance of first run is far better than second.

second test was in uphill road .
timing in second log drop to 25 after 6k rpm but afr in both is similar

I'm sure the loads between runs were different, since you're running a 4.88 FD now.

[Toyota86.ir]

Originally Posted by KoolBRZ

I'm sure the loads between runs were different, since you're running a 4.88 FD now.

first run : flat road , stock FD 4.1
second run: uphill road , FD 4.88

[Toyota86.ir]

AFR 2700rpm-7300rpm
green is first run
red is second run