some datalogging data of mine

[DarkDevilMMM]

here's my logging data from 3rd and 4th gear pull, please advice:

RPM TPS INJP INJD KNCK TIMA O2-R
2875 32 6.65 15.6 0 31 0.11
2906 42.1 7.42 17.9 0 28 0.78
2968 46.4 8.7 21 0 26 0.82
3031 65.2 10.49 25.7 0 25 0.85
3125 82.4 12.79 32.8 0 22 0.87
3218 90.2 14.84 39.8 0 18 0.87
3343 93.7 16.89 46.8 0 16 0.87
3406 94.1 18.43 52.3 0 14 0.87
3625 94.5 19.71 59.3 7 14 0.87
3687 82.4 19.71 60.1 6 11 0.87
3843 82.0 19.71 62.5 6 12 0.87
3968 81.6 19.45 64.0 5 13 0.87
4187 81.6 18.68 64.8 5 13 0.87
4281 81.2 18.17 64.8 4 13 0.87
4343 46.8 17.66 63.2 4 15 0.87

fast forward to 4th gear

3375 99.2 15.87 44.5 0 18 0.87
3500 99.2 17.66 51.5 0 15 0.87
3500 98.8 18.94 54.6 3 14 0.87
3531 98.8 19.71 57.8 11 13 0.87
3687 98.8 19.71 60.1 12 10 0.87
3812 98.8 18.68 59.3 11 11 0.87
3937 98.8 20.22 66.4 10 10 0.87
4125 98.8 19.96 68.7 9 10 0.87
4156 23.4 3.32 10.9 8 12 0.87

something like that, my FTRL:110, FTRM:100.7, FTRH:96.4 Boost:15PSI
List of equip : EvoIII exhaust mani/16G/O2, 3" turbo back, stock inj/MAF, walbro255, AVC, AFC, and last, 1 stupid driver

thanks

 

Base timing too high.

Caveat: Add fuel starting in 2% increments just before the rpm you knock on the afc. If knock doesn't go away then see top.

 

[DarkDevilMMM]

thanks, but now this is where I got confused, I thought I am having knock because I have too much fuel, since the high fuel trim is at 95, that's why on my AFC I have -4 for 3600 rpm and above, I used to zero everything out and my high fuel trim is at 91, so should I increase the "Lo" side or the "Hi" side on the AFC?

 

From now on remeber and say with me "Knock and fuel trims are not related"

To tune fuel trims use the LOW settings
To tune knock use the high settings

Now go tune and report back. Knock should go bye bye.

 

Your awesome pivvay.

 

Quote:
Your awesome pivvay.



Thanks, I try.

 

Quote:
Quote:
Your awesome pivvay.



Thanks, I try.



Hercaleese!

 

[DarkDevilMMM]

ok, here's the report, I fixed the fuel trim to 110 100.7 100.7, very cool, but the knock still here, AFC throttle point set at 30% 60% and -7(lo) and +4(hi) for 4000rpm, the knock will go away if I lowered the boost to around 13 PSI, so 2 more PSI give me around 10 knock at around 4000rpm, it's also worse in 5th gear, I will get arond 13 knock, in 4th gear I will get around 9. another problem I ran into is I overrun the stock MAS and maxed out my injectors at 5000rpm, oh well I guess I will just tuned down my boost to 13 PSI then, but again, learned something new today, thanks!

 

Just add fuel in 2-3% increments where you see knock. First get rid of knock, then try to maximize timing without knock...your timing curve should be smooth and trail off very gradually in the upper rpm's. You should still be able to see 20 degrees advance on pump gas in the high rpms on a good tune. Get rid of your knock and tune for good advance and your car will feel MUCH stronger.

 

If you are overrunning then hack the maf until you get something better. You will have to retune a bit but it should work okay. Also where is you IDC over 100%? If it is just at the very top end, keep adding fuel on the afc like you would to tune normally and you should be okay until you get bigger injectors.

Keep at the tuning thing 2% at a time. It will take a number of pulls but you should be able to get knock to go away at 16psi on pump. If you can't despite getting pretty rich, the go back and check base timing and lower it. It should be 5deg although sometimes even 2-3deg is better for more pump gas boost.