Having tuning problems with 50 trim and 650 inj.need advice

[redgst95]

i have the rs49t 50trim with 650 inj walbro 255hp fp, buschur afpr,and a afc2. My problem is i have my afc leaned out -39% on the afc i put it on the logger and i cant get over 14deg timing for nothing no matter what the settings on the afc is no matter if i turn the boost down or up not even a new knock sensor helped. not only that i got 14deg timing and my 02's at the top of third was like .96 (rich) at WOT you can feel and hear a little pop from the exhaust so that has me thinking that im still rich i can not lean this afc out to much more than it is now plus get a higher timing advance what do i need to do to correct this problem!!?? anybody!

 

[92awddsm]

i have the rs49t 50trim with 650 inj walbro 255hp fp, buschur afpr,and a afc2. My problem is i have my afc leaned out -39% on the afc i put it on the logger and i cant get over 14deg timing for nothing no matter what the settings on the afc is no matter if i turn the boost down or up not even a new knock sensor helped. not only that i got 14deg timing and my 02's at the top of third was like .96 (rich) at WOT you can feel and hear a little pop from the exhaust so that has me thinking that im still rich i can not lean this afc out to much more than it is now plus get a higher timing advance what do i need to do to correct this problem!!?? anybody!

At only -39%, Im sure you are still a little rich. Try lowering the fuel pressure to around 37-38 psi and see if that helps some. If you keep going leaner on the afc, you will end up with the timing trying to skyrocket and then knock, and the timing getting pulled low again. The afc actually fools the ecu into thinking the engine is getting less airflow which puts it into a different fuel/timing map. Only way around that is lower fuel pressure or more unmetered air(which isnt the safest)

 

[paul s]

The afc for those injectors should be around -34% check for boost leaks..

 

[redgst95]

At only -39%, Im sure you are still a little rich. Try lowering the fuel pressure to around 37-38 psi and see if that helps some. If you keep going leaner on the afc, you will end up with the timing trying to skyrocket and then knock, and the timing getting pulled low again. The afc actually fools the ecu into thinking the engine is getting less airflow which puts it into a different fuel/timing map. Only way around that is lower fuel pressure or more unmetered air(which isnt the safest)

my fuel pressure is already at 37psi

 

[1fastlaser]

boost leaks

 

[CanadianTSi]

How much boost are you running?

 

[redgst95]

How much boost are you running?

at the moment i cant run nothing under twenty or it will creep real bad due to the internal gat without a ported o2 housing of some sort

 

[Newlogics]

What is your timing right before knock comes on?

Leaning out SAFC 40% will kick ECU into much more agressive timing map (since ECU doesn't see much air coming in), and induce knock, which, in turn, will pull your timing back. However, even once your timing is pulled back and physical knock disappears, ECU will reduce knock reading gradually to avoid sudden changes in fuel delivery, therefore keeping your timing pulled.

 

[redgst95]

What is your timing right before knock comes on?

Leaning out SAFC 40% will kick ECU into much more agressive timing map (since ECU doesn't see much air coming in), and induce knock, which, in turn, will pull your timing back. However, even once your timing is pulled back and physical knock disappears, ECU will reduce knock reading gradually to avoid sudden changes in fuel delivery, therefore keeping your timing pulled.

im not really sure around 9 or 10 but my timing never goes over 14 deg no matter what!!!....could this internal gate have ANYTHING to do with all of this i dont think we understand the concept of this adjustment arm! i dunno just a thought. im just trying to get my timing advance up while keeping my 02's around .88,.89v,like i said earlier when i do a log in third my o2's are like .94 and my timing advance never exceeds 14deg timing i have checked for boost leaks and none so i really am confused about which way to go with the afc it seems like if i richin it up i will just be running richer than i am already,and if i lean it out it would just pull timing more than what its doing now! i was getting like 17 18 deg timing with my 16g so i know the timing is there i just need help finding it!?!?

 

[92awddsm]

Well, first off, the o2 voltage that high shows that you are rich. Keep leaning it up till you get it where you want it. And at the same time, look and see what timing does. If timing stays the same and o2 goes down, you have effectively leaned it up without creating knock so theoretically, it should make more power. I would honestly lean it up till it started to pull timing and the go back to 2% richer from there. Remember, timing isnt everything. Some of the fstest stock ecu dsms seem to start dropping timing as they get to the strongest part of the pull.

 

[Burnett03]

At only -39%, Im sure you are still a little rich. )

Most 660-680 injectors are around -30% to -34% So going past -39% might not be the best idea.

 

[Burnett03]

Well, first off, the o2 voltage that high shows that you are rich. Keep leaning it up till you get it where you want it. And at the same time, look and see what timing does. If timing stays the same and o2 goes down, you have effectively leaned it up without creating knock so theoretically, it should make more power. I would honestly lean it up till it started to pull timing and the go back to 2% richer from there. Remember, timing isnt everything. Some of the fstest stock ecu dsms seem to start dropping timing as they get to the strongest part of the pull.

dont tell people to tune by narrow band 02 voltage. And who says timing isnt everything? Timing and watching timing is everything on a 2g. Its the only way besides dsmlink to tell if the car is knocking. You can get rich knock too buddy.

 

[92awddsm]

dont tell people to tune by narrow band 02 voltage. And who says timing isnt everything? Timing and watching timing is everything on a 2g. Its the only way besides dsmlink to tell if the car is knocking. You can get rich knock too buddy.

I meant higher timing isnt everything and I know its the only way to tell if you are getting knock on a 2g without dsmlink or the like. If not, I would have said to lean it up till you start to get knock. Reread my post and it says "I would honestly lean it up till it started to pull timing and the go back to 2% richer from there" Actually, why dont you reread my whole post and see if that tiny, simple brain of yours can comprehend anything other than just what you want to see.

And if you really had a clue, you would know that many a people have been tuning 2g's for quite some time off of narrow band and timing alone with great success. If he doesnt have a wideband, no access to a dyno, and no tuning guru like you available, whats he supposed to do, let his car sit and look pretty?

 

[redgst95]

I meant higher timing isnt everything and I know its the only way to tell if you are getting knock on a 2g without dsmlink or the like. If not, I would have said to lean it up till you start to get knock. Reread my post and it says "I would honestly lean it up till it started to pull timing and the go back to 2% richer from there" Actually, why dont you reread my whole post and see if that tiny, simple brain of yours can comprehend anything other than just what you want to see.

And if you really had a clue, you would know that many a people have been tuning 2g's for quite some time off of narrow band and timing alone with great success. If he doesnt have a wideband, no access to a dyno, and no tuning guru like you available, whats he supposed to do, let his car sit and look pretty?

well first off i know what i am doing as far as the timing curve and the o2's my thing is i start out with -20 across the board this is after i just upgraded from 550's to 650's, i lean it out -20 just to see where i stand on the logger well it pretty much wouldnt let me go into boost it was so rich busting up real bad!!!....so what i did was i kept leaning it out until i stopped bustin up and could actually go through a gear, i think i ended up at like -29%. then i would put it on the logger did a third gear pull to about redline i only ended up with like 13%timing advance!!and my o2's were like at .96v so i lean it out some more....waited a bit and did another pullstill 13%timing and .96,.94 o2's MY POINT IS...no matter how much i lean it out it does not drop below .94v nor does the knocking go away when i richin things up,when its like at -38 across the board you can feel it pulling time bad but when i richin it upto where its a smooth pull its pig rich?? sorry so long! WTF

 

[Kevin Jewer]

On the 2g my O2 voltage was .98 whether I was at 11:1 AFR or at 13.5:1 taking apart the pistons. Ignore it.

To calculate injector compensation value, divide 450 by injector size and subtract 1. For X80 injectors, adjust them to X50, since they are rated differently. For example, a 680 is really a 650. Why they can't just use the normal rating scheme is beyond me... 450/650-1 is -31%. That will put you at stock target[/] AFR which is ~9.5:1 over 2.1 g/rev at higher rpm. That is still quite rich even for pump gas. You would need to lean out another 14% to get to a more typical 11:1 (9.5/11-1). But of course this assumes you are over 2.1 g/rev.

I'm not sure why timing wont go over 14 degrees no matter what you do. I would like to see a log with airflow, rpm, and timing.

 

[espinelli]

Peak timing on a 2G ECU will max out at 16* @ 6500-7000rpm provided the coolant and intake temps are in check.

If intake temps are above 84F or below 34F you will lose one degree of timing. If coolant temps exceed 224F then you will lose 2* of timing. If they are between 206F and 224F you will lose 1* of timing.

Lets not forget about knock retard. If your knocking that will definitely help reduce your timing advance.

 

[hellotbone]

My AFR on the LM1 wideband is between 11.1 and 11.4 for a pull my timing is 25* total timing on the logger. My afc is quite low I beleive its in the low -40% range NO BOOST leaks I have a tester. Every car is different. I will post back with my true AFC numbers.