few beginner tunning questions

[4BangerV8Killer]

ok so today is my first day of tunning with my safc and i pretty much understand what im doing from all the posts and threads i have read so far. basically im trying to keep my knock at a minimal and my 02sensor voltage between .85 and .90 which i have been doing. and to eliminate the knock by richining up the settings.

my first question is on the safc to richin up i go down in percent right? and to lean it out i go up in the percent values??

and the other question is lets say my 02volts are good....lets say .85 at any given rpm range but im still knocking like 20 counts. to get rid of that i richen it up? or what?

and when it seems i have a good tune and my knock is minimal and im not running rich/lean how then can i adjust to make more power? more boost? then readjusting the fuels?

sorry im just bearly grasping the tunning concept.

im at about 20psi right and and am running a pte50trim 720cc injectors walbro255 fmic...basically all supporting mods for a 50trim.

Thanks

 

[Jeff_Ciesielski]

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my first question is on the safc to richin up i go down in percent right? and to lean it out i go up in the percent values??

and the other question is lets say my 02volts are good....lets say .85 at any given rpm range but im still knocking like 20 counts. to get rid of that i richen it up? or what?

1. You have it backwards. lowering the values makes the car see less airflow. less airflow = less fuel == leaner mixture.

2. Running injectors of that size and trying to compensate for them using an afc will cause you you run too much timing advance. You need to richen up to compensate for that.

^^ someone verify this please, i dont want to be caught talking out my ass .

jeff

 

[Wicked96GS-T]

Correct, you are going to increase timing by making the ecu see more airflow. Any injectors over 650cc's really are not able to be tuned well by an SAFC though.

 

[4BangerV8Killer]

o i thought it was that when the ecu sees less airflow it dumps more fuel therefore you run rich and in turn can turn up the boost and with the bigger injectors the ecu will be dumping way more fuel than it thinks and you can force more air making more power? maybe im totally off on this but here are my settings and log

im tunning with an safc and im running a PTE50trim, FMIC, walbro 255 and 720cc injectors and supprting mods.

20PSI on 91octane

my HI throttle safc settings now are at

RPMS Settings

1k~~ -13%

2k~~ -12%

3k~~ -15%

4k~~ -16%

4.5k~~ -15%

5k~~ -14%

6k~~ -17%

7k~~ -16%

my log:

3500RPMS~ INJD 21%~ KNCK 0~ 02V .87~ TPS 82.4%~ TIMA 30deg~ INJP 7.1ms

4000-5000RPMS~ INJD 71.8%~ KNCK 11~ 02V .87~ TPS 99.2%~ TIMA 16deg~ INJP 16.6ms

5700-6000RPMS~ INJD 82%~ KNCK 23~ 02V .87~ TPS 99.2%~ TIMA 16deg~ INJP 16.3

6500+ RPMS~ INJD 82.8%~ KNCK 32~ 02V .85~ TPS 99.6~ TIMA 16deg~ INJP 15.3

What should i do from here? im very new at tunning and not really sure on if im doing it right.




SO what exactly does the - or + percent on the safc refer too? i want to know if i have this backwards!!!!

 

[4BangerV8Killer]

so what should i do? go to the positive values on the safc?? whats that doing exactly? making the ecu see MORE airflow?

meaning the ecu will dump more fuel?

so +% is more fuel and -% is less fuel basically?

 

[Jeff_Ciesielski]

the +/- refers to how much you want to correct the amount of airflow which the ECU will see. For example, if you adjust on the afc for -5%, the ECU will see 5% LESS airflow than is actually being registered by the MAF.

 

[Jeff_Ciesielski]

so what should i do? go to the positive values on the safc?? whats that doing exactly? making the ecu see MORE airflow?

meaning the ecu will dump more fuel?

so +% is more fuel and -% is less fuel basically?

you wont necessarily need to go into the positive values, but you will need to add more fuel. esp in the 3-7k range. 30 counts of knock will = a dead engine pretty quickly.

 

[4BangerV8Killer]

so how would i add more fuel?? basically by upping the % right...yet you guys are saying if i do that im going to advance the timing also....so how are you supposed to advance timing to the point of knock then richen it up to get rid of the knock....but if i richin it up im also advancing timing at the same time, no?

 

[Eclipsethis90]

Going positive adds fuel, imagine 0% as stock, go plus (or up) and you add fuel and go down (you take fuel away). The timing change is a effect you can not control directly with the SAFC, but it is a by product. First,I read the profile and I don't see a set of NGK BP7ES (one step colder) spark plugs, rule of thumb goes over 15 psi and you need a set badly with 20 psi. This will assist you in the ridiculous amounts of knock you are logging. Start there and go to http://www.dsmtuners.com/forums/showthread.php?t=103469
There is a SAFC tuning page that gives a basic run through the SAFC and how it is tuned.

 

[Jeff_Ciesielski]

so how would i add more fuel?? basically by upping the % right.

You are correct about adding more fuel. Just up the % to increase the amount of fuel that will be injected into the engine.

..yet you guys are saying if i do that im going to advance the timing also....so how are you supposed to advance timing to the point of knock then richen it up to get rid of the knock....but if i richin it up im also advancing timing at the same time, no?

You misunderstand. By adjusting for larger sized injectors, you fool the ECU into seeing less airflow. To the ECU, less airflow = less fuel and more timing. So by adjusting for 720cc injectors, you will naturally run more timing than a car with a similar setup with only 680cc injectors.
On a side note, honestly, an AFC seems ill suited for your setup. It is dangerous for you to attempt to tune a car at 20psi on a 50trim with an afc when it makes tuning hard as hell due to the way it screws with timing.

 

[4BangerV8Killer]

oo ok....well ya i know im just to lazy to install my emanage right now....i was just gonna wait for the new version of dsmlink to come out. and i also have a blow thru setup waiting to be installed

i kinda get it now.... i had a convo with a buddy of mine...basically hes sayin that when i take air out the ecu will throw in more timing and because of my bigger injectors i can safely handle more timing without getting knock.

and by adding more air in im adding fuel and removing timing and therefore removing knock.

but he also says the timing maps on our cars are very "agressive" in the 5-6k rpm range and thinking maybe i should retard the stock timing alittle because of me using the safc and huge injectos

what would be the best thing to do aside from installing the emanage

 

[JayRolla]

Even the emanage is a piggy back. It will also pull the timing but will work better if you have the timing harness so you can pull timing out.

If you would run 550's or 650's you will have a lot easier time tuning. You will keep adding fuel and timing will keep increasing, it will just be a huge battle and you will lost performance. You best bet is to get an eprom ecu and have it compensated for the injectors.

Your injectors are just to large expecially in a 1g to tune with a safc. You will most likely never get rid of knock. I would take them out, put the stock ones in and run 12psi till you have the right equipment to tune with or you will just keep detonating the motor.

 

[1stGenRocks]

since you have a 1g you can retard the base timing by adjusting the CAS. This will take out timing mechanicly giving the computer a lower starting point.

 

[4BangerV8Killer]

well iv gotten my timing down to about 5 counts im going to log again and post it and my emanage does have the timing harness

 

[90TTalonAWD]

i would most definately turn down the boost until you get that knock under control. no knock should be a priority, 32 counts is way to high and you could be damaging your engine. Don't make the same mistake I did, i thought that 40 knock was way too high and i only had a few days until my maf-t was coming in the mail to control the knock, it was too late and i blew two pistons.

 

[4BangerV8Killer]

well its pretty much gone now

 

[JayRolla]

Thats good, im really surprised you got the knock that low with those large of injectors. What timing are you seeing and what settings on your high throttle.

 

[4BangerV8Killer]

ya i fixed all the leaks the timing is at 5btdc plugs are cool but im gonna get some bpr7es's probably today and the knock sensor is bran-new. my new log/settings

SAFC:

1k~~ -13%

2k~~ -12%

3k~~ -11%

4k~~ -6%

4.5k~~ -6%

5k~~ -6%

6k~~ -6%

7k~~ -6%

LOG:

RPM INJD KNOCK 02V. TPS TIMA INJP

3343 20.3% 0 .85v 99.2% 29 7.4ms
3437 22.6% 0 .85v 99.2% 29 7.9ms
3531 26.5% 1 .85v 99.2% 28 9.2ms
3656 33.5% 0 .87v 99.6% 28 11.0ms
3750 40.6% 0 .87v 99.2% 25 13.0ms
4031 57.8% 0 .89v 99.2% 18 17.4ms
4156 61.7% 0 .87v 99.2% 15 17.9ms
4437 67.9% 4 .87v 99.6% 17 18.4ms
4531 71.0% 4 .87v 99.6% 15 18.8ms
4687 73.4% 4 .87v 99.6% 15 18.9ms
4750 73.4% 3 .87v 99.6% 16 18.6ms
5562 87.5% 1 .85v 99.2% 20 18.9ms
6093 92.1% 1 .85v 99.6% 22 18.1ms
6312 92.9% 5 .85v 99.6% 21 17.6ms

 

[90TTalonAWD]

do you notice how even with 5 counts of knock you are getting 20+ degrees of timing? Although timing can increase power, you can reach a danger zone with it. Alot of people i believe say that a good tune should have timing toping out between 15-18 degrees. This is showing you how those large injectors being compensated for with an afc is giving you advanced timing. Even with knock under control i would be careful, i'm going to go find the thread again that mentions why timing beyond 18 degrees can be hazardous.

 

[JayRolla]

My stock 1g DSM was seeing over 22* timing. The 1g map is way more advanced and his is normal. He still needs some fuel where its knocking. Normally with those large of injectors you should be correcting way more and seeing a lot more timing. Like around 28*. Are you sure they are 720cc injectors, just surprised the timing is so low.