16g tuning questions

[95ClipseGS-T]

lol, where does the rev limit kick in

[EclipseRST]

7500! NOW GO HIT IT! go on. then post your log

[95ClipseGS-T]

k tomorrow mornig on my way to work

[JoeWagon]

16g will drop airflow high, but it might still be worth it to go to 7500. I'd get a good tune to 7000 before a great tune to 7500.

[Very Slow GS-T]

You think tuning is hard on a 16g....try a 60 trim

[spyderturbo007]

Originally Posted by EclipseRST

add more fuel/turn down boost to get rid of the knock, alteast you have not more fuel cut!

If I remember correctly, it is safe to boost 18 or 19psi on a 16g with his supporting mods on the SMIC. He is only running 13psi. Is adding fuel the only option other than turning down the boost?

[scottsee]

i dont know alot about air/fuel tunning, but that timing looks preatty low for what you have. what is your base fuelpressure, and base timing?

[kjewer1]

Sorry guys, I havent checked back in a bit.

There are many things that affect fuel trims. I wont even begin to list them all. Every car is a little different, but if you have to stray more than a few percent from base injector compensation, something is wrong. In my case, I just go with injector comp and drive it the hell on. I adjust for WOT, and to hell with trims. But thats because I Can trust my air metering and fuel delivery because I keep close tabs on them (WBO2 vs calculated AFR).

I would pull fueling back by 5% (so minus 13s or whatever that works out to). Hopefully you will still avoid fuel cut for the sake of getting a good log. If the timing looks better, start to go plus or minus a couple percent and see what works best. I hate to go by O2s, but on a 2g .90 is almost always too lean for pump gas. HArd to say though. On a 1g, that would be right on (They seem more repeatable). The timing substantiates the suspicion that it migh be too lean.

If possible get me a log with airflow added. With that I can calculate airflow per revolution and estimate what timing should be if there was no knock.

There is no need to go over 7000, but go at least that far. Timing is "all in" by then, and thats all I need.

Looks like some good progress none the less. Good sample rate, up to 7000 rpm, and no fuel cut. We'll get it there

[spyderturbo007]

Here are 3 logs with the following SAFC-II corrections:

This is with a -11% correction on the Hi-throttle tables:



This is with a -13% correction on the Hi-throttle tables:



This is with a -15% correction on the Hi-throttle tables:



Shouldn't he be able to turn up the boost on that 16g?? Or should we wait until we get a good tune? The pull at -11% looks decent, but the timing advance just isn't there. By the way, what calculation are you using to get timing advance assuming no knock?

Thanks again!!!!!

[EclipseRST]

those look a lot better, tune it the way it is now so you get a handle for it then slowly turn up the boost and add more fuel until you are at were you want it!

[JoeWagon]

I don't understand why the timing is so low. If the boost goes up, the timing might go down more.

[scottsee]

yeah, wow, thats just really low timing, do you know what your base fuel pressure and timing is set at?

[kjewer1]

SOmething isnt right. The LOWEST timing maps in the 2g ECU (used over 2.1 grams/rev airflow) peak at 16 degrees between 6 and 7k rpm. It doesnt get over 10 until around 5k. He is not getting over 2.1 g/rev so timing will be even higher. Use airflow in lbs/min divided by rpm (pounds per rev), then convert to grams (multiply by 453.5924).

The ECU doesnt know what other things are set at like FP, base timing, etc, the only imputs it factors into the timing result is intake temp (over 84 and under ~35 degrees F it pulls 1 degree) and coolant temp (over 206 it pulls a degree, over 220 or so itpulls 2).

I'm assuming this has to be knock. On a 2g you arent supposed to be able to set base timing, but put a timing light on it anyway. Thats the first thing I would do. The next thing I would try is raising the octane, run the tank real low and add a gallon or two of the highest octane race gas you can find, 116 or 117 perfereably. Or xylene/toulene additive if you are comfortable putting paint store chemicals in your tank (plenty of info on the internet, I've never tried it personaly, but friends have used it sucessfully). Pain in the ass, but we have to start the process of elimination