afr, log, and afc question

[rsmatt]

alright guys i cant get my palm to hot sync with my pc so i cant post the log but my question is how much timming should you have at peak torque with no nock? i have 272 cams, 255 fuel pump, 780cc injectors, afc, tbe, mbc set at 20 psi, and an intake. if i run 19-20 psi the timing at 3800-4400 rpm will go all the way back to 0 then climb smoothly up to 18 by 7000 rpm. if i run 15 psi the timing only drops to 6 at 3800-4400 rpm but will still end up at 18 by 7000 rpm. im comming in real rich running at 1.02v at 3500 rpm, then bringing it back to .98v after 4500 rpm. i also have a wide band but its a aem and it wont show afr's below 11.0 so im not sure exactly what .98-1.02v is but i know its below 11.0.

[Blaze]

You're timing should steadily increase after 3500 RPM/full boost and peak between 17 and 19 degrees.

Wherever your timing drops is an area that you need to work on by adding or subtracing fuel.

If it's too rich, you're likely getting pre detonation.
Too lean and you're getting knock.

You may want to review the How to Tune an SAFC written by Scott Gray here on SoCal, or the thread written by TurboLarry on EvoTuners.net.

Good Luck,

Blaze

[rsmatt]

new log after pulling some fuel. this one looks good i think ;).

rpm timing 02v
3902 6 1.02
4132 7 1.02
4625 8 1.00
4878 8 1.00
5097 8 .98
5351 8 .98
5582 9 .98
5812 10 .96
6023 12 .96
6238 14 .96
6476 13 .96
6671 15 .96
7042 18 .96
7226 19 .96

[Blak94GSX]

Umm, lean it out a LOT from 3000 to 5000. Shoot for .94-.96 from 3000 to 7500. See how that works.

[turbolarry]

What are you getting below 3900RPM's?

[rsmatt]

ya i was thinking i could go leaner and get even more out of it. what do you guys consider a safe afr for 91 octain at 20 psi? my damn wide band wont go below 11.0 :'(.

[itsmeeeugene]

holy crap thats rich...ive got mine set at .92-.93 across the RPM

[Blak94GSX]

You must have the AEM Gauge Wideband... Heh the target AFR is 10.6, but umm your wideband doesn't read there. For now, just get the AFR in the 11.2 range so you get a reading on the gauge, then go a couple clicks up from there on the AFC once you have the AFR steady across the whole RPM range.

[rsmatt]

You must have the AEM Gauge Wideband...* Heh the target AFR is 10.6, but umm your wideband doesn't read there.* For now, just get the AFR in the 11.2 range so you get a reading on the gauge, then go a couple clicks up from there on the AFC once you have the AFR steady across the whole RPM range.
alright ill try that tomarow and post a log. what should my peak timing be with 780cc injectors running optimal?

[Blak94GSX]

Somewhere around 5-6 at the lowest point and then up to 21-23 at 7500.

The 780s might be problematic on pump gas as they are pretty big and might give too much timing causing some knock. Only way to know for sure is to tune it.

[trinydex]

You must have the AEM Gauge Wideband... Heh the target AFR is 10.6, but umm your wideband doesn't read there. For now, just get the AFR in the 11.2 range so you get a reading on the gauge, then go a couple clicks up from there on the AFC once you have the AFR steady across the whole RPM range.


10.6?

[leaveit2bevo]

You must have the AEM Gauge Wideband... Heh the target AFR is 10.6, but umm your wideband doesn't read there. For now, just get the AFR in the 11.2 range so you get a reading on the gauge, then go a couple clicks up from there on the AFC once you have the AFR steady across the whole RPM range.


you love pulling up old ass threads.

10.6?

[C-Spec]

You must have the AEM Gauge Wideband... Heh the target AFR is 10.6, but umm your wideband doesn't read there. For now, just get the AFR in the 11.2 range so you get a reading on the gauge, then go a couple clicks up from there on the AFC once you have the AFR steady across the whole RPM range.


you love pulling up old ass threads.

10.6?



damn Bevo you freaking post whore :2funny:

[trinydex]

read the title foo, i'm the forum gravedigga sucka... i get to do this.