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69camaro5speed
May 5th, 2007, 12:05 PM
ok i have done about 40 tunes from 630 hp na motors to stock tunes this ones kicking my ass.i cant keep timing in any where close to where it needs to be.tryed masair ,sd tunes its a 5.3 with 5.7 heads no mill work and a cam timing pulls back to 15 degs when i have tryed hi and low octane tables set to 27 degs and a max pe retard set to 3 degs with all other modifiers i can find turned off. i just set the min timing to 24 degs and picked up 1/2second in a quarter mile.heres a tune and log any ideas would be great thanks rich

69camaro5speed
May 7th, 2007, 09:21 AM
hmm know input

dc_justin
May 7th, 2007, 09:30 AM
Your timing pull is coming from 3 sources, it appears. First is from KR. A consistent 3* of KR. Second is from your IAT modifier table. At the intake temps you're seeing, and the manifold pressure you're at, you have 5* being pulled out. The third is your ECT table, consisting of B5910 x B5942.

Also, you don't have a reliable representation of air mass (g/cyl) since you're in speed density. Please log "Predicted Grams of Air Per Cylinder" (GM.DYNCYLAIR) in the "Air" section for an accurate representation of your airmass.

Couple of other things. Frame 85, Bank 1 swings very lean, I'd look into the cause of that ASAP.
Do you hear any knock?

69camaro5speed
May 10th, 2007, 10:15 PM
yeah i seen the air temp was pulling 5 the coolant temp never reaches a temp that shows it souldnt pull any out and b5910 and b5940 looks like 1 deg. to me.as for the nock pulling out timing i set min timing to 24 degs and made a pass and it pickes up half a second so i can figure 8 or 9 degs still missing 3.thats a big help though gets me closer. as for o2 reading i looked at my ve table and there was a small dip there so i think i will put a couple in. i did the auto ve on the bank that shows safe but with the dip in the stock o2 i would rather be safe then sorry and give it some there.thanks for the input

GMPX
May 10th, 2007, 10:23 PM
Best thing to do when faced with odd timing issues is log all the spark DMA PID's, in fact it's probably not such a silly idea to create a PID selection file with just RPM, ECT, IAT, TPS and the spark DMA PID's.
'Usually' odd timings can be tracked down to a torque reduction issue.

Cheers,
Ross

69camaro5speed
May 13th, 2007, 01:38 PM
good idea need one for timing tuning, idle tuning,fuel tuning, trans stuff thanks