02ZOh6

While logging some wot passes I noticed I'm getting 1* KR when I punch it as you would when racing off a roll from about 4-4500 rpm's. I haven't touched the timing tables at all. What type adjustments need to be made? I've read posts which say to increase ve in those areas and also some about adjusting BK and Tip-in.
Bolt-on Z06 BTW.
Thanks guys.

Haans249

iTrader: (24)

I'm no expert, but I believe a KR of 1 degree is absolutely nothing. If you were to see a consistant KR of 12 or so, then you should be worried. Even a steady KR of 4 or below is fine. When logging mine, I saw a KR of about 8 between shifting from 1st to 2nd gear, but thats probably because its a big punch, and a small degree of KR is expected. Sometimes I will see a KR of 1 degree myself occasionally while driving normally....probably bumps in the road, nothing to worry about.

02ZOh6

Thanks Haans.

Slowhawk

iTrader: (12)

You want 0 KR all the time.Even 1 degree can screw up the power output.

Did you verify that the A/F is correct too? You have 2 options. Richen the A/F if it is lean or decrease timing in those area's. Also the KR should be checked in 4th gear where the most load will be read.

02sierraz71_5.3

iTrader: (2)

Im with hanns I wouldnt worry about 1, especially with stock timing tables. Not sure if fbods have an enrichment rate if you do set it to 1. I guarantee if you havent tuned the ve and maf tables those will take care of the 1kr.

horist

at WOT you have a max of 4* allowed on F-Body's (just checked a vette and it's the same) .... so 1 degree is 25% of max..


I run 12.8:1 @ 28* peak timing with 0* KR .... ANY KR hurts performance....

Listen to slowhawk ... any KR is bad (1* of KR can pull 2-3 degrees of timing.... can toss you in the low octane tables if it's constant... any reported KR is too much KR ... )

jimmyblue

iTrader: (11)

You need to distinguish whether it is "going" WOT
or "at" WOT that drives the pinging. I think in most
cases it's the tip-in, the "lean hole" on opening
throttle, that initiates the pinging and then it just
sticks around way too long down the track.

Tip-in ping is some combination of a lean VE table
(relative to breathing mods' delivered improvement)
and late PE roll-on (PE thresholds, delay RPM, and
enrichment rate; F-bodies only seem to have the
thresholds applied, rate is 1 and delay is zero).

If you bump VE until you no longer see a "divot" in
the O2s with rising TPS%, you will see the tip-in KR
go away I fully expect.

02ZOh6

Thanks for the replies. I'll try bumping my ve table a bit and see what happens.

02ZOh6

I went out last night and logged a couple sessions. One to make sure my ltft's were still ok and another 4rth gear pull as per slohawk's instruction. I ran it wot from 2400 to 6K in 4rth and sure enough I had 4* of timing pulled from 3200 to 2* at 6000rpm. The car is rich (11.8-12afr) up until 5600rpm.
When I go from 4500rpm in second and mat it afr dips to 12.4 and comes up nicely to 13.0afr at 6300rpm. I haven't touched the timing tables at all. Anyone have time to look at my histo's?