GuitsBoy

iTrader: (4)

Which is more beneficial? Adding timing or leaning the car out? I already have 28* of timing at WOT with no KR. Should I keep it there or should I try and squeeze another few degrees in there?

Tuning with HPT v1.5 - No wideband.

Thanks,
-Tony

HumpinSS

iTrader: (1)

IMHO timing should be done on the dyno to find the "sweet spot" for your dialed in AFR for all you know it could pick up power with less timing

jimmyblue

iTrader: (11)

But he does not have a dialed in AFR, yet.

With headers and a ported MAF the mixture situation
is a big ???.

GuitsBoy

iTrader: (4)

Im still tuning for SD right now, so the MAF is disconnected while I get my VE fixed up. I started with the z06 VE table and made some changes throughout the last few weeks, and over the weekend ive been playing with v1.5 and tweaking the VE table via STrims. True that the headers may be cooling the exhaust temps down prematurely, which may be skewing my part throttle a:f. Thats all stuff ill have to work out.

Im just wondering if the majority of cars out there will gain anything by running over 28* of timing. Maybe bumping it up to 32* would net me more gain than changing PE from 1.170 to 1.165.

jimmyblue

iTrader: (11)

I believe max torque for any given mixture, will be found
about 2 degrees before you start to ping. That's how I
set my timing; creep it forward until you have 1 degree
max in all of the high-MAP Spark Retard cells and then
subtract 3. I used a reduced knock attack rate and a
high recovery rate to give a better picture of the true
knock level.

A couple weeks' worth of fiddling, which (after driving around
pinging all the time), put me right back at 27-28 degrees....

I think a lower-mods car can stand more timing. As your
exhaust side scavenging in particular improves, the charge
is fresher, faster burning and needs less spark lead.