Weird DirectScan Numbers

[Weazel]

Hello,

After FINALLY getting my DScan installed, I've been taking a lot of data. On the way to a friend's house I took a WOT run. I had the boost at 17 psi, 93 octane, and let her rip. I got a maximum reading of 6.5 deg of knock retard. That freaked me out, so when I arrived I dropped the boost down 1.5 psi.
Now the thing that bothers me is that at the time I had max knock retard, and the tranny had just shifted into 3rd gear, the spark advance was showing up as 23.5 deg. Now normally at WOT the advance is 20 degrees, and the knock is minimal (under 4 degrees). The chip is a 17 psi/93 octane chip (not sure what make) for the stock injectors. I would assume it's a 20 degree chip, since that's the lowest the spark advance goes. Is this right? Also, would 6.5 degrees of knock at 23.5 degrees advance be the same as 3 deg of knock at 20 degree advance? ie Not a HUGE deal?? If so, does anybody know why the chip and ECM seem to be fighting it out? (chip trying to advance while ECM tries to retard?)

THANKS a lot. I'm very new to this tuning game, so if what I say doesn't make any sense, be sure to let me know

 

[Razor]

Retard is retard and timing is timing..one has nothing to do with the other...if your DS says 23.5 degrees timing at WOT then thats what the chip has burned into its location....and as far as knock..if the knock occurs on the shift..dont fret about it..probably false knock..only look for knock under WOT and high into third gear where you'll be looking for no knock..or just a degree/two..

So get yourself a lower timing chip burned and it will knock less but make less power..always a trade off.

HTH

 

[TurboDave]

23.5 degrees of timing sounds very close to stock values.

6 degrees of retard at the 2-3 shift point isn't a huge deal at the boost levels you're running. If you were at the track and running 25# of boost, then ANY knock retard would be bad.

just keep it all under control, and those few degrees at the shift aren't going to bust anything. When you start pushing the envelope, then worry.

 

[Weazel]

Originally posted by Razor
Retard is retard and timing is timing..one has nothing to do with the other...if your DS says 23.5 degrees timing at WOT then thats what the chip has burned into its location

I think I see what you're saying. So my chip says that for "X" throttle position, then have timing be "Y" degrees? Because the timing changes, from high 40s when I'm under minimal load (highway cruising) to low 20s (as low as 20.0) when I'm in the throttle all the way. I guess I was just curious if 6 degrees of knock at say, 30 degrees timing was somehow "not as bad" as 6 degrees at 20 degrees timing.

Thank you guys for the responses. I've looked at a lot more data, and it's definitely worst at the 2-3 shift, and nothing over 2 degrees at WOT (and 20.0 deg timing). I appreciate it

 

[Razor]

Nope..timing doesnt follow the TPS..its based on load and rpm..and retard if any..its part of the spark table built into the eprom..