454 knock retard

[PlayingWithTBI]

This may not have anything to do with but, I don't know if they change to "oxygenated" fuel during the summer months?

 

[Christian Steffen]

Looking through the logs, it appears that it is kicking KR a little early, but not enough to call it false. Was this on 87 or the 93 octane? If it was 87, 16-19* might be all you can get at 2000 rpm for high map, where you're throwing KR. If that was 93 octane I'd expect to get more. Dump a bunch of octane booster in it and see if the KR is still there. The stock cam in these trucks does not seem to allow a ton of timing.

I agree with mangone though, in cruising areas (40-60 kpa) you should be into the 30s on timing.

 

[bigpapiray]

Looking through the logs, it appears that it is kicking KR a little early, but not enough to call it false. Was this on 87 or the 93 octane? If it was 87, 16-19* might be all you can get at 2000 rpm for high map, where you're throwing KR. If that was 93 octane I'd expect to get more. Dump a bunch of octane booster in it and see if the KR is still there. The stock cam in these trucks does not seem to allow a ton of timing.

I agree with mangone though, in cruising areas (40-60 kpa) you should be into the 30s on timing.

Of the cruising speed should be in the 30’s and it’s not how do I get it there?! Lol

 

[Christian Steffen]

Of the cruising speed should be in the 30’s and it’s not how do I get it there?! Lol

Have your tuner adjust it, or buy tuning software and do it yourself. It should handle 32-36* at light cruise, but it would be best to verify while tuning.

 

[bigpapiray]

Have your tuner adjust it, or buy tuning software and do it yourself. It should handle 32-36* at light cruise, but it would be best to verify while tuning.

He told me the vortec won’t handle that locked. My mechanic “engine builder” said bull **** it will just fine. Say we lock it at 33* what would that do at idle or low speed?

 

[Mangonesailor]

He told me the vortec won’t handle that locked. My mechanic “engine builder” said bull **** it will just fine. Say we lock it at 33* what would that do at idle or low speed?

Suck.

It'd ping like crazy accelerating.

You don't "lock" the timing. You can adjust max, or minimum spark retard, but not set it and forget it. Spark advance is determined based off theoretical air mass in 1 cylinder (engine vacuum) and RPM... like an old-school dizzy. See below as an example:

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[Christian Steffen]

So i did finally dig up a tune i did on a stock 2000 black box truck, 140k (?) miles. On 87 octane, in SD July heat this is about all it would take. I probably could have gotten a few more degrees into it across the board unloaded but the owner was going to use it for towing so i wanted to be a little conservative.

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Out of curiosity I did hook up 12k worth of horse trailer after finishing tuning, and it would occasionally throw 1-2* kr with this map below 2200 rpm.