So trying to fine tune a lil bit because car was feeling to sluggish. Advanced timing and got a big improvement, so I advanced a lil more, felt good but wanted to make sure it wasn't too much. Went for a drive no aduble pinning . Hooked her up to laptop and when heavy on the throttle was getting knock retard. Backed timing down by 2° and tried again. Same result. So I repeat and now back to original setting of 4° where it felt sluggish. Tuner pro showing about 10°knock retard (max) with minimal advance. Smooth acceleration dosent seem to cause retard. But revving hard it does.
So I assume :
1. I have a knock in motor
2. I have the exhuast (hedders) setting off sensor
3. Unhappy sensor. (But considering the smooth acceleration, not setting it off I doubt it)
🤔Your thoughts suggestions and experiences please. Thanks.

 

10° is a lot. I've gotten mine down to about 2 deg and I made my knock retard attack rate more aggressive than stock, so I'm comfortable with it.

Depending on what LV8 you're getting the knock at, you could be maxing out on the knock retard.

In PE, you get up to 18° of retard available. In non-PE you get anywhere from 0-20.

From what you're describing, you might be getting a lean spot during abrupt throttle transitions. A leaner mixture generates hotter cylinder temps, which makes it more prone to detonation.

Since it sounds like you're able to tune...

If the knocking only happens (or is much more pronounced) at higher coolant temps, then you can increase the AE Number of Enrichment Async Pulses vs Coolant temp. After 176F, this factor drops by half on the way up to 219F... a significant leaning out higher coolant temps, which could be exacerbating the knocking.

If the knocking isn't related to coolant temp, then I would probably put in a little more AE fueling at higher LV8 changes. AE Enrichment Factor vs Change in LV8.

 

unfortunate I don't do the tuning myself, I just do diagnostic by laptop. I started making timing adjustments as soon as it warmed up. So (only guessing) that it's not related to temp.
I don't know what lv8 is but is there a way to determine if that needs a change from looking at the tunerpro #s.
Additionally, today when I first went to give it gas before lowering timing to get rid of knock i hit the gas to see that knock was still there, I noticed that it still said open loop. Didn't realize it was because the car sounded like it went into closed by sound of the idle. I was surprised that it was using knock sensor info before closed loop. Thanks for your input.

 

LV8 is essentially a measurement of the engine load, in terms of airflow as measured by the MAF.

How are you adjusting timing then? Advancing the distributor? That's a bit of a brute force way of doing it... if you advance the distributor 2 deg, it'll add that 2 deg everywhere all the time.

The knock sensor is always used, yeah. Open or closed loop.

When you do get into closed loop, what you can do is keep an eye on the O2 sensor voltage output. When you give it the gas, if the voltage goes down to less than 100 mV and hangs there, that would indicate that you're momentarily going really lean during the throttle transition. The stock O2 sensor doesn't give you an indication of actual AFR like a wide band O2 would, but it can hint at lean or rich, particularly during a throttle transition. If you see the O2 sensor going way lean and knock retard occurring, then my comments about Accel Enrich might be applicable.

 

Correct thru distributor,est disconnected, ok I will look tomorrow and see what is happening with those values. Thanks, appreciate the help.