My timing tables are set, why the fluctuation in boost?
My timing tables are set, why the fluctuation in boost? 6psi is what I'm running. I had it set at 18 degrees of timing at about 11.5:1 AFR...stock CR. Everything internally stock but valve springs.
That's pretty conservative so I decided to just up the timing slightly on 93 octane and see how it ran.
I took it out on the highway and did some logging. No knock from sound or any knock retard so I'm thinking it's alright at 19 degrees of timing in boost.
What I did notice seemed to be a little hesitation while at WOT in boost. Maybe it was just the road or something...but I thought I felt just a little something while running it through the power band.
I checked the logs and saw that I was only running 18.5 degrees of timing in boost at WOT and at a couple different spots, it would drop to 18 or 17.5 and then back to 18.5... Any ideas why? Is this bad for the engine? Thanks.
If you want to see, the scan is from start up through the run(s). I ran it once in 2nd gear and then towards the end, a 2nd and 3rd gear run where the car did what I'm describing above. The file is my current tune... Any thoughts or advice would be great.
That's pretty conservative so I decided to just up the timing slightly on 93 octane and see how it ran.
I took it out on the highway and did some logging. No knock from sound or any knock retard so I'm thinking it's alright at 19 degrees of timing in boost.
What I did notice seemed to be a little hesitation while at WOT in boost. Maybe it was just the road or something...but I thought I felt just a little something while running it through the power band.
I checked the logs and saw that I was only running 18.5 degrees of timing in boost at WOT and at a couple different spots, it would drop to 18 or 17.5 and then back to 18.5... Any ideas why? Is this bad for the engine? Thanks.
If you want to see, the scan is from start up through the run(s). I ran it once in 2nd gear and then towards the end, a 2nd and 3rd gear run where the car did what I'm describing above. The file is my current tune... Any thoughts or advice would be great.
I had to change my delta thresholds to .05 grams/cyl across the board. That was enough to keep the timing from fluctuaing.
Before you go changing it though, I'd try logging the problem once more and log burst knock at the same time. That way, you can tell if it's really burst knock causing your problems or if you need to look elsewhere.
Before you go changing it though, I'd try logging the problem once more and log burst knock at the same time. That way, you can tell if it's really burst knock causing your problems or if you need to look elsewhere.
I logged it some more...the timing did not bounce around. However, I changed the burst knock retard and the timing held flat across the board. It's weird though (to me at least)...the chart and gauges showed 18.5 degrees of timing, but my histogram showed 19 degrees, which I believe is what I should accept as what the car is doing right??. Is this normal?
Sometimes when I enter values into my timing table, it rounds that number to the nearest value the PCM will accept. For example, if I enter 32 degrees, it'll actually go into the PCM as 31.992188 degrees. IIRC, this is because the PCM doesn't use the actual numbers we enter. The software we use converts the actual number into some kind of raw value that the PCM will understand. Essentially, the minimum increment/decrement for a value in the timing table is something like 0.021972 degrees. That's why sometimes the whole numbers we enter are rounded up or down.
As for the timing in your log, the sensors can only report back in half-degree numbers (e.g. 18.0, 18.5, 19.0, 19.5, etc.). I don't know for sure if that means timing is only delivered in half-degree numbers or not. I would assume it runs what's in the table...but, it can only report in the above fashion.
If you can, increase the number of decimals shown in your tuning software. Then, enter something like 19.02 degrees if you can. That should report back as 19 degrees in your log.
As for the timing in your log, the sensors can only report back in half-degree numbers (e.g. 18.0, 18.5, 19.0, 19.5, etc.). I don't know for sure if that means timing is only delivered in half-degree numbers or not. I would assume it runs what's in the table...but, it can only report in the above fashion.
If you can, increase the number of decimals shown in your tuning software. Then, enter something like 19.02 degrees if you can. That should report back as 19 degrees in your log.
Well, like I said...the histogram shows 19 degrees. It's the chart that doesn't and I understand that it won't give unrounded numbers. I'll have to play around with it more. The car pulls really well though with the up'd timing...even as small of a bump that it was 
Is my MAP table suppose to jump around like that though? All the other graphs are pretty linear when I go WOT. It tends to bounce around a lot.
My exhaust sounds a little different also. Maybe I'm just paranoid. I'd like to finalize this tune, then go back to the original and contrast sounds, etc, etc...
It has been raining so much here lately (EVERY DAY) that it's hard to find a good time to go out and drive it at all. It's the garage queen as of a month ago...
Is my MAP table suppose to jump around like that though? All the other graphs are pretty linear when I go WOT. It tends to bounce around a lot.
My exhaust sounds a little different also. Maybe I'm just paranoid. I'd like to finalize this tune, then go back to the original and contrast sounds, etc, etc...
It has been raining so much here lately (EVERY DAY) that it's hard to find a good time to go out and drive it at all. It's the garage queen as of a month ago...
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Originally Posted by pdanrichey
Well, like I said...the histogram shows 19 degrees. It's the chart that doesn't and I understand that it won't give unrounded numbers. I'll have to play around with it more. The car pulls really well though with the up'd timing...even as small of a bump that it was
Is my MAP table suppose to jump around like that though? All the other graphs are pretty linear when I go WOT. It tends to bounce around a lot.
My exhaust sounds a little different also. Maybe I'm just paranoid. I'd like to finalize this tune, then go back to the original and contrast sounds, etc, etc...
It has been raining so much here lately (EVERY DAY) that it's hard to find a good time to go out and drive it at all. It's the garage queen as of a month ago...
Is my MAP table suppose to jump around like that though? All the other graphs are pretty linear when I go WOT. It tends to bounce around a lot.
My exhaust sounds a little different also. Maybe I'm just paranoid. I'd like to finalize this tune, then go back to the original and contrast sounds, etc, etc...
It has been raining so much here lately (EVERY DAY) that it's hard to find a good time to go out and drive it at all. It's the garage queen as of a month ago...
Don't worry though...I still gave solid advice regardless of the tuning suite used. LS1 Tech Stories
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That's just Britton. He makes a living by hanging out in truck stop bathroom/shower areas. Apparently the money is good, but I'm not down with that...
I raced a guy last night on the current tune. I could have beat him except he kept flooring it BEFORE the 3rd beep of the horn. Once he got the jump, I couldn't catch him until upper 4th and of course...while I'm creeping up on him, he lets off the gas and declares victory
. His car is pretty fast...ran a 7.5 in the 1/8th mile. Auto, big stall, lid & catback, LS6 intake (2001 SS), and a 100 wet shot on stock timing tables w/ some race fuel...
My guess, making about the same power as me except lighter...me having a vert plus 150 pounds in turbo parts.
I raced a guy last night on the current tune. I could have beat him except he kept flooring it BEFORE the 3rd beep of the horn. Once he got the jump, I couldn't catch him until upper 4th and of course...while I'm creeping up on him, he lets off the gas and declares victory
. His car is pretty fast...ran a 7.5 in the 1/8th mile. Auto, big stall, lid & catback, LS6 intake (2001 SS), and a 100 wet shot on stock timing tables w/ some race fuel...My guess, making about the same power as me except lighter...me having a vert plus 150 pounds in turbo parts.
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Joined: Jul 2005
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From: Keller, Texas
Originally Posted by pdanrichey
That's just Britton. He makes a living by hanging out in truck stop bathroom/shower areas. Apparently the money is good, but I'm not down with that...
I raced a guy last night on the current tune. I could have beat him except he kept flooring it BEFORE the 3rd beep of the horn. Once he got the jump, I couldn't catch him until upper 4th and of course...while I'm creeping up on him, he lets off the gas and declares victory. His car is pretty fast...ran a 7.5 in the 1/8th mile. Auto, big stall, lid & catback, LS6 intake (2001 SS), and a 100 wet shot on stock timing tables w/ some race fuel...
My guess, making about the same power as me except lighter...me having a vert plus 150 pounds in turbo parts.
I raced a guy last night on the current tune. I could have beat him except he kept flooring it BEFORE the 3rd beep of the horn. Once he got the jump, I couldn't catch him until upper 4th and of course...while I'm creeping up on him, he lets off the gas and declares victory
. His car is pretty fast...ran a 7.5 in the 1/8th mile. Auto, big stall, lid & catback, LS6 intake (2001 SS), and a 100 wet shot on stock timing tables w/ some race fuel...My guess, making about the same power as me except lighter...me having a vert plus 150 pounds in turbo parts.
The car was pro tuned on a very conservative level. I was just playing around with the timing (ever so slightly) to see what I could do. I picked up power, that's for sure.
Did you review my HPT logs? My IAT's were like 10 degrees above ambient ...about 70ish that evening outside. Good ol' FMIC does wonders!!
Not sure about the max torque...don't know what that is with regards to tuning.
I need foff in here!! He's the tuning guru!
Did you review my HPT logs? My IAT's were like 10 degrees above ambient
...about 70ish that evening outside. Good ol' FMIC does wonders!!Not sure about the max torque...don't know what that is with regards to tuning.
I need foff in here!! He's the tuning guru!
