New guy tuning 8.1

[azcagiva]

I have the v2 and have been tinkering with my 2006 2500hd 8.1 w allison. I was having trouble with the scanner program, but it works now with the new laptop.

I fixed the speedo to the bigger tires, I removed some TM and raised the torque rpm table ( I am at work now so no access to laptop to get exact labels).

I managed to get a log in yesterday and noticed that It is pulling about 5*(KR) at light throttle around 3000. I also had to stop logging because my damn static filled dog kept jumping over the laptop to get a better view of a cat we passed.

I can post the log tonight. I also noticed that I did not get the PID that the spark table uses in my log. I will get that in the next log. Is there a PID that tells me which spark table the pcm is using?

I also wanted to add that the truck is on propane.

Any help or comments would be appreciated.

Thanks

-John

[Chevy366]

Stock .tuns will do that , I bet you didn't hear the knock it just registered in the scan .
8.1L on propane , did you notice any loss of power ?
Is it , start/shutoff on gas then switch to propane ?

[azcagiva]

The propane system is from Holland. It is a Prins system. It starts on gasoline and switches to propane. Pretty cool system, it reads the gasoline injector pulse and depending on temp and pressure adjusts the propane injector. If you are not looking at the selector switch you cannot tell what fuel you are running.

I am looking to get a wideband so I can do some more tuning.

-John

[azcagiva]

Here is my tune and a log I did. If anyone has any comments or suggestions I would appreciate it.

Thanks

-John

[azcagiva]

In doing a bunch of research I found another tune posted on holden crazy. It was for a turbo 8.1. Anyway I noticed that they had the axle torque protection disabled. I tried disabling mine and the truck lost power. I changed it back and all seems fine. Anyone know why?

Thanks.

-John

[azcagiva]

I have been working on my timing tables. I played hooky from work for awhile today and tried a few things. I zeroed the burst knock tables. I also pasted in the timing tables from one of my medium duty trucks. The spark values were a little lower in the high load areas. The optimal timing table was the same for both trucks. I did some logging and am still getting around 4 degrees kr retard at medium throttle (2500-3000). So I have been trying to adjust the tables to try to get rid of the kr. In addition the truck feels a lot more driveable with the new tables.

While I was poking around I discovered that you can watch the log playing in the scan program light up the cells in the tune program as it plays. I used this to figure out where to pull a little timing out of the high octane table. It is a slow process and I am sure there is an easier way. So my question for someone, anyone, is there an easier way to set up the timing tables to eliminate the kr?

Hopefully this is helping some of you guys with the 8.1. If anyone is interested I can post the tune from the 09 c7500.

Thanks

-John

The learning curve is pretty steep for this program, but I am happy with the way the truck runs. I have been able to increase the fuel mileage by 2mpg and hope that I might be able to get a little more out of it.

I

[joecar]

Hi John, welcome to the forum

Can you hear the motor knocking...? Are there any physical causes that are making it knock...?

You can create a map of KR to look like the HO spark table (same axes), then you can paste-subtract this map to the HO spark table.

[azcagiva]

I am not hearing any knock but just watching the kr on the scantool pull timing. From what Chevy 366 says it sounds like this is how gm tunes are.

I dont think it will hurt anything I just noticed on all the custom tunes logs that I have seen there is no kr.

Is there any tutorial on how to set up the maps? I will keep plugging away and see what I can find.

Thanks for the response.

-John

[joecar]

Try this: How to Create a Map

[azcagiva]

I just finished doing some logging and using the map feature I was able to get the kr gone. Apspark stayed at 100%. Very cool and much easier than what I was doing. Thanks Joe.

Truck runs better than ever. I am installing new nb o2s soon and when I get a chance I will start on the ve stuff. I will try to get a wideband as soon as I can.

-John