Gen 2 tuning help

[JSD69Vette]

I'm going to try this again, this time I specified that it's the Gen 2 that I need help tuning with and I hope that drew guru's to the thread. Anyway:

I'm thinking that my tuning is off(messed up) using the GenII system.

Currently blm's are within range at idle (136), cruse condition (125 - 129) and WOT passes showed approximately 840 o2 and .5 knock (worst reading a couple different times) at anywhere b/t 23mph to 55mph.

Here's the thing:

to get those readings my GenII settings are as follows:

Mainscale: +25.5%

Lo load: 800rpm; -28%, 1200rpm; -30,5%, 1600rpm; -29.5%, 2200rpm; -28% and 2800rpm; -23.5%.

mid load: 800rpm; -28%, 1200rpm; -30%, 1600rpm; -28.5%, 2200rpm; -26.5%, 2800rpm; -21.5% and 3400rpm; -7%

no high load changes made.

Also, WOT spark is set at 18* across the rpm band. All other reading are within range

This plus on one side and minus on the other seems wrong to me.

In an initial reply from a member long ago lost that I just found, I was told to use mainscale to get cruise blm's close to 128 and then stop the car and place in park and tweak idle blm using lo load page if needed(b/t 800 and 1200 rpms). Once that is set use high load watching o2 millivolts and knock to set WOT fuel delivery. This assumed all GenII settings started at 0%.

Given my settings should I zero everything out and start over? If yes, is the above advise the way to correctly tune this thing? I'd like to get out to a local track this weekend but don't want to go there with this setup if I'm way off.

One last thing, this advise also said to set my monitor to read rpm and load in order to know what load points the high range needs to be tweaked in. It said that the GenII will calculate load during acceleration. I'm not sure how to do this, does the scanmaster do this?

Any help would be greatly appreciated.
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[Mike Licht]

If you set the mainscale to Zero and add 25.5% to all the other settings low mid and high you will have exactly the same thing. There is nothing wrong with what you have, it will work fine. I would add a bit of fuel at the 400, 800 1200 low load. What sort of fuel and boost are you running?
Mike

 

[JSD69Vette]

Mike;

I'm running 93 pump gas and 16#. This system along with the FP, AFPR, scanmaster, turbo and other pieces I bought thro you.

I went ahead and zeroed out the setting and started over and most reading seem fine, in gear idle blm is 138 and cruising is around 124 - 129 depending on rpm. Except now I have a 144 in park idle as well was when I got on the car hard at 40mph I got 812mv and 3.8 knock at 55mph.

How should I go from here eliminating the knock issue. Could it be the car doesn't like the 18* of base timing?

Thank you very much for the help.

 

[Mike Licht]

18 should be fine, you wil need to fugure out what RPM range the car is in at around that 55MPH mark and likely add some fuel there to the mid and high load tunes. It is likely on the shift that is knocks a bit. You need to look at this in small chunks not as one big piece. Adjusting timing across the board does not need to be done if you only have knock at one RPM point. Remember knock comes from too much boost or timing, not enough octane, too little or yes too much fuel. Every one of these things changes the other add octane and you can add timing, boost or both. Change boost and you may need to change another variable. Once you find a balance it gets much easier. In street setups I can usually start at 16/17 degrees of timing and 17 lbs of boost. Get the fuel right and then add some boost to maybe 19. If all is well I add some timing but not all cars will tolerate more. It depends on the car and the fuel in your area.
Mike
Mike

 

[JSD69Vette]

Mike, or anyone for that matter:
Do you have a technique for trying to determine what rpm you are at at a given mph when knock occurs?

or is it simply guestimation?

 

[Mike Licht]

powerlogger or some other scan tool thats logs to a pc makes it easy. Guessing works but takes more time and can be frustrating
Mike