These are the tables I looking at using for a base tune for my 383.
with 306ish cam, 11.1 comp....
____ 4000 4500 5000 5500 6000 6500 7000
25 KPA 35.0 35.0 35.0 35.0 35.0 35.0 35.0
30 KPA 41.0 41.0 41.0 40.0 40.0 40.0 40.0
35 KPA 43.0 44.0 44.0 44.0 44.0 44.0 44.0
40 KPA 44.0 44.0 44.0 44.0 44.0 44.0 44.0
45 KPA 43.0 43.0 43.0 43.0 43.0 43.0 43.0
50 KPA 42.0 42.0 42.0 42.0 42.0 42.0 42.0
55 KPA 41.0 41.0 41.0 41.0 41.0 41.0 41.0
60 KPA 41.0 40.0 40.0 40.0 41.0 41.0 41.0
65 KPA 39.0 40.0 39.0 39.0 40.0 41.0 41.0
70 KPA 39.0 40.0 39.0 39.0 40.0 41.0 41.0
75 KPA 38.0 39.0 39.0 39.0 39.0 39.0 41.0
80 KPA 38.0 38.0 38.0 38.0 38.0 38.0 41.0
85 KPA 37.0 37.0 37.0 37.0 37.0 37.0 40.0
90 KPA 35.0 35.0 35.0 35.0 35.0 36.0 38.0
95 KPA 32.0 32.0 32.0 32.0 32.0 32.0 32.0
100 KPA 32.0 32.0 32.0 32.0 32.0 32.0 32.0


How do these look for now? Any comments or suggestions?

Thanks

 

I believe its a little high for the initial settings. What octane you talking? It might work for 93 or better.

Hal

 

Yeah itll be strictly 93 octane, 94 when its on sale on the weekends.

Does it look high throughout or at certain points? Should I post the sub 4000 RPM numbers also?

 

Matt, those numbers are a bit high for an initial tune, I would say step the whole table down 2-3 values and stop from there. You can always add more on the dyno. The important thing is to get your fuel table correct first, then move to timing

Don't concentrate on timing first cause you can have knock caused by a rich condition.

Fuel -> Timing

 

That sounds about right too me. Make sure there is enough fuel before you throw more timing at it. Lean+Extra Timing=BOOM

Know some tell me which value is WOT full load timing? Which KPA? If it's 100KPA that's not a bad place to start up there for timing @ WOT. I would imagine 32-34 is the range we are looking at, I'd be suprised if it likes less.

I'm going to learn this dam computer language. Translating Jet size to Injectory Duty Cylce and knowing what timing to run where is not going to be hard, it's what the computer says.

Bret

 

Bret, I have heard from Matt about your engine building skills, can't wait to met you one of these days. Don't forget this table is just advance, not total timing, you figure in the base timing to arrive at total timing, and yes 100kpa is WOT usually

 

In Edit were do you set the inital advance? 32 didn't seem like enough when I heard that for LT1's the chamber is just like a SBC one and I usually see 34-35 with good 23deg heads.

 

Not sure in LT1 edit, I don't use that program to tune

 

Hmm....I found this http://cmillard.freeservers.com/Z28/...rkAdvance.html

I found this too:

Load vs. Advance:

There are two tables, one for 400-4000rpm, and the other for 4000-7000rpm. These tables contain the commanded spark advance values for each set of RPM vs. Load values. If the rpm/load falls between data points the computer will average to determine the correct value. WOT values will be typically in the 90-100KPA range, depending on how much vacuum you pull at WOT. It should also be noted that there appears to be a separate value that increases timing at WOT - values in the table still change the total advance at WOT, but there is another value adding on to them.