I'm going to be tuning my timing at dyno Monday, so any help would be appreciated. I will be running 91octane

Motor is B16a stock bore/stroke
Civic Type R pistons/cams
ITR intake mani/ 65mm T/B
Hytech replica header with 2.5 exhause with single stage flowmaster
PnP head with flast valves and dual springs/retainers


I'm at 5,250ft and I never get past column 7 in my map.

Most tuned timing maps I see for na B16a end up with around 28-30* at full load after vtec in columns 9 and 10. But in the columns 6 and 7 they generally have more advance.... like another 4-6* and sometimes more.

You guys at altitude keep that kind of advance in your highest read column, or do you "generally" remove timing and see gains? For example, my basemap averages 30-34* advance from 4000rpm up in columns 6 and 7. But in columns 9 and 10 it averages 24-26* advance. Do you end up with less advance in your column 6-7 (or whatever you're at)? Something closer to what columns 9 and 10 look like or no?


I know the question is vague, but any help is greatly appreciated.




Modified by brokenojoke at 8:28 PM 7/4/2008

 

It would be more helpful if you were to convert "columns" into some sort of pressure reading. To answer your question to an extent, the less pressure you see the more timing you should end up with. You have less air entering the cylinder, which leads to less density, which leads to a slower burn.

If you're looking at maps from lower-alt cars, you should split the difference between the two columns, and increase if needed. You have less air entering the cylinder, but less backpressure to impede the exhaust. That usually leads to a cleaner intake charge due to better scavenging. So "column 7" to you is closer to a lower-alt's "column 8" since you have a higher O2 % at the same pressure.

 

I just found out (after already dyno tuning) that I can change the values of the columns.

I edit them to accomidate my high altitude, and it gives me more resolution instead of wasting columns 8-10.



And yes, you were right, it did like a lot of timing up here. More than the sea level maps.




Modified by brokenojoke at 4:11 AM 7/9/2008