jlayne wrote:
kidjedi wrote:
I know mass-hole has done some work on a 516 (the first tune I tried to load was one he made for me... looks like I wasted his time too [grrrr]). Maybe he'll chime in with some info. I can also send you the file he made for me, but I think he customized it slightly for my altitude (CO).
That would be awesome I'd be happy to try it. my email is jhlayne2000 (at) yahoo.com
Do you know what he has done with the program and what changes have been made for high altitude?
The tune has tables which can limit fueling based on ambient pressure. In the stock configuration the fueling isnt actually reduced based on this table because its low enough to begin, however, if you increase your fueling then then this map will also need to be adjusted to ensure you get your extra power. With his version of the tune I allow the increased fueling down to 800 mbars of ambient pressure, or about 6500' of elevation. Elevations higher than this and the fueling reduces up to 10%.
Boost is also limited based on ambient pressure. There are maps within the tune that will reduce fueling if boost is not high enough to prevent high soot coming out of the exhaust. While i dont completely eliminate the boost reduction, I decrease it enough to allow the increased fueling up to 800 mbar/6500'. The boost is still reduced compared to someone at sea level and will therefore increase soot slightly.
Finally, there is also a map which will reduce fueling based on coolant temperature. For some reason this map in stock puts peak fuelling at something like 50C and actually slightly reduces the power from 50C up to 107C. After 107C fueling starts to reduce somewhat quickly as a way to stop or slow down overheating. Knowing that I would be increasing the fueling beyond what this map normally allows for, I adjusted the peak fueling and changed its temperature to 98C knowing that kidjedi had a 95C t-stat, that way he would be able to run peak fuel at normal operating temps. My personal experience with the HDS t-stat was that it will swing from 93-97C during normal driving as the t-stat opens and closes, so that was the reasoning for 98C. In addition to that adjustment, I also increased the rate of defueling based on temperature. My own experience suggests that the cooling systems on these jeeps is not adequate to keep them cool on long, steep grades at high elevation with increased fueling levels. Since I now had the tune set up to run more fuel at high elevation I wanted to ensure that it wouldnt be excessively overheating during towing or just pulling big grades.
All of these mods I have done on my own jeep and have been running for almost a year now. In fact, I've completely eliminated the altitude boost limiter on my own tune and run quite a bit more fuel than the tunes I have written for other people, so my jeep is being pushed particularly hard. I live at 6500' and freaquently go up to 10,000 ft and I've found that the cooling system doesnt keep up with the tuning i have on mine when I am climbing big grades. So basically, I wrote his tune such that he would benefit from the extra fueling where he lives, but tightened up some limiters such as the coolant temp limiter to ensure it didnt cause problems under hard usage. It will basically react a little quicker to coolant temp increases.