2500HD LQ9 SS2 cam
Injectors, never used stock truck injector except my dd and I havent ever hooked the computer to it. But if your using hptuners it tells you what injector duty cycle is, if your not up approaching 100 percent duty cycle i wouldnt worry about them.
wideband, disable the down stream o2 sensors in tune and use one of them bungs for the wideband.
Timing, as I said never hooked the computer up to my truck but that may be the stock timing table. Ive seen quite a few people use fbody timing table in trucks before. I'd blend the 2 together.
wideband, disable the down stream o2 sensors in tune and use one of them bungs for the wideband.
Timing, as I said never hooked the computer up to my truck but that may be the stock timing table. Ive seen quite a few people use fbody timing table in trucks before. I'd blend the 2 together.
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Teching In
Joined: Jan 2019
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I took the truck out last night and did a rip up thru first and second gear. It hit a wall around 5-5500 rpm. This is where the timing falls below 20 all the way to 15-18. I suspect it's the lack of timing advance and possibly a fuel starvation issue. I can't see the injector duty cycle, but from the time I floor it, everywhere from 2500-6k, the LTFT for bank 1 is 8.6% and 9.4% for bank 2. My commanded AF during this is around 10:1, which I think I overshot it and need to bring it to 12.5 or so during power enrichment. But, even with the target of 10:1, it's adding almost 10% constantly from 2500-6k at WOT. I filled it up with 89 and added octane booster for about 90-91. I didn't see any spark knock but did this anyway just in case.
I went back and looked at data logs from before the cam swap and never saw the timing dip so low. I think what's happening is the new cam is building much more cylinder pressure above 4-5k putting it outside of the normal operating area on the spark table. I'm a little confused because on my data logs I can only see a table with MAP kpa on the x axis, but the spark table in the editor only shows airmass in grams on the x axis. I can't find anywhere to adjust to a common unit of measure between the two.
I went back and looked at data logs from before the cam swap and never saw the timing dip so low. I think what's happening is the new cam is building much more cylinder pressure above 4-5k putting it outside of the normal operating area on the spark table. I'm a little confused because on my data logs I can only see a table with MAP kpa on the x axis, but the spark table in the editor only shows airmass in grams on the x axis. I can't find anywhere to adjust to a common unit of measure between the two.
Plenty of shops have tuned cars and trucks by sticking their wide band in the tail pipe
A commanded pe afr of 10 will drop power for sure so get that right.
Disabling rear o2’s has no effect if set right. Google is you friend when just starting to tune, google disabling rear o2’s and you’ll have thousands of answers.
Again google advanced view for hptuners. Not sure this is still a thing but a long time ago when I updated I lost view of a lot of stuff I could change. Advanced view then brought it all back. As far as not seeing injector duty cycle again google it I think it’s called re-pull or re-populate available pods or something like that and then if it isn’t already on your graffiti you can add it.
A commanded pe afr of 10 will drop power for sure so get that right.
Disabling rear o2’s has no effect if set right. Google is you friend when just starting to tune, google disabling rear o2’s and you’ll have thousands of answers.
Again google advanced view for hptuners. Not sure this is still a thing but a long time ago when I updated I lost view of a lot of stuff I could change. Advanced view then brought it all back. As far as not seeing injector duty cycle again google it I think it’s called re-pull or re-populate available pods or something like that and then if it isn’t already on your graffiti you can add it.
