When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Making some good progress with the tune, I can cruise around at a respectable AFR(13.5-14.5) depending on load, grade, TPS etc. For a while I was having an issue with stalling while coming to a stop. After researching a bit and messing with the Throttle Follower/Cracker settings the issue is nearly gone. Next I will begin tuning the shift points, the 4.8 combined with a ZO6 camshaft and a 4L80e leaves MUCH to be desired. The 4.8 simply does not have the low end torque to support the factory low speed shift points. I have attached a spread sheet in which I have outlined purposed shift points that I intend to implement when I get home from work.
After that I will work on the Main spark table, so far I have only made 3lbs of boost but I noticed while looking at the log file that my spark advance was around 30*. I imagine this is much too high, I will need to research further what defines a "safe spark map". If what I have read is correct, 4.8's tend to like more total timing than its larger brothers. Is this a correct assessment?
I made some decent progress on the car last night when I got home. It didn't occur to me that a segment swap was necessary on the newer HP tuners v.3.6, this assumption was based on my ability to swap between predefined transmission in the program. Long story short I had not been logging which gear I was in on the scanner, come to find out I was starting in 2nd. I honestly thought that something was amiss with the transmission. I got the segment swap done and now the truck runs like a bat out of hell. No more stalling at stop lights, odd AF ratios off idle, etc.
Progress so far
Now before everyone starts saying my AFR is a bit lean, YOU'RE RIGHT! LOL, I need to adjust the PE to come in sooner and fatten up the BE to make a seamless transition resulting in a safe AFR. I think the spark is pretty safe for a 4.8L, what do you guys think? On a side note I don't think my KR PID is working correctly, does anyone have any tips for setting it up?
put it on the dyno the other night, WG spring maxes at 7 psi. I didn't have time to change it out so I ordered a manual controller. Overall I'm pleased that it put down 350hp/350tq at such a low boost level. This is an approximate 18hp per pound of boost increase over stock. I guessing the 4l80e and 3k stall aren't helping the numbers either.
In two weeks when I install the boost controller and ditch the flowmaster exhaust I should be in the 450hp range at 12lbs. To recap, this is a 4.8 truck with an LS6 cam/springs and a small MP turbo. it has excellent street manners and cruises like a dream. Perfect for someone who wants a DD sleeper.
07-09-2017, 07:33 AM
