I usually try to just answer questions and help people on here as most seem to be new to the 6.0 as I once was, but it's my turn to ask the powers at be to shed a little insight on a couple situations for me. I typically head over to PSA for the technical questions I have but seems like unless you are a part of the "group" there, or have a heavily modified truck, the vast majority of the guys that know these trucks don't bother responding. So, those of you 6.0 guru's that still cruise through the Nation from time to time... this is for you....
First off.... recently the ole girl has gotten laggy as hell. Like, mash the throttle from a stop and the gauge would slowly climb. Get on it, and boost would come on up to 22ish, but it wouldn't hold there. Just cruising around it would hover below 5psi until you mashed on it. First thought is sticking turbo. No big deal. Hooked AE
up yesterday to watch some numbers...
All seems well there... cranked the truck, cold engine at idle...
Seem right to yall? I know what the numbers should read KOEO
... just not sure what they should show at idle. EBP
does climb when you boost thought. Put the truck in gear, brought the RPM's up to about 1250, EBP
came up to like 27psi I think it was, 3lbs of boost on the gauge.
Next thought was VGT duty cycle. Immediately after cranking, it was at like 80ish%, but the longer it ran, it dropped. After about 10 mins of idling, it was down to 67.2%. Wasn't fluctuating around really... maybe up or down 1-2% at most. I assume that's acceptable?
Anyways, decided to return the truck to stock this afternoon and drive home from work just to see how she acts. Usually run Eric's AggStreet. To my surprise, no more laggy ole girl! Boost comes up as it should. Before I'd see 3-5 psi
with the cruise set at 65... stock file I'm getting 7-10psi at the same speed. Step on it, and it'll climb fast and hard to about 24psi, and actually hold it unlike before. Makes no sense to me. Why is this happening tuned, but not on stock? Also have Matt's SRL that I never run because the truck apparently hates it and shifts like crap (second issue). Loaded it the other day, and it's just as laggy as Eric's tune. Don't understand why tuned it's so laggy, but untuned it isn't. It hasn't always been this way. Been tuned for almost 40k miles. Only thing I've done differently lately is load up Eric's FICM
tunes. I don't see where that would cause this issue at all.
Ok, second issue is shifting. Truck hasn't shifted right since I bought it to be honest. Lately (past 6mths I guess), it has what I call a quick shift. 1-2 and 2-3 happen really fast... like before I hit 25mph no matter the pedal %. 3-5 will hold (will wind to 3200rpms if I'm on it hard enough), but then once it shifts to 5, it'll simultaneously shift to 6 and lock the TQ almost instantly. I've talked to Eric about this issue, and he's sent me numerous tweaks to that tune... only one helped to amount to much. The one that helped seemed to make the 1-2 and 2-3 shift hold a little bit.. still not like it should though..., but it will hold 3-5, 5-6 and lockup as it should. Unless I mash on it (45ish% pedal and up), it'll still simulataneously shift to 6 and lock the TQ instantly after making the 3-5 shift. If I'm on it, shifts are pretty harsh. 3-5 and TQ lock will almost break the tires loose on wet pavement. Jars the whole truck... way too harsh. Now... reverting back to returning to stock today. Truck shifted 100% better on stock programming. Some of the shifts are still a little quick, but it'll wind out the gears if you mash on it all the way through, and they are all smooth and instant. I don't get it. SRL... it's basically undriveable. It slams through the gears so fast I can't even count them. Super harsh, like if I stomp it, it'll shift all the way through the gears and lock the TQ before I hit 50mph. Spoke with Matt a while back and he sent me SRL 1.1 and 1.2 1.1 shifts basically the same, 1.2 sucks in traffic. It's like it wants to lock the TQ, but it won't. Don't understand why shifting gets worse the bigger the tune I run. Does this somewhat on my tow files, but not bad, and if I have a load behind the truck, the shifts are perfect.
Things I've changed recently...
New OSS sensor
No change with either. Part of me thinks its a biased sensor somewhere, but just changing sensors gets expensive quick. I've watched everything I can think of with AE
. Nothing looks out of the norm. VSS
matches actual speed, computer is commanding the shifts when they actually happen, etc. Talked with Mark K. some about it. He isn't familiar with AE
, so it's hard to translate the data I get to him. I'm going to talk with Eric again and see what he says. Just scratching my head trying to figure out what's going on. Was planning on pulling the turbo, EBP
and tube and cleaning this weekend, but now I'm not so sure I need to. The slow building of boost I'm sure is something simple and I'll figure it out eventually. But this shifting issue is driving me crazy.
So, what say ye gents? Any opinions? Sorry this post got so long. I get long winded at times when I'm trying to explain something.