ChopperDoc

To add a bit to spiders recommendations for decay rate, you can double that as he said as well as chopping the base attack in half. This also helps, and doesn't reduce sensor sensitivity.

My old PCM (97-98) was horrible with the LS3 sensors. It would show knock damn near everywhere, no matter what the timing was. It was even 0 in some of those spots, still showed 10 KR. I ended up filling up with cam2 110 octane and tuning the sensors down until it stopped.

With my "new" 0411, this problem is pretty much gone. On rare occasions I get 0.1 or 0.2* towards peak torque. This is more than likely other engine noise though, since real knock will show as a "stair step" on the scanner, and not those small "blips". Real knock will not get better on it's own. I was actually glad to see it because it confirmed my sensors were actually working with the 0411.

ChopperDoc

I will add though, that I didn't even touch the knock sensor settings in the tune I sent you. This is mostly because they were vastly different than my original settings, and even less sensitive stock than mine were in my older pcm tune. So I wanted it to show anything at all that the sensors were indeed working. I will still be making the changes spider and I noted, since I know they are working.

If you have to test the sensors, another thing you can do is log while tapping the header with a wrench. It should show up. I did this as well, as another confirmation that the swap was successful. I had to repin the entire pcm harness, so it was a possible issue for me if I had made a mistake somewhere. My first few logs showed no knock at all, wot or otherwise so this had me concerned given my previous experience with the older pcm. It didn't even show false knock at first, or burst. That's why I left it that way. I haven't had a chance to finish that tune yet for the new pcm and new injector data. Looking forward to it though.

ElQueFør

Thanks for the input guys! I'm going to take some time to digest what has been said and post back once I think I've mostly understood it and tried to implement the suggested changes.

I have spent most of my time using the AFR error % to tune the VE, but I definitely need to smooth it out!!!!

And the only thing I had done to the spark tables was to unify them, and try to definitely err on the side of conservative while I continue to get a handle on this, so I'm glad to know that I did that, rather than dump a bunch of spark in and blow something up.

ChopperDoc

The VE has to be completed before you can move on to spark. Like I said earlier, just make sure you have a relatively conservative spark table, and focus on that VE. Keep in mind, g/cyl (that the spark table uses) is based on dynamic air and rpm. In SD mode, the computer calculates dynamic air from the VE. That's why you need to get that nailed down before worrying about spark advancements.

If you are planning on using a MAF, then same thing, it has to be done before spark too for the exact same reason. If using MAF, then the computer will use that to calculate dynamic air (on most PCMs). On gen IV's it's a combination of both VE and MAF and some really crazy polynomial equations you don't really want to mess with (thank god it's built into the editor now). In either case, spark is about the last thing you play with.

Just focus on getting all your part throttle afr's as close as you can, up to 105 kpa before worrying too much about boost. That looks fairly safe on your current VE, as in high numbers, but will require tuning as well. Just don't go out and start doing wot pulls into boost right now. Work up to it. You can hit 105 kpa at pretty low rpms, especially with that turbo. Just creep up there and build your VE slope. Be patient.

You might already know this, but I'll say it just to be sure. It helps to set your hit counts in your histo up to at least 50 on your error. Some guys even do 100. Don't use small hit counts to set the VE. Also make sure you are using the average, and not the +/- or L symbols. Drive normally, as in very smooth, and try to hit as many cells as you can as many times as you can when logging. Hills are especially useful when trying to hit certain cells.

ElQueFør

Well guys I haven't been on the board in a few days but I have implemented the changes everyone suggested and smoothed out the VE and the thing runs real good and the idle AFR is decently lean now instead of stupid rich like when I started this thread.


Thanks to everyone for the help, especially: ChopperDoc, ddnspider, and Lsxford.

I come to you guys for a slightly unrelated question this time. Rather your guys' insight on a decision I need to make....

The T56 behind this turbo 6.0 in this 5000# truck finally crapped out today I think. It's stuck in 4th gear. Broken slider keys at best, or maybe other **** torn up at worst.

I'm finally making decent power with this turbo 6.0 combo and I'm now thinking that maybe it's time to hang up the T56 hat and put a 4L80 in here. I have two 4L80s already and I have both of them torn down ready to rebuild. One was going in another project I have but I'm thinking the other one needs to go in here. I have most all of the parts to rebuild one, and ATSG manual, and I have done a 4L60 in the past.

What do you guys think? To me, it almost seems better, more reliable, cheaper to build up one of my 4L80s and stick it in here instead of dicking around with a T56. At 6 pounds of boost, and in a 5000 pound truck a T56 is going to be problematic I'm afraid. That plus I intend to up the boost to 12 PSI in the future. I know a T56 can be built up to handle power, but the 4L80 seems to better option.

Here's what I'm thinking

The T56 is fun and the double OD is a nice feature. But no matter how much I build it up, it will probably always be the weak link here.

On the other hand the 4L80 being based off of the venerable TH400 is virtually bombproof as is. Also, the 4L80 will allow me to build boost even just brake stalling, and there will be no drop in boost between shifts like with the T56.


What do you guys think?????

ddnspider

iTrader: (26)

T56 are pretty strong....its not like its a 4L60E. If you had a 4L60E and it broke, sure no brainer to go 80E. Is this truck raced or just street driven? If raced, Id go 80E; if street driven then I would keep the T56.

ElQueFør

Yeah you're right man, I know there are plenty of guys that are going plenty fast even on stock T56s......... The truck is just a street driver/fun daily driver. I have no intention of bracket racing....... Hmmmm... Now you got me thinking....

I guess the good thing is I have options. I have two 4L80s AND two T56s including the one currently in the truck and stuck in 4th gear.

ddnspider

iTrader: (26)

If you'd like to donate any of the t56s or 80es I'll gladly pay the shipping to take them off your hands for you you got good problems lol.

ChopperDoc

Lol. I was thinking the same thing.

I'd go with the 80 simply because if you have a high enough stall in there you can build boost just sitting on the brake. That's particularly useful at the track, but also fun at lights when a Honda with a can starts barking at your door.

ElQueFør

I love rowing gears and it's been fun beating on the T56 for all these years, but now that it's behind something making some real power I just don't know if I want to do it anymore.

I thought about selling both of my T56s to buy a Magnum. But that is still going to be expensive and probably not as strong as a 4L80 of any kind.

And you're right about being able to brake boost sitting on the brake, that would just be awesome.

I'm now seriously leaning towards using one of my 2 4L80s, already have 90% of the parts to build it, I just need to figure out a shift kit and possibly a transbrake. If I already have it apart like I do, might as well add a Tbrake!

ElQueFør

Well I'm back on the road with the 3 bar pickup. I built up a hybrid T56 using a mix match of the strongest parts available. There's a thread in the manual forums about it. SSR 32 spline mainshaft, corvette triple double synchros etc. etc... It is SWEET!

Tune is still working good of course. Thanks everybody for the help!