CK5
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'89 K5 The Bulldozer

1989 K5, linked, caged, backhalfed, LS3, Hero case, on 42's
The prognosis is not looking great. Might have to make my own shims to get this to work. The axle seems to have moved quite a bit. I only need a monkey because I've got the football here. In other news the pinion tests great.
 
Ring gear has about .0025 runout. I got the backlash to .004 to .010, lol! Got good preload. Took .015 more carrier shim. We'll see what happens.
 
Ring gear has about .0025 runout. I got the backlash to .004 to .010, lol! Got good preload. Took .015 more carrier shim. We'll see what happens.
I don't know if a "like" is appropriate for that post. That isn't grand news in some of it.
But at least you are making progress!
:waytogo:
 
I don't know if a "like" is appropriate for that post. That isn't grand news in some of it.
But at least you are making progress!
:waytogo:

Definitely no like. We'll see how much longer it runs for. That setup has been on the truck since I built it, and its gotten good use. I bet it'll run for awhile longer. I have no idea how long the carrier was loose but it was long enough the gear wear pattern was junk and all over the place. I split the patterning differences to give it the best chance it has at survival. Then I took a blue sharpie and wrote stayin' alive on the ring gear.

Realistically, I bet the issue happened just within the last few runs. I don't think I would have made penrose with a loose carrier, I would have probably broken the ring gear.
 
I think if I was going full tilt buggy, that a 14b center section would likely be a front runner

I still consider my rig a truck. It is hydro and backhalfed on links etc. But its still a truck that I do drive to the trails. With the fact that I've got it still streetable at highway speeds I'm certain I can make any axle work. I do have lockouts, but I carry drive slugs just in case. So that setup can be kept if going 14b center and 60 C's.

But weight is always an issue and I've spent alot of time shaving weight where I can. This is more or less me thinking about my options for the future if I need it.

A dropout third would be awesome....
 
I still consider my rig a truck. It is hydro and backhalfed on links etc. But its still a truck that I do drive to the trails. With the fact that I've got it still streetable at highway speeds I'm certain I can make any axle work. I do have lockouts, but I carry drive slugs just in case. So that setup can be kept if going 14b center and 60 C's.

But weight is always an issue and I've spent alot of time shaving weight where I can. This is more or less me thinking about my options for the future if I need it.

A dropout third would be awesome....
Other than a 9" all of your drop out 3rds would be aftermarket.
But I'm not sure a 14b is "that" much heavier than a d60 center
 
Randy Slawson has a few used ones he'd sell you...

Aside from the possible ratio issue I'm not sure I'd want to travel down a road which ends up with me trying to find parts and then tripping over Doug's axles as well. That is the beauty of anything 14b.
 
So with the whole covid thing going down I decided to change my game plan and get some other things checked off the list, that weren't even on the list.

I started working at finally getting the idle tuning fine tuned. The truck always idled pretty good, but it did it at an overspeed rpm area and pulling timing in Park, then adding timing for drive.

First things first I wanted to tweak my main spark tables a bit before moving on. Got that done and feel pretty good about it. Correct way is on a dyno finding MBT but I don't have one of those. So I get close, and conservative.

After that I spent a good bit of time chasing my tail. One of the problems that was left unattended to when I first tuned this thing was the segment swap sections talking to each other correctly. I used a manual trans 2002 Firebird (0411) for the engine and a 2002 Express van with 4l80e for the tranny controls. Well we had gotten the truck to idle decently in a haphazard way then moved on to MAF and VE tuning. Got that all dialed in very well on the road and on the trail. Then Ed passed away. He was the one teaching me HPtuners.

So I still have all of his coursework and paperwork and I'm going through now teaching myself the adaptive idle sections.

First I had to get the swaps talking to themselves better. We had the truck thinking it was a manual and using the adaptive timing to work Park/Gear idle. BRAF was ok but wagged. The Tilden 102mm TB has an IAC that's really weird. It wants steps at a different number, even with the correct scalar. But it operates well and desired/commands well. So I kept those values the same.

Finally got the segment swaps talking to each other well just now. Needed the trans to think it doesn't have a Gear selector switch, but tell the ECM it should be watching for one. Got that done so now I atleast have adaptive idle control on both sides of Park and In Gear and can utilize the different tables and different STIT/LTIT values.

Right now my plan is to utilize different timing between the two. 18 in park and 22 in gear is my first guess. 26 degrees is my max vacuum at idle (about 23KPA) with no change all the way to 29 degrees. Have to see how it works out. With the full hydro I've always defaulted to a higher idle to keep pump flow up at low rpm. I also want large ECM rpm sag control on decel. It needs to be smooth. This theory gave a decent step in driveability as the flow stayed fairly linear during driving.

So now its time to log the BRAF in park and drive. Sucks because you've got to let it cool down to dead-cold. And as cold as possible. So now its a waiting game to get the entire block down to as cold as possible, then log.

full
 
I don't want to jinx anything, but I think I've got one major issue figured out. I've always fought it, and always need to work around it. The segment swap issue. There can be a PRNDL to ecm pickup issue (Even if the ecm can see the different selectors being applied). This gives random in-park desired idle rpm numbers. Once a gear change is performed it resets correctly. From reading what others have dealt with this seems to be an issue only when combining a manual engine OS with an auto trans program.

Now I can really get the BRAF dialed in. Granted I still don't have a Park/Nuetral desired idle step down vs ECT. But I'm ok with that, because once the gear selector is moved a single time it will pickup those desired idle rpm numbers from the In Gear table. It may be something I need to think about only if the truck is started in really really cold weather (Like negative temps).

For anybody reading this in the future. What I did was to limit the max in-park idle RPM to 775 (my desired operating ECT numbers). I also changed my table for PN AC Off and AC On to the 775 rpm. Left my PRNDL setting to none (tried all of them). This so far commands 775 no matter what.

Before finding this combination desired idle in-park would give random values (478, 978, 673, 1000 etc...). It would be some sort of lookup value with KOEO and continue that value all the way through start and all the way through every ECT bucket range.
 
Your posts made me laugh because I was like "I don't even know what all that means". :rotfl: Way over my head, but hopefully you've got it figured out. :waytogo:

It remains to be seen. Sucks that you get 10 minutes of data logging, only to have 4 to 8 hours of waiting to let the engine block cool down to ambient temperature. The good news is even if I left it alone it would be totally fine. It idles so well anyways that its more or less a thing of 'I can get it good like the factory'.
 
Ok. We are moving in a direction, I believe I'm getting closer. A big unknown and wonder was the IAC steps vs effective area. This is generally something that is a big tune area anyways. When I first got this engine package and Throttle Body it had a really weird set of IAC steps vs effective area in it. It was really one of the only tables changed from a 2002 Firebird. And it was changed big time. The TB was a Tilden TB and we were able to get it to idle smoothly and work the range using those values (whereas more traditional values the IAC did not like it at all). So there was always a question about the stepper motor itself. My original thinking was: The shop whose name is on that Throttle Body put in these weird values for the IAC on their throttle body, there must be something to it, AND they didn't change anything else on this ECM.

Now that the rest of the tune has been completed years ago I'm relooking at those values. I led myself down this path by looking at the data. Technically Base Running Airflow should wind up very close to the Dynamic Airflow numbers, as long as you tuned correctly. That's what the engine wants, but the STIT and LTIT idle trims and BRAF numbers want to be much higher to get the dynamic air in line. I believe as a side effect this is dumping too much fuel, bringing idle up, making the adaptive reduce timing which reduces torque. I don't have my head fully wrapped around it yet as the wideband shows stoich, but it was running way rich (via smell) as I was telling it it needed more air (hence dumping more fuel). I wonder if the low airflow AFR readings are funky and not correct due to such low airflow.

So I just changed the IAC steps to a more traditional value and data logged. The engine liked it alot, but I haven't poured over the data yet.

BTW, if anybody is reading this whole thing and has anything to add or help me on the path, please do!
 
I decided to ask for help on the Hptuners forum. Things are looking semi good, but then not so much. When changing the IAC to a more normal range the IAC goes from a decent range in gear to a positive range in park. Which then presents an overspeed condition and dumps the timing while still giving overspeed rpm.


If you've got HPtuners here's my data logs. Cold Park to temp and Cold In-Gear to temp.
 

Attachments

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Swapped in the Delphi IAC. The in-gear idle trims over multiple starts, and IAC position showed good repeatability. Re-enabled park/neutral position adaptive airflow parameters and the park position IAC was reacting correctly.

I'll also say the new IAC feels much quicker. The engine reacts quickly during initial park position startup.

Of note is the old IAC is also a Delphi IAC. Unless its a knockoff with the same delphi part numbers on the outside of the plug.

Anyways, time to log and get the trims inline. I'm hoping now I'll have good data I can use. Tonight around 10pm I think the truck will be cool enough to do a cold to temperature log. I've got the fans on the engine block right now.
 
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