Project: PolarRAM

[6DoF]

Originally Posted by Cobound

Gat damn, you got a Pro Eagle jack...dude, that might be the one most jealous thing I have on this thread

Super pimp, but even at $100 off, couldn't justify it

Yeah, this is heating season, bro!

yeah, i was pretty skeptical too ... but i'd buy another in a heartbeat without ever thinking about the cost now. they are THAT nice in the shop, and even better off road.

[6DoF]

got it up and working! love the light, but need to change some things around. also adding some extra detail.

i posted this in a FB 1st gen group and have been slammed with ppl wanted to buy one. i'm going to try and get the 3D printer files out there once updated for ppl to make their own.

[Cobound]

Originally Posted by 6DoF

yeah, i was pretty skeptical too ... but i'd buy another in a heartbeat without ever thinking about the cost now. they are THAT nice in the shop, and even better off road.

Dude, that's great to hear...I cannot stomach the cost.

Of course, if I did get one I'd be lambasted for it...you, on the other hand, are commended

Nice buy, dude!!!

[Cobound]

Dude, that lil deal is bad ass. Nice of you to provide the details for others to use...but damn, son, not everyone has a printer...so make some money - yo!

[xj_man_646]

you should keep the original stereo and use a bluetooth FM transmitter. New ones are really powerful. I did not have to change stations when I drove my f-250 from Montana to Minnesota. I'm almost considering swapping the OEM stereo back into my GMC because I hate the speaker they had to install to maintain the door / alert chime (as it comes through the factory stereo).

[6DoF]

no, i'll be swapping out the radio for sure, this thing is wonky at best. the speakers were swapped at some point back in the day, but could be swapped again n re-wired this time.

thinking about doing it with a new dash maybe ... but we'll see.

https://classicdash.com/product/1981...-8-dash-panel/

[nblehm]

Leave the heater box out and the turbo may heat the cab for you

[6DoF]

Originally Posted by nblehm

Leave the heater box out and the turbo may heat the cab for you

while heat is nice ... AC is even better!

[6DoF]

been a bit and still love the truck, so that's a win! even sold the GMC for WAY too much money, so double win.

the heater blower stopped working so the last guy wired in a huge constant duty relay and janky wiring. while doing the heater core i saw that the heater blower resister was unplugged and wondered if on purpose or not. decided ot try it, wired it all back to factory, plugged it in, and everything works the way it should now! janky wiring trashed.

the front drive shaft has no needles in one cap in the joint at the axle, and the CV at the t-case is blown out. but the NP205 front output also has more play than i'd like, so it'll also get a rebuild kit this spring some time. but while i was inspecting all this, i also saw that the 2 bolts holding the trans mount to the cross member were loose. one missing the nut entirely, the other nut was 2 threads from falling off

next major fix though is clutch hydro's. the master is leaking down and not giving me full travel. plus i guess a braided line helps get just a TAD more throw at the slave from less expansion. i also made an adjustable master push rod from the new one since the clutch pedal is a little lower than the brake and i could get a little more travel there too. if i can get just a weee bit more release this tranny should be much easier to shift.

but the biggest win was cleaning up the shop and organizing the 55. getting it back on it's own feet so i could toss it on some casters to get hank in the garage!! warm wrenching FTW

[6DoF]

oh, totally forgot i also bought another 12v

the nv4500 "swap kit" is for a buddy with a 96 who's auto is last legs.

so i've been having issues with the VE pump, basically cuz the truck is wicked up too much. First is the AFC (air fuel control) spring, it's WAY wrong leading to a lot of smoke and i assume extra turbo lag. i characterized the spring and ordered a selection of stiffer ones to hopefully fix the fuel map.

second, the pump will stall and just shut the engine off. with high boost comes high cylinder pressures, high enough that if i let off the throttle too fast it'll actually shove combustion back into the injectors and air lock them. the pump will shut down pressure faster than the cylinders and the poppet valves can't hold back enough pressure. easy fix, 3minutes to blead em and go again, but having to dead drift to the side of the road blows. if i let off slowly it's no issue, just a quick lift when trying to shift fast. the only fix for this is to swap on a P-Pump where this mechanically isn't possible. no clue when i'll finally swap it, but now i have the parts.

between not being able to let off the throttle quick, and the clutch needed to disengage more to shift easier, i actually spend more time shift than accelerating in a 0-60 run i believe the dyno numbers cuz she'll set you back in the seat when the turbo's light, but that's like these wee little glimpses of goodness.

[nblehm]

A solid looking garage line up

[6DoF]

so i started to play real tuning games with the injection. at full 60psi boost the smoke cleaned up so i suspect the injectors are sized close to properly. my research also suggests that. i know they do still put out extra fuel though since i have a dyno run where they fogged the air filter with NOS and it did make more power. 501hp to be exact. now down low they are a bit big at min pump output so i think no matter what she'll fart if i bog it on a start or smash the throttle at low R's. however, the middle ground could use some work.

i was told it had the stock AFC (air fuel control) spring in it, so that would bring in full fuel by 18psi. this spring acts against a diaphragm driven by the boost psi to compensate fuel.
needless to say it smoked a lot, and was way over-fueled most of the time. well i bought a 0-700lb spring pressure tester and characterized the stock spring. then ordered 5 different springs with the same OD and height, but different spring constants. this should let me pick a nice rate of change. i can also tighten the pre-load to adjust where it starts moving.

my thought was if i'm running 3.75x more psi, and i wanted the same travel in the diaphragm, i needed a 3.75x stiffer spring rate. functionally i don't think that's working though because of the minimum preload and stopping too much fuel down low. first test was the stiffest spring i got, and i couldn't quite get to full boost, so fueling seams limited up top. basically can't get the fuel to get the boost to move the diaphragm for more fuel. and that's with minimum preload. next spring is a mid range stiffness with more preload to start ... stay tuned.

[xj_man_646]

Interesting stuff. This might be one of the more in-depth dives into 12v 'tuning' I've seen, especially on the rotary pump engines.

For the p-pump engine, have you considered one of those adjustable fuel plates, so you can dial up the fuel when you want power but can dial it down to reduce smoke and gain fuel efficiency? I can't recall who makes them but it basically slides back and forth with an adjustment knob of some sort.

[6DoF]

the tuning logic is similar between the pumps, but the mods to gain min/max fueling are different, and obviously different parts. the P-Pump has a much wider range of operation to make all this easier, so i'll just start over at some point when i swap it.

the "in cab tuners" are way over priced to me. the big name, AFC live, is just a little box to modify the boost reference signal into the pump. an adjustable psi regulator, an orifice valve, and a bypass switch. basically set max fuel by lowering the max boost it see's, and the rate that fuel comes in by slowing the signal. the other is just basically an adjustable throttle stop inside the pump, again limiting max fuel. i'm going to build my own "AFC live" into the 55 for way cheaper. they are supposed to make a high HP setup easier to street daily.

the springs n screws still gota be set right in the pump though, these signal mods only fine tune that in one direction. something like the orifice might help mpg in the city, but you might be able to spool faster with more fuel for towing. not sure, still learning that part.

[xj_man_646]

Once you're into the smoke, more fuel is just a waste. Just keep that in mind as you are playing with it.

[Baby peez]

overfuel means you need a bigger turbo right?

[xj_man_646]

Originally Posted by Baby peez

overfuel means you need a bigger turbo right?

He's already got two .

He says it cleans up under full boost so I think peak fueling is appropriate for the turbo configuration. Just needs to tune up the other areas.

[xj_man_646]

Duramax. Cheap. Reliable. Ha!

My dad had an LBZ swapped Suburban and that thing was a nightmare. He had to deal with problematic injectors, fuel filter head, and injector return lines before giving up and sending it back to the builder. None of that should have had to do with the swap. The drivetrain had just over 100k miles allegedly.

What planet do you live on that anything associated with a Duramax is cheap???

[Cobound]

You dare question wrath's knowledge of such things - prepare to be schooled

[6DoF]

i started looking for a stock truck to ruin on my own, but this ultimately is a faster learning curve and more fun.

the weather turned sh!t again so i can't get enough traction to test for full boost. i think i still need to tighten up the AFC pre-load, but we'll see. i might never be able to get no smoke ever, but i'm now to the point that only the hippies would be mad.