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Discussion Starter #1
I have the new, to me, HY35W on the '94 NPR.

I don't have the install finished as I'm waiting on a few parts (mostly hardware) so this is a glorified mockup at this point.

First lets see the turbo.



I'm fabbing a heat shield to go between the down pipe and the Vacuum pump.

I have the factory oil drain tube modded to where it fits the HY, I slotted the bolt holes, have to see if that remains leak free, I hope.

I had to make a spacer to have the compressor housing clear the exhaust manifold, and of course I don't have a pic of that at the moment. I do however have a Pyrometer probe (type K thermocouple) and a drive pressure tap in it.:D

Ignore the coffe can, it's a cap in case it rains tonight (I'm through with it for the day).

The cobra head just clears the front of the box, I expect it to rub occasionally, but I've cut and sanded the stub that goes on the turbo inlet as much as I figure I dare this time around. I plan to keep an eye on it.

I have the oil feed plumbed in though, here's a closer picture.



That's the factory oil line with the banjo fitting cut off, the first fitting is a Swagelock brand 10mm compression fitting, to 1/4 NPT, to a Female 1/4 NPT to Female -5 (5/16) AN / JIC (37*) swivel. The 90* fitting is a -5 to 12mm (IIRC) X1.25 O-ring fitting.

Some of you may know any one of those will drive a hydraulic shop into appoplexy, all 3 in one, don't tell them you have it, they won't let you in the door.:eek:

More pics to follow.
 

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Looking good Erik.
 

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Interesting.
I don't suppose you got any baseline measurements from your original turbo?
Actually, what was your original turbo? Wastegated or freefloat?
 

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Discussion Starter #4
Dougal

It was the free floating TB25, it was damaged so the measurements I have aren't particularly usefull (except as a 'the new one is better / worse than the broken one').

The best the old Garett was able to repeat was 7 psi boost pressure (absolute best of 10 ish, once) and that was extremely jumpy, I had to average the needle swing to get 7 as the boost was so unstable. So much so that I believe the boost compensator was allowing the extra fuel, but the reduced / unstable airflow was causing the engine to trip the overheat defuel in the computer (the one that controlls the exhaust brake and glow plugs has a 'safety feature' that partially defuels the IP, by applying vacuum to the altitide compensator, if it thinks the engine is going to overheat).


My biggest concern that caused me to change the turbo (as opposed to trying to fix the one I had) is for more altitude capacity. It may not work out as well as I hoped, but the last time I had an NPR stateside it ran allthe way out of power at 3500 feet (2nd gear, 15 MPH, black clouds of smoke, probably better I didn't have a pyro on that one :eek: did it more tahn once).

I would be satisfied at this point with factory rated power, and the ability to maintain it to a higher altitide. We'll see how long that satisfaction lasts. ;)

I do have some anecdotal evidence of the vehicle takes roughly a certain distance to achieve a specific speed, over a fixed course. Also I have a rough idea how long it takes to climb a certain hill around here, but I don't know it's slope (vehicle weight I have written down somewhere though :) ).

Biggest gripe I've got at the moment is there isn't really a road with enough elevation anywhere close to me to try the 'altitude compensation' part of my theory.



On another note, some of you may have heard I wanted to slightly flare the downstream exhaust pipe to make the joint more of a fillet weld. I was unable to maintain the accuracy of the angle on the pipe required to do it that way. Most places the exhaust runs it's in a wide open space, but between the belhousing / flyweel adapter and the frame gets fairly tight (for a 3" pipe).

I have a new, to me, exhaust brake on the way, off an Nissan, and it's supposedly vacuum actuated as well (like the 2" one I'm removing) so that should be a fairly quick install.

I'm hoping the 3" flex joint I ordered gets here today, along with the 12 point nuts to hold the turbo on. There's one spot that won't accept a standard 17mm wrench size nut on the turbine housing, so I have some 12 point ARPs on the way, claimed wrench size is 12mm. I'll use 4 of those as I hate having different wrench sizes doing the one job.:rasta:

FWIW the turbo mount threads in the manifold I have (stock style, but I suspect it's a Chineese copy) are 10 X 1.5 mm.
 

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Discussion Starter #5 (Edited)
It was Christmass in July today, all sorts of stuff I was waiting on got here today.

Amongst other things I got the new to me exhaust brake and the compressor discharge elbow and clamp for the turbo.

I spent a good part of the day 'adjusting' the heat shield for the vacuum pump.

Here is an overhead shot, showing it missing the thermocouple lead. It picks up two bolts ino the manifold and has a brace that comes from the vertical bolt to a point lower on the shield so it doesn't rattle or flop (as much).





I also got the 12 point ARP nuts for the turbo, how tight a fit was it? I not only had to grind most of the flange off the nut, I had to grind the wrench down too.:eek:



I used a band type clamp to attach the exhaust brake, I added tabs that pick up a bolt on each end (one to the pipe from the engine, one from the exhaust brake) so it wouldn't just blow off.

I may have to add a secondary tab opposite the ones I have now to keep it straight, we'll see.

 

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Discussion Starter #6
Aparently I'm only allowed 4 images total (smileys or pics) per post, still have my blue star (or at least it's still showing up) so here are the rest.

......I also got the flex coupler for the exhaust, it's welded onto the pipe from the exhaust brake, it is between the exhaust brake and the soon to be installed muffler. The jack stand will be replaced with an exhaust hager somewhere on or immediately next to the exhaust brake (that sucker's HEAVY). I plan for that to be cantilevered off the trans so as to keep that part of the exhaust moving with the engine and allow the rest to flex (it's what the coupler's for, isn't it?).



Please ignore the fugly weld, it has yet to be dressed or painted.


I got the compressor inlet to air filter tube done today, not the prettiest, but functional.



I have yet to get the brace attached to the intake tube, it picks up a stud on the head. Even without it there is a fair amount of room to the cab (none to speak of to the box though).



The only issue I'm encountering now is a slight size miscalculation by me. I got the discharge elbow today (thanks Scott :) ) and discovered to my surprise (okay, chagrin) that it is a bit more gradual of a turn than I thought, if I turn it forward towards the charge air cooler and piping, it doesn't clear the driver's side cab mount. If it wasn't a tilt cab, I would be tempted to relocate the mount, but I don't have time to do that, soooo, I'm debating to either turn it down and aft (as is in the last pic) with a snake of a tube under the left front corner of the box to get it headed back forwards.

Or I can point it straight up, and have a similar issue but in plain sight (and it would be potentially more in the way if I had to work on anything.

So, tentatively, I'm going with the aft, down, around, over the river and through the woods route.

Regardless of which way I do it, I'm going to have to move the coolant recovery tank, oh well.
 

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......I also got the flex coupler for the exhaust, it's welded onto the pipe from the exhaust brake, it is between the exhaust brake and the soon to be installed muffler.
That's a good place to put it. On my 2003 NPR, the flex coupling was between the engine and the exhaust brake. I'm not sure if it was the back pressure from the exhaust brake or old age but it leaks like crazy so when the brake valve closes, there is a lot leakage from the coupling, thereby reducing the effectiveness of the brake.

Be sure that the brake valve is ridgidly mounted to the engine so that there is not movement between the engine and the brake otherwise you will eventually crack a pipe, or worst yet, the turbo housing.
 

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Discussion Starter #8
Yes, I plan to anchor it with some small amount of flexibility to the trans, as that will move with the engine too. I have yet to install the brace beteen the exhaust brake and the turbine housing (the factory had one at the belhousing, so I figure I should too.)




IT RUNS bounce

I have no video, yet, as I'm off to have 4th of July festivities with the family momentarily.


It has a completely different sound. Normally it sounded like an old model T. Now all the tinny sound is gone and it sounds thraotier (larger pipe will do that for you) it almost sounds like a CAT (aka Clatterpillar ;)).

I wasn't able to get it to bouild boost on the gauge, but it's not driveable at the moment and I wasn't expecting it to make boost parked.

I can however hear the turbo begin to spool as I rev the engine (if I power brake it it really starts to spool, but at that point I'm not looking at the gauge :eek:).

I was able to feel one of the IC silicone couplers inflate in my hand as I revved the engine with the other hand though, so there's hope.:D

The exhaust brake is working (closes when it's supposed to) but I expect I'll have to adjust the mechanism some to allow it to close a bit further (it's off a bigger engine).
 

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Discussion Starter #9
I put the muffler on (loosly) and it made an amazing difference, I can't hear the turbo spool anymore.:confused:

I have a video, it's uploaded to Photobucket, but it's took a really long time (I have a Cable connection, it took about 5 minutes:eek:) so I may try to shoot another one, or figure out how to cut down on the resolution with some editing software.

I'll play with it a bit as I don't need to post something that will take several minutes to download.
 

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Cool, the video took about 10 seconds to come up for me. you wont get any boost in park, you will have to be driving it to get any boost to come on, these things need a load on them to make boost. I suspect you will have quick spool with that turbo since I believe it has a smaller compressor wheel than my 03 hy35 ( at least I think it does if I remember right), Cant wait to hear how you like it.


Have you found a spot for the second turbo later on???? :D
 

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Discussion Starter #12
If I had the allison and a rebuild with a '1T head and pistons (ARP head studs too) I would mount the HX52 sideways behind the cab and turn the HY35 around so the compressor inlet would face forward (turbine interconnect pipe would be about 8" long that way).

I got it to make boost, the needle made it to 2 whole PSI, with it in drive, and the brakes on, I only wanted to see it make some boost on the gauge, it started turning the right duals when the needle came up off the peg.:eek: It didn't do that before (especially with brakes and the park brake on).

I lifted as soon as it started to do that as filling the garage with gravel and burrying the right duals to the axle wasn't the goal.



I have the exhaust assembled and hung (no more jack stands, yay :D). I may have to add another pipe hanger to the aft end of the flex joint as it jumps up and down some at idle (I can't see that being good for longevity).

The intake pipe is supported and away from the box and cab, painted too.

I'm working on the wiring for the tail, brake, turn, and back up, I'll pick up a few splices tomorrow in the am so I can finish that. Then I can test drive it.bounce:D
 

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Discussion Starter #13
Wires R in.:)

Test drive was good, more power, boost up to 12 PSI consistently, more stable too.

I notice the pressure falls off when it's lower engine speed, I suspect that a bit more fuel would help that (it makes 12Psi from roughly 400 RPM before it shifts till it shifts, small spike of boost to 13 maybe 14 Psi then down to 8 or 9 to climb back up the rev range, but it does it every time :D).

I had to cut the test drive short as the interconnect between the turbo and the plumbing to the charge air cooler came apart, I may have to lengthen the one pipe a smidge to keep that from hapening again.

I have yet to hook up the pyro, I have to snake the extension cable down through the floor of the cab, and route it safely back to the Type K.

More news tomorrow or the next day at the latest (I hope).
 

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Discussion Starter #15 (Edited)
Dougal, it's a 9cm housing, I know but Holset doesn't publicly use A/R, as I understand it, that's the cross section of the gas path in the scroll when it just gets to the point of being tangential to the turbine, before the housing starts to turn (as it wraps around the tubine).

As for an engine speed, I would guess 10 Psi @ 2500 ish, I don't have the tach in, yet, more on that later.


I have what Ithink is a small exhaust leak betewen the tubocharger and the exhaust brake. I can hear what sounds like an air hose leaking when the exhaust brake is working. I initially had a larger leak as the band clamp I'm using doesn't have a flap to bridge the gap between the bolts. I expected that was going to leak, but had heard enough BS from the salesman that I wanted to try it, hoping to be surprised, nope.

I installed two pieces of .005" stainless shim stock (I have an assortment) on that side to plug up the leak, they were slightly different sized pieces so that there wouldn't be a .010" step for the clamp to try and seal.

Fist pic is the spacer that goes petween the ends of the band that the salesman wanted me to believe was going to seal the pipe, it is radiused on the end that touches the pipe, bue you still get a leak between the band and the spacer (so that would be 2 leaks one abbove and one below as I have it installed).



The next pic is of the two pieces of shim stock placed inside the band.



One wraps around the pipe and the other is sticking out at the top.

It helped, but I still get the air leak sound when the exhaust brake is on, I'll have to give the system a better going over once it's cool.

I had to fix the hot pipe so it wouldn't come apart again, here's the way I was it when I looked.



The black rubber piece is a 3" to 2 1/2" adapter, I had visions of having to fab it in metal, fortunately there was another issue at play that I didn't find untill futher dis-assembly.



That's the way it came out, not the way I put it in, so I figured if I could keep the adapter from running away from the interconnect, I could keep the interconnect attached.

More in the next post.
 

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Discussion Starter #16
I was afraid when I fabbed that pipe the adapter might try that, so I welded two beads on the pipe.



The one on the end kept the pipe from blowing out of the adapter, but the one that's supposed to back the adapter up, didn't. I was hoping the T bolt clamps I'm using would hold tight enough, but even they need a fighting chance.

The fix I cam up with was to cut a 'backup flange' out of plate with a hole saw (2 5/8" for the 2 1/2 pipe to go over the beads).

Nothing special, just plate and a hole saw.



I bored the hole, then I cut the piece roughly to shape with a sawz all and finishe with the grinder (after I welded it on).



With a little paint and another test drive, it stayed put.:D

I got the pyro in, more in the next post.
 

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Discussion Starter #17 (Edited)
So I got the extension cable for the pyro snaked through the engien compartment and up through the cab floor, and found that the Hewwet lead didn't want to fit the SW gauge (one of the rings was smaller than the other). I butchered the red wire ring with a drill (no, no incriminating pic of that) but I was able to use it still after bending it back into shape with pliers and using the copper washers suppied by SW to sandwich the ring under the nut.

I have the gauge temporarily mounted in a 'lightweight composite mount'.



What? ;)

I haven't gotten the new Isspro boost gauge, tach or trans temp gauge in, yet, I plan to put the trans temp probe in the aux filter housing I hope to get installed before we leave.

As I don't have the new boost gauge in, I'm still using the old one that's racer taped to the front of the box. It's what I plan to use for a drive pressure gauge, once I get the new boost gauge in, yeah, maybe I'm a wuss, but I just don't want to pipe exhaust into the cab.

So bear in mind, when I want a boost reading, I have to look over my shoulder.

Driving though ouur 'test course' I was able to maintain more speed going uphill throughout. I only exceeded 900*F in one place that will max out whatever you are testing for that (climbing right hand turn, breif 14% grade or so I'm told). That's with 11 psi of boost and approximately 2700 RPM, it got to 950 there (yes the type K is before the turbo).

The most it gets to on level ground (till you get to freeway speeds, just under the defuel governor) is just over 800* with about 8 Psi at roughly 2000 RPM, lower in the rev range, it's 650 ish with 5 or so Psi. I didn't get a look a the boost at 70, but the pyro reads 875, (it's hapier at 60, closer to 700).

I have been thinking of taking the seal off the "more power screw" (mine has a plastic cap over it) and taking a turn or maybe two so I have a bit more boost at lower RPM as I don't think the turbo is making enough air for the engine to put out full rated torque at the lower rpm ranges (I would like to get to, say Dougal's 10 Psi, at something closer to 1500 RPM).

I figure with the info I've got here the turbo needs more heat (fuel) to make more air flow, as opposed to a waste gate adjustment (the actuator has a threaded rod that accepts the tab that controls the gate).

What say you, that I haven't put to sleep by this point?;)

Is it unreasonable to want that 10 Psi that low in the range?

Or should I leave it alone? If so please expain your reason why.
 

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I'd check your probe extends far enough. Mine pulls 430-450C pushing a rangerover on flat ground at 100km/h. That's also 8-9psi but at 2000rpm.

Don't wind up the fuel until you know you've got a true reading.
 

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Discussion Starter #19
Dougal, the probe extends to the approximate center of the exhaust stream, I took the sandwich adapter (spacer) it's mounted in to the shop I bought the probe from, specifically to ensure it wouldn't be too short.

It is a non exposed junction, so there is a slight delay in the reading, but not much (the tip of the probe is smaller in cross section, but the junction is still enclosed).

So lets see

(*C)(1.8)+32 = *F (roughly)

sooo 806-842 *F (again roughly).

(100 KMH)(0.6214) = just over 62 MPH

1/3 less frontal area, but roughly the same CD I expect;).

Hmm not sure how to account for the difference in engine speed VS ITT, especially since mine is a guestimate.:rasta:

Yes, I definetly don't want to cook anything.
 

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How big is the probe? I have two, the 6mm one was very laggy. To the point where it's useless under any acceleration. I run a 3mm now.

Come to think of it. I had peak EGT's of only 500C or so back when I had fuel pump problems. My boost aneroid was worn out and kept reducing fuel. So maybe your probe is accurate and your problems are similar.

The main problem is, not enough people have baselined the factory engine.
 
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