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#30 by Gizmoman on 02 Mar, 2014 16:53
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This is where the V band could go if you want next time. That makes it so easy to add another 180 section whenever this rusts off. You aren't in Ohio so you might not have to worry about that much.
Yeah, the one I ordered will probably arrive tomorrow
The 180 had one weak spot which I patched with some 10 Ga. Stainless would be the way to go next time (although I hope to never take it off once it's running again).
My wife keeps asking when the camping part starts
.
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#31 by theman53 on 02 Mar, 2014 19:02
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Man I wish I had the cash Id have you make me a downpipe flange and an adapter plate!
Besides no time, the tough part would be the fit-up which needs the car, and the turbo mounted. Took about five crawls under the van to get it right. The bend just slips between the motor mount support bar and the frame - neither of which move with the motor. It took a few tries to get it centered. As I was too lazy to drag the welder out and re-connect everything, I just eye-balled it (probably took longer than moving the welder would have).
As it was, this took every bit of two days.
Next chore will be figuring out hoe to make/mount the new bracket for the boost pot.
I had about 20 hours total in the dp I made. I was in and out a ton. -
#32 by Gizmoman on 02 Mar, 2014 20:29
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I had about 20 hours total in the dp I made. I was in and out a ton.
Well, now that the "huge
" rain storms are over and we are done with rain for another year, crawling under there a few hundred more times won't be too bad.
Sorry that we didn't warm this storm up a bit for you guys - brutal. -
#33 by bbob203 on 02 Mar, 2014 20:41
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Quote from: Gizmoman
Sorry that we didn't warm this storm up a bit for you guys - brutal.
Yes we have about 1inch of ice on the roads here in Kentuckiana... and Im supposed to fly out in the morning... -
#34 by RabbitJockey on 03 Mar, 2014 05:02
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something good happened with that storm, they were calling for 12-18" of snow for here in pa, last minute they changed the prediction to 4-6 and we ended up only getting about an inch. yay.
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#35 by Gizmoman on 09 Mar, 2014 17:39
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Well, I didn't get as far as I'd hoped but thought I'd update this thread.
As I had suspected, the boost pot rod went directly through the center of the oil drain port. I did slightly tweak the oil tube to get everything to clear but generally, the oil should now leave the turbo with no restrictions. On my K-14 I used a banjo fitting on the drain and I think this contributed to my oil in the compressor because it just couldn't drain fast enough. A long time ago libby mentioned not using a banjo bolt on the drain - now I know why.
Here is a shot of the rod in it's full extended position (I have 40 psi on the pot) The rod is obviously not adjustable anymore but I took careful dimensions before I disassembled everything. I suppose I could have used a coupling nut on the straight section of the rod but this is pretty kludgy already. The center of the crank pin (EDIT - from the face of the boost pot) is the same as it was, with plenty of preload on the gate. I even machined a split spacer sleeve to hold the rod extended slightly for easy assembly.
Another showing the machined aluminum bracket I mounted to the compressor. I was able to reposition the alignment pin hole for the compressor just to make sure it will never spin.
Here is the compressor housing showing the new pin location. I also machined down the v-band flange to accept a simple 1-1/2" silicone hose and band clamp. I have a brand new silicone 1-1/2 to 2-1/2 90 and it fits perfectly.
The oil port is a 10 X 1.25 and my k-14 used a 12mm banjo fitting. i'd like to keep the oil line I have so I'm making a custom Banjo bolt with a 12 mm shoulder and a 10 mm thread.. Had a good start on it this afternoon till I realized I had one of the levers on the lathe in the wrong notch and cut some odd-ball thread pitch
. Got it figured out now but I'm done for the day.
This may be a silly question but what kind of boost should I expect from this turbo if I don't install my DIY boost controller? I built the controller to raise the boost on the K14 from it's stock 8-10 PSI to 15-16 psi and it worked fine.
I plan on keeping this in the 20-22 psi range so I don't hurt the engine but the pot doesn't even begin to move till it hits 30 psi (could be my cheap pressure regulator). Maybe I don't know how it's supposed to work but as it is now, it looks like it could easily hit 40. What am I not getting here? -
#36 by 745 turbogreasel on 09 Mar, 2014 18:00
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Drive pressure on the WG is a possible factor.
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#37 by Gizmoman on 09 Mar, 2014 20:34
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Drive pressure on the WG is a possible factor.
Not sure what that means - are you saying that the pressure from the exhaust generates "additional" pressure and that it will assist in dumping the gate sooner than my rube goldberg set-up?
If so, is there any way to simulate that before I install it on the engine?
I guess my biggest concern is how to limit boost to 20 psi or so.
Somehow I get the feeling it's very simple and I'm over-thinking things (again). -
#38 by 745 turbogreasel on 09 Mar, 2014 22:40
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Wastegates do blow open at a a certain point, that is why the actuator is preloaded.
Exhaust Manifold Pressure AKA Drive Pressure is expressed as 'Pressure Ratio' in relation to boost PSI in turbo maps.
Ole school Turbos typically poop out around 2:1, but new stuff like this sometimes is rated for 4:1, and a lot of CR stuff peaks around 30 PSI... though PR is much closer to 1:1 in the efficiency range.
This might give you a general idea
and there are more details here; http://www.myholsetturbo.com/modelinfo.html
I'll not be surprised if you have to keep your foot out of it,or slack the WG actuator spring a little
You could also defuel till you don't make more than 20, but that might be a bit disappointing.
Also it is possible to add an external gate. -
#39 by RabbitJockey on 10 Mar, 2014 05:15
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looks awesome, great work on everything. it sucks that the k14 may have been fine though. I am thinking the only way to adjust boost would be to adjust pretension/rod length, which now i guess u have to either mill down the mount or stack washers between it and the compressor housing.
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#40 by theman53 on 10 Mar, 2014 05:27
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I forget what Alcaid told me on the opening of the wastegate. For some reason I think that 30 number is accurate. This is all I have in my messages and doesn't say much...
copied from Alcaid.
Only preload on the wastegate is adjustable (putting more preload on it gives more resistance to being opened by exhaust pressure and vice versa). Run a ball and spring boost controller as you normally would do and don't touch the wastegate adjustment for now. -
#41 by RabbitJockey on 10 Mar, 2014 05:33
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I forget what Alcaid told me on the opening of the wastegate. For some reason I think that 30 number is accurate. This is all I have in my messages and doesn't say much...
copied from Alcaid.
Only preload on the wastegate is adjustable (putting more preload on it gives more resistance to being opened by exhaust pressure and vice versa). Run a ball and spring boost controller as you normally would do and don't touch the wastegate adjustment for now.
only thing is, if the can won't open till 30-40psi then the ball and spring won't do anything, but i'd wait till its on the car to worry about it too -
#42 by Gizmoman on 10 Mar, 2014 05:35
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Thanks for the detailed explanation 745 turbogreasel.
I may be wishing I had some adjustability on that actuator rod afterall. If I understand correctly, I shouldn't need a boost controller at all. If I were to adjust the rod (change the preload) I should be able to "tune" it to dump at 20 psi.
Let me know if I'm missing something.
Thanks for the compliments RabbitJockey. It was scary stuff hacking off the cast mount from the compressor and drilling and tapping two holes between the edge of the housing and the snap ring groove. I like your idea of adding washers under the pot. The studs are barely long enough as it is so I may need to mill a bit off the tabs as you mentioned.
The adjuster that came with it was pretty slick and I think I can weld the bit I cut off into the straight section of the "U" bend.
Here's a shot of my new drain pipe. I actually had this in a box-o-bits left over from a turbocharged suby swap I did into a 72 bus many years ago. I cut a groove in the face and inserted an O-ring. Hopefully it can live with the heat.
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#43 by Gizmoman on 10 Mar, 2014 06:13
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I missed your informative post theman - thanks. It seems having the rod adjustable is the ticket. Besides, those welds look terrible and this would give me an opportunity to tidy them up a bit. I can't see as good as I used to, that's for sure.
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#44 by 745 turbogreasel on 10 Mar, 2014 16:28
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I think you want to work on the spring rate more than the rod length. Either adding some external spring to your linkage, cutting open & altering the boost can, or using a boost can off something else.
Since the WG opens gradually, even at lower settings, you MBC will help spool, as the WG instead of being 10% open at 5 PSI (#s straight pulled out of my butt), it will see no signal till 9 PSI(or wherever you set it) then open abruptly when needed.