Grafting a Subaru turbo onto a TD27/D21

[Wacked]

During the last couple of months, I've been collecting bits and parts for my turbo upgrade. Based on some reading and availability of parts and local expertise, I've gone with the TD04-13 turbo off a WRX.

Mr. FH2014 was gracious enough to sell and ship an exhaust manifold off a D22. From there, I've had to fab a 90 degree flange so the turbo is oriented properly. This weekend, I just finished the downpipe so it hooks straight into the stock exhaust. I don't particularly care for some of the tight angles/bends but I'm not sure it will make a huge difference on a low pressure system.

Why a low pressure system? Well, one, I just want to get it up and running. But also, I live at about 1300M elevation and suspect that running 8-10lbs boost will make a huge difference going up the hills. I'm also hoping that I won't have to mess with putting on a injector pump with compensator when running this low boost. With 8-10lbs boost, I'm also hoping to get by without an intercooler. If all goes well this first stage, I'll likely mess with it again in the next couple of years, re-plumb, and take it to around 15lbs.

Since I'm a noob on turbo diesels, I have a couple of questions?
- are my assumptions on the 8-10lbs boost accurate? .... or do I have my head up my butt?
- providing oil to the turbo. It looks like there is a 10mm "plug" in that aluminum housing for the oil filter that I can tap into for positive pressure. But on draining the turbo, I plan on teeing into the line with the drain for the vaccum pump off the alternator. Can this port/drain handle the back-flow of the vacuum pump AND the turbo? Is this the right approach?
- coolant to the turbo. I'm thinking of teeing into the lines that supply the heater core and run along the drivers side of the valve cover. Will this work or is there a better way to route coolant?

So far, its a fun project with lots of space to work with.... but who knows, maybe next weekend I'll be cussing it and beating it into submission with a 2X4 and hammer.

Wacked
Rapid City, USA

[diogenese]

10 psi will give you a decent power improvement particularly at altitude. I would consider running the drain into the sump direct or you may get oil getting past the seals into the intake.
Make sure your oil feed is after the oil filter.
To be honest with low boost on a diesel and good oil flow you can probably ignore the water cooling altogether.

[fh2014]

During the last couple of months, I've been collecting bits and parts for my turbo upgrade. Based on some reading and availability of parts and local expertise, I've gone with the TD04-13 turbo off a WRX.

Mr. FH2014 was gracious enough to sell and ship an exhaust manifold off a D22. From there, I've had to fab a 90 degree flangeGot any better images on this? bad amgles will hamper spool up time and then fuel efficiency so the turbo is oriented properly. This weekend, I just finished the downpipe so it hooks straight into the stock exhaust. I don't particularly care for some of the tight angles/bends but I'm not sure it will make a huge difference on a low pressure system.

Why a low pressure system? Well, one, I just want to get it up and running. But also, I live at about 1300M elevation and suspect that running 8-10lbs boost will make a huge difference going up the hills. I'm also hoping that I won't have to mess with putting on a injector pump with compensator when running this low boost. With 8-10lbs boost, I'm also hoping to get by without an intercooler. If all goes well this first stage, I'll likely mess with it again in the next couple of years, re-plumb, and take it to around 15lbs.

Since I'm a noob on turbo diesels, I have a couple of questions?
- are my assumptions on the 8-10lbs boost accurate? .... or do I have my head up my butt?if the turbo is running a factory internal wastegate/actuator, boost supplied by that subaru turbo could get upwards of 14/16psi as is - im no subaru expert however
- providing oil to the turbo. It looks like there is a 10mm "plug" in that aluminum housing for the oil filter that I can tap into for positive pressure. But on draining the turbo, I plan on teeing into the line with the drain for the vaccum pump off the alternator. Can this port/drain handle the back-flow of the vacuum pump AND the turbo? Is this the right approach?No, drain back into sump via own line, the drain will not drain fast enough if you do this
- coolant to the turbo. I'm thinking of teeing into the lines that supply the heater core and run along the drivers side of the valve cover. Will this work or is there a better way to route coolant? I have heard of this done successfully, just make sure the lines are the correct size. Heck, I have even heard of the turbos being run with no coolant lines before. Not recommended

So far, its a fun project with lots of space to work with.... but who knows, maybe next weekend I'll be cussing it and beating it into submission with a 2X4 and hammer.

Wacked
Rapid City, USA

[diogenese]

The subaru factory wastegate spring is 8-10 psi, higher pressures are obtained by modulating the signal to the capsule. The cooling lines are a must with a petrol motor where the housing can get glowing hot fairly easily, you have to be adding a shed load more fuel to get a diesel that hot.

[Wacked]

Thanks for the input guys!

Guess I'm dropping the pan and welding a port for the drain.

Will try to post some more pics of the turbo transition piece this next week. Am waiting for a couple of orders to come in before moving on.

Wacked

[ChurchurDan]

There should be a plug in the side of the block just above the sump that can be removed and a drain screwed in. Coolant lines come from under the lower rad hose fitting on the front of the engine, it is a 90 degree fitting under threaded into the under side of aluminum housing. The other fitting is also a plug in the block towards the back of the engine. When I put a turbo on a non turbo one all the block fittings where there but we changer the lower thermostat housing to a turbo one with the coolant line fitting.
I have heard not all engines have the oil drain but it was mainly the really early ones.

[Wacked]

Since I had a 3 day weekend, hoped to make some major progress but that didn't happen due to some parts challenges. Had OEM Nissan exhaust gaskets on order; 3 out of the 4 came in and the 4th wont be here until early March. Had some turbo/intercooler plumbing parts and the EGT guage get shipped to another state. PITA.

The Oil catch can got finished for the breather system and I finished a "solution" for the turbo oil drainage.

I did one final crawl under and around that engine looking for some sort of drain opportunity - didn't see any. Then I prepared myself to drop the pan so a drain could be welded in.... then I spied that drain plug for the vacuum pump again - it was a big old plug with a tiny little nipple at the end. Hmmmm..... took it out and found it to be VERY thick walled around the actual plug.

Sat down with a micrometer and a calculator. Ultimately, I cut the nipple off, bored out plug so it's now a "thin Wall" plug. According to math, the new hole doubles the area/volume of the drain - I hope it's enough. Next, I welded sort of a "header" onto the end of the plug so hoses could be plumbed into this drain without constriction.

That's what got done, was hoping for more.

Wacked

[fh2014]

Sounds a bit Frankenstein mate but sounds like your switched on, get up some pics! - I wish you the best! these motors are solid and can take a lot of shit.

[Wacked]

It should be a good weekend with all the Stars aligning in my favor!

Exhaust gasket came in a couple of weeks early. As far as I know all misc. parts and fitments are sitting on my bench. It will be a warm day on Saturday and I have a 3 day weekend. I should be able to assemble, turn key and drive .......

Yea, it NEVER turns out that way but I'll give it a go!

Wacked

[diogenese]

Keep.a photo record, 'cos without pictures it never happened

[Wacked]

The stars held with me an I was able to back it out of the garage last weekend!

During this past week, the Narvara's gone around 150km on this turbo set-up. Overall, I'm impressed. I'm guessing there's 25% more power and responsivness. Before it was a slug and often a menace to other traffic; now it keeps with traffic and sometimes has extra.

It's a win!

So, here's the finished set-up. The Subaru turbo is mounted at a 30 degree angle in the engine bay. The turbo sits on top of a 90 degree flange that is then mounted to a factory TD27 exhaust log with a T2 mounting plate

As for the exhaust, I was able to transition it into the stock exhaust system. To keep it off my firewall, I had to bring it down again at 90 degrees and built a down-pipe and flange so it would bolt straight up.



For gauges, I gutted that goofy inclinometer and tiltometer unit and put a boost and EGT gauge in that pod. Going up a good incline, the temps usually stay around 650C. I have bumped it up to 700C during a very long - maybe 10km - gradual climb.

[Wacked]

Hey guys, sorry about the rotated photos - I'm an old geezer still sorting through some of this tech stuff

About the turbo.... I'm mostly pleased with it's performance, but there's a lot of room for improvement.

So I'm pretty happy with my EGT's. It seems like there is some cushion for error if I'm running at 650/700. The boost, however, claims I'm only boosting up to 4lbs. Hmmm..... can't find a leak .... Subaru pals have checked it out and listened to to the turbo.

I'm trying to sort through this any my conclusion is that the whole exhaust business really needs to be massaged.

It the next month or so, I'll straight-pipe it with an old school cherry bomb exhaust - i like the sound. This may or may not help flow. The big step will have to wait until winter, and that's to build a well flowing manifold without the restrictive 90 at the turbo inlet. During that build, I can position the turbo more forward leaving better clearance at the firewall and do away with the 90 at the down-pipe.

Wacked

[diogenese]

Are you running the wastegate actuator direct off the boost pressure? It may be worth checking what pressure the wastegate opens at, it should be about 10 psi but maybe the spring has weakened. If it is opening early you could try a bleed tee to up the boost.
Do you get any black smoke? Maybe you just need more fuel

It may be that's all it can do with the exhaust system as it is

[Wacked]

Thanks for the ideas.

No, I'm not detecting much smoke at all - a little puff during start-up then it goes away. I thought this was a good sign but perhaps it means the engine is running too lean. I'll get under the truck this week and turn up that fuel screw a 1/4 turn and see what that does.

Regarding the turbo, I did shorten the actuator shaft by by one revolution in an attempt to increase boost but didn't notice any difference. I'll try that test you're describing and see what the pressure improves

Wacked

[Wacked]

House was empty tonight so had some time to play with this new turbo set up.

Diogenese suggested I look at the actuator/waste gate and when it opened. I capped off the vacuum to the actuator and took it for a test drive and easily got boost to 10ish psi.

I returned home and dropped the exhaust and took it for another test run with it straight-piped. There was small power gain but most impressive were that EGT's dropped significantly. I took it up a longer grade that I'd driven this weekend and there was a 100C drop in temp. Boost on this same grade went up to 12psi.

So, it needs a new straight-pipe exhaust sooner than later. Regarding the actuator, guess I'll buy a new unit as the old one seems knackered. Think I'll hold off on messing with fuel until exhaust system and actuator is sorted out.

This is fun!

Wacked

[fh2014]

Its all about flow. Get that gas out fast = more power = less heat