300Tdi VGT project

[will_warne]

Chaps - you can have a picture of anything but the build Engines on the table aren't much use anyway - I find them better sat between the chassis rails.

Mo, I keep forgetting to send you that pan. I will try and remember tomorrow

[Turbocharger]

Chaps - you can have a picture of anything but the build

Have you got a sister?

I've ordered some bits to pipe it up to the intercooler etc and I'll look for some piping next week, so progress will appear slow for the next week or so. I also need to tap the manifold for my EGT thermocouple - anyone got a 1/4BSPT tapered tap and tapping drill I could borrow?

[will_warne]

Cheeky

[Turbocharger]

About time for an update. I've paid an exorbitant amount of money for pipe in the colour I didn't want, and now I can mock up the turbo to the intercooler run:

I've also created a bodgetastic mechanism to feed the boost pressure back to the vanes (nobody laugh please).

In this form it's adjustable so I can tweak the leverage the diaphragm has over the vane lever (the travel of one relative to the other). It's adjustable for length too, so I can hopefully adjust the level of boost at steady-state. If this works I'll make a more permanent method to join the two.

Now I've got to work out how to feed water into the cooling gallery (pipes just visible in the first photo, pointing towards the bulkhead), buy the oil feed and drain pipes and ideally trim the air filter pipework to fit the smaller inlet too, although that could wait until after the first test-drive.

I have to admit, after buying some pipework and making some bracketry etc I'm working up to thinking that £1k for the 2.8TGV turbo assembly is actually a fair price - I might feel otherwise once mine is together and working though

[Turbocharger]

I collared the on-site hose bloke in work today, slipped him some cash and got an extension and a drain hose made up - although I'm wondering about my measurements now :S

L - R: 300Tdi feed pipe with new extension, bespoke Landsubishi drain hose, standard 300Tdi turbo drain hose (I won't use this)

[Turbocharger]

I did the Pirtek thing and it was a pain - you'll never get the hoses exactly the right length and orientation.

1 out of 2 isn't bad... my elastic tape measure struck for the return hose though, seems I'm 2" short

66gaza's tip on plumbing adaptors was spot on, I now have a 10mm -> 15mm adaptor, and I'm sure the remainder will be taken up in the jubilee clip when I buy a bagful.

[Turbocharger]

Right, after all my fairydancing sourcing all the bits above, I've been cracking on and making the thing actually fit onto the car. This probably isn't dialup-friendly anymore, sorry to those who perch on tiny islands in the southern seas...

The chap who made the manifold had made a jig from the OEM turbo assembly first so he could make sure all the holes line up. I checked, his job was spot on and it matches the old one.

but it doesn't match the cylinder head, so I've been wearing out someone else's Dremel to add a clearance around all the head studs. Through the process I began to wonder if some of the studs were bent, but I couldn't get my head into a sensible place to look along them. Trick photography didn't help:

No conclusive result. I grabbed a straight edge (a bit of chrome pipe in fact) and started measuring away:

Bingo. This stud was 0.6mm low, so I trotted off to get a hammer to bash it straight. Measure twice, cut once and all that, I feelered it again, and now a different stud is low. I tried measuring them with the straight edge underneath, and that showed that the stud pictured above was nearly 1mm high. By this point I'm confused, and put everything down to go and make tea. The chrome pipe caught my eye as it rolled off the radiator frame, particularly its wobbly-drunken motion. A brief check of my "straight" edge showed where the problem that I'd been chasing for an hour really was. Dumbass. I settled down to grind a clearance into the holes like I was doing to start with - quite therapeutic, grind, check, grind, check, take the time and do it properly.

The middle lower stud is missing, so I dug around and cut down a suitable bolt instead. It's not easy to see that stud on my manifold, but a bit more trick photography by taking shots through another bolt hole showed me which direction to grind the hole out:

I ground a bit out until the bolt would just catch in the thread, so I had a go at winding it in.

This is a Mistake. Minutes later:

This evening I got the full set of stud/bolts in properly and botched it together to see where the EGT thermocouple will go. I'm anxious not to drill a hole and then find the thermocouple points straight through the inlet manifold, turbocharger, heater box or something else equally important that I'd forgotten about.

Trial assembly confirmed what I thought - there's a tiny window of opportunity between the head and inlet manifold, under the heater rail (see green arrow).

I drilled the hole to 8.5mm - tapping drill for the 1/8" BSPT tapered fitting is 8.4mm but Bristol Kwik-e-Tool wanted to order one and I didn't see what 0.1mm would do different - it's not big pressure on the other side, exhaust putty will make up the difference I'm sure. Jase has kindly offered to lend me a tap over the weekend - cheers gent!

As an encore this evening I straightened the thermocouple out and reduced the protrusion into the manifold. I know that gripping it in the vice is a bad idea but the swagelock fitting had taken hold. I've not tested it to see if it still works yet

I'm finding that any 'quick' job takes much longer than I anticipated, even after I've doubled my original anticipation time.

[Turbocharger]

Right, after a full day working on it, I've fitted the oil feed and drain, coolant pipes and some of the exhaust. Without an EGT probe, with half the bolts missing and only half an exhaust, I checked I'd taken the bits of rag out of everywhere, cleared the car of tools, cranked it until the oil pressure light went out and then fired it up. Since I'm impatient (and probably against all sensible advice) I took it for a thrap.

Notes:

1) it's smoking as if it's on fire. I hope this is paint baking on and will clear.

2) it doesn't make very much boost. I can hear the turbo spinning up quickly but it won't climb above 0.5bar (7psi), so I adjusted the vane control lever

3) Mitsubishi put the adjuster for the vane control lever somewhere very hot

4) On a second run it doesn't make any boost at all, so I adjusted it back again.

5) Somewhere very very hot.

6) Better, but still not right. The calibration is going to need more work.

Overall, promising for reliability, disappointing for performance so needs more development - that big smile isn't here just yet.

[GBMUD]

Glad to see this project finally getting somewhere John.

Chris

[ciderman]

And I still have a 1/8 BSPT tap here for you John , Even got a BSPP one if needed

[Turbocharger]

Glad to see this project finally getting somewhere John.

You and me both - or as George puts it "you've spent a month of evenings making your car worse?!?". That may be true, just not how I choose to see it...

Jase - I'll give you a ring today sometime.

[Eightpot]

Can't see the your photos at the mo, just red crosses so not sure if my top technical tip will help solve all your problems or if you've already done it....

...the washer bottle can be shifted onto the other side of the engine bay very easily - I moved mine above the steering box. There is actually a second connector on the loom for a washer bottle on the drivers side - you should find the wiring poking out of the loom that feeds the O/S headlamp.

[Turbocharger]

Thanks Eightpot - the other wing is full of brake fluid, coolant, PAS fluid, winch fluid etc though. I'll find a gap for it, it's only a pipe and two spade connectors.

This evening I finished the second installation (doing it properly this time). There is evidence that the exhaust side leaks at every gap - no surprise here.

Since I hope it's on for a while this time it went together with a smear of exhaust gum on the interfaces:

All built up again and I went for a drive.

Note to self: engine will not make any boost at all if the "intercooler to inlet manifold" hose is missing.

Second test drive: I've found I have to think of the variable geometry as a 'big' or 'small' turbo. Small turbo gives quick response for little engines, but is overwhelmed by a 2500cc unit. At the 'biggest' setting it should be too large for a 2500cc engine and so no wastegate is required.

With the lever around the middle it wasn't making any significant boost, and this wasn't getting better as I made the turbo 'smaller' - when it got adjusted it quite 'small' the crisp turbine whine turned into a horrible 'splurge' sound under throttle, and at the worst case the engine sounded like it was misfiring. I conclude that the blades are stalling or working against excess pressure - either way, not enough air supplied and so it misfires. There was probably black smoke too, but it was dark and so hard to tell.

Adjusting 100% the other way (big turbo) gave smoother, better running but less boost. I hope by tweaking and tweaking I can find a sweet spot in the middle somewhere. I got a reasonable setup and it was running well, so I pulled over and took a video. This clearly wasn't on the road, that would be dangerous - I was using a kinetic mass dynamometer on private land. By the power of the internet, you can join me on this run:

In case you're worried, the boost gauge sometimes sticks as the pressure level falls. However, for this run it suddenly started running badly again, and at 00:12 you can clearly hear the misfire. I limped it home and garaged it, suspecting I'd broken it with the abuse of my hillbilly test method, but a quick check for fluid leaks afterwards showed this:

The nuts have vibrated off the diaphragm and the turbo was running in the 'smallest' position again. After the weekend I'll put it all back together and have another go.

[ciderman]

Note to self: engine will not make any boost at all if the "intercooler to inlet manifold" hose is missing.

Glad to see your getting somewhere with it now John .

[David Sparkes]

I think the description of the VNT in the L332 manual makes relevant reading.

Variable Nozzle Turbine (VNT)

The VNT makes it possible to vary the exhaust gas flow of turbine by changing the angle that the turbine guide vanes

are set at. With the guide vanes in a closed position, the exhaust gas flow is reduced and the gas flow to the turbine

wheel is increased. This results in increased boost pressure.

The boost pressure sensor provides a feed back signal to the ECM relative to the inlet manifold pressure. The ECM

also calculates engine load and uses this along with the boost pressure sensor signal to send a PWM signal to the

boost control solenoid valve to determine the amount of vacuum supplied to the boost control vacuum actuator on the

turbocharger. The amount of vacuum operates between 0 mbar and 640 mbar depression. At 640 mbar the vanes

are fully closed providing maximum boost.

You don't have the relevant ECM, so for your DIY project, I suggest a different control system.

The standard default is vanes wide open, which means you have to close them at tickover, something you can never do with the boost control system you are trying now, as there is zero boost at idle rpm with the vanes wide open.

If you maladjust it so you do get boost at low rpm, as the boost increases it closes the vanes, and chokes the engine.

Change the default to vanes fully closed, perhaps by re-jigging whatever spring mechanism in the VNT currently drives them fully open, or by spring loaded actuator. This will give you the conditions for maximum boost at minimum gas flow. As the boost rises it forces the actuator open against the spring, driving the vanes open.

The initial choice of spring may prove interesting, as it will involve the calculation of the force the actuator expresses, which is a function of the boost pressure AND the area of the actuator diaphragm.

You may also need a dump valve to limit maximum boost, or to act as a safety valve at least.

MAY need; personally I don't think so, but not having one probably means there is less leeway when selecting the spring.

There is an element of fail safe in this setup.

If the boost sensing pipe to the actuator fails, or the actuator fails, or it's nuts fall off, such that the vanes go to the default position of full boost, as you have already found, the ability of the turbine to flow exhaust is severely compromised, to the extent that the engine is choked. In this condition it cannot speed itself to the point it separates into it's component elements.

HTH

[TheHarv]

I haven't really been following your progress, but in case you haven't seen it there's quite a lot of discussion on VNT controllers over on the VW and MB forums, e.g.

http://www.vwdiesel.net/phpBB/viewtopic.ph...57b4c59527c4271

http://www.schumanautomotive.com/forums/showthread.php?t=791

http://mercedesshop.com/shopforum/showthread.php?t=153118

[Turbocharger]

Hopefully by now all the motorbikers have stopped following this thread...

I've found the vanes are very sensitive to positioning and my crude fully open/halfway/fully closed bludgeoning wasn't good. Now I'm adjusting it half a turn at a time and was getting some pretty good results until I stopped to get fuel. I'd got £10 of diesel in before I saw smoke rising from the car on the forecourt. I drove off the forecourt, went back to pay before they called the fuzz, and came back to the car:

The jubilee clips have cut into the rubber water pipe to give a squirting leak (which was producing the "smoke"), but the oil drain had also come undone, hence the oil slick. I'm not sure how much oil I lost but I bodged it back together so it would "nearly" get home before raining oil onto my landlord's driveway again. Deep joy. Now I'm going to bite the bullet and buy a correct-length drain pipe instead of extending the wrong'un, and use some proper adaptors for the water side.

Today's job - find an air filter box that'll fit across the back of the engine, flow well, pipe up neatly and seal better than the 300Tdi offering.

[bishbosh]

Today's job - find an air filter box that'll fit across the back of the engine, flow well, pipe up neatly and seal better than the 300Tdi offering.

How about this John? 200TDi disco airbox on the back of a 200TDi in the 300TDi position .

The airbox has 3" in/outlets and you will need to weld up the drain that is normally on the main cylinder.

[Turbocharger]

Cheers Bish - not sure what I've got originally then - a LR airbox on a 300Tdi on a bracket on the o/s of the block, above the vacuum pump.

Anyway, a scrapyard liberated an LDV van's filter which looks like it should just about fit between the block and the bulkhead. However, I've got some miles to do in the next few weeks so I've put the standard turbo back on. While it was apart I spotted that I'd not considered how to connect the pressure feed to the injector pump, so it was always giving naturally-aspirated fuelling

The break will give me time to collect a few more bits and pieces to make the whole setup more reliable, and then I'll see how it goes with a filter and full-fat fuelling too.

[nicks90]

While it was apart I spotted that I'd not considered how to connect the pressure feed to the injector pump, so it was always giving naturally-aspirated fuelling

so basically all the fiddling and calcs you've done will have to be completely re-done from scratch... as the extra fuelling on boost will totally change everything.

[Turbocharger]

Frankly I've no idea - you sound rather disappointed Nick. I hope that there'll just be more power (and even quicker pickup) as more fuel is added, since the boost side will be the same - the same boost will need the same vane position etc. The quicker response might mean the control system is unstable where it wasn't before - only time will tell.

[nicks90]

i am disappointed!

i want to see how this thing goes - as i have access to a clever man with a little machine shop and funky tig welding skills etc and fancy sticking a vnt turbo on my 90.

[rusty_wingnut]

can I ask what vehicle the turdblower came from?

[Pete Attryde]

My turbo is off a 2003 Mitsubishi L200 Warrior, which is anywhere between a 110bhp 2.5 and a 170bhp 2.8 depending on which website I choose to misunderstand today. I've got no idea of part numbers etc, it was acquired for me and seemed suitable on paper.

I'd thought about drilling the vacuum diaphragm but since I can produce some movement by sucking it with my mouth(!) I expect it'll work at a lower pressure than the 1bar boost or greater that I want to run, limiting my available power. The answer there would be to bleed some of the boosted air out before the diaphragm so it sees a proportion of the manifold pressure, but I don't know if I'd damage the unit by drilling into it. I guess the answer here is to try it, since it's scrap to me if it won't do what I want. Thinking aloud, I do need to make sure that it works the right way round for my application, eg more boost is a signal to produce less boost and not vice versa, or else it could just run away with itself. I'll have to pipe it up and see if it works...

can I ask what vehicle the turdblower came from?

Taken from the first page of this thread.

Pete.

[Lara]

Turbocharger,

With all due respect, your biggest problem here is your self.

By rushing and therefore bodging, you are causing your self more problems and actually wasting more time in the long run than doing it properly.

Un-bolt it all and re-fit it. Machine the exhaust flange flat if needed, paste is not the answer!, fit the studs and match the holes properly, Move the compressor housing a few degrees and re-position the boost actuator to get a straight line to the vane control arm, make a longer arm with a few hole positions for adjusting lever ratio, Sort out your oil drain pipe with a proper job and not cobbled together hoses, same for your oil pressure. Get the turbo water cooling sorted before you run it again, it's there for good reason!

The boost actuator will do a good job if set to closed (as you say "small turbo") with no boost and progressively opening with boost, you may have to play with spring pressure but that ain't hard to adjust. It will work!

I don't mean to sound disrespectful as it is only lack of experience showing up and fair play for doing it and sharing it with us.

I have been in your shoes and learnt the exact same lesson, but rather a lot of years ago ;o)

Keep at it!

and don't try to rush or bodge, do it right - once, not badly five times, you obviously have the skill,

Lara.

with respect.

P.S.

PM if I can help in any way with advice.