Boost Guage

[EricN]

If anyone wants one, Princess Auto has them on sale for $17 for the next week or so. Comes with everything you need but the hose is only 6' long so depending on how/where you mount everything it might be a bit short. I had planned on gutting my inclinometer/altimeter pod and putting the boost gauge and a pyrometer in there but I think I may just make a whole new pod to replace that one. It will fit in there but it is a bit of a squeeze lengthwise.
Just to note, mine is only running at 10psi, once I get the pyrometer, it will be time to push it up to 14 or so.

[TardisDeli]

Hi EricN, Can you give more info. Is this related to the Diesel Turbo? always happy to install more stuff, and always love a trek around Princess Auto, but what exactly is this boost guage and pyrometer needed for. Thanks, Christine.

[EricN]

Boost gauge- Not exactly necessary. I bought it with the intention of just using it to set up the boost pressure then sticking it in my tool box. Spec is supposed to be 12psi (I think), mine was only at 10psi. I guess after time the spring for the waste gate actuator gets weak so you loose some boost. Deli is killer easy to adjust the boost pressure on. I figured now I will just put the thing in since I want to put a pyrometer in for sure and instead of modifying my old pod, I am just going to make a replacement so I might as well just put the boost one in too. Installing it for the most part just means you get to watch the little needle go up and down but it would be handy if all of a sudden you have a problem like loss of power or something, it would help diagnose the cause.
If you go to Princess Auto, they are at the end of one of the tool isles that is inline with the cashier, not in with the rest of the gauges.

Pyrometer- As far as I am concerned, no diesel should be equipped without one. This is the one I plan on getting http://www.speedhut.com/el_detail_gauge ... 470&bhcp=1 The only reason I picked that one is the programmable idiot light so if you aren't watching the gauge, at least the light can grab your attention. You can find some for around $100 if you search, just make sure if you find one extra cheap that it comes with the thermal probe and special wire.
Probe clamps onto the exhaust pre-turbo (not sure where there is room exactly yet) and measures the temp of the exhaust pipe. The idea is that you want to keep that below a certain temp. If you are climbing a long hill or something, or the motor is out of tune or towing a heavy load, even driving in the wrong gear under load (I am not sure what else will cause it to go too high, I just know it is a way faster warning system than a coolant gauge) and the gauge gets too high it lets you know to back off. It would help avoid a cracked or warped head or melted pistons. I believe the max you would want to see is 1200f, and that is where stuff like pistons are getting close to melting. Most guages seem to have a little "redline" type thing at 1100f so I assume that would be the safe normal limit.
The main reason I want it is because I want to push up to about 14-15psi of boost so I definately need to know what is going on inside before I start playing around with that much extra psi (which will probably be fine but it is nice to have the extra info).

[DelicaMark]

Is there a way to measure you boost without putting in a guage. That is, can I take it to a place that deals with turbos and have it checked. I would assume if mine was running under pressure then it would be a good idea to increase the pressure to get the right amount of boost.

-Mark

[marsgal42]

More fundamentally on the boost gauge: an engine, gas or diesel, works by sucking in air, mixing it with fuel, burning the mixture, and pumping the exhaust out.

The engine can suck air in itself. This is a normally aspirated engine. Until recently this was how all car engines worked, except for a few exotic ones.

An engine with forced aspiration has an external air pump to force more air in. More air plus more fuel equals more power (and more stress on the engine, which is why you don't want to overdo it). The air pump may be a mechanically driven pump ("supercharger"), or a turbine driven off the exhaust gases ("turbocharger"). Our Delicas have turbochargers. Turbochargers work more-or-less for free, driven by waste heat in the exhaust. Since they spin at very high speed, it can take time for them to change their speed ("turbo lag"). Modern vehicles are better in this respect than our Delicas. Superchargers have zero lag, but require significant engine power to drive them.

One fairly common supercharged vehicle is the Toyota Previa. The engine location made it impossible to make the engine bigger, so Toyota supercharged it to make more power. A famous supercharged vehicle is the Spitfire fighter plane, whose Rolls Royce Merlin engine http://en.wikipedia.org/wiki/Rolls-Royce_Merlin used a supercharger to compensate for decreased air density at high altitude (and to make more power). Merlins always sound to me like what you would get if Ferrari started making really really big truck engines.

Forced aspiration is easy on diesels, since all you have to handle is air. Before the widespread deployment of fuel injection, the alternatives on gas engines were to blow air in to the carburetor, which required a special carburetor, or suck air through the carburetor, which meant the super/turbocharger had to be specially lubricated so the gasoline vapour wouldn't wash all the oil away.

...laura

[EricN]

Is there a way to measure you boost without putting in a guage. That is, can I take it to a place that deals with turbos and have it checked. I would assume if mine was running under pressure then it would be a good idea to increase the pressure to get the right amount of boost.

-Mark

It isnt going to hurt anything by not having enough boost, it is just alot more fun with more boost. The injection pump uses the pressure from the turbo to adjust the amount of fuel to let in (as far as I can tell).
Just unplug the hose on the very top of the injection pump, put a small "T" in place with a pressure gauge of any kind (doesnt need to be a boost one, small fuel psi will work, just be sure the range is up to 20 or 30 psi max, otherwise it might not be as accurate), drive full throttle for about 10 seconds under load to make sure any lag in the gauge is gone and note the pressure. Adjust the wastegate, try again. It took 4 full turns on the turnbuckle (shorten the linkage) to go up 2 psi on mine. When you are done, remove the "T", plug the hose back in and you are back to normal.
Any small shop should have a simple pressure gauge but paying someone to do it might cost alot more than a $20 gauge, 2 x 10mm wrenches and 5 minutes of your life. Canadian TIre used to have that tool rental thing too and would have a gauge to let you use, not sure if they still do that.
Just dont try and adjust it without a gauge. If you go too high you will get lots of power but could destroy the motor. Everything I have read seems to suggest 15psi is fine for these motors. Do at your own risk.

[psilosin]

Regarding a pyrometer, the temperature probe can be placed either pre- or post-turbo. Most pyro gauge kits come with a clamping unit to instal the probe post-turbo on your exhaust. I have not seen one of these clamps that would work pre-turbo. For a pre-turbo installation you typically need to drill and tap a mounting hole into your exhaust manifold. Most people seem to prefer a pre-turbo installation since it gives more accurate readings to what going on inside your engine. Post-turbo temps can be 200-300oF cooler than pre-turbo. On the other side of the equation, some people don't like pre-turbo installs for the very unlikely but theoretically possible chance of the temp sensor tip burning off and zipping into your turbo. Post-turbo installation is a lot easier to DIY and as long as you are aware of the post-turbo temp drop it is still just fine (ie if max EGT pre-turbo should be 1100oF...you should use a max EGT on your post-turbo gauge of 900oF).

Definately one of the best investments you can buy for your diesel engine especially if you do lots of loaded up driving or lots of driving up hills. And if you plan to be tuning your boost and/or fueling a pyro is a must.

I'm not sure if the Delica has an EGR system and if you guys like to remove it...but if you do AND you want a pre-turbo pyro, instead of just putting a plain blanking plate on your exhaust manifold...drill and tap that plate and install your EGT probe there...makes for a clean install and doesn't require a permanent modification of your exhaust manifold.

[DelicaMark]

Thanks for the input. Next thing...figure out where all the Turbo related stuff is that you guys are talking about. I know where the hatch to the turbo area is (and have looked in there) but I have not messed with anything in there before. Maybe there are some pictures around that I can search for.

-Mark

[EricN]

Here is a pic of the signal tube to tap into for the gauge. Red arrow is the tube, circle is where it meets the injection pump. I can crawl under there tomorrow if it isnt raining and take a pic of the turbo. You access the adjustment from underneath by the RF tire, follow the exhaust up, find a big blob after the connector, that is the turbo, look for a rod with a long nut in the middle, that is the adjuster.
If it is really something that is wanted, I can make another step by step instruction thing for how to do it. I sometimes forget that not everyone is a mechanic and just assume I am making sense.

[Green1]

I'm having some form of turbo issue with my wastegate opening pre-maturely... a how-to guide on turbo adjustment might be quite useful! (especially as I'm one of those who is NOT a mechanic (I'll stick to the electrical bits...))