EGT gauge, Boost gauge and EMP Gauge

[53 willys]

I wouldn't get any EGT gauge that didn't read down to 200°F.

What's the issue with the range? I don't understand?

I thought I'd only need be concerned with high temps?

In use, my guage would never more much unless I was really trying - 1/4's and sprints would see it over 700C

the reason that range is not really desirable is because you can't get a accurate "cool down" temp.... you wanna let your EGT's cool to around 300* so it does not "choke" up the turbo internals from cooking non-circulating oil...
cool down is important to me...cool down=longer life for the turbo..

Ditto that for me.... when I work in research at Federal Mogul, I baked engine bearings in a cup of motor oil (non-synthetic) at 450 F for a number of hours. The oil would turn a nasty black goo the same day. That's why I never shutdown my turbo diesel engines while the turbine is hot and spooled up.

I wish I had an oil / water cooled turbo like Subaru and other started using in the late 1980's. Is there such an animal for us small enough for a 1.6L ? I currently have the tiny GT15 on mine...

my Audi k26 turbo is water/oilcooled :wink:

[zukgod1]

Yes it is but you better tell them what we did to make it work..  

Other wise there may be people sending you nasty messages asking why the k26 they just bought wont fit their car  :roll:

[regcheeseman]

Surely there is a significant hysterisis difference between gas and housing temperatures. I wouldn't base my cool down on EGT's alone. But then my old GTD ran pretty cool.

I'd always drive the last mile of a journey with 0 ish boost and idle for a while once stopped.

Would turbo coolant temperature provide a good indication of housing temps?

Also in the UK, it's rare to see a EGT fitted, even a boost controller is alien to some - maybe it's the relative cost of replacing an engine over here?

[regcheeseman]

Thanks for that, useful stuff to know.

If installing a water-cooled turbo, one would need to have a temp controlled after-run pump to prevent coolant boiling in the housing after shut-down.

I know that my GTD had this feature i.e the coolant pump circuit was connected to battery direct. But I don't know it that is the way it was from the factory. (My GTD was in a Mk1 Caddy)

[53 willys]

Yes it is but you better tell them what we did to make it work..  

Other wise there may be people sending you nasty messages asking why the k26 they just bought wont fit their car  :roll:

you mean the K24 exhaust housing??






yes to run a k26 on a stock vw manifold you will need to run a K24 exhaust housing..and I also had to make a 1/2" spacer so that the k26 compressor housing would clear the factory intake manifold....

[53 willys]

Thanks for that, useful stuff to know.

If installing a water-cooled turbo, one would need to have a temp controlled after-run pump to prevent coolant boiling in the housing after shut-down.

I know that my GTD had this feature i.e the coolant pump circuit was connected to battery direct. But I don't know it that is the way it was from the factory. (My GTD was in a Mk1 Caddy)

not real sure if the after pump is needed from what I have seen on my car...
my coolant temp gauge is in the head and it only reads 195*-200* when I shut down at 300*EGT..(this is with a lower temp fan switch installed so I over all run slightly cooler..)

[arb]

Lot's of dieselheads get boost gauges that don't have the vacuum side of the scale, figuring that a diesel won't produce vacuum.  I always get vac/boost gauges as it will alert you to an intake restriction such as a clogged air filter (or a squirrel that climbed up and made a nest in your air-cleaner).  
Andrew

Me too. That's why mine is vac/boost.

[53 willys]

When you shut down after being fully up to normal operating temp and lift the hood, you don't hear the coolant boiling in the turbo?  Perhaps the turbo is located well enough that thermosiphon takes care of it.  If so, then you're lucky.  If you need to add a pump in the future, then adding a pump is fairly easy.

Andrew

yeah I have not noticed any boiling.....and as you know I have been all over this engine...every time I stop the hood gets popped open and I go over it with a fine tooth comb :oops: ...my wife and son have been making fun of me saying all vw hoods automatically open every time they park..lol :lol:

[zukgod1]

...my wife and son have been making fun of me saying all vw hoods automatically open every time they park..lol :lol:

HA!!

As I parked this morning at work I instinctively reached down and released the hood  :shock:
realized what I had done and shut it as I walked in.  :lol:

[gldgti]

this is a good thread.

my EGT reads from 200C to 1300C (392F start) but ofcourse it is often pegged at 200C. i figure for exhaust gas, 200C is pretty cool pre-turbine. having said that, the cool down feature is something i still look for - i mainly watch that before shutting down the guage has been pegged at 200C for several minutes.

i also notice that if i really get into it and see a 600C reading on the guage (1100F) that the guage takes a long time to come back to "normal" range, i guess because the manifold gets REALLY hot.

interesting the vac/boost should be mentioned - i too run a vac/boost guage, which is also electronic. with the small k14 and electronic wastegating, its possible to read a small vacuum on overrrun when the wastegate is open off throttle, and i also notice the guage reads below 0 when i got up the mountains (lower air pressure)...

[53 willys]

When you shut down after being fully up to normal operating temp and lift the hood, you don't hear the coolant boiling in the turbo?  Perhaps the turbo is located well enough that thermosiphon takes care of it.  If so, then you're lucky.  If you need to add a pump in the future, then adding a pump is fairly easy.

Andrew

ok so I wanted to see if I could get the turbo hot enough to boil the coolant on shut down so I took the car for a GOOD burn around town and on the freeway to make sure EVERY thing was nice and hot....I still cooled the turbo EGT's to just under 300*....when I shut the car off and popped the hood I could not hear any boiling at first...but when I stuck my ear RIGHT up next to the turbo housing I could here some boiling going on.... :cry:
good call Andrew!!
guess I'm gonna have to look into a after pump......
got any links??
thanks for bringing this up again...


does it damage coolant if it boils?? if the coolant is not damaged like oil is when it is over heated then I may not even worry about it...but if it's gonna ruin my coolant from boiling it...then I'm gonna add a pump....

[zukgod1]

Mark, Pull one off a car at the PNP.

The Audi has one as do a few VW's.

I think if you look through your Bentley you will find some mention of it on a few cars maybe?

I think I saw mention of it in the one I have for mk3's

[rallydiesel]

Yeah, that's the sad thing. Most of the parts in the yards will never get used and a big reason for that is the ridiculous prices they charge.

[Jettage1]

Not to go too far OT, but I'm with Andrew.  It also applies to stuff on Vortex - I've saved some money, but half the time when I get the part there's some minor production difference that I didn't know about, rendering it useless to me.  Or the condition isn't up to my standards, but it isn't the sort of thing that I can argue with the seller about - one does have to allow for subjectivity...

[arb]

Yes, they are available in the junkyard.  The nearest junkyard is 45 minutes away from my house.  It's funny, it's gotten to the point that few things are worth the trip.  By the time I've loaded up the tools, driven there, found out that they might have what I need in the far back corner, searched, rolled around in the dirt, dropped dirt and squirted coolant in my face, soaked my shirt, and paid them 1/3 what it costs new, I wonder on the trip home about my priorities...  When the Fedex guy knocks on the door with the new part I always seem to smile.    YMMV.

Andrew

Most of the boen yards here in Michigan are like that too, but here are a few exceptions. You negotiate up from on price. Usually $20 for any big part, and $5 or $10 for small parts. They don't care what it is - if you can carry it and they can stay in the office, that's the price.