am i pushing my deli too hard?

[Aztec Nomad]

i see, i once drove a van with a TT and it counted down only 60 seconds, i guess thats why i thought 60 seconds was enough. perhaps on the big drives, ill just leave it idling while parked for rests and other stops, and carry a second key so nobody drives it away...

Most turbo timers are adjustable for time. 60 seconds might have just been a factory preset. It all really depends on what kind of driving you do. If you were to be fighting a head wind and climbing a hill on the highway and then turn off to get fuel, you had better let it run for more than 60 secs.
Adam

[Erebus]

One of my usual fuel stops is a Flying J, just off the Deerfoot Trail in Calgary. So I've been driving at 100 km/h, and pull off. Fortunately, the diesel pumps are separate from the gas pumps, so I can legally let the engine idle while refueling. Usually, the EGT has dropped down to 500F by the time I'm finished refueling, so I can turn off the engine while I go inside to pay -- or sometimes I don't bother (turning it off, that is, not the paying part!).

That should give you an idea of how long to idle when fresh off the highway.

I would suspect the turbo timers are meant for gas engines -- or just for "cool" factor. I remember the old Chrysler k-car versions with turbo. They had both water and oil cooling, thermo-syphoned when off, and had a big grill in the hood above the turbo, so when shut off, natural airflow would cool. We don't have water-cooled (pre-94), and no natural airflow.

[oceaneer77]

Erbus...
Some thing is very wrong with your EGT gauge.. Its reading very slowly.
EGT temps do not need time to cool down as they are a product of combustion not a byproduct of the heat of combustion.

When you add fuel the EGTs go up when you back off they go down.. they are almost instant.
On acceleration max egts should be reached in less than 30seconds
(from normal driving with foot flat don on a grade). They should take the same time to come down.
No cooling period should be required.
My EGT gauge (post turbo) drops like a stone when i let off the throttle. i suspect that your gauge is holding heat some how.
Now a turbo temp gauge is a different story as the bearings compressor turbine and casing do take time to cool off and should be cooled before shut down as to reduce thermal fatigue. but i have never seen these fitted to a car and our style of driving should be sufficient to cool these parts without worrying. Unless you are full out down the road and hand brake side skid into your drive way shutting the engine down at the same time as applying the hand brake?

On the usefulness of a EGT gauge.. cannot be stressed enough as if your timing is out of adjustment or you are over boosted you will have no way of knowing until the death knock comes..
I try to keep mine under 1200F as thats what we do on the ships, i have seen lots of auto applications where they figure 1500F is ok.

Oceaneer

[Erebus]

Erebus...
Some thing is very wrong with your EGT gauge.. Its reading very slowly.
EGT temps do not need time to cool down as they are a product of combustion not a byproduct of the heat of combustion.

True, but I don't think there is a significant difference for our purposes.

When you add fuel the EGTs go up when you back off they go down.. they are almost instant.
On acceleration max egts should be reached in less than 30seconds
(from normal driving with foot flat don on a grade). They should take the same time to come down.
No cooling period should be required.
My EGT gauge (post turbo) drops like a stone when i let off the throttle. i suspect that your gauge is holding heat some how.

Mine doesn't drop like a stone. Going down a long hill with foot off the pedal the needle takes about a minute to drop down to as low as 200F

Now a turbo temp gauge is a different story as the bearings compressor turbine and casing do take time to cool off and should be cooled before shut down as to reduce thermal fatigue. but i have never seen these fitted to a car and our style of driving should be sufficient to cool these parts without worrying. Unless you are full out down the road and hand brake side skid into your drive way shutting the engine down at the same time as applying the hand brake?

Well, I'm more interested in the temperature of the turbo than the temperature of the exhaust. And the turbo definitely takes time to cool down, all that metal has soaked up lots of heat. It sounds like my gauge (installed post-turbo) is acting more like a turbo temp gauge than an EGT gauge, but that's fine with me. Even if the exhaust gas temperature drops quickly, it will take a while for that gas to take the heat out of the exhaust manifold and turbo housing, especially at idle when there isn't a lot of airflow.

On the usefulness of a EGT gauge.. cannot be stressed enough as if your timing is out of adjustment or you are over boosted you will have no way of knowing until the death knock comes..
I try to keep mine under 1200F as thats what we do on the ships, i have seen lots of auto applications where they figure 1500F is ok.
Oceaneer

Mine normally shows 800-1100, and does reach 1300 on long uphill stretches into the wind on a hot summer day.

[oceaneer77]

Hi Erbus

Just wondering how your EGT probe installed? and if its possible to get it out a bit further.
But you are right about the manifold and turbo taking longer to cool down than just the gasses.

Thanks
Oceaneer

[Erebus]

Just wondering how your EGT probe installed? and if its possible to get it out a bit further.

I'll give you a skill-testing question -- the forecast high for tomorrow is -19. Think I'm going to look at the Delica, other than through the living room window?

I didn't install the probe, my dealer did it. It is an Autometer unit, if that tells you anything. Maybe I'll have a look in the spring, or the next heatwave, whichever comes first.

[mararmeisto]

Just wondering how your EGT probe installed? and if its possible to get it out a bit further.

I'll give you a skill-testing question -- the forecast high for tomorrow is -19. Think I'm going to look at the Delica, other than through the living room window?

I didn't install the probe, my dealer did it. It is an Autometer unit, if that tells you anything. Maybe I'll have a look in the spring, or the next heatwave, whichever comes first.

Ah, ya big baby - get out there and work on your ride!

As for placement of the EGT probe, I've read that it doesn't really make that much of a difference unless you've got an inter-cooler setup. Personally, I'd watch the after-turbo side of the line because I would think that would give a better indication of how hot the turbo is (while the pre-turbo side would be an indication of how hot the turbo could get). But that's just me.

I hope it warms up enough for you to rectify this issue... before May.

[Erebus]

As for placement of the EGT probe, I've read that it doesn't really make that much of a difference unless you've got an inter-cooler setup. Personally, I'd watch the after-turbo side of the line because I would think that would give a better indication of how hot the turbo is (while the pre-turbo side would be an indication of how hot the turbo could get). But that's just me.

I don't see how an inter-cooler would affect it. Other than cooling the intake air - post-turbo - and therefore lowering the temperature of the exhaust gas, it shouldn't change the temperature gradient pre/post at all. Or am I missing something?

[audi4life20v]

Well from my basic know how of engines n stuff I doubt you really need to worry to much about the turbo's temp if everything is stock and well maintained. A glowing turbo wouldnt concern me either as long as the proper idle time to circulate oil and hence cool the turbo are used.

If anyone here wants to worry about cooking engines invest in a A/F gauge as I see that being more handy than the pyro. (becasue what it looks liek a few people here are trying to use the pyro to guesstimate the A/F ratio ect ect).

http://www.youtube.com/watch?v=VUWCo3lDjH8

This video proves that as long as your exhaust manifold doesnt melt Im sure the glowing wont kill ya XD

[audi4life20v]

HERES A REALLLLYYYY GOOD QUESTION!

Are the Deli Turbo's Ball Bearing turbos?
Cause if they arnt I'd invest into one if my stock turbo ever blew up.

[mararmeisto]

...[a] glowing turbo wouldnt concern me either as long as the proper idle time to circulate oil and hence cool the turbo are used.

And you've hit the nail on the head: IF one idles for a proper amount of time to circulate the oil, etc, etc, etc. Because the majority of North Americans are not familiar with personal vehicles which are diesel-engined, this is not something they are used to. Hence, burned out diesels.

As to your ball-bearinged-turbo question, I don't know if they are but I would suspect they if they are using ball bearings it would be the more expensive hollow bearings (for greater heat dissipation). Of course, that would drive up the price - a turbo timer would be a much cheaper alternative.

[audi4life20v]

Haha I doubt its North Americans not ebing familer with diesiel engines but Turbo motors in general. Like we Do have them now but alot of our cars are jsut lil N/A POS cars with low compression and power unless its abnormally large. Seriously, I run premium in the Audi and I get weird looks and wtf from people all the time, and It also buggs the shit outta me when people with WRX's or other turbo cars run 87 or only 89... Last time I checked proper fuel is also considered matinence...Thats another stroy all together....


And because I got curious and look It seems this way about the turbo's

The pre 94 turbos "oil only" look to be journal(sleeve) bearing turbo's relying heavly on the oil to cool and the oil pressure to keep that constant film of oil to prevent metal/metal contact. With these turbos its imparitive to keep your oil changes done to preven coking of the bearing and ruining the turbo and Oil is heavly used to cool the turbo so as we'va all kinda mentions proper idle down time is imparitive to maintain your turbo's health.

So knowing its oil only feel its probably a sleeve turbo. Now the laster 94 turbos COULD have been switiched to a BB turbo and thus the required water cooling line. Or they just added that to reduce turbo stress.


also mararmeisto what is a Hollow Bearing? I know that some BB turbos used creamatic bearings or exhaust turbine to reduce mass and increase turbo heat resistance but a hollow bearing? Do you meana foil bearing I know that its a new technology but not sure how that works.

Again Im sure its a sleeve bearing due to the vehicle and cost of a sleeve bearing is significantly cheeper than the BB.

This is an important aspect when you guys deal with your EGT setup as it seems your more monitering the turbo temp (which is good. you dont want your oil coking and destroying a turbo or letting an engine shut off without cooling the turbo.


Anyways im rambling on again... Oh how I love engines and turbo's and stuff

[floP]

Hi, audi4life,

your idea of using an A/F gauge might be difficult to implement since there is no standard oxygen sensor in the delica diesel engine.

And: Is this kind of indicator really suitable to do proper diesel tuning? It might be the right device for petrol-engines which require a lambda-1 air/fuel mixture under all load conditions. A diesel engine, however, runs with air excess under partial load i.e. most of the time (except, maybe, for flat out acceleration).

Just my questions ...

greetings from a snowy Munich, Bavaria,

floP

[audi4life20v]

Hey floP,

Guess your right eh, Im new to Diesel's and love learning so Guess this is another point to look out for!

Well back to EGT's! I guess now it boils down to proper location and mounting depth. But I still think EGT's shouldnt be used as a method to tune... Although the delicas are very limited in data so I guess every bit helps >.>

[floP]

Hi, audi4life,

Diesel tuning ist veeeerrrrry simple: You just improve air intake and raise the amout of injected fuel accordingly. No lambda to be respected. Aside from governmental exhaust gas regulations (soot) the main limit is obvious: A little more power means much more heat - hence the EGT-measurement. As a consequence you can consider intercooling and bigger downpipe diameters in the case of the 4d56 engine.

Greetings,

floP