gbentink Turbo Upgrade Users Thread (2 Viewers)

[mudgudgeon]

My EGT probe is post turbo, and responds immediately to a hill / throttle input etc, so I see no benefit to a pre-turbo as is is all relative to what the egt’s are under normal running conditions..

Post turbo egt will respond to changes, but the relationship to what is happening pre-turbo is unpredictable, and not constant.

The difference pre and post turbo could be 50c, could be 250c. It's guesswork as the difference changes constantly

 

[cruiserpilot]

@cruiserpilot - I have a hj61 with the 12ht and 5 speed. I have a EBay catch can that vents inside the front guard (not legal, but the engine gets only clean air...). Ensure the catch can has the same size inlet (and outlet) as the outlet on the rocker cover - you don’t want to pressurise the engine..
I have 591000kms on my engine, so am currently getting quotes for a rebuild - including the GTurbo Grunter (green wheel I believe).
I have a Redarc combination EGT / coolant temp / boost gauge that I would recommend. My EGT probe is post turbo, and responds immediately to a hill / throttle input etc, so I see no benefit to a pre-turbo as is is all relative to what the egt’s are under normal running conditions... My coolant temp is in the top radiator hose, and this is what I drive to in hot conditions when towing. When the coolant temp gets to 92degrees Celsius, I back off. I try to keep it under 90....

How far past is your EGT probe? I’m looking for an aftermarket 3” dump pipe, and the only one I’ve seen has the probe bung welded immediately after the flange. I have heard so many variations on location it seems arbitrary. I’m not one to chase gauges, but like to know when I’m working the engine harder.
I’ve found a really nice dual gauge, and thought I’d put in another dual oil pressure / water temp gauge they have. I’ve already got a pick up for temp right on the thermostat housing, but that gauge failed due to electrical issue in the past.
I had a seeping head gasket a couple of years ago so I just went ahead with new Toyota gasket and we freshened up the head at that time, and with approx 275,000 kms on my motor I don’t expect installing the Grunter will be an issue.

 

[Silveredition]

How far past is your EGT probe? I’m looking for an aftermarket 3” dump pipe, and the only one I’ve seen has the probe bung welded immediately after the flange.

Mine is the same - immediately after the flange

 

[wedgetail]

Post turbo egt will respond to changes, but the relationship to what is happening pre-turbo is unpredictable, and not constant.

The difference pre and post turbo could be 50c, could be 250c. It's guesswork as the difference changes constantly

this is so irritatingly true - so many people put up with post turbo temps. It’s literally like putting your coolant probe in the bottom of the radiator

 

[Silveredition]

this is so irritatingly true - so many people put up with post turbo temps. It’s literally like putting your coolant probe in the bottom of the radiator

It shows my level of understanding on this (lower than what I thought), and my ignorance to the effectiveness of about 150mm of distance from the pre-turbo position to the post turbo position...
I (seemingly wrongly) assumed that since the increase and decrease in egt’s on the Redarc gauge is almost instant to a hill / throttle input etc that as long as I was comparing the readings to what the engine usually runs at, I would have a good idea of when things are working too hard... apparently not....

 

[wedgetail]

Of course it responds instantly - that’s not the point. But the numbers don’t mean much - it ok for a vague indicator (you might as well have no numbers in the gauge just markers for all the use they are) as to what’s going on but it doesn’t actually give you an exhaust gas temperature (more a turbo outlet temp). Wouldn’t be so bad if it wasn’t so easy to put the probe in the correct place.

As I mentioned - it’s like putting the coolant temp sensor in the bottom rad tank, reading the temp after its had the energy taken out rather than the critical point where it’s hottest

 

[mudgudgeon]

Agreed with @wedgetail
It's been tested with pre and post turbo probe and gauge in the same car at the same time.
Temperature can vary be 250c or more as gases cool as they pass through the turbine.
The difference could be enough to mean you're in the danger zone when you think you're safe

 

[cruiserpilot]

Of course it responds instantly - that’s not the point. But the numbers don’t mean much - it ok for a vague indicator (you might as well have no numbers in the gauge just markers for all the use they are) as to what’s going on but it doesn’t actually give you an exhaust gas temperature (more a turbo outlet temp). Wouldn’t be so bad if it wasn’t so easy to put the probe in the correct place.

As I mentioned - it’s like putting the coolant temp sensor in the bottom rad tank, reading the temp after its had the energy taken out rather than the critical point where it’s hottest

Agreed with @wedgetail
It's been tested with pre and post turbo probe and gauge in the same car at the same time.
Temperature can vary be 250c or more as gases cool as they pass through the turbine.
The difference could be enough to mean you're in the danger zone when you think you're safe

So this is one of the most talked about topics, EGT probe placement.
Highest percentage are post turbo, within 6" of turbo outlet, usually within 2" of the flange on the dump pipe.

Most common comment I get from 95% of people I've asked is the worry of a probe failure, subsequent destruction of
turbo in a pre-turbo application. So how often does this happen? I've realized that if it wasn't for 21st century technology
within replacement parts my 19th century engine probably wouldn't run any more, that's why we use 21st century technology
for replacement parts and I think this applies to EGT probes. They must be better made than in the past.
So my question is - In recent times are probe failures common in pre-turbo?

I'm wondering, the pre-turbo installation should be a fairly consistent number, as seems to be indicated by you guys.
Where is the best placement for the probe? Should it be close to exhaust outlet, or is it a bit more arbitrary?
I've had an EGT gauge installed in the past, it's tapped into the factory dump pipe, so that's where I was going to
put the new one once we do the IC and turbo upgrade.

 

[Silveredition]

Of course it responds instantly - that’s not the point. But the numbers don’t mean much - it ok for a vague indicator (you might as well have no numbers in the gauge just markers for all the use they are) as to what’s going on but it doesn’t actually give you an exhaust gas temperature (more a turbo outlet temp). Wouldn’t be so bad if it wasn’t so easy to put the probe in the correct place.

As I mentioned - it’s like putting the coolant temp sensor in the bottom rad tank, reading the temp after its had the energy taken out rather than the critical point where it’s hottest

Such a wealth of knowledge here - I should get back into my box and stop offering uneducated knowledge...

 

[wedgetail]

Such a wealth of knowledge here - I should get back into my box and stop offering uneducated knowledge...

mate - there were some reasoned arguments presented with solid technical backing (maybe my first comment was a bit smart arse and I apologise for that) but all you can come back with is how knowledgeable others are and how much you’re not, twice. Kind of reads as you’re final statements being correct rather than sarcastic?

 

[Silveredition]

mate - there were some reasoned arguments presented with solid technical backing (maybe my first comment was a bit smart arse and I apologise for that) but all you can come back with is how knowledgeable others are and how much you’re not, twice. Kind of reads as you’re final statements being correct rather than sarcastic?

There was no intended sarcasm in my posts - I don’t think I was even on the beers when I posted! I merely wanted to point out to the person I was responding to, that when I posted I thought I knew what I was talking about - but obviously not!
@mudgudgeon’s couple of posts explaining the inconsistencies in the readings helped me to understand the problem with post - turbo.
When my 12ht gets rebuilt, I will be tapping into the exhaust manifold to go pre-turbo!
Now, back to the thread!!

 

[cruiserpilot]

There are arguments for both pre and post turbo. What I'm hearing post turbo is the protection of the turbo itself.
Cool down temps, time to stabilize. Any more? I've emailed back to GTurbo, but they have decided to not answer
any questions. Tried to contact Graeme directly, but not getting any feedback.

 

[wedgetail]

There was no intended sarcasm in my posts - I don’t think I was even on the beers when I posted! I merely wanted to point out to the person I was responding to, that when I posted I thought I knew what I was talking about - but obviously not!
@mudgudgeon’s couple of posts explaining the inconsistencies in the readings helped me to understand the problem with post - turbo.
When my 12ht gets rebuilt, I will be tapping into the exhaust manifold to go pre-turbo!
Now, back to the thread!!

Please accept my deepest apologies - I completely misread the tone of your posts! It's so much harder having an internet convo than a real one for this exact reason!

 

[mudgudgeon]

Hugs all round

Always something to learn around here

 

[Silveredition]

Please accept my deepest apologies - I completely misread the tone of your posts! It's so much harder having an internet convo than a real one for this exact reason!

Hugs all round

Always something to learn around here

And , in the spirit of this great site -

 

[cruiserpilot]

ISO: 12H-T throttle inlet adapter fitting for installing intercooler piping. Seems that there are
options through eBay etc for the 1HD-T and variations but I have not found anything for the 12HT.
Anyone have solutions? Whether home-made or not could you post them up. Pictures would help.
Diagrams or dimensional drawings too if you got them.

 

[IanB]

There are arguments for both pre and post turbo. What I'm hearing post turbo is the protection of the turbo itself.
Cool down temps, time to stabilize. Any more? I've emailed back to GTurbo, but they have decided to not answer
any questions. Tried to contact Graeme directly, but not getting any feedback.

Having recently been through this, emailing and expecting a response within 2 weeks is a waste of your time, you need to pick up the phone and call them.

 

[SHREDwagon]

And , in the spirit of this great site -

Proper placement is pre-turbo. Similar to what @wedgetail stated, Pre gives you much more time to react before the damage is done. Quality probes don't fracture. Impellars do.

Post temp and driving mountain passes alot? no way. Flatland? probably not a big deal as long as you know your exact limit.

Note: Most bungs in aftermarket downpipes - like my Beaudesert for example - are for Dyno tuning AFR only and NOT meant for EGT. Here's a brief history on AFR and diesels: the-stories-old-and-new-diesels-and-afrs-the-only-way-to-tune

 

[mudgudgeon]

Here's a brief history on AFR and diesels: the-stories-old-and-new-diesels-and-afrs-the-only-way-to-tune

For a brief story, old mate sure used a lot of words to say 'AFRs have been used for diesel tuning since the 90s'

 

[cruiserpilot]

Small update. My GTurbo shipped today. I expect I won’t see it for another week. All my research has me
with the GTurbo, a full width intercooler 12x24x3 - 2 1/2” piping. I ordered and received a silicone inlet boot for the turbo. I did also get a manual boost controller but it would seem that it will be redundant after I’ve made adjustments to fuel screw on pump. I will be installing my pyro EGT probe preturbo as recommended by Graeme @ GTurbo. So once I’m home I’ll create a full build thread and we’ll see how it goes. I already have 3” exhaust.
The only thing I don’t have and have been unable to find is a throttle body inlet flange adapter. If anyone has one or knows where I can get one with 2 1/2” piping post it up! Or send me a message.
12HT - forgot to put that in!