Outer Limits 4x4 Board

I'm trying to get my head around the statement made in a lot of places that fuelling up a turbo diesel makes more heat and you don't want to do that.

I can make some pretty safe assumptions here, turbos put more air in your cylinder, the goal is more/better bang. So I can say I'd want more fuel with more air to make that bigger bang which is going to make more power and heat either way.

From what I can understand, in a petrol the idea is that the unburnt fuel absorbs heat, and in a diesel the idea is the unburnt air takes the heat out.

So the conclusion I come to is that you do need more fuel, but too much fuel is an issue? Where do you find the happy balance.

churs

dibbz wrote:I'm trying to get my head around the statement made in a lot of places that fuelling up a turbo diesel makes more heat and you don't want to do that.

I can make some pretty safe assumptions here, turbos put more air in your cylinder, the goal is more/better bang. So I can say I'd want more fuel with more air to make that bigger bang which is going to make more power and heat either way.

From what I can understand, in a petrol the idea is that the unburnt fuel absorbs heat, and in a diesel the idea is the unburnt air takes the heat out.

So the conclusion I come to is that you do need more fuel, but too much fuel is an issue? Where do you find the happy balance.

churs

You answered it there in yellow.

how do you find a balance - with your EGT Gauge. Too much fuel creates heat as you say, and its deadly in diesels, with EGT's getting to 600 degrees +_

bogged wrote:

dibbz wrote:I'm trying to get my head around the statement made in a lot of places that fuelling up a turbo diesel makes more heat and you don't want to do that.

I can make some pretty safe assumptions here, turbos put more air in your cylinder, the goal is more/better bang. So I can say I'd want more fuel with more air to make that bigger bang which is going to make more power and heat either way.

From what I can understand, in a petrol the idea is that the unburnt fuel absorbs heat, and in a diesel the idea is the unburnt air takes the heat out.

So the conclusion I come to is that you do need more fuel, but too much fuel is an issue? Where do you find the happy balance.

churs

You answered it there in yellow.

how do you find a balance - with your EGT Gauge. Too much fuel creates heat as you say, and its deadly in diesels, with EGT's getting to 600 degrees +_

Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

RedlineMike wrote:
Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

Are you talking Fahrenheit or degrees ?

RedlineMike wrote:
Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

If your talk C not F (I can not spell them) That is a bit hot I think. Too much fuel. As bogged said 600+ is normally very bad. Aim for about 500-550 would be a good max.

weeman wrote:

RedlineMike wrote:
Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

Are you talking Fahrenheit or degrees ?

him being in scotland it would be Fahrenheit ....

Also, is sensor pre or post turbo?

RoldIT wrote:Also, is sensor pre or post turbo?

also.. how close does it need to be to the turbo if its post turbo? I was of the understanding that it should be as close to the turbo as possible.. if your trying to tune your turbo via the Pyro and your sensor is a mtr away from your turbo, you could be tuning it to over the 550c safety limit..

is this an ok position for the pyro?


From what I have read the best way is to dyno tune it while adjusting the fuel to find the happy medium between too hot/hot enough using the pyro..

Way to far from the turbo. As its not even in the photo

mine is about 100mm past the turbo flange. my hilux with surf motor and intercooler doesn't go past 400-450 max thats turning 35's at 110km/h

YB.LOW4 wrote:mine is about 100mm past the turbo flange. my hilux with surf motor and intercooler doesn't go past 400-450 max thats turning 35's at 110km/h

that might be on a cold morning but what about on a 40 degrees + day...... everyone has a different situation what you run down in melbourne may be too much in darwin....... hence with the temperature difference

i have a egt plug about 2.5 inches from the back of the turbo

No more than 6 inches from the waste gate.

sorry dibbz, didnt mean to hijack your thread.. just thought it was important thing to consider if you are going to be tuning via the EGT. .you'd want it to be in the right spot..

if you were getting 550-600c with it where it is you could easily cook your donk.. or thats my thoughts anyway..

so back on track.. how do you find out the happy medium between max performance and high EGT's?

shorty_f0rty wrote:sorry dibbz, didnt mean to hijack your thread.. just thought it was important thing to consider if you are going to be tuning via the EGT. .you'd want it to be in the right spot..

if you were getting 550-600c with it where it is you could easily cook your donk.. or thats my thoughts anyway..

so back on track.. how do you find out the happy medium between max performance and high EGT's?

more boost

Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

Yeh well, firstly the dump is off the donor and kinda old, I had asked the exhaust guy to put the sensor in straight after the join, and if he could put it in kinda vertically. Obviously I couldn't hang over his shoulder and he's put it about a foot past the join, and horizontal.

The join is only a few inches after the bend at the end of the dump and where I asked for it to go would have been suitable.

*shrug*

I'm not going to lose as much heat as youd expect, the heat has to go somewhere, it's not gonna drop more than 50 degrees in 2 foot of pipe, otherwise we could be marketing tubular high performance heat sinks :)

The exhaust being metal will reach close to the same temprature as the exhaust gas in a short time. I'm keeping that in mind when looking at the dial, common sense, If it gets over 400 there it's as hot as I'd care to see it.

I find even with the sensor there, it is pretty snappy to respond, and the EGT's are what i'd expect, it doesn't get much past 250 running constant 2-3psi boost on the highway, I've had it to 300 before when working it.

Also consider a lot of people get turbos and NO pyro and they simply rely on conservitave tuning, I'm still running it at default <8 psi and its only had the fuel turned up a little.

I'm not condoning putting a pyro there, it was a little out of my control, obviously closer is better, but I'm not convinced this is the end of the world yet.

RedlineMike wrote:

bogged wrote:

dibbz wrote:I'm trying to get my head around the statement made in a lot of places that fuelling up a turbo diesel makes more heat and you don't want to do that.

I can make some pretty safe assumptions here, turbos put more air in your cylinder, the goal is more/better bang. So I can say I'd want more fuel with more air to make that bigger bang which is going to make more power and heat either way.

From what I can understand, in a petrol the idea is that the unburnt fuel absorbs heat, and in a diesel the idea is the unburnt air takes the heat out.

So the conclusion I come to is that you do need more fuel, but too much fuel is an issue? Where do you find the happy balance.

churs

You answered it there in yellow.

how do you find a balance - with your EGT Gauge. Too much fuel creates heat as you say, and its deadly in diesels, with EGT's getting to 600 degrees +_

Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

720*C is a safe max if you are measuring pre-turbo (as you do in a 300Tdi and probably on your 200Tdi)
I wouldn't touch the max fuelling adjustment on the back of the pump, I can easily exceed 720* with the two aneroid (boost cpmpensator) adjustments on the Bosch pump. I believe you should change the diaphram spring for a 300Tdi version if you've tweaked the boost to 300Tdi levels (15.5psi+) as well.

Ian Petersen of Thermoguard EGT fame has an excellent write up on tuning 2-300Tdi's I can email you if you want to go back to scratch and re-tune.

RedlineMike wrote:Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

WTF!!!! white hot on a diesel

RedlineMike wrote:Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

I'm surprised you haven't melted some piston crowns!!!

RedlineMike wrote:Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

Put the pic up.

nic

rick130 wrote:

RedlineMike wrote:

bogged wrote:

dibbz wrote:I'm trying to get my head around the statement made in a lot of places that fuelling up a turbo diesel makes more heat and you don't want to do that.

I can make some pretty safe assumptions here, turbos put more air in your cylinder, the goal is more/better bang. So I can say I'd want more fuel with more air to make that bigger bang which is going to make more power and heat either way.

From what I can understand, in a petrol the idea is that the unburnt fuel absorbs heat, and in a diesel the idea is the unburnt air takes the heat out.

So the conclusion I come to is that you do need more fuel, but too much fuel is an issue? Where do you find the happy balance.

churs

You answered it there in yellow.

how do you find a balance - with your EGT Gauge. Too much fuel creates heat as you say, and its deadly in diesels, with EGT's getting to 600 degrees +_

Oops

My EGt goes of the scale at 920,not hard to get it there

mines normally runs no more than 820 with the pump screwed open

720*C is a safe max if you are measuring pre-turbo (as you do in a 300Tdi and probably on your 200Tdi)
I wouldn't touch the max fuelling adjustment on the back of the pump, I can easily exceed 720* with the two aneroid (boost cpmpensator) adjustments on the Bosch pump. I believe you should change the diaphram spring for a 300Tdi version if you've tweaked the boost to 300Tdi levels (15.5psi+) as well.

Ian Petersen of Thermoguard EGT fame has an excellent write up on tuning 2-300Tdi's I can email you if you want to go back to scratch and re-tune.

If you could mail it to piper2recovery@hotmail.com that would be smashing

ill try n get the white hot pic up at some point,

nicbeer wrote:

RedlineMike wrote:Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

Put the pic up.

nic

yea x2. something smells and it isnt a hot engine...

bogged wrote:

nicbeer wrote:

RedlineMike wrote:Its degress C

my probe is on the down pipe off the turbo,


got a picture on my phone of the turbo glowing white hot

Put the pic up.

nic

yea x2. something smells and it isnt a hot engine...

Give me 10 min & ill get it up

1 week old turbo

RedlineMike wrote:

rick130 wrote:

RedlineMike wrote:

bogged wrote:

dibbz wrote:I'm <snip>

Ian Petersen of Thermoguard EGT fame has an excellent write up on tuning 2-300Tdi's I can email you if you want to go back to scratch and re-tune.

If you could mail it to piper2recovery@hotmail.com that would be smashing

ill try n get the white hot pic up at some point,

found an online version here http://www.aulro.com/afvb/attachment.ph ... 1152411367

BTW, that pic is bloody brilliant, just glad it isn't my Tdi

I've seen about 650c before the turbo on my 2.4 surf. Thats bog stock.

are rover engines cheap to rebuild over there?

badger wrote:are rover engines cheap to rebuild over there?

Can pick up a complete disco with TDi for £500 (1,240.86 Australian dollars)

an engine on its own is about £900 for a defender one,

I would love a copy of this. Can you please email it to adrenalineissues at gmail.com

I can't get onto the URL below.

Thanx
Paul

720*C is a safe max if you are measuring pre-turbo (as you do in a 300Tdi and probably on your 200Tdi)
I wouldn't touch the max fuelling adjustment on the back of the pump, I can easily exceed 720* with the two aneroid (boost cpmpensator) adjustments on the Bosch pump. I believe you should change the diaphram spring for a 300Tdi version if you've tweaked the boost to 300Tdi levels (15.5psi+) as well.

Ian Petersen of Thermoguard EGT fame has an excellent write up on tuning 2-300Tdi's I can email you if you want to go back to scratch and re-tune.

Just remebered n thought id say,rather than swapping the 300 spring into the 200 pump,i just fitted a complete 300 pump,

done the diaphram on the top & adjusted the smoke screw slightly,was having problems with it eating stop soloenoids but since winding it out 1/4 turn its been fine,only smokes black when its cold at full boost & when ur giving it boot offroad