1HDT EGT and EMP guage install (1 Viewer)

[Wildnlost]

I have been running an EGT in my 1HDT powered 92 HDJ81V for some time now.
I have been curious as to placement of the probe. I placed mine as shown in the manifold just before dump into the turbo. The cast diverter was partialy shielding the probe. I drilled it blind with the manifold installed.

I die ground the diverter back a bit so as to not shield the probe. The probe is almost centred in the port.

While the manifold was off I installed a stainless 3/16" compression fitting to mount a Exhaust Pressure Guage and again question the placement.

I will post more pics of install as I go.
Please post your comments of where your probe is installed. Any rules of thumb etc.
Cheers

 

[1HaytchZed]

Not sure why you're concerned about EMP.
You headed into space or worried about nuclear fallout type scenarios?

It's nice to see a cruiser is your choice for such a mission/scenario.

 

[Wildnlost]

Not sure why you're concerned about EMP.
You headed into space or worried about nuclear fallout type scenarios?

It's nice to see a cruiser is your choice for such a mission/scenario.

I have installed a TD05-18g hybrid turbo as well as porting.., modified pistons, intercooler etc. Apparently drive pressure optimally would be about 1.2 times boost pressure. With my recent rebuild I had some exhaust valve pitting that I am not sure of the cause. Possibly EMP too high, valve seats cut too narrow. This will aid tuning and show turbo efficiancy of my homebrewed 80 setup.

 

[Wildnlost]

Not sure why you're concerned about EMP.
You headed into space or worried about nuclear fallout type scenarios?

It's nice to see a cruiser is your choice for such a mission/scenario.

Dah! Sorry I was a little slow on the pickup. The Joker face should have been a hint.

2 funny

 

[Wildnlost]

Getting closer to driving. Got the tubing for EMP port installed and heat shield on the manifold. I used brake line 3/16" steel tubing. You can see the hole in the heat shield for the EGT probe.
I added a second heat shield to keep radiant down to the top mount intercooler. The shield doubles as the mount point for the intercooler.

 

[IanB]

I was trying to learn a bit about how an exhaust manifold pressure sensor could be used for tuning, as I have never seen or heard them being used. It looks like the internet is calling it an EMAP sensor? EMP is reserved for electro magnetic pulse it seems, lol.

You need the length of pipe with an uphill run or a coil, and then a layer of steel wool or something in a canister the sensor is mounted in, to protect the sensor from temp and condensation?

What's the tuning theory behind using this data? Does pressure rise with fuel, or with air, or a combination? Is there a pressure that is too high and should be tuned to avoid?

I'm excited to see what you can do with this setup, not a lot of envelope pushers outside of Australia it seems!

 

[KiwiDingo]

Most people I know that use them don't use a fancy senor that needs all those precautions, they just use a standard boost gauge that goes high enough for the EMP they are running. Plus it's not something people tend to permanently leave installed and only there during tuning and setup changes. There's lots of ways you can install it but mines pretty similar to @Wildnlost, I have a small coil of tubing to dissipate the heat before I hook up to the rubber hose going to my 30psi VDO boost gauge.

 

[Mcreight911]

Most people I know that use them don't use a fancy senor that needs all those precautions, they just use a standard boost gauge that goes high enough for the EMP they are running. Plus it's not something people tend to permanently leave installed and only there during tuning and setup changes. There's lots of ways you can install it but mines pretty similar to @Wildnlost, I have a small coil of tubing to dissipate the heat before I hook up to the rubber hose going to my 30psi VDO boost gauge.

View attachment 2079479

I use a very similar setup that I transfer from vehicle to vehicle. Couple of coils of copper pipe with a transducer plugged in one end . The transducer is mostly plastic and I’ve never melted one . Nice manifold by the way kiwi !

 

[Wildnlost]

I was trying to learn a bit about how an exhaust manifold pressure sensor could be used for tuning, as I have never seen or heard them being used. It looks like the internet is calling it an EMAP sensor? EMP is reserved for electro magnetic pulse it seems, lol.

You need the length of pipe with an uphill run or a coil, and then a layer of steel wool or something in a canister the sensor is mounted in, to protect the sensor from temp and condensation?

What's the tuning theory behind using this data? Does pressure rise with fuel, or with air, or a combination? Is there a pressure that is too high and should be tuned to avoid?

I'm excited to see what you can do with this setup, not a lot of envelope pushers outside of Australia it seems!

I am not running a sensor per say but a boost guage hooked to the exhaust manifold pre turbo. I am curious to know what pressure I am making in the exhaust manifold. I am not sure if you saw the damage to my exhaust valves on my 1HDT cylinder head posts. I may be back stopping to much pressure and over heating the exhaust valves due to the smaller turbine of TD05 exhaust wheel.
Or possibly running to much boost for the setup. I suspect the exhaust turbine starts to spike in pressure when efficiency drops off.
Not really sure what I will see to be honest or how to use it. The closer the exhaust pressure is to boost pressure the more balanced and efficient your setup is. With 1.2 times the boost being normal. And 1.4 being the limit. (This is internet info and may be bogus)
I would assume that as pressure rises too high it becomes more difficult to scavenge the cylinder on the exhaust cycle as you would be working against boost filling the cylinders with a fresh charge during valve overlap.
If anyone has any information regarding Exhaust Manifold Pressure or data to to help fill in the blanks....please jump in.
How about ExMP for an acronym?? or XMP?

A-pic of my valve pitting. 20k on valve job. Seats were cut too narrow as well.

 

[IanB]

I use a very similar setup that I transfer from vehicle to vehicle. Couple of coils of copper pipe with a transducer plugged in one end . The transducer is mostly plastic and I’ve never melted one . Nice manifold by the way kiwi !

How are you connecting it such that it's easily transferable from one vehicle to another?

 

[KiwiDingo]

If anyone has any information regarding Exhaust Manifold Pressure or data to to help fill in the blanks....please jump in.
How about ExMP for an acronym?? or XMP?

I use the acronym EMP to keep it simple but a lot of others, especially overseas use the term drive pressure. Doesn't really matter it's all talking about the same thing, but like @IanB pointed you'll sometimes get people thinking about magnetic pulses instead haha.

In a perfect world of ideals you'd always want EMP to be less than IMP but that very really occurs on a daily driven vehicle that needs to operate over a very wide range of RPM and fueling loads. There's lots of different views on this subject and I'm sure there could be pages of arguments over this but at the end of the day not everyone wants the exact same outcome in there setups so there's always going to be different approaches. Me personally, I aim to get EMP:IMP at 1:1 during spool to peak torque and then have it not go higher than 1.4:1 at max RPM.

 

[Mcreight911]

How are you connecting it such that it's easily transferable from one vehicle to another?

Via a tapped hole in the manifold, like in the above photo . Once removed it can be blocked with a bung. Data logging equipment can be easily plugged into the transducer and un plugged from it .

 

[Mcreight911]

@Wildnlost if you don’t want to read white paper studies on emp & drive pressure google Banks performance they have some videos that touch lightly on the subject . Eclipse turbo systems have some basic info on their website also .

 

[KiwiDingo]

This thread is good timing, they just actually released an article on this very subject today. Let me see if I can link it...

1HZ ENGINES (Turbocharged) understanding the real story.

Before I start, this is also applicable to all turbo diesel engines.

We all agree that excessive combustion heat kills diesels (fact).
But what is the gauge of reliability when turbocharged? Is it,
Boost pressure?
AFR’s (Tuning)?
EGT’s?
Or is it the turbocharger causing it?

Answer, all of the above.

It seems everyone has formulated their own theories, but no one has actually put it all together yet. Understanding the big picture, whilst isolating the most common denominator with failures and or issues is very important. In this post we will summarise these contributing factors.

Boost pressure. Turbo boost pressure itself cannot harm a diesel engine in any way. Higher boost pressure usually means higher heated air, which makes the air less dense and easier for the cylinder to compress. But by raising the boost pressure too high on some turbochargers, it is inadvertently also increasing the turbine back pressure (pressure in the exhaust manifold). This back-pressure or drive pressure produces diminishing torque/power values due to some of this heated un-oxygenated gas being held back into the cylinder reducing the amount of oxygen the piston can draw in by occupying space in the cylinder. This excessive pressure also puts extra unwanted load back on the turbocharger bearing components. Accepted Industry standard for turbine back pressure, is a maximum limit of 1.4:1 (Exhaust Manifold Pressure to Intake Manifold Pressure Ratio). 1HZ engines are pre-combustion engines and have no cooling gallery in the piston crown from standard so are not well suited to removing the extra heat load generated. We feel instead of using boost pressure as the limiting factor, we suggest, progressively increasing the turbochargers shaft speed and tune until the maximum (safe) turbine back pressure is achieved is a much safer option.

AFR’s. We all know that excessive fuel can cause heat and fatigue diesel engines. But this alone as the governing factor for reliability is a false economy and I’m going to tell you why.

Turbine back pressure is a limiting factor for all diesels. It robs the engine of torque after peak boost pressure has been achieved, and raises the thermal load throughout the engine. This is significantly important to the 1HZ engine where the idea is to keep the cylinder temperatures cool to help engine reliable. When high turbine back pressure occurs, the engine’s VE (volumetric efficiency) drops due more very hot exhaust gas being held back in the cylinder. This extra spent gas occupying the cylinder from high turbine pressures, leaves less space for the in rush of cool intake air when the exhaust valve finally closes. The engine relies on this dense volume of intake air to keep the cylinder cool (before ignition) and to drive out the last residue of hot exhaust gas when the two valves are open by a pressure bias to the intake pressure being higher than the exhaust pressure. Testing has shown that the actual peak cylinder temperature (that is only for a split second) does not actually rise much, but the duration of this peak cylinder temperature under load is sustained for longer, resulting in a median temperature rise with more thermal transfer into the oil through the piston, into the water through the cylinder walls and the pre-combustion chamber. Which brings us to AFR’s and EGT’s.

A lower volume of intake air for the same fuel volume means the AFR’s will be lower and the EGT’s will be higher right – well that’s not really so. Yes, AFR’s will lower slightly and the EGT’s will also rise slightly. As the residual exhaust gas combined with pre-heating the intake air temperature, results in extra heat at the point the fuel is injected allowing more time for the fuel to burn, altering the AFR reading (as opposed to having a high oxygen content which will make the fuel burn faster). This results in high cylinder temperatures. For 30 degrees of extra EGT the cylinder temps under sustained load can rise by 380 degrees from its median, with the AFR only moving 0.6 points.
So - boost pressure, AFR’s and EGT’s are not the gauge for reliability on a 1HZ engine with the presence of high turbine back pressure. I haven’t bothered mentioning excessive pump timing or leaking injectors/ atomization etc as that is a given for diesel engine failure.

Some of the suggested possible solutions I’ve heard for running a turbocharger with high turbine pressure are,

“Run a much higher AFR to compensate.”
This goes against the very purpose of turbocharging in the first place which is to increase the engines air density in the cylinder, and is false economy. Pre-combustion 1HZ engines are designed to run lower AFR’s than a Direct Injection diesel (fact). Running a tune of 24/25:1 is a band aid fix and counterproductive.
“You should use an intercooler when turbo-charging any diesel engine.”
Intercoolers are great they add density or more oxygen to the same volume/pressure of air. This presents more oxygen in the same compressed space so the diesel fuel will ignite faster and more complete in the initial combustion cycle at the correct temp and pressure at just after TDC. We suggest fixing the turbine back pressure issue so you have less exhaust gas left in the cylinder causing late and in-complete ignition of the diesel, and making full use of the intercooler’s ability. A 1HZ engine with very low turbine back pressure can run a lower AFR safely as is the design of pre-combustion for its efficiency (with or without an intercooler).

Summary and conclusion.
Any turbocharger can be used with a 1HZ engine, some will be much better than others. It’s first and foremost limit for reliability is the turbine back-pressure, once this parameter is set and not an issue - tuning (AFRs and EGTs) can be implemented. I think you will find a lot of these “quick spooling” turbochargers will have very high turbine back-pressure and will be limited. After all, the whole idea is to burn fuel with the maximum amount air density available, and not restrict or reduce this air density in any way. Turbine back pressure is measured as a Ratio dividing the exhaust manifold pressure (EMP) by the intake manifold pressure (IMP). EMP 21psi, IMP 15Psi = 21/15 = 1.4:1 EMP: IMP. Testing of our exhaust manifolds showed the importance of a divided manifold for cylinder scavenging, by reducing the possibility of exhaust valve overlap that can also result in gasses being retained within the cylinder due to pulse energy disruption. Similar, but another subject.

Guys, before we get inundated with emails and calls – We don’t yet have a 1HZ turbocharger ready for the 1HZ engine and can only point you in the right direction. As you can appreciate it takes time to engineer things properly, but we felt it was best to share this insight so 1HZ owners and in fact all turbo diesel owners could benefit by preventing a few costly errors.

 

[Wildnlost]

Found an interesting article...

exhaust backpressure on turbo engines- Never good!

Exhaust backpressure on turbo engines is one of the most misunderstood aspects in tuning to many people, but it's pretty simple- It's not good. On non-turbo engines backpressure is a single issue,...

www.stavtech.co.uk

 

[Wildnlost]

@Wildnlost if you don’t want to read white paper studies on emp & drive pressure google Banks performance they have some videos that touch lightly on the subject . Eclipse turbo systems have some basic info on their website also .

Thats great I will check it out. You can really appreciate what gturbo and the like must go thru in testing there setups. Hours and hours of trial and error.

 

[KiwiDingo]

Found an interesting article...

exhaust backpressure on turbo engines- Never good!

Exhaust backpressure on turbo engines is one of the most misunderstood aspects in tuning to many people, but it's pretty simple- It's not good. On non-turbo engines backpressure is a single issue,...

www.stavtech.co.uk

I've seen that exact picture before in another article about turbos and performance setups. Think it might have been Corky Bells one?

 

[Mcreight911]

Thats great I will check it out. You can really appreciate what gturbo and the like must go thru in testing there setups. Hours and hours of trial and error.

Careful sizing calculations to suit requirements , then educated trial and error refining with prototypes.
Some companies more so than others .

 

[KiwiDingo]

Thats great I will check it out. You can really appreciate what gturbo and the like must go thru in testing there setups. Hours and hours of trial and error.

Obviously they were focusing on something other than low EMP:IMP on my grunter extreme I had. It's pretty easy to work out what that was is too when you can achieve full boost at 1500rpm, the price for quickest boosting turbo most certainly goes to them! I thought it was fantastic at the time when I was unaware about side effects of EMP and began testing things. Once I discovered it was 3:1 EMP:IMP it didn't stay on long! On the plus side though it did survive nearly 5 years of absolutely flogging it and nothing broke or failed so I can't complain about that!

 

[Jroc561]

Im just planning on having three gauges in my truck, EGT, AFR and Boost. But its great to see these other ideas around