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The next procedure is to replace the turbo to reduce the exhaust manifold pressure (EMP) down to 1:1 or hopefully less.

Why?
Because with the high EMP, it's a restriction in the exhaust and at above 10psi inlet manifold pressure the heat retention is ridiculous.
You could have the ultimate cooling system but under load on hot days it's never going to be stable.
I second your plans to get a better turbo with lower EMP, curious to know what your plans are for this turbo. Custom made or an off the shelf option or secrete can't talk about yet?

Also just reading your reply the thought popped into my head that maybe 95% of people who would be interested in an upgraded cooling system would be running one of these "not so ideal" turbos with much higher EMP than IMP so I think seeing results with each setup would still be of interest.
 

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I second your plans to get a better turbo with lower EMP, curious to know what your plans are for this turbo. Custom made or an off the shelf option or secrete can't talk about yet?

Also just reading your reply the thought popped into my head that maybe 95% of people who would be interested in an upgraded cooling system would be running one of these "not so ideal" turbos with much higher EMP than IMP so I think seeing results with each setup would still be of interest.
I won't divulge any details yet on turbo specifics, but to say people far smarter than me have decided upon.
Also it's the first stage and could be modified/changed for the desired results
 

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Hmmmm, if only there was a cutting edge new turbo company out there that had knowledge of TD42 performance as well as the foibles of the cooling system. 🤔😗
 

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GUII ZD30DI Wgn
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Hmmmm, if only there was a cutting edge new turbo company out there that had knowledge of TD42 performance as well as the foibles of the cooling system. 🤔😗
There is ;).
 

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SUI GENERIS UTE
GQ Ute 1990 Silvertop
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:rolleyes::rolleyes: Yeah well you just have to wait for development and more experience and knowledge can be acquired before a TD turbo can be done.

The RMS pump looks ok and probably will work, From data i do have and do know a lot about, a few things just dont gel with their graphs. One being the std pump does not develop 4 psi delta at 1000 rpm, my very efficient closed impeller can only just make 4 psi delta at 1000rpm i have only ever measured 0.3 to 0 psi delta at idle with the STD pump and this is very dependent on weather the thermostat is open or not if the thermo is open then its un-measurable pressure. As for the 10psi delta at 2000 rpm yeah well there is no way in hell the STD pump can do that, clipping the accelerator at 2000 rpm i have managed to record 3 psi delta best with a thermo just cracked open and bypass open with the std pump. My own impeller will see 22 to 23 psi delta between 2000 to 2500 and a bit less at 3800 rpm. Now for the really big issue and very difficult to measure on the engine in operation, that being flow capacity. (easy to do with a cooling tower in a engine dyno room) I did do this a few time with a external bypass and blocking off the internal bypass with no thermostat with a valve to simulate resistance. Anyway its a bit crude without a radiator in the system and the flow meters gives up recording at about 110C. The RMS graph is pretty close to what i recorded for a STD pump the best i saw was 45lpm between 2000 and 2500 rpm and drops down from there to about 10 lpm. Remember this flow capacity will change dramatically depending on how open the thermostat is and how much head the pump is seeing the values i got with the maximum flow possible using the valve in my external bypass system. But for each rpm set point i used the pressure set points recorded on the engine in normal configuration so my results would be pretty accurate for on engine results My own impeller will flow a bit better than 20lpm at idle and is stable at 2000rpm with a true 110 to 130 litres / minute between 2000 and 2500 rpm @ 23psi delta. (To note i dont have 23 psi in my radiator my thermostat has been modified so it restricts flow so most of the water and pressure stays in the block where it belongs, due to an full open internal bypass no flap on the thermostat. You cannot do this with a STD pump it needs to flow and have a respectable pressure)

Using Maths with some knowledge and data from very smart experienced engine design engineers for our TD being IDI with its precombustion chambers in the head water gallery, we need a flow capacity of a little less than 80lpm @ 2000 to 2500 rpm to maintain a stable cruse temperature when load is applied in the area of 160ish engine KW's. As you would appreciate when the engine is loaded we are usually doing 2000 to 2500 rpm which is within our torque peak rpm and where most of us work our TD42 on road or off road. So in conclusion we need better than the RMS pump of 40 to 60 lpm for our 2000 to 2500 rpm loaded area usage to keep some resemblance of total stability by allowing the thermostat to cycle due to temp loads. That doesn't mean the pump wont work, it will but is still a bandaid fix because it will just extend the kettle point longer.

And again there is no such thing as to much flow with a closed loop/bypass pump system used on a engine. Yes its possible to get too much flow through the radiator if the thermostat is not restrictive enough or not enough restriction in the system including the thermostat or restrictors to make pressure to flow the values we need here to stabilize the system by having the thermostat cycle to maintain a stable temp. Very simple guys if your thermostat is not cycling how in the hell is it suppose to maintain stable temps. So logic suggests if you cannot get loaded stable temps you don't have enough water flow to remove heat so the bloody thermostat can do its job to whatever temp set you want to use on your thermostat.. On our TD and its design its pretty much impossible to get to much flow through the radiator and still keep a stable temp. Also from Math our GU radiators and or GQ radiator is sized to have the capacity for 300+ hp of thermal load, We just need to fix the other bits in the system so it can work as intended..
 

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Screenshot_20200302-193429_Photo Editor.jpg


Just a little that some of have noticed with the JPC impeller is if,

A~ is the entry of the pump.
B~ is the discharge orifice.

This design looks to be back to front.

'A' is significantly lower the 'B'.
This would cause a loss of pressure of the water as it travels through the pump.

Ideally you want 'A' to be higher than 'B' as this would squeeze the water through the pump raising the pressure of the water discharged.
 

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Screenshot_20200303-174648_Photo Editor.jpg

The RMS impeller.
Among other things if you look at the top of the vane there is a sharp angle, which would not match up with the timing cover face. Cavitation would be a problem here and the straight vanes are also less than ideal.
 

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View attachment 516729

Just a little that some of have noticed with the JPC impeller is if,

A~ is the entry of the pump.
B~ is the discharge orifice.

This design looks to be back to front.

'A' is significantly lower the 'B'.
This would cause a loss of pressure of the water as it travels through the pump.

Ideally you want 'A' to be higher than 'B' as this would squeeze the water through the pump raising the pressure of the water discharged.
Can you clarify this a bit more plumma, I don't quite understand in what plane that A is lower. I understand why it has to be as you say but I don't understand your description in relation to the picture because I see the centre area "A" as the high point and "B" the outer edge or base being low. Obviously I'm interpreting your description around the wrong way. Do you mean that area around the boss for the shaft shouldn't be tapered up into the boss but should be separated in that the vanes shouldn't meet the centre and the area between the vanes be flat up to the base of that boss.

Either way this is also why I can't see the fabricated stainless ones being any better.
 

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Can you clarify this a bit more plumma, I don't quite understand in what plane that A is lower. I understand why it has to be as you say but I don't understand your description in relation to the picture because I see the centre area "A" as the high point and "B" the outer edge or base being low. Obviously I'm interpreting your description around the wrong way. Do you mean that area around the boss for the shaft shouldn't be tapered up into the boss but should be separated in that the vanes shouldn't meet the centre and the area between the vanes be flat up to the base of that boss.

Either way this is also why I can't see the fabricated stainless ones being any better.
It's the bottom plate/flange being tapered up to the eye of the pump, where ideally it should be flat, so when the water enters the eye it gets squeezed to the discharge orifice
Screenshot_20200303-201254_Photo Editor.jpg

If you look at the standard impeller the deepest part of the vane is near the eye of the pump, the JPC is the opposite of this.
 

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Ah OK, that's clearer. I take it by the picture of the standard impeller that if you project that angle of the vane towards the centre then it would be taller than the JPC vane is where it meets the boss around the shaft so it's not a matter of the JPC being shortened at the outer diameter because it's essentially to short at the inner diameter.
 

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You have to look at the impeller and imagine where they marry up to the wiping face in the timing cover. The vane should be as the factory impeller as taller near the eye then tapering to the end or the discharge orifice. When in position against the wiping face it squeezes the water increasing pressure.
Look at the JPC vane and it's almost flat. The tolerance between the vane and wiping face would be less than ideal. Then, the vane tapers back to the eye of the pump (wrong way)
I can't see how these pumps would make any pressure, and cavitation looks like a problem also.
 

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As you know, I am not an expert on water pumps, I have simply followed the advice of our resident engineer, who has worked on TD42 pumps extensively. So, I remember half of what he tells me, and understand about a quarter. :rolleyes:

So keeping that in mind, I have two comments to make about this video. Firstly, in order to get some measurements on the impellor I made, I used Blu Tac, just as they did. Works well!!!

Secondly, the design of the impellor looks to be terrible to me. I dunno what you think about it. I think the claim of it being high volume must be based purely on the fact that the impellor clearance to the timing case is reduced from standard. A standard pump without a gasket will still be about 3mm, so they have closed that up a lot, which is an improvement. But that impellor does not look very efficient to me.
 

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Pretty sure it's been tactfully mentioned a couple of times that the design is rather not so improved. Probably not so tactfully if we went back in enough detail.
Maybe I'm a bit over cautious about machining accuracies/tolerances but whilst i know he says he spins it at the end to check the full circumference, I'd be inclined to blu tack all of them or in different spots because if it is less then 1mm elsewhere under gentle spinning I'd be concerned when a belt is loading up the pulley and it's spinning at 4 digit RPM.
 
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