Braineack

iTrader: (62)

this post was not flame worthy.



I would still like to point out that Garrett still only saw a 25°F (~14°C) improvement in temps in a controlled environment in the best conditions possible at peak temp. And they didn't really state what temps that were measuring (water, surface, turbine, chra), when they were taking the temps (running, in boost, after shutdown), and the time delta (how much faster did one drop temps over the other).

I would also like to point out, that our fucked up method has yet to result in turbos failing from backcooling and that it's wasted effort in order to look like a huge *****.

sixshooter

iTrader: (12)

I never said it didn't happen. I just said it didn't matter. I have no coking problems and do not plan on having this particular turbo over 100k miles.

Your purposes may vary of you are an actual auto manufacturer.

Vuti

Straight from the Garrett white paper:

I like my water more at 90deg than @ 140deg.
And if it's possible to route the turbo coolant lines on my miata "the right way" I will do it.

The whole idea was exploring this and how it can be made possible, no one has made any suggestions so far how to accomplish this. Yet all the energy has gone to: "our method is good enough no need to develop it" bullshit.

Braineack

iTrader: (62)

peak temperatures of what, when, in the center housing? water? surface? oil? turbine shaft? bearings? during operation? full boost? after shutdown?

The chart also suggests that the 50°C reduction was at a rotation of 30° on the axis. But yet, they suggest that you rotate it only 20°. Which is a reduction of only 20°C of peak "temps".

You wanna know why they don't have you rotate the turbo to the more ideal backcooling rotation of the chra? because at every degree rotation you're reducing the actual cooling efficiency of the cooling/lubricating system during operation.

Notice that Volvo turbo you posted is pretty much at 0°.

I'm actually a bit shocked garrett would suggest even a 20° rotation to help improve backcooling after shutoff without discussing the adverse effects it will have on your oiling system and without study or note of those temps/issues.

You came to our site and claimed our way is fucked, yet none of us have coking issues with or without water cooling turbos but I have seen plenty of members having oiling issues when the turbo was rotated more than 10° from center. This whole discussion is stupid. Had you come in here with a more, "hey what do you ******** think of this white paper" approach instead of a "hey you ******* are wrong and im smarter than you cause i read someone else's work" approach, maybe we'd be more willing to give a **** about what you're trying to convey.

So yeah, by all means, you can go ahead and use the lower water port on the block as an inlet and then the upper hose or something as an outlet, with a 20° rotation on the turbo as opposed to the water pump port as an inlet (coolest water source) and the upper hose or something as an outlet (hottest source) with or without a 20° rotation on the turbo...but who's to say the cool water from the lower hose source doesn't flow up through the turbo, once the motor is off, up through the turbo and out the upper hose due to heat siphoning? Honestly I've put way too much thought into something I don't care about.

Leafy

iTrader: (1)

Brain, the vulva turbo looks like the water ports are setup like the EFR, where there's 4 ports, and you block 2 of them in use, have them cross flow, and use the low on one side for the entry and the high on the other for exit.

miata2fast

iTrader: (2)

I find this discussion to be very interesting and that I have learned something. Why the hate?

Braineack

iTrader: (62)

sounds like a much better approach. too bad garrett doesn't actually develop turbos anymore (only sell ancient, rest-on-laurels, overpriced, tech).

Leafy

iTrader: (1)

fixed

Braineack

iTrader: (62)

any merit in this?

Leafy

iTrader: (1)

It makes sense to me. Actually kind of thinking of re-doing my water lines like that now. Might just be a pain in the *** to get all the air out.

Braineack

iTrader: (62)

but that's the typical way we plumb it.

we plumb it to the water pump inlet, the lowest pressure zone, and typically plumb the other end to the upper hose, or water neck--the highest pressure zone.

as shown in post #1 here: the fucked up way.

while yes, the water is going to flow from upper hose to lower hose during operation (the most ideal high pressure to low pressure), when it's off, isn't this then already the ideal setup for heat siphoning? the cool water post radiator will absorb the heat from the CHRA and flow up into the upper hose?

Vuti

Let's say you have the usual coolant reroute and you take the water still from the same point. In this case the hose coming from oil cooler and TB. This point is one of the furthest points you can take the water from the pump. It gets warmed by the block and also by the oil cooler. Then you take this hot water to your turbo?

And the return to the mixing manifold. Yes it's the optimal place to return when talking about low pressure. But when talking about thermal siphoning it's too low in the system and it is too cold.

I also like to point that the up/downs on our hoses are one of the major reasons thermal siphoning can't work. Most of setups have both hoses pointing down at the turbo. In worst case they both rise up to clear the power steering (FM/Begi) before going back down to mixing manifold.

And changing the flow direction of the coolant after shutdown? That just...

Most of the OEM applications either return to heater return (if the pipe is high enough), near the top radiator hose, the thermostat neck/cover or the throttle body.

Braineack

iTrader: (62)

this water is still cooler than the surface temps of the turbo. and still well below the 250°F max temp that Garrett suggests in the white paper. A typical miata would be pushing water between 180-210° through the turbo.

water too cold for thermal siphoning? isn't that the point?

cool.

just what? why does it matter? why does it matter what direction the water pump forces water while the motor is turning? so you're saying thermal siphoning cannot happen when the inlet of the turbo is too cool and the outlet is in the ideal location, higher than the turbo, because at one point the water was flowing in a different direction? does not the whitepaper itself say that the inlet should be the cold side, and the outlet the hot side? so what's the problem here?

okay. point being? you just listed all the points where we might return as well.


anyway, i've already been saying for years the water port above the oil port on the block is probably a better location for water source for the turbo. but not much has changed after the motor is shut off between before the WP and after. They are both about equally low on the motor, and they are both the coldest source for the "inlet" and the outlet will still be the same. The only change being the flow during operation, which will be more ideal for sure without a doubt.

18psi

iTrader: (76)

I think OP is expecting a drastic improvement based on a theory of his that's derived from a vague statement by a turbo manufacturer.

I think OP is in for disappointment.

Braineack

iTrader: (62)

I do have to concede that Garrett did put in one quick line about adverse effects on oil drainage. I missed it the first time i skimmed through.

ill even concede that the way we do is wrong, not fucked, only because we should be using the lower coolant port (if you even have it on your block) as opposed to the water pump inlet. As this will allow the coolest water to flow through the turbo instead of the warmest.

but i still don't see why the fact that there is a water pump between these two setups, that when off, siphoning will only occur in one.

Efini~FC3S

iTrader: (4)

Eff it

What do the F1 teams do on the new turbo engines?

If we don't do it the same way as them we might as well take the turbos off our cars until we can do it right!

My turbo miata project is on hold until this problem can be fixed!!!

TurboTim

iTrader: (9)

Thats what I did. After some spirited driving and shutting her down hot, I might hear some blubb blubb from the heater core. My 2560 is 12 years old and the turbine blades are eroded to near paper thin at the tips, but the oil drain port looks new/clean.


This is what I think happens.

Vuti

Take a close look at the pictures.





1. How does the water rise to the bottom of the turbo? All I can see is a feed line that starts at the mixing manifold, goes straight up, then down, then up to the turbo
2. How does the water flow freely upwards from the turbo? All I can see is a return line that points straight down from the turbo, then goes back up to the water neck?

Constant uphill and great success?

I believe that a solution where coolant flows to the right direction in every situation is still the right one.
You all know which is the right way of doing this, thinking about reversing coolant flow etc. is just band-aid.

Braineack

iTrader: (62)

i forgot water can't flow if it's not in a straight line hose from low to high. Probably why my garden hose never works unless i unravel it and stand on the roof.

this is also probably why normal siphoning never works either. I was never EVER able to siphon water out of my fish tank to clean it, or gas from a gas tank, because i never had a perfectly straight hose.

i also dont understand phsyics and thermal dynamics.

18psi

iTrader: (76)

Thread is starting to deliver.