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70/30 Racing
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No picture, but it comes off of the small hardline right behind the T-stat, so if the feed to the TB is reduced when the T-stat is open, the feed to the turbo is as well.

Either way, even with reduced flow, as long as there are no bubbles in the system, convection will still carry the coolant away. When you turn your car off, coolant is still circulating around the system.

You guys are worrying about this too much, IMO. This effort, as I said earlier, is better spent eliminating the HOT WATER RECIRCULATION going on with the small hardline on the back of the engine. Look at it: hot water leaves the head, travels to the T-stat, then goes into the "cold" side input from the radiator and back into the water pump to be circulated throughout the engine. Horrible.
 

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Discussion Starter #26 (Edited)
You guys are worrying about this too much, IMO. This effort, as I said earlier, is better spent eliminating the HOT WATER RECIRCULATION going on with the small hardline on the back of the engine. Look at it: hot water leaves the head, travels to the T-stat, then goes into the "cold" side input from the radiator and back into the water pump to be circulated throughout the engine. Horrible.
I see what you are saying now.. With the way that the SR20DET turbo water lines are routed you basically bypass the radiator and recirculate the hot water from the turbo right back to where it was first gotten from.. It would almost seem that the best place to tap the coolant line for the turbo is from the inlet neck above the alternator and return it to the Tstat housing. This way you get the coolest water from the radiator to the turbo directly and return the "hot" water from the turbo right to the radiator without running it through the engine again. I dont know if this would work however - if the pressures/or whatever recirculates the water would give enough water flow through the turbo- meaning would it still flow water even though this was before the water pump and not after it.
 

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S12 NUT
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I don't remember if the FWD t-stat setup is different than the RWD one, but on RWD S14 SRs, the coolant return is on the upper water neck (returning directly back to the radiator)... So why not do that?
It's not going back into the block, and as for not being enough flow... It's not to cool the turbo while the engine is running, the oil already does that (though with a BB turbo, it works with the oil to cool), the point of coolant lines on the turbo is more for when you shut off the engine to reduce CHRA oil coking.
But either way, the 3/8" hard line on the OEM setup has more than enough flow to keep the turbo happy.
 

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713 ways to be a dick!
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Additionally you want the coolant to flow through the motor BEFORE it hits the turbo. The coolant leaving the motor is still cooler than the CHRA and as such will do it's job. If the the coolant went through the turbo first and then the motor you would be creating a larger issue.

Ideally you could run a separate heat exchanger and run the coolant line through that before the turbo if you wanted to get nuts with this, however I don't believe that is necessary with proper cooling upgrades.

In all I believe a swirl pot would provide much more benefit than these modifications.
 

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going thru life @ 1 bar
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where can i find reading material on a "swirl pot"?

Additionally you want the coolant to flow through the motor BEFORE it hits the turbo. The coolant leaving the motor is still cooler than the CHRA and as such will do it's job. If the the coolant went through the turbo first and then the motor you would be creating a larger issue.

Ideally you could run a separate heat exchanger and run the coolant line through that before the turbo if you wanted to get nuts with this, however I don't believe that is necessary with proper cooling upgrades.

In all I believe a swirl pot would provide much more benefit than these modifications.
and looking at the FSM, the coolant goes from the radiator to the WP thru the cylinder head to the turbo to the engine block.

 

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Discussion Starter #30
Above is interesting.. it appears that the hot water from the turbo is constantly recirculated throughout the motor rather than going directly back to the radiator.
 

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Discussion Starter #36 (Edited)
The only reason I can think that on the DET motors the turbo is plummed the way it is, is that by tapping into the block the water is constantly flowing through the turbo even though the T-stat is closed (recirculates through the engine block) and receives the highest water flow. It would seem that by tapping into the TB lines the water does not get much flow until the T-stat opens. If this is true, the turbo would actually run much hotter because it has very low or no FLOW through it at all until the T-stat opens.


Can someone please post a picture of where the turbo gets its water supply in the back of the block?
 

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p10 Newbie
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The only reason I can think that on the DET motors the turbo is plummed the way it is, is that by tapping into the block the water is constantly flowing through the turbo even though the T-stat is closed (recirculates through the engine block) and receives the highest water flow. It would seem that by tapping into the TB lines the water does not get much flow until the T-stat opens. If this is true, the turbo would actually run much hotter because it has very low or no FLOW through it at all until the T-stat opens.


Can someone please post a picture of where the turbo gets its water supply in the back of the block?
In that case u can always upgrade ur thermostat to open at lower temp, that way its always flowing thru the turbo.
 

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TunerCode
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The water is constantly being circulated at the same rate through everything, except the heater core when the heater valve is closed.

When the thermostat opens, it blends enough cooled water from the radiator to maintain the thermostat temperature. Its always the same amount of water being circulated through everything, it's just that some of it splits off to go through the radiator when the thermostat is open. What water doesn't go through the radiator is blended back with the water that does in the thermostat housing.

Dave
 

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Discussion Starter #39
Downgrading to a lower temp T-stat is not a solution. I found a picture of the turbo water feed and return points and now understand why it is done this way - on the DET engines. First on the DET engines, the turbo gets its water directly from the radiator when the T-stat is open - supply is right behind the T-stat housing, second, even when the T-stat is closed there is a steady flow of coolant through the turbo that would otherwise be low or none when tapped to the TB until the T-stat is open because it uses the feed and return from the same source. I beileve that the best way to isntall water lines is to Tap the block for return and weld on a nipple right behind the T-stat housing for the feed. The turbo then completes a loop which is driven by the water pump directly. This will get the turbo best cooling possible at all times and highest water flow through it.
 
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