I am putting a 13B-REW into my FC chassis and have a few questions about how to hook up the AST and coolant overflow lines. I am not using the stock twins and would like to block off all un-necessary coolant lines. Below are pictures of my waterpump housing and where the lines go.

My questions:

What do I do with the overflow nipple on the AST? I already have an overflow nipple on my radiator (pictured below, remember the FC uses a vertical mount radiator). Do I block one of them off? Which one? Can I tee them together?

Should the AST be mounted so it is the highest point of the cooling system?

When I fill the engine with coolant, do I completely fill the AST as well?

What type of caps do I use? I will need one on the thermostat neck, one on the AST, and one on the radiator.





Red - twin turbo coolant - block off
Orange - to throttle body lower
Green - to heater piping - block off
Blue - twin turbo coolant - block off
Purple - to AST "side"

 

Do you plan on running an AST? There are a lot of 3rd gen owners that run no AST. Because you have a vertical mount radiator with an overflow nipple on it, I would run that overflow nipple to your overflow tank and block off the AST lines. As you are not running stock twins, you could block off the TT coolant lines unless you plan on running the nice Tial water cooled wastegates. Then you could use the supply and return for the turbos to cool those.

Are you still running the throttle body coolant line? When filling the cooling system, a good trick is to unhook the coolant line at the throttle body. As that is highest point in the block, it'll be a good point to bleed out air as it fills.

Matt

 

I have heard mixed reviews about running an AST. If I dont need to, I would rather not. I am still trying to figure that out. I do plan on running the two coolant lines to the throttle body. I am running an oil-cooled only single turbo and non water cooled wastegate.

 

Forget about the AST, if you are using a FC radiator, here's what you need:

Defined Auto Works waterpump outlet:


Dayco 71863 (upper) radiator hose

Dayco 71526 (lower) radiator hose

I had to trim down both radiator hoses (both were a couple of inches too long). The bottom one fits perfectly, the upper deforms a litle near the 90 degree bend on the radiator side. The deformation is not too bad, but you can see how the hose starts to turn oval instead of its round shape.

 

interesting. and you just use a lisle funnel to fill the coolant from the radiator since it is not the highest point in the system?

 

find a mechanic friend that has the coolant fill tool. it basically puts the entire system under vacuum and then sucks the coolant back into the system. no air bubbles and completely full no matter where you do it from.