I have been reading alot of threads here, but as far as I can find, noone has this answered in any of them. I want to retain the stock (or aftermarket replacement) coolant tank, but I have no idea where the 3rd hose from the tank goes to. 2 obviously go to where they do in stock form, being thermostat housing and radiator, but on the Renesis, the 3rd one also goes to the thermostat housing. The REW thermostat housing doesnt have 2 hose connections as far as I can see.

Can someone shed some light on to this, as its been hauting me for weeks already

 

two lines go in and out of the thermostat assembly, one line goes to the top of the radiator to burp out coolant, and the 4th port on top of the overflow tank is left open as its a overflow..

I use the rx8 front cover and thermostat housing on my REW swap so i'm not sure on the REW cover/thermostat....

 

Yeah I know how it runs on the Renesis front cover, but I wont be using that, keeping the REW front cover. Forgot to mention it.

 

Ignore my previous post as I just went and checked.....

One line from the overflow goes to the top of the radiator to bleed air, one line goes to the top of the thermostat housing to bleed air, and one goes into the side of the thermostat housing to feed coolant....

The other side of the thermostat housing goes to the heater core, from the heater core the line goes to around the top of the motor to the driver side and into the rear iron....

If the REW has one less line, my guess is where the renesis takes bleed air from both the top of the thermostat housing AND the top of the radiator, the REW only takes it from one of those locations.....

 

Its the one on the side that the REW doesnt have, as originally, the REW thermostat housing has one hose to the AST which in turn goes to the radiator. The thermostat has on the lower part a heater core hose and a hose to the turbo as far as I remember.

So the "feed" line from the rx8 coolant tank has nowhere to go, I am not mistaken.

 

Here is the coolant diagram for the FD.... This shows exactly how the coolant system runs..... If this doesn't answer your question, I don't know what would....

 

My only question would be is it going to matter that the overflow nipple is at the bottom of the radiator for the REW, and at the top for the RX8?

That diagram also doesn't seem to show where it goes to the heater core. I know that it's on the rear iron where it goes to it. I can see the nipple in the picture above, I just dont know where it comes back into the system on the FD. For the FC, there is a nipple on the radiator inlet.

I guess the question is where would you route the heater core return and overflow tanks for an RX8 style overflow tank and radiator.

 

I know how it runs, but that doesnt change the fact that the rx8 has 3 hose connections on the coolant tank from which 2 go to the thermostat housing. The REW thermostat housing only has one hose connection which goes to the AST, the other ones on the bottom are for heater core and turbo.

 

Not really sure why you’re making such a big deal about it. Not to mention all the information is on here already:

https://www.rx8club.com/rx-8-racing-...4/#post4602821

https://www.rx8club.com/series-i-tec...3/#post3432330

 

Problem solved. T on the turbo line.

 

Well you could have just put a silicone cover plug on it, but that’ll work too. On the Renesis it’s just one more air bleed escape path.