New rotor housings have plugs in the coolant passages. The old ones had the coolant passages open, however coolant is only allowed to pass through the intake manifold through the rear iron. The car is an S4 T2.

Is this coolant passage necessary? What does it do? It bought the project to a halt until I can figure this out.

Thank you!

******************************

New housings have plugs


Old housings have no plugs


Coolant flows through the intake manifold only from the rear iron

 

Turbo coolant feed passage. If you have a stock turbo, or a water cooled aftermarket turbo fed from the stock location, you need to remove the plug from the rear passage.

 

Thank you very much. It is a stock turbo. How would I remove the plug?

 

If it's just a steel cap that's pressed in, I'd try to hit in the center to dent it. If you dent it hard enough it should make the outside curl in and then you might be able to grab it with some pliers and pull it out.
You might have to just beat the dhit out of it. You also could probably drill the center, insert a pick in the hole and pull.

 

Thank you. I just watched a youtube video http://www.youtube.com/watch?v=Cru1X9hbZ20 that describes hitting the bottom to make it twist horizontally and then pulling it out. Hopefully one of these methods works trouble free. I just don't want to actually push it into the engine and not be able to get it out.

 

We have a problem. Closer inspection reviels that these are not plugs, but rather they are part of the housing possibly with a tiny bit of filler on the bottom.? I was told that these were s4 t2 housings. What housings are these?! Or am I being retarded and jumping to conclusions
because I'm fustrated.

 

could be turbo front housings or NA housings as these all lack the coolant passage

personally i block these passages if they are open
,, cause the most painful fix of all is when you strip turbo and LIM to fix that pissant O ring

me i take the old wax cam coolant path from top of rear plate ( wax cam deleted ) and feed that to the turbo instead

 

Thanks bumpstart. Do you have any pictures? I'll try to do some more research myself as well.

 

I do the same as bumpstart.. I don't want coolant flowing thru my manifolds any way just cut the flange off the coolant line to the lim and route it to the rear iron

 

If you want to run like stock, you can still drill out a passage on your housing. It's aluminum after all, and should be easy enough to put a hole there.

 

Ok... I think I know what you guys are talking about.

Coolant inlet line on turbo:


Nipple on rear iron that should now feed the turbo?


Where the nipple on the rear iron went. What is it and what do I do with it?


I talked to mr SMG who built the engine. He thinks the housings were either s5 or s6 housings. Due to the s5 still having a coolant passage in the intake manifold and the s6 not, I'm thinking these might be s6 housings?

 

yes cut that flange off and route a hose to that nipple on the iron.. i do not run coolant to the tb either
they could be NA with the exhaust sleeves swapped..
I also bought a block off plate to cover the unsed hole on the lim

 

S5 turbo housings have the passage ported also, they're obviously n/a or S6 housings.

 

you can tee from the nipple on rear iron to feed the turbo or you can delete the wax cam and steal the water path directly

if you steal the wax cam water entirely then you need to blank the return nipple in back of the water pump
( some may choose to use this as the turbo water return and instead delete the usual one that recycles the hot turbo water to the pump inlet spout )
you also need to lift the wax cam lever slightly and wire it out of position
this is to prevent the wax cam warming slowly with conducted heat and changing the TPS and throttle rest spots
also,, in some early rx retrofits ( in RHD vehicles ) the lower return pipe in the water pump is compromised for space and is very close to hot turbo manifold
and so many choose to return the coolant to back of the water pump
( the turbo takes the wax cam supply and return path )


NB1- usually done with aftermarket ECU's and in warm climates , hugely simplifies removal of the UIM
( no need now to lose coolant in doing so )
NB2- water through the BACv valve is also deleted ,, in warm climates it is not required ( anti icing )


PS

while you can drill the water passage through the housing , those cast with no intention of coolant passage lack the landing for the o ring to sit in
while this can be machined,, likely not while the engine is assembled

 

It took me a long time to do the coolant line. I have a bunch of setbacks. Missing gaskets, getting sent te wrong items, having to have a machine shop drill out frozen studs on the intake... Etc. things never go as planned.

I figured I would post pics for the final okay before installing the engine harness and uim/tb. Did I do this correctly?

 

Is that tee fitting plastic or metal? I only ask because I wouldn't suggest plastic. A few heat cycles and it could crack

 

Crap. It's plastic. I got it from napa along with the fuel hose. Any idea of where to find a metal tee fitting?

 

^home depot plumbing section?

 

^ I have a home depot brass 90 degree bend in my turbo coolant return line. The line would kink and leak before, but I've had that fitting in there for years and it's never leaked, and my turbo can get unrestricted flow now

 

Why not run the coolant from the rear iron -->thermowax-->turbo and plug the coolant return on the back of the water pump?

You're not using the BAC?

 

Huh, I always thought the nipple on the back of the water pump was a source, not a return. Learn something new every day.

 

This option sounds better since it provides full water flow to the turbo rather than splitting it (with a T) ~50/50 with the TB.

I can see why some are tempted to eliminate the Thermowax to prevent this split, however it seems like a bad compromise during cold start.

Also, one advantage of returning the water to the back of the WP housing (per bumpstart) is that the turbo return doesn't bypass the radiator, although admittedly it's only a trickle.

 

Heres my last revision. Thanks for all the tips. Girlfiend wants to keep her thermowax. I used a brass tee from home depot this time. I also picked up a 90* elbow to sit atop the iron, but I couldn't see how it would work out.? It would have to slightly bend to the left due to the height hitting the uim, and then it would get in the way of me connecting the hose to the tb. Should be okay with the bend. It's the same bend the stock hose took.

 

Alrighty... It's killing me now known that those slight kinks could be issues.

I ordered 2 3/8" 45* silicone hoses and 2 90* hoses from HPS performance silicone hoses. The idea is the use two 45* coming off the TB in opposite directions, joined by a brass fitting. And use a 90* off the rear iron towards the turbo side and a 90* off that towards the flywheel. Should meet at the brass tee fitting near the vacuum hoses.

Turn radii is .5" and all leg lengths is 2.5", so all should be good. Hopefully this is the final revision that will never pose any issues. Now I need a turbo snuggie because I forgot to install the rear heat shield before installing the turbo.

 

.