was wondering if anyone has done any aftermarket turbos that are oil feed only, and what they have done with their coolant feed/return lines on the stock turbos? Would you recommend blocking those feed / return source ports or just looping the lines together somehow? I am swapping to a turbo that runs oil feed only and am just looking for any input as far as who has success with what. I have searched for "coolant blockoff" and "coolant reroute" dealing with s4 turbo coolant lines, but to no avail, so any input is appreciated. Thanks!

 

make it nice and neat and put a block off on the Manifold coolant port and cap the nipple on the waterpump outlet to turbo..(piece of hose with a cap or bolt shoved inside the hose/clamp/silicone affair does just fine)
This way you can still use the option of a water and oil cooled aftermarket turbo later on down the line if you wish to do so.
I put an N/A pump on and later I got a Water/oil cooled turbo..I kicked myself.

 

Oil and water would be best for turbo longevity, especially since rotaries run so hot.

If your intake manifold is off you could also buy the freeze plug block off at the engine. That way your coolant won't flow to the intake manifold. I saw some people use that coolant nipple on the rear iron to feed the turbo instead if you were to ever want coolant feed to the turbo.

I'm not a huge fan of those vacuum caps to block off nipples, but I haven't had one fail because I keep changing them. I haven't tried, but 034 motorsports sells heavy duty caps.

 

is there any downside to not flowing coolant through the intake mani any more? i .e. capping off at the plenum and water outlet nipple?

 

No coolant going through the intake manifold is good, especially here in CA. Capping of the water pump is fine, justy make sure whatever you use to cap it off doesn't fail

 

i guess what are the benefits?

 

No hot coolant going through the intake. The coolant at the intake and throttle body are for cold start, especially places that snow