Some people choose to leave this upper coolant line attached to the car. I left it attached to the turbo.
The other end of the upper coolant line attached to this barb with the EPDM hose and constant tension clamp. So, this joint is very easy to undo.
I had to by this right angle Torx wrench to get to the screw holding the lower port coolant line to the turbo. That line is completely a hard line. I battled with it for quite a while, trying to remove it from the center housing.
I traced the hard line up and found this anchor location to the block. Once I removed that screw, it gave me enough free play to easily remove the line from the turbo. I’ll tell you what though, it was a pain getting this screw back in! There was a lot of prying on things to get the new turbo in.
A good amount of coolant will drain out. Only about half of it ended up on my face. Don’t forget the safety glasses.
9 comments
I personally think you can actually hear those minute surface flow improvements in the exhaust note. At this level, you’re not chasing performance gains, but rather aural pleasure, instead.
Way back in the day, I did gas stand testing to quantify the turbine efficiency improvement due to extrude honing a turbine housing. The gain was measurable and worthwhile for those seeking maximum turbine efficiency. The two major areas where surface smoothness mattered were the turbine inlet section and at the narrow throat section where the flow exists the housing volute and enters the turbine wheel. Basically, wherever flow velocity was highest. I couldn’t smooth out the throat section on this turbine housing, but I got the entrance section done and I bet the difference is measurable on the gas stand. The compressor side, not so much. I also like to call it arts and crafts time and it’s relaxing. Sure, the hand smoothing of the turbine housing is a small incremental improvement, but so is a drop-in air filter, thermal barrier coating, compressor inlet, or my x-pipe exhaust tip. Keep on adding them all up though and it comes meaningful 🙂
Awesome and thorough write-up! After a bunch of 4 cylinder miatas, I don’t think I could upgrade to a Porsche with a 4 cylinder though lol
I had glanced at the GT4, but it was essentially a $50k premium taking into account the ADM dealers were asking. The 4.0l GTS was roughly a $25k premium over my T. But in the end, I still really like turbo-4s.
Initial engineering meeting for the 718 6 cylinder : “What would be the best engine layout and displacement to give customer’s high levels of power with a linear powerband?”
Initial engineering meeting for the 718 4 cylinder: “Who has a copy of China’s engine displacement tax regulations?”
For the higher trim GTS, I don’t disagree. For the base trim, the 2.0l turbo stomps all over the 981 base 6-cylinder in torque, power, and fuel efficiency.
That said, the 2.0l with this turbo upgrade, good fuel, and some exhaust mods is 350wtq and 400whp capable which puts it in the range of a bolt-on and tune 4.0l 6-cylinder. I’m straddled with Cali 91 octane and keeping the stock cat. The 2.5l engine with larger upgraded VGT turbo is 500-550whp+ capable, over 400wtq, and still good response to boot because of the VGT. No NA modded 4.0L can touch that.
Not that everyone cares about fuel economy, but I can get 32-34mpg highway no problem. The 4.0l can’t touch that.
“The 2.5l engine with larger upgraded VGT turbo is 500-550whp+ capable, over 400wtq, and still good response to boot because of the VGT. No NA modded 4.0L can touch that.”
565>500-550 https://demanmotorsport.com/4-5l-cayman/
“I’m straddled with Cali 91 octane and keeping the stock cat.” –> We forge the chains we wear in life.
Mmm… A bit extreme as that’s well past bolt-ons and a $50k+ engine package. But it’s possible. RaggDoll is also working on a non-VGT big turbo package that will be good for 600-650whp on the 2.5l. A built bottom-end is recommended at that point. Of course, it’ll have some lag that the NA engine won’t.
Did you cerakote the compressor housing? Also, since the boost was holding with higher flowing wheels, did you notice a mass flow change in the data logs?