KPower Industries K24 swap

[Four_wheel_drifts]

Has anyone with the swap tried to remove their transmission with the engine in place? The local tuning shop doing this swap found that there wasn’t enough clearance. So engine and transmission came out and the tunnel mounts were welded and redone.

[URL="https://www.dropbox.com/s/gtagsgwby3gz4oz/kpower%20BRZ%20trans%20mount.jpg?dl=URL]

It looks like it came from the factory this way. Absolutely beautiful.

[Irace86.2.0]

Originally Posted by captain awesome

Try removing the trans insert. It’s worth a shot and I think you’ll be surprised how much it helps.

I removed the bolt holding my mid pipe, and I removed the Whiteline bushing. There were some very minor improvements when driving, but not to the idle. Most of the improvements were in some gear noise that I liked before this swap, and I don't think is the chief source of my noises. I'll have to drive around for a few more days and see if it really makes any difference, but I'm still thinking most of the vibrations are happening from the engine and from the transmission. There is an obvious clutch sound that just wasn't so loud before, and while it could be anything, I believe it is from having the bell housing open. I don't know if a dust shield would make a difference. My exhaust is just too loud too. I'm not a fan, but I don't know if I would need just a complete cat vs the high flow cat, or if I would need thicker metal too.

I'm not sure if the engine vibration will resolve with dyno tuning. Shawn and I did another remote session today, and we should be doing a dyno session soon.

What is also annoying is now my audio system is acting up, making static noises during the songs, as if it was AM radio with terrible reception. I don't know if all the shaking annoyed some components, but now I don't have my music to drain out the noises.

EDIT: I forgot to add that the extra slop now present in the shifter is also less desirable than the noise I think. I can feel the transmission twisting under acceleration, so I will probably go back, but I'll give it a week or so of driving before putting it back.

[Irace86.2.0]

Originally Posted by Four_wheel_drifts

Has anyone with the swap tried to remove their transmission with the engine in place? The local tuning shop doing this swap found that there wasn’t enough clearance. So engine and transmission came out and the tunnel mounts were welded and redone.

[URL="https://www.dropbox.com/s/gtagsgwby3gz4oz/kpower%20BRZ%20trans%20mount.jpg?dl=URL]

It looks like it came from the factory this way. Absolutely beautiful.

I asked Kpower if it is possible, and they said yes, but that it was easier to do the engine and transmission together, which is what I did. Clearance is probably an issue, even with dropping the sway bar.

[RedReplicant]

Anyone familiar enough with Haltech software to post the max VTC commanded by the KPower base map? I'd like to pin my VTC gear for safety but I'm still waiting on the kit.

Also, a brief note...
VTC gear is supposed to be unlocked when torqued to prevent damaging the internal pin then locked afterwards before the chain is put on. New gears come unlocked, but used gears are usually locked. I paid $50 for my used gear, can probably find them cheaper.

Most guide online talk about about removing the intake cam, taping the holes up, using compressed air, etc. Screw all that.

Remove old gear with 17mm on bolt and 24mm on cam. Open up the 50* cam gear and make sure not to push the center section out - you only want to mess with the front and back faces - and remove the plastic piece, spring, and pin. Rotate the center section to the unlocked position (the position that the pin doesn't drop through the center section into the hole on the back plate), reassemble, put on cam, torque with 17mm on bolt / 24mm on cam, rotate cam gear clockwise to lock it. Done.

Also, it appears that Subaru oil sandwiches fit the K24, at least in the case of my Mocal thermostatic one.

[Irace86.2.0]

So I followed the guide in the video I posted on my first page of my build. The guy made a thorough video with part numbers and torque specs, but he didn’t mention anything like you are mentioning. Hopefully I didn’t mess anything up. Basically when putting on the gear it is loose and moves, and then it twists to the right I think and locks. I just did that and torqued it down before installing the belt. Did I need to loosen the gear or something?

My gear is working, but for a second it seemed like it got stuck when my tuner and I were doing remote tuning, but then it opened. Hopefully it isn’t damaged or anything. Hopefully nothing is off timing wise, even though everything was lined up after.

[RedReplicant]

Originally Posted by Irace86.2.0

So I followed the guide in the video I posted on my first page of my build. The guy made a thorough video with part numbers and torque specs, but he didn’t mention anything like you are mentioning. Hopefully I didn’t mess anything up. Basically when putting on the gear it is loose and moves, and then it twists to the right I think and locks. I just did that and torqued it down before installing the belt. Did I need to loosen the gear or something?

My gear is working, but for a second it seemed like it got stuck when my tuner and I were doing remote tuning, but then it opened. Hopefully it isn’t damaged or anything. Hopefully nothing is off timing wise, even though everything was lined up after.

Yeah, if you can turn the gear at all then it is unlocked and you don't need to do what I was talking about. It sounds like yours was unlocked, you installed it onto the cam, locked it, then torqued it?

The correct procedure is to leave the gear unlocked until you torque the gear down to the cam and then you can turn it to lock it and install the cam chain.

They seem pretty simple internally and you can probably swap the center section and pin assembly to a non-50* gear if you damaged the pin or pin hole.


edit: Ran out and took apart my stock TSX gear.

Locked position:


UNLocked position:


Cover removed:


Note: plastic piece may stick to the cover on disassembly


Pin, pin spring, and plastic piece removed. Center section rotated to locked position, note the hole in the back cover that the pin drops into:


Center section rotated to unlocked position, note that the pin can't drop into a hole:

[Irace86.2.0]

The problem is I wouldn’t know how to tighten the gear without it locking. The process of holding the cam and tightening the gear naturally twists it, or at least, that is what I remember. Maybe I installed it and twisted it after mounting it just trying to see if the bolt would twist things. I remember hearing the loud click of it locking in place and figured it was normal because it was the only way to tighten the bolt was to have it lock, but I can’t recall.

This is what I believe was my sequence: Pins in the back, wrench on the cam, slid the unlocked gear on the cam, spun on the bolt, torqued the bolt until the gear locked, then I finished torquing it, and then I put on the chain.

It is entirely possible the cam gear locked, I removed it to inspect it to see if it would unlock, and then I installed it locked, but I can’t remember if this happened, if I examined the old, stock gear for movement, but never removed the 50 degree gear, or if none of this happened It all sounds plausible, and I honestly can’t remember. If it was locked, I could have damaged the pins inside the gear, or something. Hopefully this didn’t happen. Things seem to be working for the most part.

[captain awesome]

So I think there's still something funky about the thermostat situation with this swap. I'll type out my thoughts and see what you guys think.


If I start the car, let it idle until warm, the thermostat will open and all is functioning properly.


If I start the car, go for a drive, the car gets warm enough for the rear temp sensor to kick the fan on. Unfortunately the coolant down by the thermostat is getting cooled too quickly to pop the thermostat open. The car now is stuck with the fan on. It can't cool that loop enough to cycle off, but it keeps it cool enough that it will never trigger the thermostat to open. The good news is I am not overheating, but the system is only functioning through the water pump bypass with a fan stuck on. Less than ideal for sure.



So. What are some good options here to alleviate the problem? Some folks that have swapped will just remove the thermostat but I don't think that's what I want to do. At least not yet. I can get a lower temp thermostat and see if that helps. Mishimoto sells a 140f unit that may just work as the stock one is set to 172f. I still don't like this idea but there's no real way to get the temp at the thermostat to rise enough to open without delaying fan engagement. If I delay fans I'm running the risk of serious crap to spiral fast.


Any other suggestions to try out?


Am I the only one with this issue? I thought I had it all figured out a couple months ago, but now that we have been getting some warmer days I noticed the lower coolant hose staying cool while the rest of the system tries it's best to work overtime.

[captain awesome]

Another option that may work is to use a Kpower Miata neck or modify the one for the 86. If we add a port at the neck for the heater core intake line, then send the line that's at the intake manifold to go to the thermostat housing it will get warmer quicker?


TracTuff has a barbed fitting that can replace the delete we are provided with the kit so there will be two heated lines going into the factory thermostat housing like it was from the factory.


This is probably the correct solution but a lower temp thermostat could be enough and way cheaper.

[captain awesome]

So for those unfamiliar with the current flow:


Blue line goes to upper rad hose.
Yellow line goes to the heater core intake line.
Orange line is the return from the heater core which has technically seen a heater matrix so slightly reduced in temp from that.
Green line is to the lower rad hose.


What's been changed from stock? The throttle body heater line is deleted. No biggie. BUT there's also one less line to the thermostat housing. You can see it's now blocked off next to the orange line. This line would normally go to where the yellow line comes out of the intake side of the head. The heater core line would have normally come from the neck on the back of the head.




What I'm suggesting is to add the fuscia line below and add a port on the rear neck for the heater core line. This is what the stock configuration was using essentially just snaked around in a different manner.





Or this which I think is more correct on flow pattern:

[hedtrip]

I was thinking about this the other day. I was watching a s2k kswap video & he had his routed like your sec picture. I do think the T Stat would get hotter faster with that setup.

[captain awesome]

Originally Posted by hedtrip

I was thinking about this the other day. I was watching a s2k kswap video & he had his routed like your sec picture. I do think the T Stat would get hotter faster with that setup.

It was s2k and the mr2 swaps that got me thinking on it as well. I think even the Kpower Miata and E30 swap still uses both ports on the thermostat neck if keeping your HVAC.



To tap or weld a bung on the Kpower neck wouldn't be too difficult, just not convenient if it's something you drive daily. I'm thinking of ways I can do it without being down for a week but worried there may not be enough meat to tap the housing safely.

[Irace86.2.0]

I don't believe I have this issue. I'll have to check next time, but I believe the fans turn on and off, and the lower neck is hot/warm to the touch. I do have a turbo, so there is more heat in the system, but my coolant temps are always in the middle. I didn't have issues with burping the system, and I didn't drill holes or anything. I also live in California, so ambient temps are higher, so maybe that makes a difference.

I don't know if this really is an issue of not having enough heat going to the thermostat to open the thermostat. The thermostat sits in a housing that is getting filled with hot coolant constantly. When the thermostat is closed, the water still circulates through the thermostat housing back into the motor. When the thermostat opens, part of the water goes to the radiator, and the other part continues to circulate into the motor. You can see the hole here where the water returns to the water pump. If the hose going to the thermostat housing was just a dead-end branch that relied on convection/conduction of heat to the thermostat then maybe two lines would bring heat faster to the thermostat, but that is not the case. Maybe the heater is pulling off so much heat that the coolant is cool enough, but I can run my heater full blast on high, and the hose leaving the heater is still hot to the touch.

If you don't like the fans going so much then I would change the fan setting to be higher than the thermostat open point. Did you cut holes in your thermostat or do anything to modify the system? Do you get super hot air from the heater and feel the system is fully burped?

The last thing I wonder is that the Hybrid Racing plug seems to be widely used without much discussion from heating issues that I have found, but maybe I didn't search well enough, so is it not an issue because people are racing their cars more or living in warmer climates or something that doesn't cause an issue, or is this a widespread problem?

[captain awesome]

I haven't modified the thermostat at all. It's a brand new Aisin unit and if not in any movement or airflow does open as it was intended. I haven't ever shown signs of overheating or of air bubbles being trapped in the system. The problem only arises when in motion where the radiator gets cool air. This starts the cycle of a fan always on to keep it just cool enough that it never opens but also can't really get it down enough to shut the fan off.



I already have the fans kicking on multiple degrees later and also both are staggered for a later response. I'll double check what I set it at but I believe it was north of 200 for both fans. Unfortunately the heat at the back of the head where the fans get their signal is considerably higher than when it finally reaches the thermostat housing. I can feel the thermostat housing is warm to the touch. Just not quite warm enough to open. I think a second heated circuit that hasn't been cooled by the heater core ever so slightly will get things like the Honda/Acura system was designed for.


A simple band aid that could be done quick and easy is a 140 degree Mishimoto thermostat.


One last thing would be setting when the fans shut off, but if I remember correctly it's already a fairly narrow window that I have set so that it wouldn't stay on too long.