The head cooling is really just a function of surface area (as are most heat transfer calcs). I can see how necking all of the exhaust flow into one port in the head creates a big thermal hot spot for the head as you are reducing surface area for the exhaust to dissipate heat into evenly.

That said, it does seem that if you move to a non-integrated port head and didn't change anything else, you are still dealing with a ton of thermal energy that would now be sitting in the exhaust valves and turbine wheel as Engineered2win mentioned... The turbo efficiency map that was posted paints the picture that you are approaching the point of diminishing returns and falling off the efficiency map (naturally making for hot EGTs). If you want to be running in the 600+whp power level, finding a turbo that is more suited to efficiently run at those flow rates and pressure ratios to meet that goal seems like a necessity.

...into the rabbit hole we go!

 

I'm using these EGT sensors: https://thesensorconnection.com/prod...3tPJOVAK&v=503
3/16th probe with exposed tip, claims response time is 250ms.
Going forward the EGT warning will kick on at 1500F, with engine protection engaging at 1700F sustained.
I had been warned from others in the know about EGT's being an issue. I just had interpreted this as danger to valves... not danger to manifold. Cracking the head itself had never even been on my radar.

950C huh....



What's the hiveminds thought on continuing to run this turbo for a season or so? Worst case is that turbine wheel continues to chip and eventually shred itself right? Obviously performance will be affected but I don't see any dangers otherwise?




I was going to just find a RBB 4 port head, but it ended up just being easier to grab a complete motor to ensure it came with the proper VVT/VTEC valves, cams, towers, valve cover, ect. Why on earth are the K24A TSX motors now $5-600 cheaper then any of the K24Z3 TSX motors I've ever bought? Half the point of the Z3 swap was the motors were supposed to be cheaper...
Mmmm, REAL, dual cam VTEC, yo!(K24Z3's only had intake cam VTEC...)



This motor was a laughable $800, $400 cheaper then any running Z3 motor I've ever purchased, not counting the OG motor that spun a rod bearing within a few weeks of install. It did have high mileage(250K) and had been burning a good bit of oil judging from the internals, but that didn't matter a bit to me as I just wanted to rip the head off and send it to the machine shop to pack it full of aftermarket goodies.

The good news is that the RBB heads *almost* drop right on to the R40 blocks. One oil drain at the rear of the head doesn't quite seal up, as demonstrated by overlaying the R40 headgasket on the RBB head:



The "ghetto" way of just applying some silicone works fine for most people, but since I have the head off and heading to a machine shop anyway, I just stacked up some weld in this area, then filed it down to roughly the right height, allowing the skimming process at the machine shop to make it perfect. You can see from this photo the differences in the orientation of the RBB head oil drain vs the R40 block oil drain. All in all, a pretty minor modification required.




Now obviously, my old single port turbo manifold doesn't match up to the new, 4 port head. Thankfully, Artec recently released a compact, cast stainless manifold for the K24! No need to custom fab a manifold or deal with one of the aftermarket china welded manifolds liable to crack. Additionally, Kpower apparently got their hands on one of these manifolds and was able to "confirm" that they would fit the NA/NB chassis with only minor modifications. Yippie!

Kpower claims that to make this manifold fit the NA chassis, all you gotta do is...

• Factory fuel hardline relocated/removed
• Factory EVAP hardline relocated/removed
• Bend or remove spot weld tab where collector portion of manifold is positioned

And it drops right in! Right? Kpower wouldn't be wrong about this surely....



Hahhahahahahah

NOPE, you're looking at less than 1/8th inch clearance here, at room temp, with no exhaust manifold gasket to boot.
This fitment is so tight that to even get the manifold on, you'd have to pull all the studs out of the head and switch to bolts. And if that motor rocks at all(which, if you have a turbo K24 making beeefy numbers, its gonna) that manifold is gonna pound the frame rail like a cheap-- uhh.... umm... bell. yeah, bell.

After staring at this, trying to figure out how Kpower markets this as "fitment", I realized something else. Waaaay back when they only had the NA/NB K24 swap, people complained that even with trimmed hoods and modified valve covers, their hood still hit the engine. Kpower chalked this up to "chassis irregularities" and offered to sell you "1/4" steel laser cut subframe spacers" as seen here: https://kpower.industries/products/n...r&_ss=e&_v=1.0
These lift the body off the subframe a touch, allowing some more hood to engine clearance. Suffering from this issue, I DIY'ed and installed my own version of these spacers. All that to say:
*IF* I didn't have those spacers, my frame rails would sit fractionally lower in respect to the engine, and that manifold clearance would be *larger* due to the way it curves. Still probably wouldn't be a ton of clearance, but it would be something.

TLDR: If your modified valve cover from Kpower clears your hood, then you don't need Kpower subframe spacers, which might allow your turbo manifold to properly fit.


"Never let your framerails get in the way of a bigass turbo, son" is what my great great grandpappy always told me while harvesting the fields. So I said **** it and chopped my framerail.


Welded in some L bracket, and boom, turbo no hit frame.



Is the hood gonna clear this setup? probably not, but like my grandma always whispered to me in the basement while shucking corn, "never let extraneous sheetmetal get in the way of a bigass turbo, son."

 

With both a K24Z3(AKA, R40 head, R40 block) and a K24A2(AKA, RBB head) sitting in my garage, I was able to test fit parts from one to the other to see what all actually fits.

There exist a variety of aftermarket dual locking chain tensioners for the A2, but none for the Z3, something that always irked me after the tensioner failure I had end of 2023. Unfortunately, while the bolt pattern is the same and bolts up to the block, the A2 is fractally shorter and doesn't fully cover the oil galley behind it that feeds the tensioner pressure. Booo.



Something I had suspected for awhile and was able to confirm, is every single Z3 motor mount bolts up to the A2. Same threads, same placements. So wanna do an A2 swap but don't wanna deal with the V8R tubular subframe? Just buy the Z3 mounts and figure out a header solution.

-need intake side mounting photo-
And big news in the not-something-engine-related-department!
The Getrags have been sorely missing a good torsen option. The only ones that exist are the Quafe(and it's not good from first hand reviews) and some company in Italy... drexler or something, and never found anyone running one, so no data on them. The only non-open option was the OEM G80 Getrag, which was... ok, but leaves a lot to be desired by many accounts.
I knew @ThePass had been working on an OSG option for Getrag diffs for a few years. Well finally, it happened, and I hit that "buy" button so fast as soon as I got the email they were live.
https://www.good-win-racing.com/Mazd...t/61-3825.html


After the disasters I had trying to setup a miata diff, there was zero chance I was going to try it with this $1800 unit. I took mine to a Cadillac specialist in NC who made short work of it.



Between the OSG+seals/install parts/labor+OSG fluid+junkyard donor unit I'm at close to $2500 for a diff which... ouch, I'd rather not think about. But I am pretty excited to finally experience OSG goodness for myself after hearing everyone that's driven one RAVE about them.

 

Sorry, but I love referencing this thread as a "crystal ball" of failures I can expect. Sadly- I seem to trail right behind you with the K24Z3 issues. Hopefully Keeping my G25-550 near wastegate at 340RWHP will make me avoid a similar fate!

 

Hey there, Great posts. Thanks.
I've been reading through your posts on the ABS and wanted to know if you have an updated thread, or if your posts from 2023 are the most recent.
Specifically, you mentioned "I sat around for 3 months waiting on this box before being told there was no solid ETA on development." to make the miata/brofab abs rings work with the e5 sensors.
did anything ever come of that? I'd rather avoid "precision grinding" if possible.
Or do you know of another post that is pretty comprehensive and ironed out the MK60 E5 install?
I have an ecotec swapped miata.
Thanks,
Len

 

Follow the facebook group "MK60e5 and MK60 ABS Retrofit Group"
The happy Cactus adapter is what he is referencing.

I'm in the middle of my MK60E5 install. I'll be machining adapter rings and running the sensors that are compatible with the E5

 

And things are starting to move again, so time to start playing catchup



Data nerds, fear not. Version 42 of this car has four, count them FOUR(4) EGT probes, AND properly setup EGT alarms/safeties to avoid a repeat of last time. As well as an added coolant pressure sensor so that can be monitored to ensure coolant pressure =/= boost pressure.
I have a 5th EGT probe on standby in case I feel like tracking post turbine temps, but for now I think inlet temps should be sufficient.



Since the G25-660 previously on this engine had redistributed the turbine blades during the singular track outing of 2024, it's been reduced to a show piece only. I thought about just getting a replacement G25-660, but the more I looked at the data, the more I realized pushing that turbo as hard as I had was half(ok maybe not half, but at least 39.7%) the reason everything had imploded to begin with. I don't track impeller speeds(sorry guys, I'm out of ECU inputs at this point unless I feed stuff to the IC-7 dash then canbus it over to the Maxx, but making the Haltech OUTPUT data to a non-haltech device is its own can of worms currently), but I suspect I was damn near at/over its maximum speed. My reasoning being, to hit that 530whp mark, I was adding boost, and more boost, and just some more boost, as you do, but at the end I was adding 5psi and gaining... 12-15whp out of it. Compared to down in the 300whp range where 5psi was netting me 40-50whp. That turbo was just completely out of breath, overspeed, and pushing more hot air then a politician facing re-election season. If I wanted to run that 550whp number, oooorrr just a little more, I'd need something bigger.


Well hello there




EFR 7670, .82 AR, 3" vband inlet, externally gated.

I did a ton of research to decide just how "big" I was going, and I think this one should do nicely. I found an Evo thread where a built 2.4, 10:1, 4G63 on 93 put down 600whp with better spool then my Garrett had. Like, 150 MORE whp at 3500RPM while still carrying a steady powerband out to almost 8K. If those numbers hold up for me... I'll have significantly more area under the curve then I did with the G25, while making more up top, and breathing far easier to help keep those EGT's in check. Fingers crossed.
Of course, new turbo and manifold meant I had to redo all my exhaust, intercooler, cooling and oiling lines, but the EFR is both larger(duh) and seemingly less compact than the Garrett it replaces, making it easier to route oil and water lines around it. Also I'm unsure if the turbo will clear the hood, so I might have to chop another hole in the hood to let the turbo peek through, but that's a later me problem.


Ohhh what's in those tractive boxes under the car you say? Did you finally send your 4 year old Xidas out for a much overdue rebuild?

lol nah, my finger slipped late one night and then these showed up at my door two months later:

But more on those at a later time


I sent all the bottom end stuff to the machine shop so they could double check everything was A-OK before I slapped a new head on it and tried to send it back to orbit.
Need to apologise to everyone that selected "cracked cylinder" and missed out on a bingo. Turns out you can, indeed mark that spot down. I didn't noticed it, but machine shop did when they did their initial inspections of my block and realized the bores were back to being eggs, not cylinders. I believe they said #3 and #4 were cracked, but this conversation was 3 months ago so there might have been more than that.



Okie dokie then, big cylinder pressures+high EGT+some retard ignoring the warnings and standing on the throttle= cylinder wall cracking sauna. Gotcha, noted, well with cracked cylinder walls this block is scrap I guess.... OR IS IT

I AIN'T HEAR NO BELL


Literally less hassle/stronger/cheaper to grab a set of Darton sleeves and have the block machined for them then it would be to grab another junkyard motor and tear it down for just the block. Plus I'm... kind of out of room for engines in the garage.
And if I crack a fully sleeved block... LS swap time for sure.

Images coming from the machine shop this morning(wait, sorry it's now the next day, so I guess these came though yesterday morning...)
I find photos of this process fascinating, so I'm sharing for anyone else that finds them likewise. It's a fully hollowed out block, it just looks... weird




Sleeves should go in tomorro- err, today now. Everything should be ready for me to pickup by end of week, so I can start assembly asap and put this car back together.
Which is good, because I kinda.. signed up for a thing... thats less then a month away at this point.



and then my finger slipped again and I signed up for another thing the week after the first thing... no pressure right???

 

You might need to add some grippy gloves to that slippery finger.

 

I was wondering what was going on with the car. Will be interested to see the updates on the latest sprint.

What's going to be the weak link on the car now? Is most everything in the drivetrain rated for ~600, assuming you're going to be running around there?

 

cripes

boy isn't messing around

In for moar boostages

 

CD009 transmission is happy till around ~1000whp, Tilton twindisk is rated for 760ft/lbs, driveshaft shop said the aluminum shaft they built me would be fine at ~1000whp, Cadalic diff/OSG is good for... a lot? And the axles Bronson built me have been used extensively on the drag strip at 800hp. So the driveline *should* be trouble free at 5/600whp.

Few more photos post sleeving, and new 4 port, RBB head is together with new valve seats, seals, guides, springs and valves.

 

Dang, I had no idea the CD009 was that stout. Awesome stuff man, can't wait to follow along during this months sprint.

 

If it's the same diff as the Gen1CTS-V (which I believe it is) Then you're good for 800+ In my experience. (granted some blew theirs up doing wheelhop burnouts, or with bad launches at stock ~400. Also the CTS-V weighs probably 2+X what you weigh)

 

Oh jeeze, this is getting even spicier. Psyched to see this come together.

 

Weak spot? I'm guessing you'll rip the front or rear subframe off of the unibody, lol. Or simply buckle the unibody where the doors won't open and close anymore.

 

Placing bets on the Wingman 2025 bingo card. I'm guessing the weak link is going to be the nutcase behind the wheel of this brutal monstrosity.

[[I mean this in the most uplifting and positive way possible]]

 

I think yall forget this car made 530whp previously. It's not going to be that much more power... I think... maybe? Just and extra 70whp or so for a nice even 600, should I feel ballsy enough pushing it that high? Regardless the cage is tied into most of the suspension/subframe mounting points so the car shouldn't fold in half like a soggy graham cracker.
Yeah... you ain't wrong. I haven't really properly driven a car in over a year at this point. That outing at RA had so much happening at once I never got a chance to really get comfortable in it and fully feel it out. I've tried to stay somewhat current with some sim racing but... it ain't the same.

Past me playing catchup:
Got a deal on a carbon trunk lid. Not amazing finish quality, but suuuper light, proper carbon layup made by a dude in his garage(not me, some other dude). I think this was his test piece or something, dunno, anyway did I mention it is light? I think adding the aerocatches doubled its total weight.


I was stoked at the ~15lbs of weight savings, then as I was perusing the Gridlife rules, realized all Unlimited cars were required to have a full fire system, not just a kiddie bottle in the passenger seat. Hmm, ok, unfortunate.... Orrr I could move down a class to Track Modern, run buy some 60tw tires, and... eewww, add a dash back in? No thanks, fire system installation and Unlimited class it is. So those 15lbs off the rear of the car got added right back with a big steel bottle full of not fire. Oh well, this car was overdue for a real fire system anyway. These actually are not crazy expensive like I had previously feared, $500 got me an FIA rated system complete with 5 nozzles and ample tubing. Hope I never have to use it.




Whooosh back to current day


Block and head are back in my hands. Booooooiiii they pretty.



Wasted no time getting everything assembled, pretty straightforward stuff. Only snag, during one of the conversations about the sleeve installation the machinist asked if I was going to be reusing the headstuds that were in the motor during all the EGT events. And then suggested that due to the heat they probably saw, it would be a good idea to get a new set. Uhhh sure, first I've ever heard that studs can get heat treated, but this would be the 4/5th use on them so why not, new studs it is, I'm in this deep anyway.
Anyway all that to say I'm waiting on new studs to come in before I can torque the head down and carry on.
With time at a premium I couldn't let that completely stop progress, so I installed the old studs, snugged all the nuts, and put everything in the car. When the new studs arrive I'll remove the old studs one at a time, replace and snug the new, and then carry on with torquing. I don't really want to seperate/remove the head due to coating the head gasket in hylomar, which was suggested to me as a superior produce over copper spray. And I have a feeling I'll need all the help I can get keeping the head sealed/down on this thing.

I just blue myself. hehehe



Together enough to mockup/final fitment checks for everything.



Past me was right. Turbo didn't even come close to clearing the hood. Future me got drastic and chopped another hole in the hood to let the turbo peek through. Well, subtlety was never this car's strong suit...

 

I spy new coolant pump delete plate and alternator mount. nice nice

 

I have pictures of the reinforcements that Winning Formula does to reinforce the front subframes they use on their car I'm willing to share. I'm sure if you spoke with Emile Tabb he'll share what he's done on the rears as well. Thats just on their GLTC/WRL cars.

 

Well this went from (paraphrasing) “ I didn’t have much money but a lot of time to **** it it’s just (cubic) money pretty damned fast. Love it, and hope it boils the hides from corner exit to entry!