Lof8 - Andy said:In reply to Andy Hollis :
What engine management do you use on your K swapped cars, and why did you choose it? Thanks!
Hondata KPro
It was really the only comprehensive solution 13 years ago when I did my first K-swap.
But that's all about to change...
In reply to Andy Hollis :
Hmmm. Please elaborate. I'm probably 6-12 months from doing my k swap. I'd love to hear about what's coming. Or are you saying you're going to try a different management?
Lof8 - Andy said:In reply to Andy Hollis :
Hmmm. Please elaborate. I'm probably 6-12 months from doing my k swap. I'd love to hear about what's coming. Or are you saying you're going to try a different management?
With the return of the One Lap CRX to the big show, I am going through the whole car. The wiring is 30 years old, so its getting redone, along with a modern ECU/Dash/PDM setup. More deets as they materialize. Watch the project car page for that vehicle.
In reply to Andy Hollis :
My guess is the Haltech R3. Seems like the current sweet spot for aftermarket, affordable-ish ECUs.
As far as general K swaps go, I've always looked at them as a strong possibility once I blow up the stock engine in my w2w Miata - or when I decide I want more power to play in higher classes. Seems like the "low power" classes are slowly dying in the org I run with since most new cars slot into higher HP/weight classes and I don't see that trend reversing.
On the other hand, I've heard a decent amount of discontent regarding the quality of the Kmiata parts and ongoing issues (although solvable). Also seems the price keeps going up, making an LS swap not toooo much more money. LFX seems great too but expensive and less documented. Really just ranting as I have no immediate plans anyway, but curious on any thoughts.
In reply to Lof8 - Andy :
Mine was run off of ms3pro, not the fanciest but open source and worked well - especially in the context of a race car.
In reply to spedracer :
Friends with a K20 miata endurance racer have really struggled with reliability for a full 3 yrs.
Lots of little and not so little issues which is weird as our K powered crx then eg hatch and now 9th gen civic have all been pretty solid.
kevlarcorolla said:In reply to spedracer :
Friends with a K20 miata endurance racer have really struggled with reliability for a full 3 yrs.
Curious as to the kinds of problems they've been having? Engine problems, chassis problems or problems stemming from the combination of Honda engine into Miata (ie, swap parts, clutch, etc.)...?
The swap itself is pretty well documented at this point, but it's harder to find information about ongoing experience, especially for track builds.
I bet they are revving to the moon. Keep the revs on the lower side and they will run for a long time even in endurance, as a few of us here have experienced
In reply to Sonic :
No,lots of niggles in an otherwise VERY well put together car and a built engine.
In reply to kevlarcorolla :
Not doubting, but could you share the failures? Redline, build level, etc? I'd be keen to learn from the failures.
In reply to kevlarcorrolla and accordionfolder :
Yes, we would all like know the details. Pretty much every K-swap I know about has been rock-solid. Like almost better than stock and in a coupla cases, WAY better than stock. I'm thinking about one and knowing the pitfalls someone who knows what they're doing is going through would be educational.
In reply to rdcyclist :
Its a sister team to us but they very much do their own thing so I didn't get much info along the way.
Main issue was and still is driveline related,major vibration at speed that they can't figure out despite having the driveshaft sent across the country to whomever is supposed to be the best to build it,then sent back to be rechecked.
I think it went to another place or had another driveshaft built,same issue.....I said the diff and trans angles need to be sorted.
Its ALL kmiata stuff in the car so something is up.
Lots of little things with the wiring/tune etc but like I said I wasn't privy to what was wrong or how it was sorted.
The car is a long ways from a hackjob,all top shelf stuff used so I'm as suprised as you that its still struggling to finish a race.
accordionfolder said:In reply to fidelity101 :
haha - Yeah, that's why it's ubiquitous and a bit annoying at times, but it does work for not a lot of money. It isn't as easy as the internet makes it seem, but definitely a well documented swap.
then you add an adapter
then you add mounts
then you add an intake because it faces the wrong way
then some more plumbing
and it gets real expensive real quick
In reply to fidelity101 :
The engine package itself is cheap relative to building a similar HP engine in family for most chassis.
Race cars aren't cheap, and swaps are never cheap - but for the same reason LS are ubiquitous, K's are. I have an LS miata I built so I know well the expense of the sum total of swapping.
So not going Challenge budget cheap but doing this on a reasonable budget. So K-swapping a Triumph Spitfire, using the K-power pieces for a Miata - so intake, oil pan, adapter plate for a Miata transmission, etc.... So what do I use for the ECU and wiring? Sounds like the cheapest solution is a stock ECU and doing the Hondata upgrade?
Looks like the two harnesses and a Hondata modified ECU are all I need, and if I want to save a few bucks, could pull a junkyard wiring harness and modify it to suit?
What are your thoughts, anyone done a similar RWD conversion?
dherr (Forum Supporter) said:So not going Challenge budget cheap but doing this on a reasonable budget. So K-swapping a Triumph Spitfire, using the K-power pieces for a Miata - so intake, oil pan, adapter plate for a Miata transmission, etc.... So what do I use for the ECU and wiring? Sounds like the cheapest solution is a stock ECU and doing the Hondata upgrade?
Looks like the two harnesses and a Hondata modified ECU are all I need, and if I want to save a few bucks, could pull a junkyard wiring harness and modify it to suit?
What are your thoughts, anyone done a similar RWD conversion?
I built the second-running KMiata customer car. Yes, use their harness and Hondata. Easy button. You can roll your own if you like reinventing the wheel, though.
In reply to dherr (Forum Supporter) :
Look at what Joe Curry did with his Tiny Tim K swapped Spitfire ... then address the weak points.
I've been running a K24 BRZ for about a year and a half now, I'm not really happy with how KPower has handled communication on issues, but that it is what it is for this chassis right now - there is no other game in town. This will probably be a long post that no one really needs to read since it is specific to the 86/BRZ/FRS chassis. I'll give a distilled overview of track issues I've come across with it for others looking to do similar.
Most of the annoying issues have been on the electrical end and required me diagnosing them myself - everything from the wrong ground used for oil temp causing temp to correlate with DBW position, pins not being fully crimped and working themselves out, or earlier adapter board revisions missing the connection to control the fuel pump relay they sold. You also have to tie the harness down well or it'll chafe right through on the valve cover, I ended up wrapping mine in Roundit 2000. Turning the car off without starting it isn't possible on push start cars right now, but that is a Haltech issue since it worked at one point and was broken during an update.
I broke a few throttle body bolts with the stock BRZ throttle body so I tried moving to the Bosch 74mm TB. The KPower adapter leaked air because it was designed in such a way that there are two spots where the gasket has less than 1mm of overlap so it gets squeezed out, after realizing that and sealing it I still broke throttle body bolts. I also tested another throttle body adapter by Ichiban Engineering that used o-rings to seal on both sides instead of traditional gaskets, but I found the next issue which was that the vibration destroys the Bosch throttle bodies. The internal TPS traces get worn through or the plastic gears get eaten at WOT, I killed a new OEM Bosch in 3 track days.
This ended in talking to Winning Formula, testing a one of his welded vibration resistant adapters, having it leak air, having a friend sketch up a set in Fusion 360, and test running the car on the 3d printed ones. WF ended up taking inspiration and ended up with a modified version of the design sealed with o ring route. He sent my friend and I a set, which I thought was really cool. No issues since the new adapter.
The original swaps were sold with Sachs pressure plates and clutch disks, I ended up ordering a set from a german company but quickly heard through the grape vine that the pressure plates were exploding in track cars. I pulled mine out and replaced it with Exedy OEM BRZ stuff and it has been fine... for the most part. Steel over aluminum for flywheel is much preferred, but I found this out too late.
My 1pc KPower driveshaft vibrated above 50mph and made grinding noises on decel, I ended up having my OEM driveshaft cut down 5.5" and spaced down the center support bearing. Everything has been fine here since.
Get a valve cover that vents out the top rather than the side, mine pushed oil out in right hand turns until I fixed this; same issue as the S2000 has stock. I basically no oil in the can now.
I had a Miata water neck on the car because I cut the thermostat jiggle pin and also routed the normally blocked off thermostat outlet back to the water outlet in attempt to get the thing to be easier to bleed. Apparently this port had been drilled and tapped improperly for years, I ended up pulling the water neck out of the car and realized it'd been leaking out the threads since I put the motor in back in May 2022. I bought another water neck in September 2023 only to realize it was improperly tapped too, so I called KPower. Apparently they'd been like this the whole time so they fixed the CAD stuff and sent me another but I still had to pay.
It seems that a lot of the non-OEM coolant temperature sensors are extremely thin walled, I had a Hella one crack and break off a few weeks ago at an event, which was a gigantic pain since its against the firewall. I put another Duralast into the waterneck and it immediately broke off before it fully seated, which let me see just how thin they are (like .1mm at the first thread). New OEM Honda one has been fine.
In September I misshifted the car at an event - top of 3rd to 2nd, about 10k rpm and the pressure plate came apart - one of the rivets popped and got ejected. I've never had a misshift on track before, so I was kinda confused. Turns out the shift rod KPower sells is aluminum with steel pins, the steel pins open up the clearance over time and eventually lead to a ton of slop due to tolerance stacking. I put a new motor into the car because I didn't want to find out it wasn't all fine the hard way an event or two later. I ended up emailing KPower about this and they basically told me that they knew and that they'd consider fixing it in the future, so I ended up buying a new one at full price.
Anyhow, that has been my experience so far - I generally find it painful to spend over $10k with a company and have to track down issues on my own or have the company say tough luck time after time. If you make public posts about issues on the FB group you get the standard "We've been working on XYZ for a while guys" reply.
I think I've done about 40 events with the car since the swap - I've managed to sort it and keep it on track reliably enough to win a NASA TT5 regional championship, as well be current defender of 7 TT5 records. We will see how it goes.
In reply to RedReplicant :
Reading all that really makes me content to keep the k motor in the chassis it came in.
dherr (Forum Supporter) said:So not going Challenge budget cheap but doing this on a reasonable budget. So K-swapping a Triumph Spitfire, using the K-power pieces for a Miata - so intake, oil pan, adapter plate for a Miata transmission, etc.... So what do I use for the ECU and wiring? Sounds like the cheapest solution is a stock ECU and doing the Hondata upgrade?
Looks like the two harnesses and a Hondata modified ECU are all I need, and if I want to save a few bucks, could pull a junkyard wiring harness and modify it to suit?
What are your thoughts, anyone done a similar RWD conversion?
Just to note, they have other oil pans if you're not doing the direct chassis intended for their swap kit. i.e. the supra I had used the e30 oil pan - it sat higher.
https://kpower.industries/products/k24-swap-oiling-system-for-bmw-e30
They have their swap guides here:
https://kpower.industries/pages/installation-guides
In reply to RedReplicant :
Ouch. That's a tough read - glad you got it worked out.
In reply to accordionfolder :
This is helpful as the Spitfire chassis will need to be modified to fit the transmission and engine. Been down this route before, but the k-series is a new animal. But I'll definitely look at the oil pan options between Miata/E30 and FRS to see which will mean the least amount of cuts.
clshore said:In reply to dherr (Forum Supporter) :
Look at what Joe Curry did with his Tiny Tim K swapped Spitfire ... then address the weak points.
Absolutely, Joe did pave the way with his S2000 powered Spitfire! Since I did this with a Miata engine/transmission, and am doing one now with a Rover V8, the bigger question will be the placement of the engien in the chassis. I'll know more in a few weeks as I tear down the car to start seeing how it all might fit together.
Oh, a couple tips regarding K-series engines:
If you disconnect the MAP and TPU sensors, be careful when reconnecting them, as they're the exact same connector size. Worse, you'd think they'd at least have the power on the same pins, but nope. Result: it'll idle but falls flat giving it any gas. As a bonus, swapping the connectors blows up the MAP sensor, so even after fixing the problem, it still won't run.
Not that this ever happened to me...
Oh, and the TPS sensor fails fairly often due to being a mechanical potentiometer. The solution is to replace it with an aftermarket Hall Effect sensor, which is no-contact.
You're welcome.
In reply to kb58 :
Definitely good to know!
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