People seem to drool over K-swaps, but after swapping 5 of them now (not all miatas), I'm unimpressed. Although they make 200-230 out of the box, any Honda reliability seems to be lost in aftermarket parts issues, torque is unimpressive, and there's no way you can convince me you're saving money of a turbo BP after all costs have been added up. You still need larger injectors, ECU, exhaust, intake, engine work, about the only thing you're saving money on is the header, which is $769, and Kraken's builder kit is less than $300 more. Yes, heat and bolt issues with a turbo BP that are difficult to fix, but the track K-swaps I've serviced have plenty of their own problems.

I will say that I've never driven a K-swap on track yet, only a 2.4 Ecotec swap, which was great. 4 of the 5 I swapped were built as track cars.

And I don't wanna hate on K-power, they've done a lot for the community and continue to develop their products, which I really appreciate. But they do seem to release products a bit early, followed by a lot of "V2" releases.

 

At this point, I should have gone V8. But that involves another vendor with less-than-stellar post-sale support, so MMMV. This has been an interesting adventure, to say the least.

Drive one on the track. It's nothing earth-shattering, but it's a hoot.

I agree - I'm not here to hate on KPower either, but I will take the opportunity to contrast them with 949 Racing / SuperMiata. When SuperMiata customers had issues with the orange urethane bushings in their 863 bushing kit, I was notified of the problem, the availability of a fix, and the replacement parts were made available to me. When there was an issue with a component of their BX11 duct kit, I swear the replacement part arrived before I knew there was even an issue. And again, they let me know there was an issue. I've had more than a few email exchanges with Ed at SuperMiata. I don't know how he does so much - starring in Instagram reels, getting product out the door, answering email questions - but I've never felt ignored or dodged. And he's always been very clear about what is and isn't in stock. This is far too rare for aftermarket part manufacturers.

The oil feed system is important enough that I would have appreciated a note from KPower "Hey, we don't think there's a problem, but some customers have had issues with our v1 oil pump adapter. You might want to check on X, Y, and Z, or update to our newer version". Sigh.

One of the points KPower mentioned when we discussed my issues was the time that had elapsed since I purchased the kit. That's fine, but I want to repeat for everyone reading here that the swap had 24.2 hours of run time on it. Less than one season worth of events with one group.

 

You guys are making me nervous...

The weld on that oil pickup was terrible. I'm pretty sure I have V2, but it's still disturbing. Moreso is KPower's attitude towards the failure, although I got the 'shrugged shoulders' response from them on my clutch issue, so I guess it isn't really that surprising.

My whole motivation for the K swap was 200+ hp at the wheels with 'stockish' reliability. Over the last year, I'm starting to see more failures, but even if I'd known that before ordering my parts, I'm not sure I would have done anything different. With the way things are today, the odds of a KPower part failing probably aren't that much worse than a machine shop bungling a BP build. One of the factors that pushed me over the edge to the K swap was a hearing about a Keegan engine failing in less than a year of track use. Stockish build and naturally aspirated from a known quality builder, and it didn't last. When you're racing, you pay your money and you take your chances.

I hope you get the Miata back together, and have better luck in the future.

And Curly, you really need to drive a K Miata.

 

Yes I do, I think it's what they were designed for and I'd probably be a little less pessimistic if I experienced that. I had a blast in our 185hp Ecotec swap, definitely had our fair share of failures with that kit too, but with a $3-400 GM engine and a $2900 swap kit, it's a bit easier to swallow those failures than with a $5-1000 k24 and $6000 kit. To be fair, K-powers is much more complete, but still.

And I'll agree with thebeerbaron's opinion of Ed and SM, super helpful and fast to offer replacement parts. I feel like if K-power recognized a potential issue in the oil pump pickup, it should have been shipped out to all customers of the old design. That way it's the customers fault if they don't swap it.

Remember, if you want to make a small fortune racing, start with a large fortune!

 

In the garage, so limited responses.



I’m sitting in front of the engine, getting ready for another pass at cleaning the Hondabond residue off the timing cover flanges. I’ve already done the block side of the oil pan surface. I’m not looking forward to the oil pan flange or the timing cover itself. I wish I was less neurotic about cleanliness here.

With the new pickup in place, I noticed a lack of clearance in a couple of places. After a few curses, I was able to gain fractions of a hair of clearance with some prying and banging. Sigh.

This is the before shot.




This weld looks a lot better than the v1 weld. Let’s hope.



And this is the one piece v2 oil pump half. Gone are the four tiny socket head screws that backed out on me. The KPower kit includes a stainless M6 button head screw to hold on the oil pump pickup tube, with some sort of anti seize already applied. I swapped in my own plain steel screw with Permatex orange.




At some point, one of the engine mount screws was rubbing against the driver side engine mount. It shouldn’t do that, but just in case, I dropped the chassis side mount into the mill and carved out a 1/8” deep pocket where the contact happened. If the mount sags again, at least the bolts won’t be riding right on the mount.



That’s it for now…

 

I cut away some of the cast bracing on the back of the “everything” casting on the driver side of the engine.

I don’t think that the intake manifold will allow direct access like this, but it should allow better access to this fastener, which is easily the most difficult to reach.

 

The quote often thrown around with KPI parts in the Miata GLTC chat group is, "we have never heard of that problem, but we have a solution to fix it." Actual quote from KPI when one of our members brought an issue to their attention.

 

Comment chains like this are sobering and super disappointing to be honest. I've wanted more power for years, and it was so bad when I lived in the midwest I almost ditched the Miata and bought a Corvette. Thankfully I got on track soon after, but 7 years and many events later I'm still running a stock engine and ECU. I just can't seem to find a route to appreciably more power that checks all the boxes for my needs, at a price that isn't in the ballpark of just buying that C5Z.

Thanks to everyone for sharing their opinions. It's extremely valuable to those of us daydreaming about the possibilities out there.

 

My turbo track car ended up being pretty reliable and could catch C5Zs on the back straight at Sebring, FWIW. It's doable.

 

It’s absolutely doable, and to a large extent that’s thanks to this site and the people who contribute here. The fact that there is much less “how do I …” content and innovation posts here in the last few years is, I think, at least partially because most problems are solved.

For me though, I took a look at all the things that Andrew had to do to make (and keep) his Miata reliable in the local NASA region and I just didn’t have the stomach for all that. Not only is he a far better driver than I will ever be, but he’s got years of experience and engineering know-how that I simply do not possess.

Anyhow. Turbo is a great answer. It just wasn’t the answer for me.

 

I about bashed my head into the desk when KPI told me that the torque specs they list in their instructions aren’t the values that they torque fasteners to on their builds.

 

I cannot understand how this is so common. Why do so many vendors choose to spend their time individually parsing out advice to customers on multiple forums, social media platforms, and DMs instead of one easily referenced and regularly updated file or web page? And why does it seem like so few customers are willing to call out this crap?

I tried going down the boosted BP route and had too many issues with Megasquirt to continue. I had a similar complaint about documentation - a very well reviewed ECU supplier had no publicly posted firmware or instructions on their site. Instructions could be found on the reselling vendor's site, but there was no version tracking or anything included to tell you if the instructions you were reading were applicable to your unit. When I found that ECU manufacturer made a forum comment to the tune of "don't flash this latest publicly posted firmware into your older unit or you'll brick it" instead of in an updated instruction sheet, I about lost my mind. I bought my unit used so I don't think it's fair judge the vendor entirely on my experience, but it certainly didn't make me want to recommend them to anyone else, or go back to them for a new unit with no PO screwery.

 

Does KPI employ engineers from Boeing?

Don't get me started on Corvettes. Everyone keeps saying they're going to sell their Miatas for a C5 corvette because they've dumped $5-10k into their Miatas and it's still not a perfectly reliable track car, or fast, or both. So they think an American car with worse build quality, higher wear/tear, and more complicated to take apart is going to be better? No, it'll be twice as fast and cost twice as much if not more. Oh, and your interior will be falling apart.

A clutch is 7.5 hours of labor for the Corvette, 4 for a Miata
Engine is 22.5 hours for the Corvette, 10 for a Miata.
Corvette BBK: $2k. Miata BBK: $1k

I could go on forever. Corvettes are a very capable chassis, LS engines are also very capable after a bunch of modifications. But otherwise giant piles of ****. /rant

 

What the actual ****
This explains why one of my 10mm oil pump bolts stripped the adaptor threading, and why torquing the oil pan bolts always felt like it was going to snap something. Bloody ******* hell
Also if I had a nickel for every time I've been fed the "Well it works on our turbo shop car, so this issue you're telling us you're experiencing definitely isn't happening despite your evidence to the contrary" line... Well, I'd have a LOT of nickels.

 

The owner of a car prep shop out of here put it best, "The C5 is a great, reliable track car once you put $10-15K in them. The just look good on paper before you realize what they need"

 

Also, if I had a dollar for every woman who didn't find me attractive, eventually they'd find me attractive.

 

I'm loving the discussion here, thank you all for your input. It'll take me a little while to reply to you all...

Engineers create solutions, not products. It's easy enough to design a widget and sell it. Supporting the solution in the long-term and with variables inherent in 35-year old cars is a completely different thing. Then add different levels of customer talent... it's difficult.

In most cases, these vendors are the sole source for the solution they're selling. If you **** them off and then need a replacement part, you may be SOL. I waited until I had the KPI-only parts in my hand before I shared my struggles publicly. If I need parts in the future, I may be SOL. But at this point, I think the next step is to create my own solutions.

 

You know, that's something I hadn't considered. Thank you for sharing all the same! I really wanted to do a K swap, but by the time was right I was hearing enough inklings of complaints to give me pause. Now I've read enough threads and complaints like yours to know this just isn't a path for me.

 

As a fellow kswapper here, I might as well chime in. I can't say that I've had major issues up to this point. I had a very early gen adapter harness that I thought I picked up for a good deal. Turns out it was an old gen for a reason (it was updated quite early on in the kmiata development craze) and the wiring crimps left a lot to be desired with some intermittent connection issues that caused me to pull my hair out for a while. Once I addressed those connectivity issues, it's been green flag racing the last 3 years.

No matter how you slice any engine swap or power adder, you are compromising something. Doubling or tripling the power (or even more in some cases) in a NA or NB just isn't a cheap or easy thing to do while also expecting the same level of reliability that the old gutless tractor motor the car came with had. I have my full parts list, what I paid, etc for the swap and it came in at nearly exactly $10k for the necessities after selling my BP powertrain stuff. I had chose to put in another $1200 of extras for temp gauges and general engine bay tidiness and swag point items, but none of those were needed functionally speaking... so in total, you could say I spent $11.2k out of pocket for the kswap to make 230whp/186wtq. I could have made more power going with an LFX or LS, but then I know that I would have been spending MUCH more as there are hidden costs with all those swaps as well that people don't talk about. I could have saved a few thousand and pieced together a Kraken kit with MS3 on the factory BP to make similar power and more torque, but spending a few grand more up front on the swap to get a newer, cheaper, and more supported base engine felt right for my long term higher hp goals where I know a built BP would be required. I could have also just kept the factory BP in the car and bought an entirely different car to track with more power from the get-go, but old hondas and miatas are always going to be the consumable cost kings at the track for their track time they lay down (that power:weight ratio baby!!!). You will also never get around the fact that speed and reliability and subsequent lap times cost money no matter the platform you start with....

So... At the end of the day, I would absolutely do the Kswap again. I wasn't the first guinea pig in line to try out the A2 Kswap from KPI, nor would I be for any vendor that offers something that costs this much. Designing, testing, failing, redesigning, retesting, etc is part of the design/build process with swap parts like this and EVERY vendor has been through it. I let KPI mature a bit before I pulled the trigger on them personally. Failures are inevitable, but how you handle them as a company is key. I'd approach the customer service mentality a bit differently than KPI has the last couple of years, but that's not my business to run. I will say that taking care of your early supporters, listening to solutions you may not have initially thought of, and solving issues as they become known so that they continue to take care of you through good word of mouth is marketing 101 for long term success... YMMV with KPI on that mindset.

 

100% agree with you on this.

Would I do the K swap again? Maybe. I just wish I had gone in with my eyes a bit more open. I think I dismissed some of my own concerns early on because I trusted KPI.