18psi

iTrader: (76)

Yikes, that thing looks intense. I'm guessing uber long tubes for torque?

ctdrftna

iTrader: (1)

i wouldn't say they are uber long, theres not much room between the block and frame rails, so you need to make your runner lengths and collect them up high, the down pipe brings the exhaust under the car to the driver side.

ctdrftna

iTrader: (1)

i went with the big tube version so I'm not buying another header when i build the engine down the road. Eventually i will build it with 12.5:1 pistons, a 4piston racing cnc head and drag cartel 3.2 cams.

Im gonna put the motor in the car with a set of 60mm Kinsler ITBS, it should make some pretty damn good power and torque for a N/A street car.

KMiata

Can't wait to see your car Josh. Our customers are putting together some pretty wild builds.

What are your power goals? Staying with an 87x99 motor? With the Kinslers I'm guessing 300-330whp?

ctdrftna

iTrader: (1)

87.5 or 88 x 99. probably super tech pistons. K1 lightweight I-beam rods.

Would you be able to take a picture of a 12" scale (ruler) off the side of the head, inline to the intake port angle? I would like to visualize the runner length of the ITBS. I would like to try and make a 12" runner work, to utilize 2nd order harmonics at 8200-8500.

Im not setting any goals other than i want a broad power band with good torque. If i loose some up top to keep some grunt in the middle I'm fine with that. I don't see 280whp/230 wtq being out of the question.

AndyHollis

Greetings gents,

I haven't frequented this board often in the past, but will likely do so now as it's the best place (IMO) to discuss tracking Miatas.

I was part of the original group buy on the K-Miata kit. I have lots of experience with the K-series in my CRX track car and will be putting that to good use during this swap. In fact, there are currently four working motors in my garage (three built, one stock). And as of the past weekend, there is once again a Miata in the driveway. Black 2000 PEP. Once I find a place to store the CRX for a bit, the build will commence.

Haven't decided yet where to put the primary build thread (I hang out on a variety of forums), but for sure some level of updates will come here.

The current plan is to put a bone-stock TSX motor in the Miata first to solve packaging/logistics issues, then do the suspension, cage the car, and finally put one of the built motors in. We are working with various partners to accomplish much of this (including some guy out west called Emilio ), and the car will likely see exposure in GRM, since I write for them. In fact, one goal is to display a running vehicle at the GRM tent at the Rolex 24 in Daytona this winter.

Here's a teaser on what the power band on a built K24 looks like:



That's an 87x99 K24, stock K20A2 head, 13:1 compression, moderate cams and E85. Motor can also run on 100 race gas or be detuned slightly to run on pump 93 (that's what we did for the One Lap of America last year). I have another lump that's sleeved to 89.5 bore, ported head, and slightly bigger cams. It makes 300.

I picked up a 6-spd trans and 3.9 Torsen rear end to put behind it. That gives me very similar gearing to what I run in the CRX. Eventually an OSG will go in there to replace the Torsen.

asmasm

iTrader: (1)

I saw something on facebook about you doing a k24 miata for one lap and got really excited. It's awesome to see you posting about it here.

AndyHollis

I strongly suggest you do NOT go 88mm bore on stock sleeves. Here's what happens when you track that for six months:



And if you sleeve it, might as well go to 89.5 or 90.

As for pistons, Supertechs are nice, but I prefer Wisecos. While the Supertechs are 4032 alloy which should expand less than 2816 used by the Wiseco, the former is spec'd at .003 piston-to-wall where the Wiseco is .0025". Something about the Wiseco design keeps expansion down, according to a well-known K-series engine builder.

My 88x99 Supertech motor (pictured above), rattled more on cold start than do either of my current Wiseco-piston motors. Cast OE pistons, of course, run at less than .001 clearance and make zero noise. RS Machine even makes cast pistons in 12:1, so that's an option. But I prefer the stronger forged parts to support higher revs (once you beef up the rods).

In short, Wiseco 12.5 shelf pistons on Manley H-beam rods is a pretty standard K-series combo that will rev to 9000 in a 99mm stroke motor, though limiting to 8500 or less is advised for extended track use.

Splitime

iTrader: (24)

In case you guys don't recognize this guy... look up the name and OneLap. He's a good reference check for some of the thoughts for builds.

Efini~FC3S

iTrader: (4)

Ahhh...sheeet Andy Hollis is on this board meow?

Best place to discuss tracking miatas?

What happened to turbos?

And Miatas?

hornetball

iTrader: (4)

Happy to help you with that. I'll even exercise it at MSR-C for you. LOL. Neal B will vouch for me.

ctdrftna

iTrader: (1)

Im building it as a street motor, thats why i want the low expansion super tech pistons. Most likely i will stay with 87.5.
Your the 1st person i have seen post issues with the 88mm bore though, but thats cause most guys doing 88mm are drag racers.

Any way I'm not boring anything right now, my build is off to a slow start, until the car in my garage sells this project is just sitting collecting parts that i need.

KMiata

Glad to see you here Andy. Very excited to see your car come together.

etikoner

iTrader: (1)

Sweet, I'm suscribed to GRM, and loved reading about the underdog CRX in one lap.
I'm super jelly all you guys are doing bad-*** honda swaps.

KMiata

So who else needs a K swap kit? Got a few more available for pre-order, scheduled to ship in December.

glade

iTrader: (2)

So....Damn.....tempting........

Edit, has there been any NA builds?

KMiata

Few NA builds in progress right now, but not necessarily on this forum. You'll start seeing a lot of these cars popping up early 2015.

Midtenn

iTrader: (15)

Very temping since I have to pull my VVT motor this winter....

KMiata

I have a feeling you will never look back to the VVT motor after doing this swap

Just email us if you have any questions!

AndyHollis

here we go...

Main page: OneLapMiata.com

Why a Miata?

The One Lap CRX has had a very successful run, especially this past year where we topped 170 MPH at the Texas Mile, won our class and 4th Overall at the One Lap of America, and won the SMF national championship for SCCA autocrossing. Performance-wise, there isn't much more we can do with the car other than incremental improvements. The weak links are FWD, 65/35 weight distribution, and small wheel wells that limit our wheel/tire size.

Recently, David Calzada and Adam Jabaay from the Chicago area prototyped the swap of the same K24 we run in the CRX into the NA (90-97) and NB (99-03) chassis Miata. That early effort has evolved into a kit being offered for sale. See K Miata Home for details.

In addition to Hondas, we are very familiar with the Miata having run one successfully in SCCA autocross some years ago in the STS class. The all-aluminum Honda K24 weighs the same as the cast-iron block 1.8l Miata BP motor, so the swap does not mess up the amazing Miata handling. The Miata is the same curb weight as the CRX, but it is equally distributed front and rear (50/50) so it makes more efficient use of the tires. It's RWD, so more power gets put to the ground. The wheel wells are larger so we can fit bigger rubber. Best of all, the cars are raced all over the country every weekend in a variety of series and prep levels. So real racing parts are available off the shelf and do not need to be custom fabbed.

Our plan is as follows:

1) Do the basic swap using a bone-stock TSX K24A2. That will allow us to work through all of the logistical issues with the basic swap.

2) Install race suspension/brakes, and start dialing in the car on the track using our existing wheels/tires from the CRX (they fit).

3) Get safe: Cage the car, install a race seat, safety net, fire system, etc.

4) Install one of our 300hp race motors and better LSD.

5) Add aero.

6) Put a tag on it, take it to One Lap 2015...and kick butt.

In progress now.