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Disclaimer: a lot of this is blast from the past. I started this build in December 2015. I figured I'd start from the beginning to bring ya'll up to speed.
As of today it looks like this:
So back to the beginning we go...
In 2014 I traded my first PTE Miata race build for a 1991 prepped for Spec Miata. We met at Hallet in OK, swapped cars and titles, and the deal was done. I ran SM for a while, and it's fun as hell, but after getting pwned by SM's that make more than 110 hp (which is like, all of them,) I decided to go a more fun direction rather than try and pour money into pro-built SM parts.
To transfer the title I had to pass emissions in Texas. I bought a catalytic converter to use for a single day, and hit one of the few remaining dyno-sniffers in the area:
Pass!
Original dry weight of the car in SM trim was 2156 lbs. Pretty light to begin with really. The car was already caged, most of the interior removed.
Aside from the SM legal intake pipe and an aluminum radiator, the engine bay was almost entirely unmolested.
I began ordering parts from KMiata and others, and started the tear down process.
Believe it or not at this point I was planning to leave the car mostly as-is. Drop in the swap kit, then tinker with other things after I got it running. I had no plans to mess with the body wiring, remove more of the interior, or anything.
But as we tore down the car we started to get more ambitious. The factory wiring is a mess and largely unused. I pruned my last car and it was a painful process. I wasn't doing that again! It had to go. We literally tore every scrap of factory wiring off of the body. Lights, engine, everything. It would be easier to re-wire the stuff I wanted to keep from scratch than try and prune the harness.
In addition, we found that there was no dash bar on the cage. It's not technically required, but something you generally want.
Most of the cage is beautifully welded. It was a selling point of the car. But we found some welding on the firewall that was added by a... less experienced... welder:
Out with the OEM dash bar...
Painted over rust? Great!
Guess we'll just tear the car down to a tub then.
Dash bar added:
Firewall welds fixed
De-zebra'd
... annnd a room full of Miata.
Removing sound deadening. This Harbor Freight oscillating / vibrating tool works pretty well!
And wire brush on an angle grinder takes the rest off along with seam sealer.
Why NOT sandblast?? (side note: NEVER AGAIN. EVER.)
And a coat of gray epoxy primer:
I almost wish we would have left it all this color. Looks so nice.
and an 85,000 mile motor from an '08 TSX in the garage
It was time to get to the fun stuff.
Intake and exhaust manifolds are throw-away items, along with a bunch of other peripherals. The engine was alien to me, with hoses and pipes that I had no idea what to do with.
What crazy trickery, with all the cam lobes and rocker arms!
With not too much fuss the subframe dropped right in. The rest of the project will be just as easy, right?
To fit the subframe and oil pan, I prepped an NB steering rack. This also requires replacement of the connecting shafts.
The hydraulic fittings have to be shaved to fit under the oil pan. I plugged the holes with JB weld.
On to engine prep. I had an RBC VTC (a 50 degree ecu-adjustable variable intake cam gear) and a fancy oil pump to install.
The factory oil pump on the TSX has a huge balance shaft assembly with swinging weights designed to reduce vibration.
It had to go to in order to clear the steering rack and make room for the KMiata oil pump and pickup tube. Minor grinding of a corner needed to the OEM pump housing to fit on the block. I also blocked the oil passage to the balance shaft assembly using a bolt. The Moroso-built pickup tube didn't seal well and had the mounting tab break, so if you have this design I'd recommend reinforcing the mounting and filling in the gaps around the tube o-ring flange with JB weld, as well as using RTV when assembling the tube to the oil pump.
KMiata adapter plate and flywheel installed.
I had to "machine" a socket to get thin enough to fit in the flywheel bolt wells.
I installed the oil pan and bolted up the transmission. The Moroso oil pan leaked very badly when installed with a thin layer of Hondabond, seems Moroso has a pretty liberal idea of what constitutes "flat" when it comes to their flanges. KMiata now instructs you to use Ultraflange which works like a charm.
I used a 5 speed transmission from an NA8. The engine adapter plate is designed for 6 speed, so several of the holes didn't line up and went unused. I also made the necessary notch in the bell housing to fit the K series starter.
With the right angles it's not too hard to get in.
I ripped out the drivetrain from the 1.6. Driveshaft, diff, axles, all had to be replaced.
With a 25 year old car, a lot of the bolts were corrosion welded together.
I rebuilt the knuckles and outfitted all the various parts with Energy Suspension bushings.
I went with the fancy Paco Motorsports rear upper control arms. You can turn the adjustment in or out to get 0.25 degrees of camber in or out per turn. I re-installed the SM suspension as well.
I went with extended ball joints in the front to gain some camber there as well.
I also installed FM's "little big brake kit" which uses Wilwood calipers all around with OEM NB Sport rotors.
I got some more engine goodies, like the KMiata 1st gen race header.
For the IAT, I got this bung from SiliconeIntakes.com:
And I discovered that the hood wouldn't clear a K24 in an NA chassis. (I guess I was the first to actually try this; KMiata had insisted that it would fit with no issues, or maybe a modified valve cover.) We tried a modded valve cover, but the hood sat on top of the timing chain guide even with the valve cover completely off...
A modified hood or a hole in the stock hood is needed to fit the K24.
Normal Miata clutch hydraulics. I painted the hard lines blue because I'm a dork. Stainless line to the slave cylinder from 949Racing.
For fueling, I bought a modified "big fuel kit" from Flyin Miata. You can call them up and they'll tailor a kit to your needs. In hindsight I didn't need this big of a pump (300 lph!) which will run a V8 or mega turbo. Oh well. I mounted the FPR in the back near the fuel tank. I later modified this setup with a better filter and different line routing.
I received the modified ECU from Hondata, and made a plexiglass cover with a jigsaw.
I wanted to route cooling on the driver's side, and selected a massive radiator from Advanced Autosport. My cooling system evolved significantly from this early setup.
I had to use an NB steering shaft as well, and welded the plate to the dash bar. I kept the top bit of the original Miata dash to look nice and cut down on glare.
An early version of my cooling system. (Don't do it exactly like this probably since you'll end up needing an external thermostat.)
I should note that I used the K-tuned water neck on the water pump inlet, and opted for the "race" configuration which eliminates the stock plastic housing - the OCD in me couldn't stand the idea of plastic parts - and bypass line entry point. As a result, the car had cooling issues from the get-go since the Honda relies on the hot water bypass from the head to get the water in the block up to temperature quickly and open the thermostat correctly. By moving this bypass to the other side of the T-stat I screwed it up. The thermostat would see cold water from the radiator mixed with bypass water and never open. Doh. I used KMiata's upper rear water neck as an alternative to KTuned or similar. I was disappointed with the machining quality on the AN threads, but otherwise it's a nice piece.
First pass at everything was coming together and looking great.
I bought a brand new wiring harness for a 2004 RSX to work with the KPro setup. Then I chopped it into tiny pieces.
In hindsight, I should have invested in some pin tools and pins, then shortened each connector and re-pinned it. Instead I used Westinghouse splices with solder, and protected each with marine grade heat shrink tubing.
Yikes! Nose bolt to sway bar clearance is scary!
Kill switch
Gauge and switch panel:
Switch panel installed. I also put in a turn signal setup since at the time I was still aiming for street legal.
I wanted cockpit adjustable brake bias, so I built a bracket to attach the Wilwood valve backwards toward the firewall.
With the car on the ground for the first time in months, I pressed on.
With a front-facing intake, you give up the OEM tensioner mounting spot. A center feed intake may be an option here to keep it... Lucky for me KMiata came out with a pulley and belt kit. It doesn't have a tensioner mechanism (in the same way the Miata doesn't) so you shim the alternator using washers to get it tight enough.
The nasty yellow plastic coolant reservoir from the Miata works fine. But I couldn't stomach the look of it in the engine bay, so I added weight and cost for what amounts to looks.
Worth it.
Garage Blob Cat defending the frontier from bird invaders.
I mounted the ECU, relays, and a Painless fuse block on a piece of T6.
I was playing a parts waiting game so I was working on stuff randomly.
I went with a pull-handle fire bottle as well as a smaller bottle. It's added weight, but I like the ability to extinguish myself if on fire. The handheld is great for those times when your exhaust sets fire to the ground below your stalled/broken car or when your fiberglass hood ignites from header radiation.
More switch panel work...
For my brake bias valve adjuster, I pinned a metal **** to the valve ****, then attached a shaft through the firewall.
On the other side of the firewall, a small U-joint is in line.
Which then goes to a **** mounted within reach:
So off to my first track weekend with the K build. NASA at TWS, April 2016. Almost a year ago.
I learn that the cooling setup with thermostat omitted is running too cool. I'll need a thermostat. I also have a pretty serious oil pan leak and a leak from the valve cover. I also learn, disastrously, that the fuel filter provided with FM's big fuel kit is nowhere near effective enough to block small particulates. I chased a misfire all weekend, thinking it was coils, but finally thinking it was injectors.
Sure enough the injectors were packed with sediment. I'm assuming from the bottom of the fuel tank. Very unusual! Fuel rail had crud in it too.
Undaunted I replaced the injectors and put on some livery.
I also put a FueLab 5 micron filter in line.
I used 949's inline thermostat housing to solve my cooling issue:
And for my first aerodynamic adventures, I installed a fiberglass air dam/splitter combo and APR wing.
Another NASA track day, and another slew of problems to fix. Oil temps were through the roof.
Oil cooler mounted and filter relocation kit too.
I wanted to box out the intake. I know ideally it should be much longer for the K motor, but for now I want to get it cooler air.
Using cardboard and my trusty Harbor Freight edge copying tool, and some bamboo skewers...
Tracing on to aluminum:
Jigsaw and hammer...
Cold air intake!
And after a great day at the track, I ran up on to the trailer too quickly and caught the oil cooler, which in turn pushed the radiator.
Toast. The tank was cracked and whole thing was deformed.
I also discovered that Wilwood pads are junk!
With only a week or so to the next event, I put Hawk DTC-30's on it, remounted the oil cooler, and put in a Mishimoto Miata radiator. Back to TWS with NASA for their October event!
After a great test and tune, the KMiata header came unglued. Seems you need to put a flex pipe after the header and the guys that built my exhaust decided it was not necessary. Luckily Texas Track Works let me use their MIG welder to patch it up.
But after getting home it was obvious this thing is toast.
I at least installed a flex pipe for the replacement:
And started looking for ways to lighten the car.
I pulled off the rear trim, lights, trunk latch etc and ended up with almost 7 lbs of stuff.
Replaced with aluminum sheet. 4 lbs off the car.
I also cut out the trunk floor - a net savings of 2.5 lbs
I also got a new fancy header
Much lighter than the original. I also went with a lightweight battery.
Installed on the passenger side floor.
Unhappy with my original hack job, I spent some extra time and made a rear deck cover with aluminum sheet.
And then the wrap happened. I sent all the fiberglass parts to Maaco for some real paint instead of rattle can and vinyl. I hadn't even painted the hood yet since it came with white gel coat.
I spooled up the vinyl cutter and went to work.
Microchip racing stripes? Why not.
About half way through I got distracted and built a bigger splitter from aluminum and dibond.
I also installed a Frost Fighter / Bimmerworld front defroster:
And a Pokeball shift ****.
At the last minute I realized the front splitter would probably rip right off, so I cut it down right before loading for a track weekend.
And then got hit from behind during Race 4 of said track weekend!
The hit was directly to my exhaust, rear bumper, and front fender.
I had a rubber radiator hose bust at the track as well, so opted for a full AN/braided hose setup. I routed it on the passenger side.
With the passenger fender well crumpled from the punt, I cut off both, making an aluminum cover for the jack well.
For fun I made a tube steel rear bumper and took off the skin entirely. Not sure I like it, but it works.
I designed some templates for the air dam/splitter so they could be cut out in vinyl and overlayed on material to cut out. I need to tweak them, but getting there. Using the templates I made splitter #3 and a spare cutout to keep in the trailer, #4.
I also bit the bullet and ordered fancy suspension.
Initially I ordered Xida's from 949. They were "IN STOCK" and I wanted them on the car for the next event in time to align and corner balance. Well turns out "IN STOCK" means "we'll probably have them soon, we hope, as long as all the parts get here in time and our staff can assemble the kits and ship them out." After waiting quite a while I finally cancelled the order, and ordered Fox suspension from Flyin Miata instead.
They were extremely helpful in selecting the appropriate spring rates and whatnot, and I had them in just a day or two.
Having driven on them a few events, I can tell you they are amazing. The car soaks up bumps like a maniac, and suspension travel is off the hook. I've had many people approach me in the paddock to tell me how it looked like the car was leaving the ground but stuck like glue. 100% happy with Fox shocks!
I made it an entire track weekend keeping a splitter on the car! WOO!
I also got a custom sway bar setup from Luis Rivera, complete with reinforced mounts.
Using this setup, at his suggestion, I completely removed the rear bar and get really great grip and handling dynamics. I know that it's not the best in all situations, so I might add a small rear bar later on, especially if I increase tire grip.
To fix my bent up exhaust from the punt, I installed a KTuned straight through muffler.
It's much lighter than the Magnaflow that was on there, and makes nice sounds.
Tired of re-aligning over and over, I gave these a try. They work like a charm, especially since my rear arms are for toe adjustment only (rear uppers handle camber.)
This brings us to March 2017. With the new suspension all corner balanced and happy, alignment all set, a new set of Maxxis RC-1 225's and a shiny new splitter, I drove 5 hours for a track weekend across the state.
Test and tune went great and I was giddy with the performance of the car and suspension. It finally felt solid and fast. Then CLUNK. tap tap tap knock knock knock clunk. Engine was toast.
You know it's a bad weekend when a Subaru has to pull you to the garage.
Let's drain the oil and see if there's anything shiny.
Yep. Motor is toast. Pulling the motor went pretty quick.
My bet was on spun bearing.
Yay I win!
During the autopsy we found that the oil pickup was hanging loosely from the oil pump. The mounting tab had broken. DOH!
Has it been like this for a while? Damage from the punt? Who knows. Definitely not good though.
I first considered a rebuild with fresh rods and bearings, but the crank was damaged. Looking at the cost of a crank and new bottom end hardware, it's more cost effective to find another junk yard motor.
Oil pan was full of surprises...
A few weeks later I had a "new" junkyard motor delivered.
I cleaned everything excessively. For the pickup, I welded the tab back together, and added a second mounting tab. I also filled in a large gap on the flange that had swallowed up the o-ring.
Against my better judgement, during some down time (engine was delivered across town and truck was broken,) I got to thinking about my gauges and switches. The side net blocks the gauges in the center, and the wiring was a rat's nest.
So I just dove right in.
While rewiring I saw a FB post about a melting wire issue with the early KMiata engine harness. Sure enough mine had melted too. The wire is not sized for an upgraded fuel pump, and mine is quite big.
It was an easy fix. I just cut up the wiring to the relays and added independent fused feeds to each. I used new relay connectors with larger gauge wire to solve the ampacity issue through the adapter harness.
Having already done it once, installation of the special bits went really quickly.
Type S oil pump and KMiata housing / fixed pickup.
Adapter plate:
Installed and back to life!
The KMiata flywheel cover had cracked under stress, so I made a crappy replacement out of stainless steel. I had to take it off and put a bend in parts of it because the flywheel was barely touching it initially.
Took it back to the track, and after one day of running had a near disaster!
I had installed a brand new OEM tensioner and a Beck Arnley timing chain with the motor, but when I took off the valve cover, the chain was slack. CRAP.
Another tow from the Subaru to the garage and I discovered that the tensioner had completely extended and the timing chain had stretched! CRAZY!
A leakdown and endoscope inspection were good. It looks like no piston-valve contact. WHEW!
This is why you buy OEM timing components. Even if they cost more.
I put everything back together with OEM components and started prepping for the next event with NASA at TWS.
I built a cool shirt cooler / pump using Amazon stuff for under $100.
I also wired up a coolant pressure light to let me know if I have a busted hose again. I have all the peripheral wiring stuck behind the gauge cluster arranged on terminal strips. It looks messy but it's actually not too chaotic.
Over the weekend I had a successful, non-exploding event. I finished 2nd out of 4 in two races and managed to win some tires and brakes.
I did manage to lose another splitter. Sorry buddy, you were a trooper.
RIP Splitter #3.
I attached the spare splitter as best I could from the salvaged bracket, but it came off during Race 3 and got me black flagged while they finished it off.
RIP Splitter #4.
But now I at least I have some good videos of the car in action!
Here's a video of my personal best lap and the car basically performing as good as it ever has:
And a compilation of race starts to give you an idea of the madness I willingly participate in. Check out the 2:25 mark to see why I kill so many splitters.
04-25-2017 | 11:04 AM
K24 race build!
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