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I set out to copy the tractuff water neck but adapt it for the Z3 motor, basing my creation off the Kmiata waterneck. After some initial planning, I realized that the Kpower water neck is just really badly designed. For starters, the outlet is pointed slightly down, so that there's a nice 1/2" pocket right at the water temp sensor(drivers side) that almost seems purpose built to trap air. If you had a heater core this probably isn't an issue, as the "pocket" is right where the barb for the heatercore inlet would be.
Since the higher end of the water neck is the drivers side, and opposite the water flow direction, I couldn't just weld a tube to the normal outlet and sit the cap there, as that would still leave the air pocket. So I removed the plug for the heater core(which I don't have anyway) and built my extender tube off that side.
You can see how much of an angle the Kpower neck sits at on the motor, as my extra tubage is angled to sit vertical.
Welding the 6061 tube to the Kpower neck was a bitch, I assumed that the Kpower bit was also a 6061 or something very close, but it didn't seem to take the weld very well without insane amounts of heat. I'm not a good enough welder to tell you if that's just a characteristic of billet material or not, but the radiator neck welded up very nicely, and that was cut off my Chinese "aluminum" radiator.
Having the radiator cap in this spot made bleeding a bit less of a hassle, I actually jacked the rear of the car a little to help force air backwards. Seemed to go pretty smoothly, only needed one heat cycle on/off cycle before the bubbling stopped and it seemed happy. If nothing else jacking the rear 3 inches is waaay easier then jacking the front 3 foot in the air.
I don't think having the extension on that side is 100% ideal, as its opposite the flow of water coming out of the head and heading to the radiator. Could make it a little more difficult for air to find its way out, but it seems to work well enough for the moment.
Also fixed the shifter **** that kept rattling loose/breaking off. Last method of failure was the entire threaded assembly stripping out of the lower section. I thought initially I could weld it back on, but realized the **** was aluminum while the shaft was steel.
So I cleaned out the JB weld, stuffed it full of hysol, and then drilled/hammered in a rollpin to make sure that it couldn't go anywhere, ever again.
Keen eyes would have seen a non-miata steering assembly in one of the above photos. I was tired of muscling my car around track like a raging bull. Feedback is great, until you're getting feedback from 10" slicks and aero loads that want to rip your arms out of their sockets. Also quite jealous of some others that do have powered steering that can basically steer with their fingertips, not yank the wheel in the general direction you want to go and try to get within a metric mile of the apex.
Epower steering sells miata kits(same one that Kpower offers) that adapt a GM electric power steering column to fit. But these kits are $900+ and are meant to bolt into a stockish car. Lots of extra wiring, brackets, and other stuff I didn't need. So with advice from a few friends, setout to DIY my own.
Where every good story starts, the junkyard. Compatible steering columns are found in the 02 – 07 Saturn Vue, 05 – 07 Chevrolet Equinox, and 03 – 06 Saturn Ion's with a metal ECU case.
Mine came out of an '06 Equinox. Half hour pull with an impact and assortment of sockets.
Junkyard charged me $100 for the ECU/motor/column assembly, so pretty good start. I got it home, removed the tilt assembly, and make sure my hub bolted up.
From Epower steering I ordered the canbus ECU controller, assist potentiometer, 60amp fuse/fuse holder, and a 3/4" to 16.5mm spline adaptor(3/4 being the miata size, 16.5mm being the chevy size). I think the entire order plus shipping was under $120 so I'm into this for well under $250. I've been told by others to request the 10K pot, not the OEM one, for better resolution on the adjustment, so passing on that information. Since Miata's are so light, with the stock pot it hovers between "off" and " almost too much" assist. I *think* the exocet kits also come with the 10K pot.
I cannibalized my old rack for the lower splined section that goes into the first u-joint, and welded this to the spline adaptor, creating an chevy-mazda steering adaptor.
Drilled and hammered in a rollpin so that the only thing holding these together wasn't just my questionable welding.
Entire assembly ready to go into the car:
Thanks to my bussman location, I had to trim a little bit of my brake bracket assembly to rotate the column so the motor would clear said bussman.
Cut the mounts off my miata steering rack, and with a little hammering, they fit almost perfectly around the GM rack. Tac'ed into place:
Once welded fully I realized the lower section could/probably would rotate over time with the quite heavy motor hanging of the side. So added small bracket to prevent rotation here. The upper mounts hold 99% of the weight, bolted to the OEM miata crossbrace locations.
Said bracket seemed as good a place as any to mount the canbuss controller and adjuster pot to. Out of eyesite, but reachable with the belts loose. Not that I think I'll need to adjust it often, should be a set and forget kinda deal.
After some fiddling with the calibration, everything seems to work perfectly. Fully off on the pot reverts to OEM heavy steering. Turning it to max I can move the wheel with one finger while stationary. I've only done a little driving around doing errands, but its definitely going to take some recalibration on my part to get used to this. I can be veeeery light on the wheel and it turns in so nicely, even with the assist turned quite low.
Great DIY, can you link the coupler or confirm it was this one. I just saw a 2006 unit Ebay for roughly same $100 and will attempt this. Any advice on how much to cut the lower section for the miata spline join ? Did you not bolt the bracket miata column uses ?
Great DIY, can you link the coupler or confirm it was this one. I just saw a 2006 unit Ebay for roughly same $100 and will attempt this. Any advice on how much to cut the lower section for the miata spline join ? Did you not bolt the bracket miata column uses ?
what's the zip ties holding on the coupler?
You can measure your stock column length and match that measurement for the new one. The GM column is 3-4" shorter then the Miata one so there's plenty of room to work with. It's easy to mock up everything before you weld it.
There's many ways to mount it. I opted to cut off the GM mounts completely and just mount with the modified Miata mounts. A buddy of mine kept both the GM and Miata mounts and just adapted them together. Pick your poison. https://preparedmiata.wordpress.com/2017/09/
Zipties are just spacers between the rubber washers sealing the top of the column and the steering hub.
Headed up to the SCCA Chasing the Dragon Hillclimb tomorrow morning. Going with a small convoy of three miatas. On the hill should link up and paddock with a fourth, which will be 4/5th of the Miata representatives signed up.
SU crowd looks tough this year. RB25 swapped Datsun, several modded vetts, GT350, V8 swapped BRZ. Looking forward to some fierce competition.
I ponied up and bought some 245 A7's. Fuuuuck my wallet hates me now, but excited to try out the fresh purple crack for the first time. Ironically looks like the weekend is going to be constantly wet, rendering slicks useless. If it stays damp, it will even out the playing field and I think I have a good shot at FTD. Or perhaps my goals are overly ambitious. Time will tell. If the car holds together I'm going to give it my all and try to leave nothing on the table.
Arrived in Robbinsville mid day Friday with my group of 3, grabbed a good paddock spot, passed tech with no issue, grabbed dinner and did a semi-traditional light hearted Friday evening Dragon run.
And then it was time to get serious and drive for real.
Weather for Saturday looked like it was going to be a mixed bag with showers rolling in around noon, and Sunday was predicted to be a complete washout. But weather in the mountains during the summer is unpredictable, as anyone that lives in the area knows. My initial goal had been to run some slower, warmup runs for Saturday, get a good feel for the car, then not put the hammer down till late Sunday. But with the forecast looking like morning runs were going to be the only dry runs we got, I decided to move with some speed right at the start.
My previous best the year before was a 120.04(all times measured in seconds), agonizingly close to the vaunted "sub 2 club". The class record sat at a 117.2. I felt low 117's were doable, 116 should be attainable if we got perfect conditions and I could pull it together, and a 115 was a pipe dream.
I ran a friggin 116.6 my first run. Obliterated my PB, smashed the class record, broke the Miata record, and sat in P1 overall. So much for sandbagging, it was time to run and let them chase my time. Plenty of time to be found, and find it I did. Second run kicked off a 115.4, then final run before lunch, with dark clouds above, a 114.6. I had a narrow lead at that point, right behind me with a 115.8 was an 850whp RB25 swapped Datsun from Canada with slicks as wide as my motor(pictured here on his "wet" setup). Beautiful car.
Also breathing down my neck was an LS powered, tube chassis, 1970 "Camaro" that was more accurately a homebuilt nascar with a Camaro body draped over it. Spoke with the driver later, and it was his first hillclimb, but had tons of dirt, circle, and track experience. Regardless, he was ******* fast right out of the gate and wheeled the hell out of his car.
The rains came down heavy just as the first run group went out after lunch, a brief but heavy shower that soaked the course. No one would go faster, and I was sitting pretty in both a class and overall P1. I made one more run to confirm the track was too wet to go quickly, then parked it for the day, not daring to hope that I had somehow lucked myself into a fluke win, helped by the weather.
End of day 1 results. Yup, that's really me at P1 overall.
.
I spent the night back at the AirBNB going over footage from that day with my little group, alternating between checking the weather forecast and calling each other slow pansies that need to stop lifting.
Day 2 dawned and a trip in a tow rig up the hill showed it to be damp, but there was no rain coming down, and the heavy storms predicted seemed to be splitting and going around us. If they held off, the course would dry.
First run up a few hours later was a recon run. The hill was patchy, but drying up quickly with cars at speed.
Second run I gave it as many beans as I dared, as a few corners were still moist. Went quicker and kept my #1 overall spot.
Unfortunately some stuff started breaking at that point. The first thing I noticed at the top of the hill were my brake lights were stuck on. Some investigation revealed that one of my homebrew steering column mounts had sheared, and the motor assembly had rotated around the steering shaft with enough force to snap my brake switch cleanly in half. I had built the bracket out of aluminum, and apparently that just wasn't up to the torque of the motor from moving 245 A7's combined with the brutal bumps of the road.
Additionally, my rear tires were being cut up by the fenders. When I had setup the suspension, I had 245 RC-1's mounted... and Hoosiers run wide. Wide enough they didn't clear the fender arches during heavy up travel. With large loads and big bumps, substantial contact was made. I couldn't roll the fenders any more in the paddock, and it didn't occur to me to ask around for an angle grinder, so I had to resort to both raising the rear and adding a few clicks of stiffening. I think I had to add a full 3/4" to the rear driver to give the tire a prayer of staying off the fender, and about a half inch to the passenger side.
I ghetto fixed the steering shaft with about a dozen zipties. Not pretty but they held.
Didn't make another pass before lunch due to making repairs and checking anything else that might be falling apart. I told myself if the rain held off, the course would be faster then and I would go again. If it rained, that was that, and I would be happy with the time that I had.
The rain held off, and the sun actually came out. The course would be as dry as it was gonna get, so I geared up for another run, put my head down, and told myself to just NOT LIFT in some corners to see if I could take a stab at the overall course record, set last year at a 112.6.
Unfortunately, it didn't occur to me in the moment that raising the rear of the car such a considerable amount would have a.... drastic effect on handling. So combine a now suddenly VERY loose rear with me pushing, trying to stay flat on bumps that I had been lifting slightly for, results in... this:
Car was perfectly fine, only two wheels went off into the dirt and didn't sustain any splitter damage. It spun so hard I lost enough oil pressure that the ECU kicked in safies and shut it down, so I had to cycle power to get it moving again. I was a little shaken up, but realized quickly why it just kept rotating on me. I knew at that point I wasn't going faster. I did one more run to just hop back on the horse that bucked me, but only did a 115.something, having to keep a heavy hand on the rear the entire run up. My 113.98 would be my fastest run of the weekend, set on a course that was only 85% dry and still had time to grab.
The rain held off for the rest of the day and the competition got faster. A Goblin kitcar(1500lb, 400whp) was first to pass me with a 112.3, then Mr **** you fast Camaro broke the course record twice, first with a 112.5, then a smashing 111.1, which is nothing short of insane for anyone, much less a first timer with no experience on the hill.
The Canadians in the Datsun opted to start back for home early, so I held on to my P3 overall/P2 in class. Got some hardware at least.
Then packed it up for the three and a half hour drive home.
Really, I can't complain. I ran 7 seconds faster than my PB last year thanks to A7's and a K24, but that taste of P1 overall I had for 85% of the weekend was really nice, and I was mega bummed when I lost it. I take solace in the fact that both cars that beat me were more tube then car, and made more than double my horsepower each.
Still, there's always next year, and I did break the record of the fastest Miata ever up the hill(was a 117.2). But dang. I really wanted that P1. I think a high 112 is doable as the car sits, but after that I already need more power to compete for top dog, and **** me the G25's are pricey. This car really could use turbo noises though. Well, that and suspension that can actually keep up with the bumps. Maybe it's time to actually see if anyone's foolish enough to entertain a sponsorship of some sort.
The broken steering mount was properly fixed. It was not a primary, weight and load supporting mount that broke, but the one that holds the torque of the motor and prevents rotation. I think I tried to save weight in the wrong areas here, making it out of aluminum.
Out with the old broken aluminum bracket
In with a new, thick steel bracket, along with a new brake switch so my brake lights work. Was flicking my running lights on to substitute for brake lights on the drive home.
Added my most recent plaque to the wall. Not pictured, my third place in CSP mug from my first Dragon Hillclimb in 2018. That I followed up with another 3rd place in SU for 2020, and now we seem to be on a second place streak.
Fenders really did a number on my tires. I think the tires will be fine for future use, but definitely need to address this. Anyone have suggestions for rear flares? I'm sure as hell not buying $1000 overfenders, or $500 fiberglass flares that are going to crack as soon as some track slag hits them, but the best option looks like cheapo $100 ebay flares.
Congratulations - great result, well done! Savour that lead feeling, it doesn't come often to most of us, if ever!
Back in the day I competed in my first ever competitive motorsport event, a dirt motokana that was no less than a round of the State Championship, in my bog standard Fiat 500. I actually led the field for most of the first test, but in my case I was never going to hold that lead because the really quick cars, many 'specials', were last to run. Sure enough, as soon as they ran, I was shuffled well down, and I helped that process with a WD or two. But that hour or so at the top of the times lit a competitive fire that 50+ years later still burns ...
I am looking forward to your future exploits!
BTW - what were you doing with your right hand? That looks like a distraction you could do without going up there - half a second there at least!
Congrats, man. I was watching the times all weekend and your runs were crazy fast. For those who have never run the Dragon, mid 120's is uncomfortably quick for the average person. Sub 120's is big cajones territory. Quicker than that is mind blowing, keeping in mind that the course record was originally held by a pro driver in a factory Porsche cup car on slicks and tire warmers, and that was a 117-something...
BTW - what were you doing with your right hand? That looks like a distraction you could do without going up there - half a second there at least!
The course is very bumpy. Helmet smacks the seat wings and bounces up on my head, so I'm pulling the chin bit down. Honestly don't even notice doing it, so I don't think it's slowing me down.
Originally Posted by sixshooter
I enjoyed the story and really like your livery on the car.
Thank you. Its actually spraypaint, but it passes the 50/50 rule. 50ft at 50mph.
Originally Posted by Supe
Congrats, man. I was watching the times all weekend and your runs were crazy fast. For those who have never run the Dragon, mid 120's is uncomfortably quick for the average person. Sub 120's is big cajones territory. Quicker than that is mind blowing, keeping in mind that the course record was originally held by a pro driver in a factory Porsche cup car on slicks and tire warmers, and that was a 117-something...
114.something was the overall record set by that Porshe up till Mark smashed it last year with his 112.6. Which was then beaten by Cody this year with his blistering 111.1.
Anyone have suggestions for rear flares? I'm sure as hell not buying $1000 overfenders, or $500 fiberglass flares that are going to crack as soon as some track slag hits them, but the best option looks like cheapo $100 ebay flares.
You're in a pickle.
Any investment in flares means cutting the quarters out.
Once you cut the quarters you have no reason to stay on the narrow compromise-for-fitment 9.5" wheels.
As soon as you commit to the proper wheel for the current tire, you realize you have room for more tire since you cut the rear quarters out.
You should probably just do drop spindles, 18x11s and new full length dampers, you know.. "while you're in there"
You're in a pickle.
Any investment in flares means cutting the quarters out.
Once you cut the quarters you have no reason to stay on the narrow compromise-for-fitment 9.5" wheels.
As soon as you commit to the proper wheel for the current tire, you realize you have room for more tire since you cut the rear quarters out.
You should probably just do drop spindles, 18x11s and new full length dampers, you know.. "while you're in there"
I'll admit, you had me till 18x11's.
The 9.5" wheel wasn't a compromise on fitment. Cutting up the car wasn't hasn't ever really been a concern. The 9.5's just allowed me a wider range of tire fitment(fitting on the wheel, not fitting to the chassis), anything from a 245 Hoosier to a 245 street tire would fit near ideal, and a 225 street tire could fit if for some reason I wanted to run those. More fitment options on the wheels means I need fewer sets of wheels, which means lower costs sunk into wheels.
Drop spindles... man those would be nice. As well as more suspension travel and xidas. I could REALLY do with that in some places. But thats all high dollar stuff that's really out of the budget currently.
114.something was the overall record set by that Porshe up till Mark smashed it last year with his 112.6. Which was then beaten by Cody this year with his blistering 111.1.
You're right. I think I was thinking of Jeremy's old SU record in the EVO. Either way, you and everyone else were absolutely flying. It's crazy how far the times have come for the top 25. Seems like yesterday that sub-130 runs were on the Saturday leader board.
Yes, the level of competition has grown rapidly in just the last two years. I remember my first year of running the overall winning run was a 118.1. The former overall record stood for almost a decade, and now its been broken 4 times in two years. This year, nine drivers ran times faster than the entire field of 2019.
So yes. The sport is growing, and attracting faster cars and drivers for sure, which is definitely a good thing. But also means you can't waltz in with a stockish car on stickers and dominate the field anymore.
Slice and dice time. No more fears for cutting tires on fenders, and now I can lower the rear to something reasonable ride height wise.
This is the clearance I did have for 245 hoosiers... basically about the same as negative valve lash. This was at about .5" of suspension travel from static ride height.
Big ugly cuts.
Maximum suspension travel achieved.
And mostly painted to match. Need to track down some Laguna Blue in a spraycan, but this will do for the moment.
Can't wait for some hardparking stanceboi to tell me that my fitment is garbage
Flag Rock Hillclimb in Norton, VA is next weekend. 15 turn course looks to be a mix of mid speed sweepers and low speed horseshoes. Definitely not as favorable a course for Miatas as Dragon is, but certainly looks like a fun one. I think the saving grace here should be that the tight horseshoes are generally grouped together, so there should be space to regain and carry speed before the next set. Compared to Pine, where the horseshoes are both nearly vertical(forget about corner exit traction, it's a one tire fire in RWD cars) and spaced perfectly to kill momentum just as you regain it. Fresh course for everyone, so no records to break, or benchmarks to hit. I'm sure there's going to be a target on my back after demolishing expectations at the last hillclimb, but I think I'll be lucky to pull a podium here.
Last edited by Wingman703; 08-21-2022 at 03:10 PM.
07-04-2022, 03:40 PM
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