Chrissmith said:I'd say it totally worth it.
I think so too!
Chrissmith said:I'd say it totally worth it.
I think so too!
Great build! Thanks for sharing!
I went from DD'ing a 99 NB to a 13 FoST and this seems like a best of both worlds build
So we're well into 2022, I figure time for another update.
With the cooling problems solved, and the aero package getting sorted (see page 3), and upgraded shock package (thank you Whitener racing), the car has been a lot of fun. I've been working my way up the learning curve of a higher HP RWD car after years of driving low HP FWD cars (thing stock motor CRX). So it's been a "learning experience"... And as I've gotten more comfortable with the car, you guessed, new...opportunities for improvement have shown themselves.
One of these was the brake system. To date the brakes have been OEM with decent pads and brake fluid. One of the last track nights at the local TNiA at a smaller course, the ambient temps were in the 90's and the brakes got pretty warm. Like melt the dust boots and the plugs on the ends of the slider holes warm...
So the first thing I did was add some brake cooling ducts. Being the frugal guy I am, I repurposed the OEM dust shields and added some exhaust tubing to hold the cooling hose. I started by adding some "oval" 3" to the dust shield at an angle trying to get as much of the air as possible pointed at the opening int eh back of the rotor that feeds the internal vents. this piece pokes through the dust shield to be withing 1/8-1/4" of the rotor surface. Once that was figured out I added a section of 3" round tube for the 3" duct hose to connect to.
I found some 3" flanged opening peaces available at Amazon Racing and after cutting a 3 1/8" hole in the air dam, riveted those in place.
After that it was just a matter of connecting the 2 with a section of 3" high temp duct. And Bob's your (or my?) uncle.
So that's what I could do with what I had on hand. The next stage will be upgrading the brake. I have a pair of Wilwood 2 piece 11" rotors that I picked up cheap a few years ago. Remember my bump steer solution (see previous discussions) involving adding a circle track "adjustable outer tie rod"? Turns out the Miata knuckle has the outer tie rod mount at an angle. As a result the extended part I am using puts the rod end just barely outside of the OEM Miata 10" rotors. This was so close that is the rod end was rotated to the limit of it's travel in one direction it would lightly rub on the OEM 10" rotor. While this wasn't perfect, it had worked so far, but would certainly not work if I wanted to use 11" rotors.
So after some thoughtful time in front of my laptop and google I found a couple posts from guys making "Locost" Lotus 7 clones. They were using Miata knuckles and also had issues related tot he angle of the tie rod mount. Their solution was to heat up the arm and tweek it into a more advantageous position. I had a couple spare kknuckles, so I thought I'd give it a shot. I don't have any in process pictures, but what I did was to wrap most of the knuckle is a water soaked towel to keep the rest of the part, well, not cool, but at least less hot. Heating the arm with a oxy/act cutting torch did the heating trick and a big adjustable wrench did the "adjusting". It didn't have to move much, and now I have room for 11" rotors!
So, that's where we are today. I have Wilwood Dynalite calipers on order (they should show up tomorrow), and at that point I can get the 11" rotors on as well!
One thing I forgot to mention was a clutch upgrade over the Winter. The first clutch I used was an ebay special/"Proof of Concept" purchase. I started out with that when I wasn't sure if everything was going to work, and didn't want to invest in a "real" clutch if I was just going to throw it all away...
Once I got to the point that I could tell everything was going to work (and realized the first clutch wouldn't even hold 4th gear without slipping) I upgraded to my second clutch, which was a Clutch Master FX350. By Fall 2021 this one was slipping if I did a "hard launch" at an autocross event, and went ahead and upgraded to a Clutch Master FX400.
After I had the 3rd clutch installed I started looking at the rest of the clutch control system (yeah, a little late, I know...). With an NB Miata clutch master cylinder and peddle assembly, driving an NC clutch master cylinder which in turn controls an aftermarket NC clutch kit, the peddle "feel" wasn't great. I replaced all the hydraulic parts, bled it a bunch, but still the engagement/disengagement was really close to the floor.
The NB Miata clutch master cylinder has a 5/8" bore. I considered a Wilwood master cylinder with a 3/4" bore, but found someone had used a 1986 Toyota Land Cruiser clutch master cylinder (also has a 3/4" bore) on a Miata with minor mods. The mounting hole "angle" is correct, but the hole spacing isn't quite right. A couple minutes spent with a rat tail file "moved" the holes enough that it bolted right up! The bigger bore moved more fluid then the OEM Miata master, so the engagement point moved higher to where it was more manageable (and it was about $30 instead of the $125 Wilwood part!).
So now the clutch seems happy. Was my problem last year really the FX350 clutch (it was rated for the power levels I had...), or was it really the combination of parts that I was using that maybe wasn't completely disengaging, was often dragging a little, and wearing/heating up? As with so many questions in the world, we may never know. I'll just be happy if the clutch stays happy going forward...
This did give me the chance to add another vehicle to the list of donors though, so there is that! Complete list as we stand today;
Good info on the larger master cylinder. Is there any adjustment in the throw-out fork or is it all just install-and-forget?
In reply to TVR Scott :
All the hydraulics are plug and play. The only adjustment is at the peddle.
I believe that the cooling duct for the brakes should go to the hub part of the disc. This allows the air to go through the vents in the rotor.
DrMikeCSI said:I believe that the cooling duct for the brakes should go to the hub part of the disc. This allows the air to go through the vents in the rotor.
The cooling ducts do direct the air as close tot he hub as it can. It's a 3" hose, and I even used "oval" 3" tubing to get more of it to the center of the rotor.
In reply to TheTick58 :
I could be wrong but those black hoses aren't rated to as high of a temperature as the orange hoses are. Just something to consider.
Another update;
I had the car on a dyno last year and it looked like the ECU pulled some boost part way through, I assumed it was due to bad gas.
I got back recently and had 3 clean pulls this time. Pretty pleased with the results (stock motor, just the FPP tune), final answer is 260hp/355tq.
I have suboptimal exhaust and intake currently (the turbo has a 3" Vband clamp, and I immediately reduce to 2 1/2"). Planning to make a full 3" exhaust over the Winter, hoping that helps a bit too.
So I am in the earlier stages of an ecoboost NA and have a couple of questions about your build.
Regarding the cooling system. I plan to mainly use focus st/mustang radiator and hoses for around the motor, and was wondering how you tackled the issue of having the coolant fill on the radiator as well as on the reservoir. my main concern is that the ecoboost uses a higher coolant pressure than the Miata.
On the stock engine harness, did you have any leftover connecters? Mine has some for egr as well as what appear to be connectors for the transmission. Did you just leave those unplugged?
Any other little things you learned along the way would be greatly appreciated. Thank you!
In reply to c_allen :
In reply to c_allen :
I used economist Mustang plumbing to bring what is now the rear hose connection to the front. I can look up the part numbers if you're interested. I ended up with a big block Fox body mustang radiator to get enough cooling. I used the cap that came with it. The highest point in the cooling system is a hard line from the Mustang, it has a fill point, so that's what I use.
I made a copy of the FRPP harness (I have the diagrams if you need them). There are a couple plugs that aren't used, they are identified in the kit instructions (I have that available as well if you need it).
What are you using for engine management?
In reply to TheTick58 :
Thanks for the reply! Engine management was going to be done with the ANT steering harness from ebay. I would definitely be interested in the instructions for the FRPP harness. I was planning on running a mishimoto radiator with the stock shroud, but after reading your post I might spring for the dual pass. Mind linking the one you used? I already have the mustang coolant pipe installed, I just have to swap the sensor for the mustang one and run some longer hose from the turbo coolant line to mate that up. Im not running a heater core, so I am just going to loop the coolant outlet from the mustang pipe to the right side of the T on the right side of the engine, and retrofit a stock focus coolant tank to the other side of the T. I appreciate the reply on such an old post!
In reply to c_allen :
Sorry, just seeing this now. If you need any help with the FPP harness, let me know. As far as the radiator goes, it was from Amazon for a Fox body mustang with a big block motor. It's not offered on Amazon anymore, so no link is available, sorry. I just did a search for the biggest thing that would fit.
The stable is getting pretty full, and I just don't have the time to properly play with this thing, so I'm putting it up for sale. If anyone is interested, let me know!
In reply to TheTick58 :
How much are you thinkin'? You're in Minnesooota, right?
In reply to rdcyclist :
Yep, Minnesota. I have it listed at $13.500.
Car is sold. New owner may continue the story here. Stay tuned.
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