I don't think you'll actually get any coolant flow at all using those 2 ports that you made once the thermostat is open. Why not just use the same solution that everyone else uses and use the hose barb that was already there as supply and the barb on the mixing manifold as return. That would've been much easier, and is proven to work great.

Also, why go through all thee trouble to remove the pan and and weld a hose nipple on? Why not an Npt bung or a male AN fitting as a second best solution? Seems like a lot of effort to just put in a braided AN line.

What is a ZMDET motor? I'm intrigued.


Interesting choice on the CT26 turbo. I run one on my daily driver, but i can't imagine response to be anything but "lazy" on a BP. Will subscribe to see how this turns out.

SOVIET the turbo inlet and outlet of coolant have a heigh differential to help coolant recirculation on shutdown but i really think that coolant helps cooling the center section when the engine is running so cooling the center section will in fact put less heat into the oil and will remove the need for a better oil cooler than the factory one.(BTW nice build with the EFR, I've seen your dyno with the 6258 and it look very nice but keep reading my tread and i promise you will be surprised with the dynosheet i have)

BARON340, There is a flow of coolant in the lines even when the thermostat is open because even after a couple pulls on the dyno i was able to touch the turbo center section with my bare hands witch is totally impossible on my oil cooled s256 on my supra or my s256 on my protege. As for the oil return fiting in the pan i did that way because i needed to remove the pan to drill the hole anyway and it was easier for me to turn a firing on my lathe and then weld it with the tig :)

CONCEALER404, a ZMDE is the 1.6L engine from 3rd gen protege, the T is because i turboed it. And i can say that the turbo don't feal lazy at all on the car, not more than when it was on the supra...but the fact that the miata always rev higher than the supra helps too ;)

now that every mods are done to the block to accept the turbo, there is one more thing i have done before putting the block back in the car.

Intercooler intallation:

I had to cut the bottom of the plastic bumper in order to make the intercooler fit in the bumper.
https://www.miataturbo.net/attachmen...ine=1385599576https://www.miataturbo.net/attachmen...ine=1385599576

here's another shot with the bumper installed.
It fit right there
https://www.miataturbo.net/attachmen...ine=1385599896

after the intercooler was installed, it putted the engine back in the car and started to do the manifold for the turbo.
It's a totally custom made manifold with sch40 1.5'' mild steel pipe bends.
I tried to make the runners as short as possible for response while still having a really smooth transition into the turbo. This is probably one of the parts that lead to making power all the way up to redline :)
(sorry no picture early in the manifold building process)

https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503https://www.miataturbo.net/attachmen...ine=1385600503

After that i started to rebuild the turbo and fabricated all the fittings that would go on it.

here's both turbine and compressor wheels, they were in pretty good shape considering they are more than 25 years old

https://www.miataturbo.net/attachmen...ine=1385601208

here's one in the middle of the rebuild

https://www.miataturbo.net/attachmen...ine=1385601208https://www.miataturbo.net/attachmen...ine=1385601208https://www.miataturbo.net/attachmen...ine=1385601208

here with the compressor
The compressor is powder coated anodized red over oem wheels gray
the center section and the waste gate actuator are satin black.
(yes i powder coated the actuator and putted it in the oven at 450f, at first i didn't realize that there was a diaphragm in there until it was already cooking, so let it cook and thankfully the was no damage to the diaphragm)

https://www.miataturbo.net/attachmen...ine=1385601208

now it was time to build the fittings.
One strange thing about the CT26 is that the oil feed and return are both located under the housing one beside the other

https://www.miataturbo.net/attachmen...ine=1385601653https://www.miataturbo.net/attachmen...ine=1385601653https://www.miataturbo.net/attachmen...ine=1385601653https://www.miataturbo.net/attachmen...ine=1385601653https://www.miataturbo.net/attachmen...ine=1385601653

this one is for the coolant fittings the were made the same way as the above fitting, i mean a steel tube was welded on the center. I have no pics of it finished tough..
Also both coolant and oil fittings were powder coated satin black for a sleek look and to prevent corrosion

https://www.miataturbo.net/attachmen...ine=1385601653

After that it was time for final installation of the turbo !!!!
As you have previously seen the manifold is a top mount. I did it that way for two reasons, first is that the ct26 has really big turbine and compressor housing for it's size and second, it has a better look when you open the hood and what you see is the turbo up top beside the valve cover!!

Here is the turbo installed with the intake pipe and the bracket i made to hold the MAF in place since i had to keep it with the FIC

https://www.miataturbo.net/attachmen...ine=1385680755

Heres the intake pipe and bracket powder coated gloss black for a more sleeper look

https://www.miataturbo.net/attachmen...ine=1385680755

after that i made the intercooler piping, sorry not a lot of picture of that but here is the final result, powder coated gloss black to make it clean but not to visible.

https://www.miataturbo.net/attachmen...ine=1385680755

Extra pics, it is possible to see the diverter valve recirculating hose in the intake pipe.

https://www.miataturbo.net/attachmen...ine=1385680755https://www.miataturbo.net/attachmen...ine=1385680755https://www.miataturbo.net/attachmen...ine=1385680755

With the turbo in place i started building the down pipe and all i can say is that it was a tight fit with my manifold....

but before doing the down pipe i installed a brace for the turbo to support it. I don't like the idea of having all the weight from the manifold, turbo, down pipe and exhaust only on the flange of the manifold. I think this brace will give a lot more resistance to manifold cracking or exhaust gasket failure.

https://www.miataturbo.net/attachmen...ine=1385682543

Building the down pipe
i tried to give the waste gate port a good flow path to prevent boost creep issue and im glad i did because event with a MBC the boost don't spike and only move by .5 Psi throughout the rev range. (from my personal experience (used it on 3 different engine at boost varying from 4 to 21 psi), internal wastegate on the ct26 is particularly good. it has a low boost on waste gate spring and boost can be turned way more than twice the base boost on a small engine like a 1.8)

https://www.miataturbo.net/attachmen...ine=1385682543https://www.miataturbo.net/attachmen...ine=1385682543https://www.miataturbo.net/attachmen...ine=1385682543


Here with the o2 bungs installed

https://www.miataturbo.net/attachmen...ine=1385682543


on the car


https://www.miataturbo.net/attachmen...ine=1385682543


finished product


https://www.miataturbo.net/attachmen...ine=1385682543


And i wrapped it fo better under hood heat control (One of my favorite pics taken by one of my friend)


https://www.miataturbo.net/attachmen...ine=1385682543

At this stage pretty much everything was done under the hood so there is only the exhaust remaining and it will be a first start.

the exhaust has a 3'' flex pipe and a vibrant resonator and tubing.. that's it

https://www.miataturbo.net/attachmen...ine=1385683094https://www.miataturbo.net/attachmen...ine=1385683094

Ready for final welding

https://www.miataturbo.net/attachmen...ine=1385683094

and finished product

https://www.miataturbo.net/attachmen...ine=1385683094

I'll try to make a video of the sound of the exhaust but thrust me it is absolutely amazing.

I hope you have heat sinks for those o2 sensors, because they're way too close to the head to last long without it.

And that turbo brace is pretty weak. Add a gusset along the vertical angle section all the way down to the 2nd bolt, if you want it to actually pretend to do something.

Forgot to mention, it is not shown on the exhaust pic but since i still use the stock ECU and the car have no cat I had to figure a way to mount the second o2 so the signal simulate the stock cat. so i used a 90 degree o2 extension and still no cell to this day (1 month later)

Now that all was done it was time for a first start!!!

This is the fun part of using the FIC, it start absolutely like stock because it is still the stock ECU. NO idle to tune, no cold start nothing.
the only thing i had to do is change my injector size in the software from 265 to 550cc and voila, the fuel table was generated and the car started right up like if it was stock.

here is the air fuel ratio 20 sec after startup

https://www.miataturbo.net/attachmen...ine=1385683894


a shot of the tuning software

https://www.miataturbo.net/attachmen...ine=1385683894


Before startup i was a little worried that the accel fuel and throttle response would be screwed up because the MAF was now far away from the engine than in stock for but i was happily surprised that it was not even noticeable that the MAF had moved. The car still have that crisp throttle response of the stock VVT engine. such a nice thing :)

The next thing that surprised me the most was the fact that i could build boost from neutral just by playing with throttle up in the rev range (not in the limiter it would have been too easy). not a huge amount but around 1.5 psi witch is really interesting since it was promising in term of turbo response with the ct26. I knew this turbo would not be bad spool wise because I had already mounted it on a 95 bp engine in a protege and even with a restrictive 2,5" exhaust (had a cat and a chambered muffler) It was still able to build around 18psi at 4000-4100 (YES I BLEW THE ENGINE AT THIS BOOST LEVEL BUT IT WAS A TEST AND I WANTED TO BLEW IT, HERE WAS THE COMPRESSION RESULT OF THAT SCRAPYARD ENGINE : 110 180 90 135 SO IT WAS ON BORROWED TIME AND I WAS REVING IT TO 7800 WITH THAT BOOST LEVEL, WELL IT STILL TOOK THE BEETING FOR AROUND A MONT AND 20 DRAG RACES BEFORE THROWING A ROD WHILE ON THE LAUNCH CONTROL)

Honesly it was very very fun to beat the shit out off that engine :)

In the next post ill talk more about the response of the car on the street and ill try to find some pictures of logs to show te spool and the boost recovery between shifts

stay tuned !!

LEAFY, I know that the sensor bung is close to the turbo but the sensor going in is a narrowband witch is supposed to be a lot more tolerant to heat than a wideband sensor. The wideband was only used for tunning and is now removed from the car and the hole is capped

I don't know why, if it has something to do with my tubular manifolds i build that makes less exhaust heat ??? but the wideband on my supra is in the exact same location (6" from the turbo ) and it's been there for 50 000 km and still work just like new. And my supra is putting around 500 to the wheels so i think it produces more heat than the miata.

well we will see, if the stock o2 sensor fail in a short period of time i will relocate it on the exhaust.

As for the turbo brace, this part work in nearly pure compression or tension. The purpose of it is to form a triangle between the manifold flange , the turbo and the bottom of the block.
it has to move to accept a little movement of the turbo when the manifold heats up to prevent stressing the manifold even more.

I haven't read the entire thread, but I didn't see any mention of rods. How exactly do you plan to keep them inside the block?

He just said he blew the engine already.

No he blew up his 95 protoge engine (I went back and read again). I'm thinking it will be at least another week before he blows this one. Probably not more than 2 months I'm guessing.

I'm really surprised you're doing all this and sticking with such a crappy turbo. Genuinely surprised.