The No Kits Budget Build
 

So you may know me from my Megasquirt series, and Tuning series, and Miata Boyz 6: Hard up (I was young and needed the money), but I'm finally doing a build thread and series for a turbo on my 1994 NA 1.8.

This has been a long time in the making, I started buying turbo parts about a week after buying this Miata. I spent hours researching on this site and elsewhere on the dark web putting together my perfect and hopefully still budget build. If I had any sanity I would have bought a kit from MKTurbo and called it a day, but I really wanted to go through the entire process myself. I've put up a number of videos so far on YouTube documenting my progress. I got started for real a few weeks ago and it's been slow going due to the time I have available to wrench, seems like only a few hours a week. But now the end is in sight so I figured it was time to start posting some stuff.

So on youtube my series is called "no kits" because unlike most turbo miata vids it's from scratch with a lot of fab work. And also different from popular ones like Greg Peter's Broke and Boosted, I wanted to do one that was reasonably cheap but with fully real parts -- no skimping on the ECU, etc.

Here's what makes it "budget":

The ECU is built from the kit via trubokitty.com's guide. - $550
The turbo is a used SR20 Garrett -- $50
Ebay manifold - $110
I will weld the downpipe and exhaust -- $mmffermdfmf
Ebay intercooler/piping -- $200
Cheap coolant reroute (more info later) - $20
Build all my own AN lines - $100
DIY Toyota COPs - $90

However I have some areas without corners cut:
FF 640cc injectors
Deatsworks DW200 fuel pump (needed a new pump anyway)
Decent hose for the water and oil lines
Heat management
Turbosmart Kompact BOV

So on to the videos! These are meant for a wider audience so a lot of this is old hat to you guys. Help me out with some feedback or corrections or anything else you'd like to share, I'd really appreciate it.











Thanks for checking it out!

I'm disapointed. This "No Kits" build has "The ECU is built from the KIT" as the very first item. 0/10 no expectations. Jk, I glad to see another clean turbo miata in Houston. I've been running a Bosch bov for about 4 months with great success. It's a bit loud if you vta but I wouldn't consider it ricer loud. You'll save a small bit of money without sacraficing anything.

https://www.ebay.com/itm/Bosch-Blow-...kAAOSwkClcaeZ~

Bosch blow off valve crew checking in. 22 PSI with no leaks.

Aw man, busting my balls for soldering a megasquirt? OK I'll design my own ECU for next time. :) But thanks for that info on the Bosch, looks good.

More cats than posts? Impressive...

Just about to start on a build with nearly the exact same parts and goals, so this is a huge help! As a beginner to turbo systems, ill watch it all and let you know if there's anything that would have confused me a few months ago when I first started researching. So far looks like a quality series and gives a great basis for anyone to start researching off of.

Thanks, much appreciated. Yeah I think this basic plan is also pretty flexible, a number of turbos can be swapped out for the sr20det, either initially or later as funds allow. Eventually I may swap to a true gt2560 ball bearing.

Added episode 6 above in Post #1 for the coolant reroute. This one is a bit different -- I don't use any kits, just a couple of cheap hoses and a pipe. This is mostly the Miata Mike method where you swap the front and rear housings, put the thermostat in the back and pipe the flow around to the upper radiator -- deleting the original upper rad hose in the process.

Only parts purchased were two 1.25 hoses with a good shape, a 12 inch 1.25 steel pipe, and some gasket maker. About $30 which is better than $250-300 for a full nice reroute kit from a major mfg.

The main issue with reusing the front housing is the angle is up mostly. This is needed to use the existing port for the temp sensor but will interfere with the coil pack. You can modify a corner of the stock coils or else plan to go COP and then you'll be all set.

Oh my god, it's killing me how long this is taking -- i probably only have 20 hours into the build right now but the car has been on jackstands for a couple of months now because I have no time to work on it! Arrrggg!

Only things remaining now:

Weld up my downpipe and connect to the rest of the exhaust. I have an sr20 5 bolt flange for this and a v-band flange for the other end. I'm doing 3" so it will be tight. Hopefully I won't have to notch the rear of the shelf to make it fit. I've bent the water hardline out of the way a bit. For now I'll connect it to the 2" exhaust that's already there -- not ideal but I want to drive the thing a bit before doing the rest in 3 inch. I'll need to decide on a muffler. I'm looking at the mt.net approved magnaflow but that thing is so giant -- I'm not sure.

I need to put in a check valve for the PCV line. I need to make a bracket for the waste-gate actuator. Actually buy the colder spark plugs, lol. Put some 93 octane in there....

I have a turbo blanket but need some shielding for the manifold and downpipe.

I have the hoses but need to tee in the lines for the BOV and wastegate.

I'm probably forgetting some stuff.

So downpipe fabrication is a challenge if you have little experience. The 5 bolt flange is at an offset position relative to the vertical and also the pipe needs to be turned about 15 degrees from vertical to dodge the steering column. In this episode I go through some trial and error with a couple of different radius mandrel bends.

I also wanted to cover some safety issues for the pcv system when going turbo.

New episode video posted above in #1.

It's alive!!! Got the turbo build finished this weekend. No oil leaks and only one coolant leak, a split line I was reusing as part of my diy reroute. The flange on my eBay used sr20 turbo is not perfect and has some noticeable exhaust leaks. But it's not affecting anything that I can tell except maybe a bit of spool. Honestly I'm happy it's not smoking like crazy. I didn't rebuild it, just partially disassembled and cleaned it.

Did a little street tuning and it's doing great, spools up to my fuel cut setting at about 4 psi because I lack the will of the warrior. But I'm really happy with it!

I plan to go to about 12 psi eventually.

Congrats!

Really enjoyed your MS-Videos on YT.

Show us some pulls, when it's up to 12psi :likecat:

Maybe dont build your own AN lines, i built my own AN lines for my "budget" dumpster fire 1.6 build, and had a fire due to an AN line i made not being crimped well enough. its slightly more expensive to order some custom ones and the peace of mind is worth it IMO.

a crimped AN ferrule requires very specific equipment. Standard screw together typ AN fittings are pretty easy. use name brand.

Awesome videos! Really enjoyed it.
If you need anything let us know and we can get you a nice discount.

Really glad for the MS videos. Those are bookmarked so I can reference them when I'm ready for one of my own!

I used a combination of Jegs branded stuff plus Russell fittings and they've all been working so far. No leaks on any of the home-made lines. The one that split was an original (rubber) hose that I cut to connect the turbo outlet to the heater core inlet. That part seems to be working actually! I wasn't sure if that part of my reroute was going to work, but it seems to be flowing fine and the heater is blowing very hot, like normal.

I'm going to do a video later on the overall build cost, but mt.net folks get the early access -- I'm at $2329 for my build, not including the COPs (+$90 for DIY Toyota COPs).

It includes the following:
Garrett 2554 turbo (sr20 - used)
ebay manifold
custom exhaust piping - 3" down pipe
custom AN oil and water lines + fittings to turbo and block
MS3X - from kit plus IAT and custom PNP harness
FF 640 injectors
DW200 fuel pump
Spartan 2 wideband (sensor and controller)
GM flex fuel sensor
misc wiring
copper nuts
studs for manifold and turbo flange
weldable 5-bolt flange
ebay intercooler
Flyin Miata hot side IC piping
custom 2.5 cold side IC piping
Turbosmart Kompact Blowoff valve, misc fittings
Hose and piping for DIY coolant reroute
Speedhut AFR gauge
Speedhut Boost gauge

I have enough of the 3" exhaust piping left over to build it all the way out. But so far I've just linked it up to the 2" mid pipe for now. Still spools reasonably decent actually. I have not picked out a new muffler yet and the cost of that is not included in the price above.

Some spool data, reasonably happy with this given the 3" down pipe that goes to 2" at the mid pipe. Exhaust has a cat, resonator, and muffler. All those are 2".

rpm kpa
1600 111
2000 114
2300 120
2600 126
2900 132
3200 138
3300 140.6 fuel cut

Rolled into it in fourth gear.

Start pulls at 2k. That's how everyone here does it so it'll be easier to compare. 140 is what... 6 psi?

Yes...wastegate is 7.5 psi I think based on the model number. I'm staying low until I can verify my waste-gate actuator is working. Also I need to put some 93 octane in there and change the plugs. I was happy it started getting boost pretty low in the rev range, that was a design goal.

Also I'm trying to decide what to use for the boost control -- mechanical or electronic.