BOOST NOOB tax return turbo build!
 

ok. noob to boost. not to building cars. so gonna have lots of questions and lots of research ahead of me.. a little about me and my car. im 23 and recently picked up a 94 miata. love the car. but it lacks powa! no point and trying to coax every little bit out the 1.8 while it is in n/a form as it will not satisfy me... i love working and tinkering with cars. been doing it for a while now. car i sold to buy this was a 97 cobra. not super modded but was respectable. im hearing 225ish hp will eat my old cobra up and still be a reliable dd. so im going to put that to the test :)

ok. things i know.

megasquirt. i need it. i just dont know how to tune. so thats my worry. ill get all this done and will screw up on the tune

i have a tdo5h 14b. has about 10k miles on it and i hear its a great turbo for a stock 1.8. i know its an oddball turbo and most people stick with the t3/t4 style. but i got the turbo at a good deal from a friend who is going with a 20g on his dsm.

im being told from a few friends i need a cast mani as tubular ones crack easy... i have one bud who is a professional welder and builds custom exhaust and roll cages for a living.. he says he can make a mani for it. my question is. is there a good way to brace the turbo/manifold to not crack? i dont think i can find a cast manifold for a tdo5h. and is there a certain steel and thickness that would be preferable to last longer?

intercooler. need to figure out a size that fits and has the inlet-outlet in preferred locations. not looking for a super expensive unit and im being told that the ebay coolers are actually pretty good. so if someone has a link to one known to fit that would be awesome!

rx7 injectors is what im being told i need.

things that are easy for someone who knows to explain.

do i want a higher rated waste gate spring and the boost controller will control lower pressures? or do i want a somewhat weak spring and a controller will allow it to hold more before opening.

plan is to cut corners where i can without worrying too much about reliability.

hearing i may need a restricter for the turbos oil line to save the seals?

ok. budget. tax return total came to 2100 doll hairs and i have 600 saved up. so 2700ish. bought the turbo for 100 bucks as my friend is being nice and wants to see my car turboed :p
ill be researching but anyone that can point out threads they know of that have very useful info it will be much appreciated :)

only pic of my car on my pc right now. soooo adorable :p

Welcome Trent
It's not too late to intro yourself in the noob section.
Location?
Are you going with a stock motor?
TD05 14b is a good choice.
Search "steam pipe" "weld els" for manifold parts.
Most people get the Megasquirt first so you get the car running well before boost.
Everything will take 10x longer than you think.
Cheers,
-JB

lol been on a lot of forums... forget to introduce myself on some of them. will do so in the morning as i am just checking this before bed. yes the car is bone stock down to the paper air filter. only thing i see is an aftermarket fan/radiator combo. engine wise. car has suspension work.
will do on the search thanks!

if need be i will setup the megasquirt first before installing the turbo. im buying everything up and then will go thru an installation process. guess megasquirt is first to go in :)

forgot to ask if i really need the latest and greatest megasquirt 3 or if im fine settling with an older one.

and im fine if the build takes a while. if all goes well and i like the results ill build the motor next tax return and push more boost. :)

EDIT: located in Denton TX

Start here: https://www.miataturbo.net/useful-sa...ig-post-10821/

Ah hah! Actual numbers for goals this time!

You have learned well, young padawan.


Welcome.

Diesel pointed you in the right direction.

Lots of turbo Miatas in the metroplex if you want to see examples. I'm out at MSR-Cresson frequently.

You can make do with an older MS. Heck, I run an original MSPNP (MS1 based) and it does everything I need, even AC and EBC (although I did write my own code to get the AC functionality where I wanted it). That said, each generation has better features and support than the last.

I'd say if you can find a really good deal on an older MS in known-good condition then go for it. OTW, a new one with warranty and support is the way to go.

This guy.... :p
OK cool. I'm still looking at all the mega squirt options. I might do the one you have to build. I'm very comfortable with wiring and soldering.
Will do :nice:

Welcome to the forum!

Welcome, i'd recommend getting ms2, not ms1. For some reason folks selling ms1 still expect to get the same money they paid 8 years ago... which is about 50 bucks less than what ms2 go for.

If I was going new I'd get one of Braineack's built MS's the price isn't bad considering the cost for the kit new diypnp ms3

I had similar fears about tuning, and did tons of research. I threw together a YouTube Playlist of a 10 part series that's basically a video guided tour of megasquirt, as well as a few other videos I found helpful. It's not all miata specific, but most of it is really good info.

The guy for the 10 part thing rambles a bit, but it's still pretty good stuff.

Megasquirt Tuning - YouTube

I was planning to make a new post in the megasquirt specific section with this to see if anyone else found it helpful at all.

Regarding Wastegate and Boost Controller:

A boost controller can't take your max boost below the wastegate spring pressure. So go for a low wastegate spring pressure, then use a boost controller if you want more than that.

So lets say you have a stock DSM 14B wastegate actuator that has not been messed with. That will probably crack open at about 11psi. So when the actuator gets 11 psi through that little hose, it pushes on that little arm and opens the internal wastegate on the 14B, bypassing the exhaust around the turbine wheel and keeping the turbo from making any additional boost beyond 11psi.

A boost controller (electronic or manual) can only act to restrict/reduce the pressure that that wastegate actuator "sees" such that the actual boost is higher than 11psi. So say you have that same actuator, but now the boost it sees through the little hose is routed through the boost controller. The boost controller restricts/reduces that pressure such that 14psi out of the turbo only results in 11 psi at the actuator. Now the max boost will be 14 psi. Only then will the actuator see sufficient boost pressure to move the little arm and open the internal wastegate on the 14B and bypass the exhaust gases around the turbine and keep the turbo from making higher boost.

ok. before i dish out for a megasquirt on ebay. is there someone on the forum that sell them at a good price and has a good rep? money is burning a hole in my account lol

good price?

4 750cc Injectors RX7 Civic Integra Acura All D B F H K R Series Engines ZC Vtec | eBay

DIYautotune.com is a vendor here and has been helpful. Sounds like you have a good plan. Good luck.

OK. Starting to work on a manifold. Would 1.5in piping be sufficient or should we go 1.75. Or 2

1.5" for what? for the runners?

Yes lol... Did more research and it seams miatas use 1 inch piping

750cc rx7 injectors good enough for a while? 160 a good price for the set?

meaning how much power can be made on those injectors till i would need to upgrade?

750 cc? Aftermarket?