Budget Turbo Build
 

Hey guys just joined the site. I just got a 90' miata a few weeks back and am looking to add some power to it. The car did come with some turbo parts and I will be trying to use as many of those as possible to minimize cost:

Used Garrett t25 (pulled out of a Volvo)
FM BOV
CX Racing Intercooler
DIY Megasquirt (currently soldering components on the board--I still have a wase to go with that)
FM Manifold
Megan Racing downpipe (Yes I know this is crappy stuff from eBay I know im not supposed to be using, I will replace it with something better as soon as I find something)
Ebay oil line kit
Heat shielding tape from Mcmaster (for brake mc and hoses close to the turbo)
Red Top RX7 460cc injectors

I'm looking to get about 200whp with this setup. I do want to keep a/c (I live in Florida) and power steering. Have not picked out a tuner yet, but do you guys know anyone good in the central/north florida area? Anyways let me know what you guys think. I'm still a newb here so any advice you could give would be greatly appreciated. Thanks.

Ah man this guys already doing way better than me :'(

Good luck with your build!

Is the volvo t25 a standard t25 or a volvo specific one with volvo specific flanges?

Had no idea they could be different..ill have to take some measurements to verify its a t25 and not a td04. The hole pattern and sizing appear to match that of a t25 flange. The 3 bolt pattern on the compressor housing matches that of the downpipe so at least that side should be a non issue.

The craigslist ad I purchased the car from is still up with pictures of the turbo and associated parts: 1990 Mazda Miata

The bolt pattern discussed is between the turbine and the FM manifold. No photos of it in the ad. The volvo t3s did have a unique turbine-to-manifold flange.

Got my brother to take some pics (turbo is in jacksonville im in orlando). Should be attached.

Can anyone confirm whether this is a t2 or t3 flange? Believe it is a t3.

Looks like t3.

Take measurements, my friend.

https://www.miataturbo.net/useful-sa...flanges-52542/

^:werd: looks t3 size to me

Yeah I verified that it is t3..and there is some shaft play though not enough to make me throw it out. Would just get a t3 to t25 adapter flange to fit it to the fm manifold I'm planning on running, but then that would require me to purchase additional studs etc (im planning on getting inconels for durability but they are expensive). Not to mention adding in an adapter plate increases the potential for exhaust leaks which is something I don't want to deal with. And the t3 flange on the volvo isn't standard because it has a conical surface that isn't flat and requires a special mating surface that is not standard t3 so I would have to adapt that.

I'm thinking about switching over to a dsm turbo. Convinced this guy to sell his td05h for 100 bucks: eclipse turbo. Im forseeing fewer headaches going this route..

I have heard that td05 will bolt up to a t25 manifold no problem. Anyone out there with experience that can confirm that? If thats not the case would it be easy to adapt it to t25?

Once again, your answers are HERE---> https://www.miataturbo.net/useful-sa...flanges-52542/

If that one has shaft play, sell it or whatever and get an s13 T25 from Zilvia for $100. They practically give those things away.

I found a used dsm td05-12a for 80 bucks so Im gonna go that route. Took a look at the flange dimensions link and I think I'll be able to get away with drilling some holes on the td05 flange to deal with the td05/t25 flange mismatch issue.

Did find an sr20 turbo for 150. That was about the lowest I could find...dsms have been going for way cheaper so far. Almost got a td05-20b evo turbo for 150 with a fmic and piping. That would have been way to big for my power goals though.

so you're gonna hack and splice things together that don't belong together because of a 70 dollar price difference? ughhhhhhh

Ok I've settled on another sr20 turbo for 125. This has a t25 flange so it should work well with the fm manifold I plan to purchase.

If you not on a rush keep checking weekly on zilvia. I got one with absolutely no shaft play for $70 shipped. and another for $90.

Also can you post a link to the megan racing downpipe and are you 100% sure it will line up with the FM manifold and mate with oem exhaust flange perfectly?

Ended up getting the sr20 turbo for 125. Considered waiting and getting something on zilvia, but I wanted to get something local that I could look at and check the shaft play on. Didn't want to get burnt on something that got shipped but turned out to be junk when it arrived.

The exhaust side of the turbine is different and will not bolt up the megan racing downpipe (6 bolt connection on the turbo side vs. 3 bolt connection on the downpipe side). This was also the case with the dsm turbos i looked at (5 bolt) so I knew I wouldn't be able to get it to bolt up directly. They do sell 6 bolt to v-band adapters that will bolt up to the sr20 and I plan on going this route as I cannot for whatever reason find a 6 bolt to 3 bolt adapter flange that will bolt up directly to the megan racing downpipe. Was considering getting another downpipe, but the only inexpensive replacement I can find that will fit a Miata is an OBX with a 5 bolt connection to turbine exhaust. The are no cheaper downpipes with 6 bolt connections that I could find. This means I have to:

1) Adapt the megan racing downpipe to fit a v-band flange setup.
2) Spend $$ for a decent downpipe

I have not purchased a manifold yet, but I believe the turbo will bolt up as it is a t25 (yes I did take measurments to confirm) and the fm manifold is advertised as having a t2 flange.

The biggest concern I have is fitting the intercooler. I've been basing my plan on this thread: https://www.miataturbo.net/diy-turbo...r-ac-ps-60009/. I do plan to get rid of the maf and use both a iat and maf in replacement so this should free up some room on the turbo side.