MattPasta

SO my 1.8l 1994 miata is about to have some $$ spent on her. Ive got a tap in the top end as of last week so I've decided this is going to be the perfect time to force some power into my cylinders.
This is going to be my build thread and any advice/help you guys can offer would be awesome as I'm new to the turbo scene.
I have built a few cars back home including my N/A Alfa Romeo 75 (milano) from the bottom end to the exhaust tip, so I like to think I'm pretty savvy as far as engines etc go, that being said I have never owned an F/I car! I have decided that a bolt on kit from FM or otherwise is too convenient for my liking, however a 100% fabbed build may be a little ambitious so I'm planning to go 50/50 and piece together my own bold on kit.
So here's the plan, blank fields are tbc and I'm planning to use this thread as a checklist recipe for my build.

Forged Internals

Pistons -
Rods -
Crankshaft -
Complete gasket overhaul -
*My miata has over 200k on the clock so a turbo without a rebuild is honestly a bad idea. That being said why not put some tougher bits in while im at it?! I haven't looked into forged parts in great detail further than the FM page here so some suggestions would be great.


Turbo Kit

Manifold - eBay ( jk im going for an FM prefabbed manifold for sure )
Turbo -
O2 Wideband - Thinking a GFB
Piping -
IC - Here is where im planning to save some money and go for a cheaper option, possibly an ebay kit, pretty hard to mess up this bit right?
Exhaust - Planning to go somewhere local for a custom fab with a varex muffler here.
Oil feed/return - Braided lines
Injectors - Around 1000cc
Fuel pump -
ECU - Megasquirt
Clutch - FM happy meal seems to be the best option here, possibly stage 2 depending on how much power i'll roughly be making?
Wastegate -
Vairiable boost controler - GFB

Misc mods.
These will mostly be done after the engine overhaul and turbo, as asides the engine the car is in great condition.
Break upgrade, full brace kit, bigger wheels, coilies probably set to near stock height and i really need a new steering wheel!


Being my first turbo build I've probably left out a bunch of important stuff so any help on where the best place to source parts from, what to avoid (other than craigslist and ebay) and general bits and bobs as well!
Im looking for around the 300bhp mark, and ideally the boost would kick in around 3.5 - 4.5k. Ive heard that building your own kit is cheaper than the bold on kits available (also way more fun) but im still open to kits if they are the cheaper option!
Looking to spend around $2-$3k on the forged rebuild and about the same for the turbo kit, is this a realistic estimate? Bearing in mind I plan to do nearly all the work myself.
Thanks for help here, I cant wait to get started!

ThunderKunt

read this thread https://www.miataturbo.net/diy-turbo...big-post-4288/

Chilicharger665

iTrader: (2)

You need to do lots of searching and make a decision on how much power you want. If you plan on doing a mostly FM kit, then decide what turbo you want. If you plan on rebuilding the engine, then you can get a bigger turbo, such a 2860 and above. You don't need a crankshaft at any miata power level. The rods will go first at roughly 250 wtq, followed by pistons at roughly 300. Look into the FAB9 intercooler kit for a reasonably priced one that fits right in. It is way cheaper than the FM one, for instance.

MattPasta

Thanks for the replies.
What kind of tolerances does the big end have bearing in mind its a 200k engine? Should anything else in the engine be uprated, such as valves and cams?

sixshooter

iTrader: (12)

Your noise in the engine is likely a stuck or collapsed lifter. It is common on our engines if they sit awhile or have been using old oil. It is very loud but will go away if you use some Shell Rotella T6 Synthetic oil for awhile. There are 300k+ mile boosted Miatas on this forum, so don't assume you need to go with a rebuild yet unless you want to. Do a compression test to determine engine health.

If you decide to build the engine, 949 Racing has good forged rods for a reasonable price. And good pistons. And pretty much everything else.

If you want to save money, the ebay intercoolers and piping are great. Many of us are using chinachargers from ebay as well. Avoid their exhaust manifolds like the plague, though. For manifolds I recommend either having one fabricated from Absurdflow or Artech or someone like that. If you are looking for less expensive options, watch for a used one to come up for sale here, and possibly have a downpipe made locally to fit with it (you may need to buy an outlet flange to make it easier for them).

MS Labs (a vendor here) or Braineak (site admin here) can build a good MegaSquirt for you. Or you can go to DIY Autotune for a MSPNP. They sell widebands there as well.

Good luck.