So you want to Turbocharge your miata?
Lets say you bought or own a Miata, or maybe even are looking at getting one. You like the car, it runs well, and you've performed all the necessary maintenance to ensure the car is in good mechanical condition(at least I hope you have), but you wish you had more power? Welcome to the club!
Turbocharging a Miata is not overly complicated if you are hands on and do your research ahead of time, but its not all just about slapping that snail on and choochooing across town in a jiffy. You need to take multiple things into account! So let's set a 200+whp power goal as an example and start with that. 200whp is a good achievable number and a great power level for a Miata!
Phase I: The Car
Whether you have a stock 1.6 90-93 car or are starting with a 1.8 1994-2005 car, your engine is capable of making this, or more without internal modification(Up to around 230whp safely), but what about the rest of the car? You will at least need a 1.8 style 1994-2005 differential which are considerably stronger than the glass 1.6 diff, and preferably a torsen, so get a car equipped with one or if you have an older car then swap it. Differential swaps are common because it is not always easy to find a good car equipped with one for sale. Click here for a how to video, it is not a difficult undertaking just time consuming and a little heavy.
So now your differential is good for the power, now what about your clutch? The factory clutch is not going to hold up to 200whp for very long(Maybe not even one good pull through the gears!) before turning into dust, so you better upgrade that ahead of time too! ACT, Flyin Miata, 949 Racing/SuperMiata, Clutchmasters, and Exedy all offer good options to replace your clutch, and while your in there a lightweight flywheel is a great idea as well. Click Here for a detailed how to video on replacing your clutch.
Now those items are addressed, if you're making double the factory power, you're going to need better brakes! If you aren't tracking the car or driving very hard you can just go with upgraded pads, lines and fluid for a more affordable upgrade. If you're pretty serious about driving and really push the car you may want to invest in a Big Brake Kit, or budget big brakes from a newer car. Click here to see our video on the budget big brake option for installing NB sport brakes with upgrades pads, brake lines, and fluid onto a 1992 Miata. Wow what a difference those made!
Next you have suspension to consider. It is not required, but the whole point of a Miata is to handle well. Also with more power, and more brakes behind the car upgraded suspension will help keep it all under control and easier to manage. Coilovers, Sway Bars, and also Chassis Stiffening are all great Mods that Miata's respond well to!
Last but certainly not least, Tires. Tires are the ONLY thing on your car that are actually in contact with the road, definitely give consideration picking out decent set of tires for your driving conditions and driving style! There is a lot to choose from and many reasons to choose different tires for different purposes, do your research!
Now that all those things have been considered in the plans of the car to be boosted, lets get on with what you actually need to turbocharge your Miata!
Phase II: Planning The Turbo Kit
Here is a list with each item and a desription -
- Aftermarket ECU, Megasquirt or the like, so that you can control fuel and timing and be able to actually tune the car.
- Wideband O2 Sensor & Air Temp Sensor, will work with the ECU you install for tuning properly so you don't blow up your build.
- Turbo, manifold, downpipe, and probably 2.5"+ exhaust behind that all matched up with the right style of flanges etc.
- Intercooler & intake piping, gotta cool all that hot air off before going into the engine, this is a must.
- Blow off valve, optional but most people do and it helps reduce spool time when shifting gears.
- Fuel pump & Fuel injectors. If you're only going for 200whp or less, you can keep the stock pump and just go with bigger injectors, but a bigger pump is not a bad idea, and is pretty much required if your going to 220whp and beyond.
- Boost gauge, don't you wanna see how much choo choo dust your snail is making?
- Oil feed and return lines & fittings for the turbo. 1.6(and 94-95 1.8's) cars have an easy to access spot on the right side of the block for a feed line, Later 1.8 cars will need either a T-fitting to go from the oil pressure sender port on the left side of the block, or a sandwich plate from the oil filter base.
- Water Hoses & fittings to cool the turbo, if you have a watercooled turbo.
I probably forgot something, but for the most part that is what you will need and it should give you a good idea!
You can buy a kit pre-made from Flyin' Miata, Fab9, mkturbo, or bell engineering, they all make high quality kits that include everything you need, but you have to be willing to pay extra for that luxury. So I'll tell you the route I took.
I bought the Flyin Miata turbo manifold & downpipe and sourced the rest of the parts myself, a few things used but in good condition, waited for sales on parts, shopped around for what I wanted etc etc. I have a Garret 2560R Turbo with an upgraded compressor wheel, Innovate Wideband O2 sensor, Injector Dynamics ID1000's, a Deatschwerks DW300 fuel pump, Megasquirt 3x Ecu, CXRacing Intercooler and Silicone Intakes piping, thats all the notable stuff. Total cost on my turbo setup was about $2800 including everything on this list, and that easily got me to 232whp/232ftlbs. A similar quality kit and setup from Flyin Miata to make the same power would have cost me closer to $5,000 for everything I needed, so I consider what I did to be somewhat of a budget build in that aspect.
I am also aware that it has been done much cheaper than that, and its possible if your willing to sacrifice in a few areas, so lets talk real quick about other ways you can save money but still get boosted and beat the average Miata at the drag strip!
Lower Boost Budget Options
If you set a lower power goal, you might be able to get away with driving on the stock clutch for a while, and also have less of a need to get a serious brake upgrade. 1.6 differentials also have a better chance of survival below 180whp or so. For cheaper options in your turbo build itself, a Cast Iron log style turbo manifold off of ebay is a cheap choice that is strong enough to last, and even some of the chinese turbo's on CXRacing's website have been proven to hold up pretty good as well. Stay away from the cheap, shiny, tubular exhaust manifolds for sale there and on Ebay though. They are known to crack somewhat easily and are not of good quality, if your on a budget stick with the cast iron log, it'll allow more power than the stock block can handle anyway. If you claim to be on a budget but still don't want to pony up the money for a Megasquirt or other ECU, you can use a rising rate Fuel Pressure Regulator to handle fuel for a low boost build as well, but don't do this unless you plan to only run 5-6psi of boost. There also are Boost Timing boxes on the used market from the past as well, but personally I would recommend against these and the FPR, you will end up spending almost as much or more than if you just built your own Megasquirt, so why not!? If your willing to learn go to DIY Auto Tune's website and you can find instructions there, a steady hand and patience is all you need to save a good amount of money vs buying a new one!
Well I think that pretty much covers it, at least what my simple brain can muster for now! I hope this answered some questions and gave you insight on what you will be looking at if you choose to do this! Miata's are a great choice for a fun project car and are easy to work and learn on. Feel free to message me on our facebook page or Instagram and I will get back to you if I can, and keep an eye on our youtube channel, we've got 2 miata's we are building so there will be lots of content and info posted about all of this there as well!
- Jesse S. of GearHeads