I am posting this thread to ensure I am not making any glaring errors (I am new to Miatas and turbos).

The car is a 1994 Miata C-Package (Torsen!). I decided to build a turbo Miata because I took a ride in a friends turbo Miata. There was no turning back at that point. I actually found it on MT and flew down to TN to pick it up. The image below is after I had it for a few months and did wheels/tires and put a roll bar in it.



I am aiming for around 230hp. I want to be pretty close to the maximum without ever having to worry about breaking the transmission or other parts of the driveline. I instruct at track days with the SCCA, so it will likely see some track time, but probably just to show students the line. I do not plan on serious track use with this one.

This is the plan (items in bold are items that I have already purchased):
-MS3 with MS3X board, built using Frank Westfield's method
-DW700 injectors
-Greddy VTA BOV
-ARTech tubular short runner manifold, downpipe, and exhaust
-used SR20 turbo (disco potato) OR Garrett 2560
-eBay intercooler and piping (something like this... https://www.miataturbo.net/diy-turbo...tercool-83180/)
-FM Happy Meal

I am going to pull the engine to install all of this and clean everything up. When that happens I will also be doing things like a coolant reroute, timing belt, water pump, etc. But that isn't important for this thread.

Is there anything that I could improve? I may upgrade to ID injectors at some point down the line, but I got a good deal on the DW700s and figured it was a good starting point. I am also completely undecided on whether I should just start with the 2560 or if it would be better to start with the disco potato since I will be able to sell it for what I paid once I am ready to upgrade.

I am going to run the car for the first time on MS this week. Once I get the basics of tuning and tunerstudio down I plan to install the DW700s and get the car running well with them.

Let me know what you think!

 

Also, I plan to use this thread for here on out for any questions I have or issues that I run into so that I don't clutter up the site too badly.

 

Don't get a 2860, its not an overly good turbo for the miata engine. Stick with a 2560, it will spool slightly better and have no trouble hitting the power levels you want. The rest of your list looks good. Make sure you get inconel studs from TSE. They are the only studs proven to not stretch on track.

 

Looks nice! Not sure if you already have one, but you'll need an aftermarket clutch.

 

Got it. I was leaning towards doing it the right way from the start anyway, this is the push I needed. Any idea if something like this can be trusted? Genuine Garrett GT2560R Complete Ball-Bearing Turbocharger GT28R 330HP 466541

They say they are a certified Garret distributor. But I would hate to pay all that money for a knock off.

 

Completely forgot about that. Adding it to the list. Thank you!

 

I am not sure. I have never purchased a 2560. The only official garrett I have bought new was straight from tial and it was a 2871. Overall that seams like a decent price for a new one. I know if you do some searching on here you can find the nissian part number for their 2560 which was a little cheaper then buying from ATP Turbo or such.

 

That's pretty cheap for a 2560r.

Here's another source for a brand new turbo if you don't trust the ebay seller.

Nissan Factory OEM S15 Spec R SR20DET Ball Bearing Turbo Garrett GT28R

No affiliation. Bought some parts from them and no complaints.

 

Just for inspiration, here is a chunk of my log..from yesterday. 2560, ARTech. dont mind the droop, not dyno tuned, I haz other problems. That funny yellow line for instance, that is when a plug wire is hanging like a 1/2" from the coil, but the 585 still has power to try and make it work.

 

Found it. Thank you!

 

Thank you! I have heard of this company before. I will have to decide if the piece of mind is worth $100 though!

 

I still have a lot to learn. What exactly am I looking at here? 22psi full boost at 4407 RPM? That means there is a lot of room to build my setup further if I ever decide to do rods/driveline work! That is awesome!

 

The 2560 will top out right around 300whp on a 1.8l miata motor. With a perfect manifold and a perfect exhaust, you may be able to hit 325whp, but I'm doubtful of that happening.

 

I am not planning to exceed that any time soon (maybe not ever), so I should be good to go for now.

 

Yes, 22@4407. It's fun.

 

I am sure that is insane. What other modifications are necessary to handle that power without ripping the car apart? RX7 diff and axles?

 

1.8 rear end will handle the power fine. You might snap an axle if you get wheel hop drag racing. Other then that our rear ends tend to hold up pretty well. If you are using a 5 speed it might eventually start having synchro issues.

 

I had no idea the factory driveline was that robust. I don't know why I had it in my head that 250 was the limit. When do the stock NA8 rods go? (assuming there are no issues with the tune)

 

Rods in the 90-05 motor tend to bend between 225-250ft/lbs of torque. That does vary though. I have seen motors running 275ft/lbs of torque fine for years, I have seen them bend at 190ft/lbs. The 5 speed usually holds up fine on a stock motor, but it all depends on how nice you are to it. 3rd gear synchro's tend to be the first to go. You either swap in another cheap 5 speed, or get a 6 speed.

 

Building a turbo miata is a slippery slope..