99' 159k miles, 150 psi all 4 cylinders. I have had my car for about 2 years now, it is my daily driver. All maintenance is up to date. (Motor was pulled twice by me to replace the oil pump, water pump, timing belt, ALL gaskets, and valve seals. So far zero oil leaks.)

My plan was originally to buy a used bp4w motor, tear it down, and rebuild it completely brand new with a brand new turbo kit on it.

My power goal is 160-180 whp. I want a low boost set up for the street. This being, am I better off doing an engine rebuild? Or is it safe to just slap a turbo on my healthy high mileage motor? What is everyone's experiences on putting a turbo on a high mileage engine?

I also have been ready to pull the trigger on a MSPNP2 so I can learn how to tune my N/A car before I add the turbo.

Thanks!

 

Boost is addictive. 160-180whp will not be enough after a short while. You can safely turbo what you have and tune it to 200whp and have a reliable safe car. No need to rebuild anything. At 159k though, don't expect it to last forever. Just don't let it get hot and run a conservative tune. MK turbo kit would be a perfect fit for your goals.

 

Thank you for the response. MK turbo kit was the route I was taking. I am going to buy their turbo kit, and source out the intercooler and piping, oil and water lines elsewhere.

I know boost is addictive, so yeah the power goal of 160-180 whp is not going to stay for long. If I can hit 200 whp on my current motor, I'll be more than happy.

What do you mean by not running a conservative tune?

 

Get a MS3 and bigger injectors (700cc+) The MS2 will work, just not as well and the price difference is minimal
Learn to tune on the original stock engine.
Do a hot compression test and a hot leak down after you are comfortable with tuning (4-6 weeks)
If you're within 10% on all cylinders with a leak down below 20% on all cylinders...
Get a MK turbo set up and boost the old engine.
160-180 is too conservative.
I'd shoot for low 200s on the original engine.
I'd purchase a used engine before rebuilding one for any power goals below 250.
If you go the rebuild route you should do a BUNCH of reading before purchasing any parts.
Stock perfectly rebuilt engine will have issues past 250HP.
H-beam rods and forged pistons are a waste below 250HP and a requirement above...
You might have a failure on the old engine but by the time this happens you will be far more educated than you are now.
You also need to drive a low 200 HP Miata. It's really all the car needs. It will be fast enough that you will not let beginners drive the car. It will be damn dangerous in the wet.
All the newbie threads stating 350- 400 HP are pipe dreams. It's possible but the ENTIRE car will need mods.
My list for low 200 HP Miata
MS3 with injectors
Mild fuel pump upgrade
Mild clutch upgrade
MK turbo kit (comes with exhaust)
Decent intercooler
one/two heat range cooler plugs
Stock ignition in good shape
Coolant bypass
Good radiator with factory ducting in place
Decent tires, 205/50/15 on 7-8" rims is a sweet spot.
An LSD. The 3.9 in a 6speed NB will work well.

And lastly something you will NOT like. Purchase a 2nd beater for your daily driver. Get something that has room. Early Toyota 4runner or something like it
Having your play toy as your only driver is a mistake. It can be done but you have no room for mistakes or you're carless.
Then you're jobless...
If you don't have a back up driver you will have problems. If you do you will have fewer problems and not need the second car nearly as much- Murphy's law

 

This is exactly what I needed! Thank you a ton for the response!

Now two questions..

Why MS3 and not MS2?

Is a LSD really required for a 200 whp goal?

FYI I have a beater already! 2003 Nissan Sentra. It's stupid reliable I tell you.