Miata Reliable Power Increase N/A or Turbo for track car

I am looking to increase the HP of my 1990 1.6 Miata. The car is mainly being built for a track car but I still enjoy driving it on the street. This past year I have worked on getting the suspension sorted out, and I am now running 700f and 350r springs with Hoosier 205/50/15 SM6’s. The car handles great. I am thinking of power goals of 180-200WHP. I have come up with those numbers based on other cars power to weight ratios, and just wanted to keep up with the rest of the pack and having some fun mixing it up with faster cars. My home track BIR has some has a pretty long fast straights, and I would also like to start going to Road America which as 3 long straights. The car is mainly used for lapping days and HPDE’s by two drivers. Having a reliable car that can take up to 50 mins of track time is very important to me. The original plan was to install a 99 motor, Standalone ECU, intake and exhaust. But now we are looking at turbos. We have about $4000 to work with this year. These are the options we are looking at

1: 99 motor, Standalone ECU(megasquirt), intake and exhaust. I am guessing we would be at 150WHP, is that a good guess?

2: Install 94-97 motor, Stand alone ecu and prep for a turbo next year. The thought being with a 1.8 we could run less boost, so less heat and the issues that come with it. 120WHP this year, 200WHP next year( if we have the budget next year)

3: Turbo the 1.6 short noise(which has 80,000 miles) and get to 180whp. But how will it hold up?

I am open to all suggestions and ideas. What has worked for people and what hasn’t? I know the LS1 would be great but out of our budget range.

1, although drop your expectations by about 10 hp. Basically, have a look at what the Supermiata guys do.

Turbos can be made to be reliable on track, but you do need a certain amount of mechanical empathy to run them hard for nearly an hour. Concentrate on cooling first.

You could always buy* a LEEN conversion for the 6 speed out of the 99 Miata... and then you can bolt a Toyota 4AGE, or if you want the stroke a 7AGE... 200hp (240 from the 7A) isn't a problem... neither is a reliable 9k rpm.

• • some kind of sponsorship deal might be able to be hammered out...

also if you want to run boost, you can easily plant in excess of 400hp with a boosted 4A, or 7A

What Keith said.

If want a little more power, do a port job on the head and shave it .060". Maybe pay for an overpriced square top intake manifold if you're feeling rich.

With a 1.6L, turbo, and megasquirt, we are reading about 185 hp to the wheels.

But we are not optimized. There's a lot of room for improvement.

My solution: I am sticking with the 1.6L for now, and working to optimize all the aspects of it (tune, air flow, aero, exhaust, broken manifold, cooling, boost control, etc). Pretty sure I can hit 250hp.

I am also pretty sure it won't last at that point.

So, I have 2- 1.8L's on the shelf. I can build one while I am running the 1.6L, then swap easily when the time comes.

Turbo Miatas are hideously expensive to keep together on the track. Suppose it depends how hard they're being used/abused.

You see a LOT of guys on MiataTurbo ditching their turbo setups after a few track days.

And often not going much slower. Maybe it's because they get more seat time because their car isn't broken all the time.

It does all depend on how hard they're being abused. If you drive like you're running an endurance race instead of trying to qualify on every lap, the turbos aren't that hard to keep together. That's true of any car, of course. Pay attention to prep, pay attention to the car on track and you'd be amazed at how well they can work. You also see a LOT of guys who don't have problems, but you don't hear from them because they don't constantly post about it.

buy a cheater SM motor that is no longer useful to the previous team

Keith knows whereof he speaks. I've been tracking a 1.6 turbo Miata for 8 years, running 219 hp at the wheels. Heat is a huge issue, both oil and water. I've gone to a Racing Beat type 2 nose on the car to run twin small oil coolers in the side openings and an FM Race Rad. This has been a very reliable setup for me, even on hot days. However, I find the oil temp gauge functions as a "cumulative revs meter". If I use 6800 rpm as a redline, it's generally OK. If I run 7200 (balanced motor, steel rods), the oil temp climbs steadily. Regardless, you do need to keep a sympathetic eye on the temp gauges, and don't even think about running without an oil temp gauge.

4shadesofblue: I think I saw you at the SCCA PDX at DCTC this fall. I was driving a fairly stock white '94 Miata. I'm considering a turbo setup for this spring as well. My current plan is a Flyin' Miata Voodoo II with lots of cooling bits, but that could change as I think about it over the winter. I'm looking forward to seeing what you decide on. Hopefully I'll see you at DCTC, BIR, or RA in the spring. Maybe the long course at BIR won't be so boring with a little more power.

SVreX wrote: With a 1.6L, turbo, and megasquirt, we are reading about 185 hp to the wheels. But we are not optimized. There's a lot of room for improvement. My solution: I am sticking with the 1.6L for now, and working to optimize all the aspects of it (tune, air flow, aero, exhaust, broken manifold, cooling, boost control, etc). Pretty sure I can hit 250hp. I am also pretty sure it won't last at that point. So, I have 2- 1.8L's on the shelf. I can build one while I am running the 1.6L, then swap easily when the time comes.

How has this setup held up so far? What issues have you had?

So if we did go the turbo route, is it worth it to swap in the 1.8 with our power goals? Or run the run 1.6 and swap to a 1.8 down the road when we need a new motor?

I am just a little concerned about a turbo, I watched people on track having to come in early with cars that were hot, no Miata's just various other hopped up cars. Cars that looked they would have been built the right way.

http://www.superfastmiatas.com

Just cause no one else mentioned them.

FYI, we're testing an electronically controlled water pump that is showing great promise. We may have the cooling issue licked soon enough.

In reply to 4shadesofblue:

My car is a budget build- built for under $2K. It has a lot of crap cobbled together. It is a 200K stock motor.

It has been thoroughly abused for 6 years (including 8000 rpm redlines for 1/4 mile runs, and being used as a student car at a racing school). It has never broken down, but it has been pulled off the track for over heating. It has not done any long distance running.

I am making a few cooling mods now, but keeping it low budget for 1 more year.

Seems to me a great setup if you spent a little money on some cooling goodies with Keith.

If it was me, I wouldn't dump $4K into a whole new setup. I'd tweak what I've got, spend $1500-2K on improvements that can be reused later, then take my time building a good 1.8L to swap in later, while enjoying driving it for another year. But that's just me.

I am not looking at the 1.8L to be more reliable. I am looking at it for 10% more horsepower.

Gieb wrote: 4shadesofblue: I think I saw you at the SCCA PDX at DCTC this fall. I was driving a fairly stock white '94 Miata. I'm considering a turbo setup for this spring as well. My current plan is a Flyin' Miata Voodoo II with lots of cooling bits, but that could change as I think about it over the winter. I'm looking forward to seeing what you decide on. Hopefully I'll see you at DCTC, BIR, or RA in the spring. Maybe the long course at BIR won't be so boring with a little more power.

That was me. I remember seeing your car but I never made it over to check it out. That event turned out to be a little frustrating, to many cars that were not going to let a Miata pass them, even with me spending 5 laps right on their bumper. I even was able to catch up to the GTR. It would be great to see more Miata's up at BIR. The BMW event in June is a lot of fun.

I have been looking at the FM kits too. If I go that way I might go with the no electronics kit and use a Megasquirt, I hear get things about the Hydra but for $1500 more it is hard to justify. I also talked to Bell Engineering about their turbo setup. I don'tknow enough about turbos yet to compare the two.

option 1, but with a squaretop, you'll easily have the budget for it. Spend the rest on tires

Most of the Miata turbo guys here spend a lot of their track time worrying about heat. On a hot summer's day that's: turn laps for up to 15 minutes, then start backing out of the throttle to manage heat. They compare notes in the paddock about how many laps they turned before they backed out.

I'd go option #1 personally.

Option #4, fit a 13B .

What are the gains you would see with a square top? I am guessing that would be a JDM part? I have been looking at the JDM motors. They seem like they would be a good since you would get all of the little pieces with them and a 6 speed transmission.

So what I am hearing is, going with a 99 normally aspirated motor would be the wise choice. And if I choose to go turbo to keep my 1.6 and really work on the cooling side. No votes for putting in a 1.8 and installing the turbo later?

I understand that every track is different, but would would a good power level to shoot for? I came up with the 180-200whp based on what a E36 M3 would be.The goal is to try to have a quick car that is still relatively inexpensive to run.

Or you could swap in an LSJuan :)

Of course a 1.8 is not a bad idea, no replacement for displacement as they say and a turbo can be added later if you still need a little more powa!

Too bad the 2.0 isn't an easier swap :/

but mostly plan on investing in serious cooling improvements before upping the power significantly with a turbo.

4shadesofblue wrote: What are the gains you would see with a square top? I am guessing that would be a JDM part? I have been looking at the JDM motors. They seem like they would be a good since you would get all of the little pieces with them and a 6 speed transmission. So what I am hearing is, going with a 99 normally aspirated motor would be the wise choice. And if I choose to go turbo to keep my 1.6 and really work on the cooling side. No votes for putting in a 1.8 and installing the turbo later? I understand that every track is different, but would would a good power level to shoot for? I came up with the 180-200whp based on what a E36 M3 would be.The goal is to try to have a quick car that is still relatively inexpensive to run.

The square top was sold on the European market NBs. IIRC it's good for 5-10 hp in the 7-8K range. I have been told that there can be quality issues with the Japanese used motors, but I have no personal experienced with it.

If your budget for the motor is $4K, then you want a nice NB motor. Putting on a turbo and making it track-reliable is 3x that much, if not more.

If you did want to go turbo, I wouldn't go with either 1 or 2. Get an NB 1.8, and then turbo that later. IMHO buying any go-fast parts for a 1.6 that won't interchange to a 1.8 (which is pretty much all of them) is a mistake, because no matter what you do to the 1.6 you'll never get those 200ccs back. As for the 94-97 motor -- an NB head flows much better, and doesn't really cost all that much more.

Have you swapped the differential yet? With a 6-speed you'll want a different final drive ratio, and the 6" ring gear that came in the 1.6 diff is supposed to be very weak.

As for how much power is "enough", I suspect that no matter how much you put in there, you'll want more, especially at a track like Road America. Decide how much you want to spend first. :)

4shadesofblue wrote: I understand that every track is different, but would would a good power level to shoot for? I came up with the 180-200whp based on what a E36 M3 would be.The goal is to try to have a quick car that is still relatively inexpensive to run.

It's pretty simple:

• you won't ever have "enough" power

• you don't have "enough" budget for a track ready turbo setup

• so option number 1 has to be good "enough." If you go this route, I'd stick with a 5 speed

Wow. You guys spend a butt load on turbos.

I would never spend that kind of change.

The $2K figure I stated included the ENTIRE CAR.

You're the gross minority, though. $2k wouldnt build the bottom/head combo in my Miata.

If it were that easy/cheap, there wouldn't be people taking baths on their turbo setups to go back to n/a.

Regardless, if you want a 1.6 car to hold together at 200whp on the track, you need to upgrade the trans and rear end. Brakes will need attention. You'll need 1.8 parts. May as well start with a 1.8 car, or move forward with putting the 1.8 in anyways.

Whether he spends the money for boost later or not, a comprehensive bp4w (or vvt swap) makes a lot of sense.