look at the ford ecoboost line of turbos. Tiny turbo, quick spool no boost creep. if you look at the wastegate port it is in some cases just as large as the turbine diameter. The path of exhaust flow through the waste gate is also much more ideal than the garret gt25 turbos most people run. These aren't exactly "low boost" turbos but it all comes down to the design of the turbo.

Every turbo is different. Some will handle creep better than others.

https://www.miataturbo.net/attachmen...ine=1462217904

If a German forum about French cars can be trusted, this is a 1446, specifically from an Abarth 500:

https://www.miataturbo.net/attachmen...ine=1462219206


Now, I've no idea whether the Fiat-Chrysler partnership means that the Darté is running the same turbo, but it seems reasonable.

These Brits believe that said turbo peaks out around 225 HP.




I'm usually quite critical of the "I found this random turbo that isn't well-suited to the application, and I'm going to base my whole build around it because it was slightly cheaper than the correct turbo, so screw you guys and your logical arguments. Oh, and by the way, this is going on a 1.6 failblock to boot" builds. But in this case, I kind of want to see what will happen.


https://cimg5.ibsrv.net/gimg/www.mia...3828863773.png

I still think that's too small. Much smaller than a GT2554r. I don't see how 225 hp is possible as that would be like right at the edge of the compressor map for the MGT1446 (not right side of efficient part, like almost off the map). This turbo was matched decent to our 1 cylinder 450cc dirtbike motor. We ended up using the compressor off of an MGT1238 and the hotside form the MGT1446, but either way, it's ideal for a small motor. I can't see it having much room to grow on the Fiat 1.4L.

I'm really torn here...

On the one hand, it does intuitively seem too small for a Miata.

On the other hand, it's obviously not entirely too small for a 1.4L Fiat engine making 160 hp / 184 tq in what one supposes is likely a conservative factory tune.

On the gripping hand, it's quite probable that even the French have, by now, figured out how to design a head which is considerably less horrible than the 80s vintage copy of a 70s vintage tractor engine that Mazda stuck into the early Miatas, and that would shift things around on the compressor map quite a bit.

Still a teensey little turbine section...

https://www.miataturbo.net/attachmen...ine=1462221550

If you want a sliiiiightly larger starting point, my friend needs to off load a brand new turbo from a 1.6L turbo Nisan Juke. That could be a fun build for 160-170 at the rear wheels on a 1.6 Miata. He was going to run it for shiggles but a nicer setup fell into his lap for cheap. I am rather sad, as it would have been fun to see what would happen with it.

Figuring the juke is 188hp, but likely a conservative tune/pressure, but the B6 head is a POS, so maybe about the same max.

Or gasp one of those silly supercharger kits that also make about 150 hp and bolt on. They seem to pop up on craigslist more or less complete with or without their bandaids for like $350 from time to time.

You could make close to that with a 1.8 with bolt ons. If you don't want a ton more power right now just swap a 1.8 and have the upgradeability to do a turbo later on and get moarofit

Probably one of the most "successful" attempts at a k03 This happens when you put a tiny turbo on a Miata : Miatapower List Archive : MX-5 Miata World Forum : MX-5 Miata World

I helped tune a TD04L-13T setup utilizing a turbo from a WRX. Running just a 2.5" exhaust, could hold 7psi or 12psi no problem. Thing made 175tq/175rwhp on a Dynapak dyno, which always read 12% lower than all my dynojet runs.

TQ was flat at 175 from like 1.5K till about 5.5K. It looked a lot like this:

https://www.miataturbo.net/attachmen...ine=1463051188

https://www.miataturbo.net/miata-par...-%24500-53553/

I've been considering trying out a ford fiesta 1.6 eco boost turbo on a bp engine. It's a tiny borg warner turbo. Lots of torque down low but it would most likely choke up at higher airflow. It would probably make for a great DD fun but now what I'd be looking for at the track.

What do you guys think?

https://www.miataturbo.net/attachmen...ine=1463062822

https://www.miataturbo.net/attachmen...ine=1463062822

https://www.miataturbo.net/attachmen...ine=1463062822

same as what you already think / know

Power wise I'd be happy with 180 or so whp at the track. But what would concern me is operating at a low efficiency part of the compressor map for an extended period of time and what that would do to intake temperatures.


It looks like it would kick the ass of a stock msm setup. I think I need a DD turbo miata and a track turbo miata.

https://www.miataturbo.net/attachmen...ine=1463065486

if you have proper fmic and ducting I don't see how it would be any worse than a bolt on msm or any of the MANY other small turbo cars that get tracked.

the biggest drawback is having to custom fab everything and likely having a non-interchangeable turbo/setup, not much else.

people track focus/fiesta st's all the time

touche.

I picked one up off ebay for $200. maybe I'll get around to testing this some day.

I always wanted to do that (create a diesel powerband setup)
just sounds like fun and amusing for a daily driver
never got around to it. hopefully you'll actually do it

Buying a random cheap turbo and building a setup around it is stupid, you should pick up a standard t25 off an SR20 and just run that.

/s

I don't think even a t25 would outspool this thing

but is it worth it? I dunno. I never found out

It's not a random cheap turbo. It's a carefully selected modern technology borg warner turbo that spools like nothing else out there. I pulled the trigger since you can buy them for cheap since Ford is using them everywhere. I still think it would be a really fun turbo setup. I'm just torn between should my dual duty weekend/track toy be more track or street oriented and if it will be worth the fab work. Plus I like wrenching on this car and no one has tried this combo yet so it's something I'd eventually like to test.

In for spool at 2000rpm.

We were going to do this on my friend's 1.6 (though with a brand new turbo from a 1.6L Nisan Juke he got for $100). But he ended up with a stupid good deal on an upgraded greddy kit (only thing original to the kit is the turbo and the oil lines...) For stupid cheap.

Maybe run a pair of the tiny turbos?

The /s was to show the end of my sarcasm. I think it is a very interesting idea and you are not a noob who does not know what they are doing. So I look forward to seeing the results. Sometime in the future I might even grab one just to play with if I ever get some free time.