1.0L Geo Metro engine swap into 1990 Mazda Miata!

[drmiller100]

nope. problem is if you just raise the compression ratio, will the head work ok without detonation?

[MetroMPG]

Originally Posted by fujioko

Hi,

I found this post while doing a google search. I'm the person who did the engine swap in the Miata.

Hi Jim -

Cool project! Mind if I post some of the pics from your build thread into this thread?

Darin

[fujioko]

Hi Darin,

Feel free to use any picture you want. Thanks for asking!

Jim

[MetroMPG]

Interesting... from the build thread:

MPH @3000 rpm

Gear...Metro........G10 Miata
1...... 13.58........ 12.97
2...... 24.50........ 24.33
3...... 36.25........ 33.29
4...... 50.77.........47.37
5...... 61.3..........59.59

[MetroMPG]

Originally Posted by fujioko

Feel free to use any picture you want.

Great - added a few pics and links to your YouTube vids in post #1.

What an impressive build - congratulations.

As for the goal of better highway economy, have you compared the Miata's CdA (drag coefficient x projected frontal area) with the Metro's? Aero losses outweigh everything else above ~25-30 mph.

FYI, the default values in the aero/rolling resistance calculator here are for a Metro of the same specs as your engine donor: Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

I saw you mention the hard top option as a potential aero gain. If you're talking about the tapered aftermarket "fastback" hard top I've seen in pics of some racing Miatas, it will likely help. The OEM hard top, probably not so much.

[MetroMPG]

I have been investigating a different camshaft that reportedly helps fuel economy in metros. I'll probably order one soon.

It makes a noticeable difference in low-end torque. I added an XFi camshaft (OEM fuel economy cam similar to 3tech's economy version) to my car. Though I didn't try to measure the change in fuel consumption (too difficult to get an accurate A-B-A comparison). http://ecomodder.com/forum/showthrea...leted-102.html

In combination with switching to the tallest possible final drive (for reduced highway cruising RPM) they made for a good combination. http://ecomodder.com/forum/showthrea...-gain-107.html


But my driving environment is very different from yours: I never take the freeway. Always secondary roads, so I'm rarely above 55 mph.

[California98Civic]

Originally Posted by fujioko

I would really like to get the MPG up into the 60's. I have been tweaking the car with various little mods.

I have not published any experiment results since November because the winter gas formulation upset all my previous claims. So far I can only claim 45+ on winter gas.

Milling the head should give me an improvement. Is there any published data on what to expect?

Jim

Wow Jim. Cool work! As for the MPG targets, I would think several known effective aeromods would be a breeze for you with the skills and verve you demonstrate: lower the ride 2-3 inches, put on a belly pan and/or an airdam, get LRR tires and pump them up solid, and make good aluminum rear wheel skirts using a wood hammer frame. And lastly and more involved would be to create a fastback using a donor car like some of the Miata tuners do.

But the car is cool as is too and 50mpg is a really good number. What did it originally get? 22mpg? 27?

[EDIT: correction. I wrote "Miata tuners" when what I was thinking of was Mazda in general. I think it has been mainly other models that have been chopped and "fastbacked" using donor vehicles.]

[MetroMPG]

At what speed do you want to attain 60 mpg? That's the $60,000 question.

If you're looking for 60+ mpg at 65+ mph, it's going to be quite difficult without extensive aero mods. I think I read you're planning to play with the fuel mapping via megasquirt (?) as well, which would also increase NOx emissions (assuming your goal is leaning fuel trim).

I can vouch for the rolling resistance performance of Bridgestone Potenza RE92 14 inch tires designed for the gen 1. Honda Insight: http://ecomodder.com/forum/showthrea...eet-19126.html

[FXSTi]

Originally Posted by Arragonis

Can't help thinking it would be easier to just get one of these



660cc and a turbo.

It is not emissions which keep these out of the States, it's safety. They don't meet crash test standards. We really need to get safety regulations to add an exemption for Kei class cars, or allow lower standards.With airbags and other safety based designs, they are still safer than early Metro's or Festiva's.

Kirk

[MetroMPG]

A Kei car wouldn't necessarily be a good substitute for what fujioko has built. They're designed as urban cars, and generally have very short gearing. Not a good recipe for fuel economy on the open highway (which is what he's after).