Calling all Geo Metro heads! Advice sought.

[zonker]

Hi everyone,

Not new to ecomodder, but new to the Geo Metro ownership experience. I just picked up a creampuff 1989 Metro XFi last month. 1.0L 5 speed 3.79 final drive ratio, 12" wheels.

I wish to hear from other current and previous Geo Metro Ecomodders what mechanical or aero items did you do that helped you the most regarding your fuel mileage.

1. What aero modification did you make to see the largest improvement?

2. What engine / transmission / tire change netted you the greatest improvement?

[oil pan 4]

A Kubota diesel is the best engine to put in them.

[freebeard]

I've drunk the Kool-aid after decades of air-cooled VWs. Respect the green Eco light.

Don't listen to oil pan 4. He's trying to distract you from bennelson (Ben Nelson) and the Electro-Metro Build thread from 2008.

ecomodder.com/forum/showthread.php/ben-nelsons-electro-metro-build-thread-848.html

He did really good work, unfortunately Internet has eaten all the pictures he posted. In 2018 he migrated it to Youtube.

https://www.youtube.com/watch?v=BSA2...XAVwpRRCqMv7Ny

The Kubota weak and dirty compared to a Lexus rear exle.



And it would even fit under the hood.

I will of course run the three-cylinder as long as it lasts. I've cut pieces to start the front aero but won't have the time for a week or two to carry it forward. It looks like the grille block will be a longitudinal plate that divides behind the grille in half, the radiator being on the left. Then instead of an air dam, a modest splitter that won't compromise the approach angle but will spill air off the ends setting up a potential for front wheel air curtains.

Others have found success with a Kamm-back. Were I to do so, it would be more modest -- really only a 'Faschenfeld tearing edge' in the parlance.

[redneck]

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Get a MPGuino to see instant mpg and average mpg. Replace original 12” wheels with newer 13” Geo metro wheels for a better selection of tires and more importantly, a lower final drive ratio. Inflate tires to the maximum pressure stamped on the tires sidewall. Drain transmission and fill with Valvoline™ Synchromesh Manual Transmission Fluid. Install brake pad return springs. Have a all wheel alignment done and set tow in to 0 degrees. Install a remote engine kill & start switch. Install a partial grill block. Install a hot air intake. Make a cardboard engine blanket to retain heat. Remove side door mirror and relocate to the inside.

That should get you started.




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[freebeard]

Do you have cites on the brake return springs and hot air intake? TIA.

Not to threadjack [he says] but I want my XFi to be a good example and I'm looking at the paint. I've never Bondoed a car, but what would be an accepable level; <1/8th"? I have a Unispot to pull up the lows.

My thinking is instead of the stock white, an automotive Ultrawhite with titanium dioxide calcium chlorate. Probably in a Rustoleum base. As a palliative for not having air conditioning.

[zonker]

Originally Posted by redneck

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Replace original 12” wheels with newer 13” Geo metro wheels for a better selection of tires and more importantly, a lower final drive ratio.

Thanks for the solid advice. I wonder which one did the most for you? As for tires/wheels, the car has the 3.79 final drive and I'm running 155/80-12 Nankang tires, with an OD of 21.8". With the ratios and diameters calculated, it is turning 2750 rpm in 5th at 62 MPH.

I get why you'd want to increase the OD of the tire, but would adding rotating weight also sap some of that savings? the 12" set I have are a combined tire/wheel weight of 20.5 lbs! I've never seen anything that light on a passenger car.

Lets say I ran the 13" Metro wheels with a 155/80-13 tire, the diameter would be 22.8" and the weight would be 5 lbs more, at 25.5 lbs. The RPM I now would be turning at 100 KPH (62 mph) is 2650 rpm.

Is reducing engine RPM from 2750 to 2650 RPM at 100 KPH going to offset the additional 20 lbs of rotating weight I will be adding to the car? Plus the expense of all that new stuff would probably not pay for itself during the life of the vehicle. Perhaps it's something I can play with when these tires have reached their expiration.

Originally Posted by redneck

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Inflate tires to the maximum pressure stamped on the tires sidewall. Drain transmission and fill with Valvoline™ Synchromesh Manual Transmission Fluid. Install brake pad return springs. Have a all wheel alignment done and set tow in to 0 degrees.

Good advice there - all that has been accomplished so far. I also added Motorkote friction reducer to the engine oil and the synchromesh. I've zeroed the alignment and cut the coils to lower the car about 1".

Originally Posted by redneck

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Install a remote engine kill & start switch. Install a partial grill block. Install a hot air intake. Make a cardboard engine blanket to retain heat. Remove side door mirror and relocate

Of that listed, I've completed the passenger mirror delete and inflated the tires to 40 psi. I was thinking of disabling the steering wheel lock so I can turn the car off with key at will and not worry about a potential calamity. Grill block and heated air intake tube are on my radar of things to try next. Right now, I've just removed the cold air fender snorkel and added a 1" lower lip made from landscape edging.

[redneck]

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The hot air intake is nothing more than disconnecting the air filters cool air intake hose, rerouting and adding how ever much is needed to draw air from near the exhaust manifold. Clothes dryer vent hose works just fine.

Brake return springs are nothing more than old bicycle spokes bent to fit the application. Recently produced spokes (China) seem to be softer, less spring (junk).

[freebeard]

I've got lots of old bicycle spokes. Is there a template or pattern anywhere?

[Ecky]

Nappa also sells the return springs, and you can get them on eBay for any specific application.

My wheel of choice is the Honda Insight wheel (2000-2006). The Bridgestone tires that came on them were among the lowest rolling resistance on any production car, past or present, and the 165/65r14 tires + wheels are only ~22-23lbs, and have great aero. They're also a hair larger (22.4 vs 21.8).

[redneck]

Originally Posted by zonker

Thanks for the solid advice. I wonder which one did the most for you? As for tires/wheels, the car has the 3.79 final drive and I'm running 155/80-12 Nankang tires, with an OD of 21.8". With the ratios and diameters calculated, it is turning 2750 rpm in 5th at 62 MPH.

I get why you'd want to increase the OD of the tire, but would adding rotating weight also sap some of that savings? the 12" set I have are a combined tire/wheel weight of 20.5 lbs! I've never seen anything that light on a passenger car.

Lets say I ran the 13" Metro wheels with a 155/80-13 tire, the diameter would be 22.8" and the weight would be 5 lbs more, at 25.5 lbs. The RPM I now would be turning at 100 KPH (62 mph) is 2650 rpm.

Is reducing engine RPM from 2750 to 2650 RPM at 100 KPH going to offset the additional 20 lbs of rotating weight I will be adding to the car? Plus the expense of all that new stuff would probably not pay for itself during the life of the vehicle. Perhaps it's something I can play with when these tires have reached their expiration.



Good advice there - all that has been accomplished so far. I also added Motorkote friction reducer to the engine oil and the synchromesh. I've zeroed the alignment and cut the coils to lower the car about 1".



Of that listed, I've completed the passenger mirror delete and inflated the tires to 40 psi. I was thinking of disabling the steering wheel lock so I can turn the car off with key at will and not worry about a potential calamity. Grill block and heated air intake tube are on my radar of things to try next. Right now, I've just removed the cold air fender snorkel and added a 1" lower lip made from landscape edging.

If your tires are good, I would wait to replace. No sense in wasting good tires that are paid for. In the mean time I would be looking for 13” wheels. 12” tire selection is poor, 13” is slightly better. I don’t remember what my wheel weight is. I’ll try to get a number for you.

Personally, I wouldn’t mess with the factory ignition switch. Installing a remote stop start switch(s) is easy. Plus it could be used as a anti theft device of sorts to boot.

If you’re interested in aero stuff check out my thread.

https://ecomodder.com/forum/showthre...tml#post373841




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