How to improve power/mpg on EA82?

[smallwwb]

I'm trying an experiment to improve power and fuel economy on my 88 Wagon.

I removed the A/C system; can I remove the belt-driven fan and hook up the electric fan to work with the radiator thermostat?

How hard is it to remove the catalytic converter?

I've heard removing the EGR system will improve power and mileage as well.

The best I have gotten is 32mpg on the highway. 204k miles.

Already did the distributor, plugs, new air filter, etc.

 

Does anyone have experience with any of these things?

[crazyman03]

from my experience, I Kept it simple. Get some decent spark plugs, air filter, keep up with the maintenance and don't drive it like a retard. Hypermiling works too especially on the 5speeds. You can take out the belt driven fan and put a electrical one in there. i think the mounts are there anyway even if its not there. on the left side (looking into the engine bay).

 

I've seen mine (88 GL SPFI) get 30's mixed driving and 35-(sometimes)39MPG Highway. Corse that's practically flat hills and taking it easy up hills. That's what i got on my last trip to Wyoming, Denver to Cheyenne, Casper then Rawlins 1 tank, Rawlins, rock springs then Evanston 1 tank, than 1 tank back from evanston.. and i still had a couple gallons left.

 

 

-Justin

[GeneralDisorder]

I'm trying an experiment to improve power and fuel economy on my 88 Wagon.

I removed the A/C system;

 

Won't do anything unless you turned it on. Otherwise it's just a belt turning a dis-engaged clutch. No load.

 

can I remove the belt-driven fan and hook up the electric fan to work with the radiator thermostat?

 

The water pump driven fan also has basically no load unless things get pretty hot. It's on a thermostatic clutch. The electric fan already is the primary - you can remove the WP fan if you like as it is part of the AC system that you already removed.

 

How hard is it to remove the catalytic converter?

 

Don't bother unless it's plugged (if you are getting 32 then it's not). Best mileage is from part-throttle cruise. The cat is designed to flow at WOT - part throttle cruise is only demanding maybe 1/3 or less of the flow capability of the cat. There is no win from removing it unless it's damaged.

 

I've heard removing the EGR system will improve power and mileage as well.

 

Nope - won't do anything.

 

The best I have gotten is 32mpg on the highway.

 

That's excelent - get some used cheap tires and inflate them to 60 psi for less rolling resistance, run ATF in the manual transmission for less drag - pull the rear axles if you have a 4WD so that stuff isn't spinning.... Install a vacuum gauge (the original MPG meter) and learn to use it.

 

Does anyone have experience with any of these things?

 

Yep.

 

GD

[WoodsWagon]

 

 

That's excelent - get some used cheap tires and inflate them to 60 psi for less rolling resistance, run ATF in the manual transmission for less drag - pull the rear axles if you have a 4WD so that stuff isn't spinning.... Install a vacuum gauge (the original MPG meter) and learn to use it.

 

GD

 

NO NO NO on the ATF in the tranny. That works fine for most transmissions that have all helical gears in them, but with the hypoid ring and pinion in the front differential, you have to have hypoid gear oil. The shearing and pressure forces in a hypoid gearset is way higher than in helicals.

 

Any other tranny, you can get away with running ATF. Not a subaru though, it would burn up fairly quickly.

 

Pulling the rear CV's off of the hub stub shafts is a great way to improve the MPG though. You could make some straps/hooks to hold them up and back to the mustache bar so the axles would be out of the way of the suspension but you could re-attach them if needed.

 

Running tires at high psi is a sketchy way of trying to get more MPG. Yes, the rolling resistance goes down, but the traction needed when braking and turning goes way down too. The gamble of getting in an avoidable accident vs getting 1-2 better mpg isn't worth it.

 

You can try advancing the distributor a couple more degrees. Listen closely for "ping" or detonation, but it may help the part throttle mpg.

[GeneralDisorder]

I didn't say any of that stuff was safe or a good idea for long term. But he did say this was an "experiment".

 

And yes - the ATF thing isn't good for the hypoid gear set long-term. But short term I use it to flush and clean out MT's. It's ok for a few hundred miles - especially if you are easy on it and you don't haul a whole bunch of weight around. The Subaru front diffs are built like tanks and frankly they rarely fail even if the gear oil is never changed. Fresh ATF isn't a lot worse than 20 y/o gear oil with 200k on it.

 

And at the end of the day - EA82's are sub-$1000 cars. Hell you can buy one most any day of the week for under $500 anymore around here. So if you ruin one in the name of science then it's not really a big deal.

 

Ultimately there isn't much you can do that won't sacrifice *something*. And I would bet that driven carefully, 60 psi and ATF would actually last a surprisingly long time.

 

GD

[opus]

NO NO NO on the ATF in the tranny.

 

I've got many, many years on ATF, still no issues on any of them.

[NoahDL88]

Reduce weight, strip out everything you don't need to go down the road.

 

Reduce drag, tape over your door handles, pull down your antenna, remove the roof rack. Ground effects might make a positive difference. Don't forget air resistance on the bottom of your car.

 

 

Sell wagon, and get an XT?

[Markus56]

 

 

Sell wagon, and get an XT?

 

+1

 

find a 2wd XT and do all the things GD said. you could get 40 mpg plus

[smallwwb]

As far as the belt-driven fan, it runs all the time. I don't think there is a clutch there.

Removing the AC got rid of about 50lbs of dead weight.

Gotta keep the 4wd system, otherwise I would drive a Honda.

 

Does anyone have experience using the electric AC fan with the thermostat switch in the radiator?

 

Front diff makes a lot of noise, and I need a new clutch- it probably drags a bit.

I also want to improve power as well as mpg.

Yes, this is an experiment since I have about $450 total into the car.

[SoobieDoo]

Does anyone have experience using the electric AC fan with the thermostat switch in the radiator?

 

I also want to improve power as well as mpg.

 

The stock electric fan is already set up like that, so try it out and keep a close eye on the temp. Just be prepared with some wire strippers and wing nuts to make it run continuously, if needed. If your cooling system is good, (for an EA82) then it won't overheat if run all the time. Come summer you may want a second fan, but your location may not even need it!

 

You never mentioned if this is carbed or FI? A SPFI or EJ swap, if already FI, would give you the most gains in power and economy. Otherwise, for more power let me sell you some turd polish.

[vagen]

I have two questions and a couple tips.

 

1. Is this car a manual or auto?

 

2. does it have anything bolted to the roof or hatch?

 

MPG depends a lot on how something is driven. My RX for instance if given the beans will suck fuel down to the tune of 18mpg but if driven gently and short shifted it can hit 37mpg. So if you have a manual shift early and keep the RPM low. Now if you have an auto this advice will seem counterintuitive. With an auto accelerate briskly and get it into top gear as quickly as possible then let off and cruise. the fuel used getting to top gear is balanced by the time not spent in the lower gears. Tires don't get crazy with tire sizes here just use the stock size or as close as you can get but.... inflate to 80-90% of sidewall rating or what the tire manufacturer recommends for the weight on the tire. this sounds crazy but each tire is built differently and has slightly different load ratings. Inflated to the correct pressure your tires will not only deliver better milage but they will last longer.

 

 

(standard disclaimers apply YMMV)

[smallwwb]

I'm a regular hypermiler; read the ecomodder website thoroughly.

Things i have done so far:

Antenna tucked, stock size tires at 40lbs (44lb max), side mirrors folded in, 5spd short shifting, EOC as much as possible, nothing sticking out on the outside to create drag, car is always empty of stuff, 55-60 max mph during mpg testing, etc.

Soobiedoo you said the AC fan is already set up to come on via thermostat? I thought it ran on a switch when the AC was turned on? The fan blades are different between the belt and the electric fan as well.

[GeneralDisorder]

Soobiedoo you said the AC fan is already set up to come on via thermostat? I thought it ran on a switch when the AC was turned on? The fan blades are different between the belt and the electric fan as well.

 

You have the common misconception that the AC fan is the electric one. It is not. The AC fan is the belt-driven thermostatic clutch fan (yes - it DOES have a thermostatic clutch). The passenger side electric fan is still the primary fan and DOES come on via a thermoswitch *or* via a relay bypass when the AC is turned on.

 

You can remove the thermostatic clutch fan and replace it with another electric or if you aren't going to use the AC then just pull it. Models not equipped with AC did not have the belt-driven fan.

 

GD

[smallwwb]

Skeptic,

 

So if the belt-driven fan is the AC fan, why does it run all the time?

[Numbchux]

Skeptic,

 

So if the belt-driven fan is the AC fan, why does it run all the time?

 

the electric fan is ONLY wired through the thermoswitch in the radiator. it is unaffected by the A/C system. So, the only way to insure airflow when the A/C system is on without re-wiring the car is have a fan that runs all the time.

 

and yes, it is clutched. here's a picture of me holding the fan stopped while the engine is running:

 

 

 

yea, the A/C system doesn't cause any resistance on the motor. But, it's weight. IMHO, if it doesn't work, yank it out. I always have.

 

ditto on the clutch fan. maybe it doesn't cause much resistance, but it is spinning, and isn't needed. chuck it. 4 10mm nuts, pull it off, throw 2 or 3 washers on each stud, put the nuts back on, you're golden.