I recently found myself the owner of a 1987 Subaru GL hatchback. Kind of a fun little car that should get us through the winter.
The only problem with it is the engine is a little tired after 27 years of service and 141,000 miles. No illusions here, the car had every bit of 73hp when it rolled out of the factory so I’m not expecting to win any stoplight races. Nevertheless, I think it’s reasonable to expect better than 65mph in good driving conditions, and that’s a bit of a struggle right now.
I suspect the power loss is really a combination of many things that simply wear out–rings, head issues, carburetor, etc. And while I’m not afraid to tackle the deeper engine work, I’d like to avoid it if I can. So where would YOU start, and how much power can I expect from each project?
Plugs/wires/cap/rotor/timing is easy, how noticable would that be really?
I think you’re getting everything you can get out of it. A completely new engine, even with some tweaks, isn’t going to give you much more pep.
The worst car I ever owned was a 1979 Mustang with the smog-labored 2300… a whopping 88 horsepower and not a very good power curve to boot. It choked out going up the moderate hills to the east of Sacramento. Similar car sizes and weights… and mine, godelpme, was new.
for a naturally aspirated engines, bolt-ons can get you maybe a few horsepower max, and even then you’ll only get that at WOT. you’re simply bound by the fact that you have a 73 horsepower engine, and if it’s an automatic, even worse by the lack of an overdrive.
not at all. if you have a problem with the ignition system, you get misfiring. Not a loss of performance.
Nothing short of dropping in a different engine will get you much.
This is where I would start. If you’re having misfires at high RPMs, that would prevent you from utilizing all 73 hp. I had to look it up, but assuming it’s the 1.8L EA-81, it should have throttle body injection, not a carburetor. If the ignition tune-up doesn’t help, check the fuel pressure, there could be a problem with the fuel pump or filter. But I’d start with the ignition stuff, double check the timing, maybe adjust the valves if it hasn’t been done in a while.
ETA: Let’s not pooh pooh 73hp in a car that probably weighs about 1800 lbs. That’s roughly the same power to weight ratio as your average 4-cylinder mid-size sedan. You should be able to do 80mph in that thing no problem.
I totally agree it SHOULD have fuel injection, but I have personally stared into the abyss that is the carb mouth (tiny little thing, too–like maybe 2 inches across). And this little feller is reported to weigh just shy of 2,500 lbs, actually. I know it was never intended to be a racer, but it also means every horse lost & found is a big deal.
It might save a lot of time and trouble to have a full engine analysis run by a reliable shop. They can spot F/A, ignition, compression and other problems in about 20 minutes.
If the car is running well, odds are not good that any significant amount of horsepower is going to be found laying around. It’s a weak engine, probably weakened a little more by mileage, and a $250 carb rebuild to get back 1-2 HP is not likely a good budget choice.
If it’s really underpowered for your needs, sell or trade it up for something better suited. If you lose $500-1000 net on the deal, it still seems better than pumping money into a car that you can at best tease back to its initial underpowered state.
I agree with AB about having a compression test done. If the engine doesn’t have good compression, any sort of external add-on will be a waste of money.
I’m definitely a gear head.
My father and grandfather were professional mechanics. I have 2 pickups, 5 motorcycles and a car with a turbo and a manual transmission.
There is no way to predict how much power will come from what ‘project’. Life nor engines are that simple.
First step is standard diagnostics; compression test, cyl leak test, oil analysis and test for vacuum leaks.
That will tell you if it’s worth working on.
The next step is tuneup; Plugs/wires/cap/rotor/timing/
On a car that old I’d replace fuel line, radiator and vacuum hoses. And check brake lines.
But, if you can’t tell the difference between a carburetor and a throttle body, I suspect you’re in over your head.
I would also check wheel bearings and brakes.
Valve adjustment is a maintenance procedure that often gets overlooked. It’s a good place to start.
Check that the throttle opens fully when the accelerator pedal is pressed all the way down. If it doesn’t, adjust (or if necessary replace) the throttle cable – having first made sure there’s nothing preventing the pedal from making full travel.
Make sure the air filter isn’t super dirty, and if there’s any question about the fuel filter replace it.
Inspect the timing belt to see if it has stretched significantly, or possibly jumped one tooth, in which case replace it.
How much additional power you might get depends on if, and how much, these items are off.
The absolute best thing you can do to restore the feeling of power is never, ever drive a newer car. Not winning stoplight races is a serious understatement-- people forget how unbelievably slow old economy cars used to be. They were getting better by '87, but the 4wd Subarus were hold outs. This car should be able to maintain 65 on flat ground, but it’ll feel like it’s working at it.
Anyways, that said, I agree with the others that basic tune-up stuff and making sure the drivetrain isn’t dragging should be your first steps. Beyond that, one of the best relatively cheap things you can do is ditch the old stock smog carburetor (assuming you can get away with it where you live) and replace it with a Weber DV-series progressive one. The DV is a little 2-barrel carburetor that has a primary and secondary throttle operation just like a 4-barrel and they can really improve the cold starting, fuel economy and throttle response so it at least feels like you’ve got more power. You should be able to get one with an adapter for about $200, or else they’ve been around long enough you might be able to find a used one.
This is an intriguing idea. It doesn’t look like Weber makes one for the car, but Edelbrock does.
Couple questions about this. 1) does a worn/old carb affect performance (suspect ‘hell yeah’); 2) would a modern carb increase performance above factory specs; 3) would a modern carb (the one I’m looking at won’t ship to California) eliminate the octopus orgy of hoses currently swarming the OEM one?
Oh I fully intend to. If it isn’t clear, I am really appreciative of all the suggestions made here. I’ reasonably competent under the hood when it comes to swapping out like for like–right down to doing a long block overhaul. But my principle weakness is not always knowing where to start and stop, where points of diminishing returns are, that sort of thing.
I’ve never heard anything about the Edelbrock one, but I’m 100% sure you can get a Weber kit. They’re pretty ubiquitous on the old GLs that still run around here, as well as most any 70’s or 80’ Japanese car. The keyword you need to search for is EA82, which is the name of the engine you’ve got. Redline is the company that makes the kits for them and their part number for the EA82 is K-731. Googling the forumspheres, it looks like there are possibly some clearance issues with the power steering reservoir (if so equipped) and it won’t work with the stock aircleaner, but otherwise it bolts right on. Redline doesn’t sell them direct, but I’m seeing kits that include the carb, adapter and an air cleaner for about $300. ISTR you can find them cheaper places, but it’s been a while since I bought one. If you can find a used carburetor you can just buy the adapter kit, just make sure you get a 32/36 DGEV and you may have to do a little bit of tuning.
But the smog issue…
If you’re in California, forget about it. If you’re in another state that does emissions tests, you might be able to pass with the Weber on. Some of the kits are compatible with the stock emissions equipment (although I don’t think this one is) and I’ve heard rumors that you can sometimes get a DV-equipped car to pass emissions through the aid of timing shenanigans, but I wouldn’t count on it.
*Repairing *the car to near original HP output has been discussed by the pros above. That’s worth doing all the diagnoses & then fixing the items in order from cheapest to most expensive until your budget runs out.
*Hopping up *the car with aftermarket parts is plumb dumb. And would only be a good idea after doing all the repairs, even the most expensive ones. e.g. bolting a turbo onto an engine with bad compression won’t do a damn thing except destroy the motor quicker.
LSL: Agreed. I’ve got an ancient MR2 for when I want to scratch my hopping up itch. My concern with the 'roo is that it’s almost not safe to take on the highway for want of power. If it is substantially below spec and that can be corrected without removing the head, fantastic. If it requires a head rebuild, then I have something fun to do come springime. If this is basically all it was ever meant to have, then the kids use it for getting to and from wherever it is they go–slow cars don’t tend to inspire daring, ticketable offenses.
GSJ: Makes perfect sense. I had noticed that several folks upthread interpreted your OP to be asking how to hop up the car to better-than-stock performance. And I was weighing in that that was not a good idea, especially on a known-to-be-tired engine.
If you’re meaning the carburetor I suggested, it is an aftermarket part but it’s not really a go-fast part. The major attraction is that it’s much simpler than the OE carbs. They’re easy to tune and they stay in tune. They’re really popular with people who drive things like Toyota trucks or other other older vehicles that still get tons of miles put on them on (which in my part of the world includes lots of old Subaru wagons). The progressive 2-barrel design gives a lot better driving behavior at lower speeds and a bit more top-end than the OE 1-bbls or non-progressive 2bbls that normally came on older Japanese cars, but that’s just icing on the cake.
Considering that they cost about the same as a rebuilt OE unit, they’re really a no-brainer if the carb is shot and the local rules allow it.