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Horsepower vs gearing vs Tires and lift


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So I have a subaru over here in CO came with some wide 28 inch tires. It's got an 84 brat transmission and I absolutely roast my clutch trying to climb really steep trails like aspen mountain 4x4 trails. I only have a 4-hi transmission. Trying to climb from time to time my car will stall out because my engine just can't turn the gears with the 28s. I'm stumped. Accept my subaru sucks on trails. Smaller tires and lift it(wheel wells are chopped for the tires). Different gear box. More hp? I'm not keen on a regear as I'm broke and 18.

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Can u do the swap if the starter is at top of the motor? I heard u couldnt??

 

If the starter is on top, the motor isn't an 84 ;)

The last year for starter on top I believe was 81 or 82. After that all the EA71's were "fat case" and had the side/corner mounted starter.

I haven't ever seen a dual range top mount tranny myself, but they may exist.

 

Twitch

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We'll I have an 84 brat tranny and it's definetily not the stock transmission. I believe the transfer case is innermarried to these older subaru transmissions. So I'd have to get a whole dual speed transmission. And this 4 SPD blows for my setup. I can't get my car going fast enough to use 4th. Granted I can do 70 in 3rd. I'm leaning towards a 5 SPD dual range. If I can find one!

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What about just switching to a weber 32/36 carb? I heard it can boost hp from 70 to 100? Correct my numbers please. I have an old stock carb that's getting towards the end of its life.

 

Extra HP would be a short term solution for off roading. If you're hitting the clutch hard now, you'll only do more damage with more HP. A weber is a nice power upgrade but not a gearing solution turning 28s. That low gear will make all the difference for off road. If you get a 4 speed dual range from an EA81 car it will bolt right in - no modification necessary. Last tranny swap I did took maybe 6 hours total. They're a little heavy, but it's not a very difficult job, especially if you have a buddy to help.

 

A 5 speed dual range requires an EA82 drive shaft, and modified shift levers and a few options between redrilled flywheel, EA82 clutch/flywheel or some such thing. I forget the specifics. Not a terrible job, but more involved than just bolting up the 4 speed dual range. The last two transmissions I purchased for cars of this generation cost me $100. and $65.

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Extra HP would be a short term solution for off roading. If you're hitting the clutch hard now, you'll only do more damage with more HP. A weber is a nice power upgrade but not a gearing solution turning 28s. That low gear will make all the difference for off road. If you get a 4 speed dual range from an EA81 car it will bolt right in - no modification necessary. Last tranny swap I did took maybe 6 hours total. They're a little heavy, but it's not a very difficult job, especially if you have a buddy to help.

 

A 5 speed dual range requires an EA82 drive shaft, and modified shift levers and a few options between redrilled flywheel, EA82 clutch/flywheel or some such thing. I forget the specifics. Not a terrible job, but more involved than just bolting up the 4 speed dual range. The last two transmissions I purchased for cars of this generation cost me $100. and $65.

 

No flywheel modification necessary for the 5sp aside from resurfacing it to the right clutch spec.

Modifying shift levers is minimal, the biggest issue is the crossmember, and that only requires downspacing, and if you want to retain a chrome shift lever or not.

Everything else is pretty straight forward for the swap.

Just talk to Jerry (Bratsrus1) and he can hook you up with one of his kits.

You just supply the transmission, clutch and the driveline (and the money to buy the kit of course :P )

 

 

Yah I dig the 4 SPD brat tranny I've got besides the transfer case. So it's any 4spd from an ea81 with 4 hi-lo I want?

 

You can go that route, look for a low mileage one. I have killed 2 of those transmissions myself, 1st gear in one and 3rd in another.

Find a low mileage one that has clean gear oil. That will be your clue to its life so far. Also, if you get the chance, check the magnetic drain plug.

Lots of metal shavings, bad juju. Very few metal shavings, good news. No metal shavings, somebody flushed and changed the fluid and cleaned the drain plug. Who knows...

 

Twitch

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So I have a subaru over here in CO came with some wide 28 inch tires. It's got an 84 brat transmission and I absolutely roast my clutch trying to climb really steep trails like aspen mountain 4x4 trails. I only have a 4-hi transmission. Trying to climb from time to time my car will stall out because my engine just can't turn the gears with the 28s. I'm stumped. Accept my subaru sucks on trails. Smaller tires and lift it(wheel wells are chopped for the tires). Different gear box. More hp? I'm not keen on a regear as I'm broke and 18.

 

How often you use it for mountain Trials? ... If you Also use it as daily Driver?

 

In my Case, I chose 25" tires and 2" lift because my "Mixed" kind of Driving:

 

40% Offroading on Weekends + 60% of on road duty, 'cos is my Daily driver,

 

Also I Placed a Weber Carb ... I don't have Dual Range,

 

but my "BumbleBeast" goes Strong Everywhere with that Combo.

 

Kind Regards.

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What about just switching to a weber 32/36 carb? I heard it can boost hp from 70 to 100? Correct my numbers please. I have an old stock carb that's getting towards the end of its life.

I am seriously doubtful that Any carb swap as a single upgrade can make 30 hp -unless you are seriously starving the motor currently. If there was that much lost power, I believe Subaru would have done something different in the interest of efficiency.

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We'll I have an 84 brat tranny and it's definetily not the stock transmission. I believe the transfer case is innermarried to these older subaru transmissions. So I'd have to get a whole dual speed transmission. And this 4 SPD blows for my setup. I can't get my car going fast enough to use 4th. Granted I can do 70 in 3rd. I'm leaning towards a 5 SPD dual range. If I can find one!

While you're technically right about the transfer case being intermarried, there technically is no transfer case. Its just a gearset at the back of the transmission that locks the rear output shaft to the front. And the low range gearing actually engages before the power hits the rest of the transmission. That gearset is right up front in the transmission housing and its actually a totally different part from the 4 wheel drive.

 

Disom93, that will require an engine swap to make it work, as the 'fat case' and 'slim case' EA bellhousings are incompatible.

 

Twitch

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If the starter is on top, the motor isn't an 84 ;)

The last year for starter on top I believe was 81 or 82. After that all the EA71's were "fat case" and had the side/corner mounted starter.

I haven't ever seen a dual range top mount tranny myself, but they may exist.

 

Twitch

Much confusion added at this point, since someone other than the OP asked about top mount starter.  So, to clear things up:

 

PA Grown, is your starter on the side like an 84 Brat should be, or on the very top-center like a much earlier Brat?

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 I'm not keen on a regear as I'm broke and 18.

 

2.5 and a 4.44 would be a great setup, but probably not fitting for an 18 year old on a budget.

 

If you can post up a picture of where your starter is mounted, we can tell you concretely which transmissions to go for. Chances are that you have options for EA series transmissions. The quick and simple solution find a 4 speed dual range and swap it in - no modification necessary.

 

The other option, which will probably be a bit more expensive and a little more labor intensive project - swap a 5 speed dual range with the added parts/modification. The 5 speed has better gearing, the 5th gear for highway driving and is less prone to failure than the earlier 4 speed. The 4 speed isn't a bad trans, just not as bullet proof as the later 5.

 

PA Grown- what's your automotive experience so far? There are a lot of options available to your car, but if you're new to working on it/modifying it, best to start small and manageable. If we know what you're up for we can give better advice for your needs. Either way, go easy on that clutch until you've got something line up. Unless it's just a wheeler.

 

Twitch - Isn't there a re-drilling option for the flywheel to keep an EA81 clutch? Or some such thing? It's been a while since I researched the particulars of it. I have a low miles 5 speed for the Ski Team Wagon, but the project is on hold for now until I get the car out here.

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If your trans is single range, it's not from an 84 brat.

 

all manual trans second gen brats had 4spd dual range trans.

 

 

Weber carb will not yeild 30 hp increase.  I'm not convinced they add any power at all, just make it louder and "less cluttered" under the hood.

 

I personally preffer the Hitachi carbs, and a few air bleed hoses don't scare me.

 

Help us help you here and please tell us the year, model, and engine OF THE CAR!  not what year you think the trans is from....not very helpful information.

Edited by Gloyale
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We'll the reason me and the guys at the track think it's an 84 brat is those are the only axle we can get to fit the front end. Of course all the splines for these old subarus seem to be the same so far. This cars a junkyard dog I'm finding out new things about its history every other repair I make.

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What Gloyale said, 

 

Help us help you here and please tell us the year, model, and engine OF THE CAR!  not what year you think the trans is from....not very helpful information.

 

You still didn't say the year of the car. Maybe look in the door jam for a date code if you don't know? 

Edited by capn_r
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