June 27, 200421 yr Pretty much as the topic says. I'm used to other vehicles which have much longer gears and a much lower 5th/freeway gear. 4,000 seems high to be turning for multiple hours on a freeway. Is there a way to change the gearing to bring this down some or is it just fine and I'm a lunatic? BTW: The vehicle is an 1988 RX 3dr liftback, EA82T w/dr 5spd, stock 13" wheel/tire combo.
June 27, 200421 yr Without doing drastic drive train changes, you could put on some 15in Pugs. This might help a little.
June 27, 200421 yr Author I assumed as much, but I was just making sure that no one out there had performed a radical modification to the DR setup or the final drive ratio. By Pugs you mean 15" Pugeot rims that match the stock wheel bolt pattern?
June 27, 200421 yr that seems high for a 5 speed. my 4 speed is about 4200 at 80. are the rx trannies different than a manual dr 5speed?
June 27, 200421 yr While I drive an EA81 auto ive put the better part of 100k on my car at around 4500 rpm. No problems for me. Also those kit builders that use ea81's liek to gear it so that the engine is at 5000 rpm for the flight, as that puts it at the top of the power band and you get good fuel usage out of it. Alex
June 27, 200421 yr Pretty much as the topic says. I'm used to other vehicles which have much longer gears and a much lower 5th/freeway gear. 4,000 seems high to be turning for multiple hours on a freeway. Is there a way to change the gearing to bring this down some or is it just fine and I'm a lunatic? BTW: The vehicle is an 1988 RX 3dr liftback, EA82T w/dr 5spd, stock 13" wheel/tire combo. Hey targarose, I have a '89 GL Sedan, DR 5 speed. I'm not ready to put it back on the road just yet so I can't run out and check it. With the 3.90 gear @ 4500 RPM or so, it runs 105 mph, in fourth. The tach may be off. Do you have it in low range? Under sized tires? Please report what you find out. Q
June 27, 200421 yr My XT is about the same, about 4k in 5th at 80. Let's face it, old-gen Subarus are small cars with small engines. To put a really tall gearbox in it would only make it slower and use more gas since the engine would have to work harder. Like Turbone said, you can put bigger wheels on it, but that's about it. No other gearbox that will fit an EA is going to give you drastically longer gearing.
June 27, 200421 yr With the 3.90 gear @ 4500 RPM or so, it runs 105 mph, in fourth. 105 in fourth? I don't think thats true for a second.
June 27, 200421 yr First, the rpm/speed you list is about right. +/- a few mph depending on fine tuning. Upgrading to 15" Pugs can boost about 10%. Second - why do you need to go faster than 80? Do the speed limit, live longer, enjoy the countryside. Don't be in such a big hurry. If time is that important, fly.
June 27, 200421 yr First, the rpm/speed you list is about right. +/- a few mph depending on fine tuning. Upgrading to 15" Pugs can boost about 10%. Second - why do you need to go faster than 80? Do the speed limit, live longer, enjoy the countryside. Don't be in such a big hurry. If time is that important, fly. somebody's showing ones age again (j/K) but I don't think 4 grand is that high a crusing speed for the engine
June 27, 200421 yr Just back a few months ago I got a whopper. 87mph in a 70mph zone. Cost me $100 in court costs. Northguy, you may want to look at the calender for next month :-p Oh, and sorry for the H/J :-\ 3.90 gears make for a higher rpm, the 3.70 is better for hiway use.
June 28, 200421 yr you shouldnt need to change the gearing.... subaru motors are designed to run at high rpms for long periods of time... in fact, i have noticed that the ones that are used in that aspect, last longer and run better- so I would just get used to it... (think of it like a sport bike! they run about 8000rpms for a crusing rpm ) cause your motor will run good at that rpm (besides, if you get to a hill, you will need it to be in the powerband anywyas to climb it)
June 28, 200421 yr I agree. I get alot better mileage when I'm on the freeway. I think I'm doin about 75ish at 3500: 3.9 axel ratio DR 5sp. Kinda hard since the speedo sticks between 55 and 75. So, 4K at 80 sounds about right.
June 28, 200421 yr Author My speedo sticks as well, but I took the average. I understand that the flat-4 motor is designed to handle turning 4,000 just fine, it just seems odd coming from driving vehicles that turn sub-2,800rpms on the freeway.
June 28, 200421 yr on the road trip the second time, the RX averaged a 500 rpm higher difference than trashwagon's part time dual range, but it got better fuel economy in danny's loyale, h connected one of those vacuum gauge "gas saver" and as you increase rmp for the same amount of pedal travel, the needle moves up into the good and excellent. if you notice, say at 50-55 mph in 4th gear, there is less pedal effor than trying to keep the same speed in 5th at a lower rpm 3500-4500 rpm is optimum range for the ea82 motor, right smack in the powerband. whenever i go baja'n in the field, the tach is always about 4500 to 5500 rpm all day, and the motor doenst complain one bit!
June 28, 200421 yr whenever i go baja'n in the field, the tach is always about 4500 to 5500 rpm all day, and the motor doenst complain one bit! I seem to remember it hovering around 7k for quite some time...
June 28, 200421 yr The final drive of the RX FT 5speed D/R and the PT 5speed D/R are very close. Without all the math…. RX F/T 5speed D/R 5th gear ratio = .871 Final drive = 3.7:1 Tire size = 185/70HR13 (23.2” Dia.) 3268rpm @ 70mph 3735rpm @ 80mph 4WD P/T 5speed D/R 5th gear ratio = .780 Final drive = 3.9:1 Tire size = 175/70SR13 (22.6” Dia.) 3167rpm @ 70mph 3620rpm @ 80mph These numbers seem to agree with my ’87 RX Gary
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