Is 2.2 "zippier" than 2.5?

[91LegLS]

My friend recently bought a '00 OBW LTD with 60K. He just had the 60K maintenance done (oil change, fuel filter, air filter {K & N} spark plugs and wires, trans filter change, etc. etc.) He remarked that my 2.2 accelerates much quicker than his 2.5. Sea foam has been used to clean his engine. Injectors cleaned with 44K. He said that his performance improved after the engine cleaning but it doesn't accelerate as easily as my car. Is there something wrong with his engine? Does the '00 OBW weigh more than the '91 LS Wagon? I've driven his car and his does seem to be slower but it will hit 90MPH no problem. Just slower from stop.

[Manarius]

Is this a "Auto vs Manual" comparison? That would change it a lot.

 

Has he changed the knock sensor on the OBW lately? That can really give you crappy starts.

[outback_97]

Does the '00 OBW weigh more than the '91 LS Wagon? I've driven his car and his does seem to be slower but it will hit 90MPH no problem. Just slower from stop.

Yeah.... Your 91 might have a higher ratio of power / weight even with its smaller 2.2. Plus they could be geared differently, but even if not that weight difference is pretty significant. The Outbacks are rather portly compared to first gen Legacies.

 

Steve

 

 

*EDIT: I searched on the wrong models, only 290 lb difference between the cars being discussed here, as nickb21 noted below. Still a good amount of weight though.

[91LegLS]

Is this a "Auto vs Manual" comparison? That would change it a lot.

 

Has he changed the knock sensor on the OBW lately? That can really give you crappy starts.

 

I'm going to assume the knock sensor is the original. Both vehicles are automatics with AWD.

[outback_97]

n/m

 

EDIT: no message, never mind

 

when you edited your post prior to this one it made my post irrelevant.

[91LegLS]

n/m

 

I'm sorry, what does "N/M" mean?

[nickb21]

N/M = nevermind

 

According to cars101.com; the '00 OBW LTD is 290 lbs heavier than your '91 LS. (non-LTD is 205 lbs heavier)

 

I'd say that is the main reason it feels/is slower. The '00's 2.5 only puts out 35 more HP, I don't think that's quite enough to compensate for the weight.

[ericem]

isnt nevermind nvm?

[Manarius]

isnt nevermind nvm?

It can be either.

 

My friend's like 97 drove like crap until the knock sensor was replaced. The ECU had retarded the timing so much that it drove like it was a slushy.

 

I do have to admit though, the Torque Converter on the older 4EAT's is pretty aggressive. I don't know if that has anything to do with the "butt-o-meter" rating, but I personally think that my 91 L AT AWD is better off the line than my friend's 97 even with the knock sensor replaced - and her car has mor HP than mine (not too much though).

 

It could be a final drive ratio as well. The 91 is 4.11, the 00 may be 3.9 or 3.7 which would make for a very tall 1st gear, with slow start.

[nipper]

My friend recently bought a '00 OBW LTD with 60K. He just had the 60K maintenance done (oil change, fuel filter, air filter {K & N} spark plugs and wires, trans filter change, etc. etc.) He remarked that my 2.2 accelerates much quicker than his 2.5. Sea foam has been used to clean his engine. Injectors cleaned with 44K. He said that his performance improved after the engine cleaning but it doesn't accelerate as easily as my car. Is there something wrong with his engine? Does the '00 OBW weigh more than the '91 LS Wagon? I've driven his car and his does seem to be slower but it will hit 90MPH no problem. Just slower from stop.

 

this is not a fair test. You cannot compare two cars from two differnt generation of model. Not only is the newer car heavier, but the 00 has a 16" tire, and the older one has a 14" tire. Thats a HUGE difference. Also they are most likely geared differnetly.

 

nipper

[firstwagon]

this is not a fair test. You cannot compare two cars from two differnt generation of model. Not only is the newer car heavier, but the 00 has a 16" tire, and the older one has a 14" tire. Thats a HUGE difference. Also they are most likely geared differnetly.

 

nipper

 

Actually that depends on the sidewall ratio. The 14 inch rims on my 91 come with 70 series tires. I could install 16 inch rims with 215/50/16 tires and the diameter (and thus the effective gearing) would be exactly the same.

 

I think it's a combination of a short 1st gear, tight torque convertor and lighter weight that gives the early 2.2's such a great jump off the line.

[91LegLS]

It can be either.

 

My friend's like 97 drove like crap until the knock sensor was replaced. The ECU had retarded the timing so much that it drove like it was a slushy.

 

I do have to admit though, the Torque Converter on the older 4EAT's is pretty aggressive. I don't know if that has anything to do with the "butt-o-meter" rating, but I personally think that my 91 L AT AWD is better off the line than my friend's 97 even with the knock sensor replaced - and her car has mor HP than mine (not too much though).

 

It could be a final drive ratio as well. The 91 is 4.11, the 00 may be 3.9 or 3.7 which would make for a very tall 1st gear, with slow start.

 

When we were researching the availability of Limited Slip for the '00 OBW LTD we confirmed the vehicle had it and the gear ratio is 4.44.

[cookie]

Those early Legacies sure did seem peppy off the line. I always assumed that it was due to the light weight. The 2.5s have more torque when you climb a hill I think.

[Virrdog]

Take them both to a drag strip and get objective numbers. 60', 1/8th mile traps and speeds along with 1/4 mile traps and speeds.

 

Conjecture over...

[Andyjo]

I agree w/ nipster, when i went up to 16" rims from the 15"ers... huge gearing difference.... it could also be that when you give the 2.5 some go juice, it has more mass to move, than the 2.2... i mean.. that's why you can't rev an 8cyl to the sky... there's just way to much mass moving around in there

[BruceyWV]

.double post.

[BruceyWV]

I disagree Unless we're talkign some revving to infinity honda engine, or those 3 liter V8's that rev to 15,000 RPM.

My first 4.6 V8 had the same redline as my 2.5 boxer: 6000 RPM.

 

The problem with the 00-04 is simply weight. They are the heaviest vehicles Subaru made those years, and have the worse power to weight ratios. The SVX weighed about the same, but it had an 3.3 liter engine backing it up. (It was still slow) I've driven an RS and an 05 Outback (both also use the EJ25) and they are a lot faster.

 

It could be due to gearing, but I thought the automatics had 4.11 gears, with the 4.44 for the manual? (maybe I have that reversed?)

[nipper]

It comes down to wheel thrust.

 

http://www.webcalc.net/calc/0774.php

 

Wheel thrust is simple, the higher the number the faster the get up and go

 

Lets use simple numbers

wheel thrust = drive wheel torque / rolling radius (from axle to ground)

 

200 ftlbs of torque/ (assume a rolling radius of 10") .83' = 240 lbs of thrust

 

200 ftlbs of torque/ (assume a rolling radius of 12") 1.0' = 200 lbs of thrust

 

As you can see larger the tire, less push at the axle. What you do gain is however is less engine rpm and better gas mileage (in theory).

Also with less thrust you get more torque at the rear wheel. The more force it takes to move something, the more thrust will be needed. So unless

 

Now add in the rolling resistance of a wider tire, and hte heavier car, it wont accelerate as fast as the older car.

 

nipper

[Megell]

Keep in mind that "anything" that you do to a four cylinder car can make a drastic difference in the performance. Changing gear ratios due to tire/wheel combinations, especially larger, will sometimes seem like someone stuffed a potato in your exhaust. After all it is only a four cylinder engine. For example(?), if your eight cylinder engine is "missing" on one cylinder, you still have the other seven cylinders firing and the performace drop is noticable, but it's only 1/8th of a drop. On a four cylinder engine, it is a 25 percent drop in hp and performance.

So, my point here, is it doesn't take much to make a more significant difference in performance with a four banger engine. Add a several pounds of humans to the car and performance will drop accordingly.

Mike

[destey]

performace drop is noticable, but it's only 1/8th of a drop. On a four cylinder engine, it is a 25 percent drop in hp and performance.

 

I'd think it'd be more than that. When a cylinder goes down, now not just that cylinder isn't producing power, its also along for the ride. It takes power to move the mass of the piston, piston rod, 1/4 of the valves and 1/4 of the crankshaft. Not to mention the biggest hurt of all, the compression.

[nipper]

I'd think it'd be more than that. When a cylinder goes down, now not just that cylinder isn't producing power, its also along for the ride. It takes power to move the mass of the piston, piston rod, 1/4 of the valves and 1/4 of the crankshaft. Not to mention the biggest hurt of all, the compression.

Not to mention it is now working as air pump. Mathmatically it is 25%, in reality its probably a bit more.

The way some of the engine analyzers work (the huge ones in shops) is that they shut down one cylinder and measure the rpm drop to come up with a compression ratio (along with a few otherparimiters taken while the cylinder is firing) it is extreemly accurate. So mathmatically at 25% it does work.

 

nipper