Stock 01RS hp. (flywheel)

[2sour4u]

Just wondering...how much hp. does a stock 01' 2.5RS put out at the flywheel?

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[rupteur7000]

165hp
166ftlbs

[munkis]

hi, im your owners manual, please read me

hi, im the search button, use me



but yes 165hp/166lb ft.

Jay

[Reciprocity]

To be exact...

165 hp @ 5600 RPM
166 lb ft @ 4000 RPM

NC

[mcu81]

actually you are both wrong, the 2000 and 2001 actually make more, thats the readings from the 99 motor, figure you got 5-7 more ponies than that stock, subaru just never dynoed, and used the same #'s

-mikey

[Penphoe]

Originally posted by mcu81
actually you are both wrong, the 2000 and 2001 actually make more, thats the readings from the 99 motor, figure you got 5-7 more ponies than that stock, subaru just never dynoed, and used the same #'s

-mikey

How do you know that? Where is your source? The el-butt dyno is known to have a high correction factor!

Then again, there are manufactures like Nissan who (ahem) made a very optimistic guestimate on their HP and torque numbers for the Spec-V. Then they had to "tone it down" after they actually dynoed it.

LaterZ!
Darren!!

[Reciprocity]

Originally posted by dcrawford
To be exact...

165 hp @ 5600 RPM
166 lb ft @ 4000 RPM

NC

I got that from Edmunds...for a 2002 2.5L motor. I don't think there are any differences between the 2000-2001 and 2002...well, a slightly revised intake I believe.

NC

[mcu81]

i forget my source, sorry guys, but the but dyno will back it up!

[Chav]

I have heard the same thing. Subaru dynoed the phase I engine, but never bothered to dyno the phase II design. Would be nice if someone could confirm this and give us numbers.

-Chav

[Basshead]

every motor is different and will give you different power output within a few hp, but the design has been the same for the past 3 years, and should be very close...power output is the same as the phase 1 1998 dohc design, but switching to the sohc design flattened/widened the torque curve, and put more usable torque down low...i've seen dyno graphs for both, just don't have/know where to get them anymore....at our local events i can creep up on 1998 rs's..but the 2000/1's never pull away from me, 5-7hp due to a change from a MAF to a MAP? hard to believe.....l8

[Section 8]

165 hp @ 5600 RPM

166 lb ft @ 4000 RPM

Thats what my Subaru Media CD ROM says for 2001 as well.

It also says that the 2001 RS has 9.7:1 compressin ratio. I always thought that the compression ratio was 10:1 and the peak HP was 169.

THis gives me even less respect for the media......

Greg

[Section 8]

at our local events i can creep up on 1998 rs's..but the 2000/1's never pull away from me, 5-7hp due to a change from a MAF to a MAP? hard to believe.....l8

There is/could be a difference in compression ratio. This could affect the ignition timing curves that Subaru decided on, and the ECU's were programmed differently in 00-01 anyway. (The recent reflash recal proves that).

5-7 HP on an auto-x course is nothing. To many variables involved generating noise to try and compare accuratly.

cheeRS,

Greg

[Layman]

Originally posted by Basshead
5-7hp due to a change from a MAF to a MAP? hard to believe.....l8

It has less to do with the switch from a MAF than the switch to SOHC.

[Basshead]

1999 = MAF SOHC
2000-1 = MAP SOHC

both are exact same engine

[Section 8]

Some 99's slipped out early in the build year with DOHC...... but they are by far not the norm.....

cheeRS,

Greg

[HndaTch627]

IIRC the 99's had 165hp/160ft lb torque...ask revision, he knows all the numbers

Jeremy

[mcu81]

Originally posted by Basshead
1999 = MAF SOHC
2000-1 = MAP SOHC

both are exact same engine

nope

99 compression 9.7.1
00-02 10.0.1

[BOY]

MY 98 Phase 1 DOHC
MY 99-01 Phase 2 SOHC

Yes, MY 00-01 had 10.0:1 compression
Yes, MY 99 had 9.7:1 compression
Yes, MY 99 had MAF sensor
Yes, MY 00-01 had a MAP sensor

The heads are the same for 99-01, the blocks are listed under different part numbers, the only change is probably a few mm deck height. The MAF sensor, although fragile, reads the incoming air mass and are more accurate for A/F calculations.

The MY99's are dramatically different from the MY98's, I don't buy it that Subaru could "accidentally" put the wrong engine in the car. The ECUs are very different, the ignition system is different, the MAF sensor is different. Too many parts would have to "accidentally" be switched. As for the few hp difference, woohoo! You'll get more change than that based on weather conditions . Each car is different, factory hp numbers are an average.

[Patrick Olsen]

Originally posted by Chav
I have heard the same thing. Subaru dynoed the phase I engine, but never bothered to dyno the phase II design. Would be nice if someone could confirm this and give us numbers.

-Chav

Highly unlikely that any manufacturer would put an engine in their car without extensive testing. Completely changing the heads and valvetrain (as Subaru did going from the Phase I to the Phase II) is not something an automaker would do and then send to market without dyno testing, endurance testing, etc.

And, if you look at the specs for the '98 2.5RS and '97-99 2.5GT (all of which used the DOHC Phase I engine) you will find that the ratings are different than those for the '99+ 2.5RS and '00+ Legacy/Outback. The Phase Is were rated at 165hp @ 5600rpm and only 162ft-lb @ 4000rpm. Not a huge difference, but the peak numbers don't tell the full story. The SOHC cars have a much better torque curve, and part throttle response is also much improved.

I think it is worth noting that Subaru's torque numbers seem to be under-rated. I know that all of the dyno results I've seen during dyno days at Adrenalin Motorsport in Massachusetts have shown the 2.5L cars (both DOHC and SOHC) to have about 10-15 more ft-lbs of torque than they do HP. Check out this graph that I compiled from one of my stock runs compared to a stock SOHC 2.5RS run:

Both cars peaked around 105hp, so based on the factory ratings one would expect the torque peaks to be in the 105ft-lb range. In actuality the torque peak for my DOHC 2.5GT was around 112ft-lb, and the SOHC 2.5RS peaked around 122ft-lb (I have the actual numbers at home, but reading off the graph should be good enough for now). I've seen the same type of results for a number of stock or lightly modified (intake and exhaust) RSs. Now, it could just be the dyno that Adrenalin uses, but I vaguely recall seeing Dynojet graphs with the same sort of HP/Tq mismatch. Interesting....

Pat Olsen
'97 Legacy 2.5GT sedan

[phucvtec]

Im learning a bit, so please correct me if im wrong, but... isn't is safe to say that if someone is concerned with the HP and Tq of an engine, they are really concerned with acceleration, or more specifically, quicker straight line times? If this is the case, then why are sooo many people concerned with PEAK HP and Tq, rather than how broad their ranges are? Ill tell ya one thing, I did not buy headers for my impreza because I wanted to maximize my vehicles peak HP and Tq, I bought them because I know that the HP and Tq curves would broaden greatly, especially in mid to high ranges. As was expected, my vehicle accelerates much faster now, though I doubt that my peak HP and Tq have gone up any. Its my belief that peak values are mearly an advertisement tool for automotive companies to push their product. I feel that there should be some means of quantifing how "peaky" an engine's power is, and that should be quoted as well

[2.5GT]

phucvtec, I believe you are correct . . . partially . . . it all depends on what you want out of the engine.

For a daily-driven street car, you'd want a flatter, broader torque curve. This basically means that you'll have useable power throughout the rev range (or most of it anyway). Honda's are notoriously known for being "gutless" at lower rpms. Why? Because they are peaky engines. Compare that to a VR6, per se, and you'll see crazy variances in powerbands, or should I say torquebands.

However, this peakiness shines at the track, where for the large majority of the course, the driver will keep the engine within the optimal powerband.

Its my belief that peak values are mearly an advertisement tool for automotive companies to push their product. I feel that there should be some means of quantifing how "peaky" an engine's power is, and that should be quoted as well

Yeah, that'll happen

I did not buy headers for my impreza because I wanted to maximize my vehicles peak HP and Tq, I bought them because I know that the HP and Tq curves would broaden greatly, especially in mid to high ranges.

I'm sure the acceleration advantages had from changing aftermarket parts had more to due with changes in the height of the curve at certain parts of the torqueband, rather than an overall broadening of it (unless you did some major engine modifications to it). Either way, the resultant area under the curve is greater.

Now someone please correct me, if I'm wrong

Jason

[Section 8]

I don't buy it that Subaru could "accidentally" put the wrong engine in the car. The ECUs are very different, the ignition system is different, the MAF sensor is different. Too many parts would have to "accidentally" be switched.

They didn't. They simply put DOHC heads on the blocks and used everything else for the 99 year.

There are people who have that configuration from the factory in their cars, it has been refered to as the "silver bullet", and this is not any new information. For an example there is also a difference in rear calipers, if you order pads for a 99, they could fit or they might not, depending on what the build date was, 2 different part numbers for the same part in the same year. Same situation, different part. Porsche CONSTANTLY changes spec, and it must be a pain in the butt getting parts for the car unless you know exactly what you are doing. (of course you probably wouln't need to worry about that, if you own a newer Porsche, odds are you don't do the maintenance on it anyway).

cheeRS,

Greg

[LordBass]

And all this thread just from a small failure to use the search button, read a manual, or check out any number of websites that have the answer to the original question..

Interesting discussion, tho.. I even learned something with Pat's dyno post! Imagine that! .. I had no idea the torque number was so much higher than the hp.. That explains why my TS pulls like a frieght train from ~3250rpm on up. Even stronger after cat-back exhaust/ghetto CAI.

lb
www.trancelab.com

[Section 8]

I had no idea the torque number was so much higher than the hp..

Thats at the wheels in probably 3rd or 4the gear. Since those gears are not 1:1 they are multiplying torque . Thats why your car pulls the hardest in 1st gear and has the least pull in 5th gear (A bad example due to air restance, but your acceleration is less and less as you go through the gears).

cheeRS,

Greg

[Patrick Olsen]

Originally posted by Section 8
Thats at the wheels in probably 3rd or 4the gear. Since those gears are not 1:1 they are multiplying torque

Ahhh, that's a good point, and probably does explain the mismatch. Greg, go ahead and work the math to figure that out for me.

BTW, what the hell's up with Subaru not having a 1:1 gear to dyno with??!!

Pat