Peak torque and HP - 2.5L ??

[billgin]

1046709

Anyone know at what RPM a 2.5L in a 1990 YJ develops peak torque and HP? I've been looking for this info on the Net, but can't find anything. I'd like to know how to balance power/acceleration/fuel economy. I've got that upshift light, and it insists that I upshift at 2100 RPM, which has me in 5th gear by 40 MPH. Good for fuel economy, lousy for fun and acceleration. Any info appreciated.[addsig]

 

[erhild]

1046713

I NEVER put my 4-banger in 5th... IMHO, it is far to dangerous to have NO ACCELERATION ability... Screw the gas mileage... What's a few bucks here and there???[addsig]

 

[MudderChuck]

1046716

My manual says 116 ft.lbs. @ 2600 RPM´s and 83 HP @ 4200 RPM.[addsig]

 

[Bounty__Hunter]

1046734

83hp? And I thought the MPFI 2.5L was around 110 or 120hp, must be the old TBI holding ya back. Wait until the new 2.4L of the '03 TJ makes 170hp, knocking on the door of the 4.0L hp range

[addsig]

 

[billgin]

1047010

I got the following info from <www.off-road.com>. It answers my original question about peak torque and HP for the 2.5L, but makes me wonder why MudderChuck's manual quotes much lower torque and HP numbers, and different RPMs.



AMC 150 I4

Bore x Stroke 3.88" x 3.19"

Displacement 150ci (2.5L)

Compression Ratio 9.2:1

Horsepower (net) 117@5000

Torque (net) 135@3500

Main Bearings 5

Valve Configuration OHV

Fuel TBI



The above supposedly applies to 87-90 YJs. From 84-86, the numbers were 105 HP and 135 torque, and 91 and later had 123 HP and 139 torque.



I guess you just never know which numbers to trust. Maybe it doesn't matter - my YJ's 4 cyl. seems to think it's a V-8 most of the time anyway![addsig]

 

[Quik8slvr]

1047021

my 2.5L used to like to think it was a V8, but now that i've got a V8 i'll tell you that its a whole other ball game...i will tell you some quick ways to give the 2.5L some bigger balls, and thats Hollow out the Cat (or buy a free flowing one), Cat Back Exhaust, Borla Header, Air Raid intake, and the Throtle body spacers are good, all of the following mods and you should be in the 150 HP and torque ranges[addsig]

 

[JE420EP]

1047027

I have a 90 yj and i put a header on it and a flowmaster, clifford makes the header and i also put 488's gears in the front and rear. Right now i have 31 inch tires and i got some much torque i need bigger tires i can fry the 31s and my 5th gear is soooo killer. This set up will give you lot of power out of a 2.5l.

[addsig]

 

[MudderChuck]

1047068

The differences are probably, how the motor was measured. On a dyno or at the rear wheel. I´ve noticed, very different numbers, in different manuals. I was looking at posted horsepower numbers for insurance purposes, and came up with many different numbers for the same vehicle, I always use the lower number for the insurance and the higher number when talking up my Jeep.

[addsig]