Actual horsepower?
12-18-2005, 04:14 PM
#1
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Thread Starter
Join Date: Aug 2005
Location: Buffalo, NY
Posts: 4,967
Actual horsepower?
I kno this has been asked before but real quick,,,,,, why is the Mustang GT advertised with 260hp when it actually gets significantly less? how do they get away with it? How much hp am i actually getting stock? How much for a V6(195hp as advertised i believe)? Are all automotive companies like this? I think thosed damned SRT4's are advertised as 230hp how much do they get? thanks
12-18-2005, 05:30 PM
#6
3rd Gear Member
Join Date: Sep 2005
Location: Washington State
Posts: 938
RE: Actual horsepower?
ORIGINAL: pj1010
This dude has all theses performance parts and asked this question....what roads do you drive on so I can stay off of them,
This dude has all theses performance parts and asked this question....what roads do you drive on so I can stay off of them,
12-18-2005, 07:16 PM
#8
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Thread Starter
Join Date: Aug 2005
Location: Buffalo, NY
Posts: 4,967
RE: Actual horsepower?
Thanks to all those who replied, I was just wondering about this, i didnt kno so I thought i would ask, I am only 19 and have limited experience with this, i am sorry i am not a genious and btw with the exception of the gears i installed everything myself (not many "mustang performance shops" around Buffalo NY) and more money than knowledge, haha well everything i have i work for in addition to going to college so the more money part is deff not true. When you dont know something i thought you ask and find out, isnt that what a forum is?
12-18-2005, 07:30 PM
#9
2nd Gear Member
Join Date: Dec 2005
Posts: 309
RE: Actual horsepower?
No need to apologize and yes, this is what these forums are supposed to be for - not for beating up on people who ask questions. Everyone has to learn, and there are no dumb questions, only dummies who don't learn the first time and ask them again. You've done a lot of the work yourself, so keep it up.
SAE (Society of Automotive Engineers) has a way of defining what a car's HP rating means and how it is determined. Over the years they have updated this from time to time, most noteably in the early 70s when the convinced the whole industry to go from gross to net HP ratings -- a '70 427 Vette was rated at 435 HP gross but that same engine would be rated about 310 net.
How this is defined and what it means is pretty technical and takes pages to lay out specifically, but the important point is that it is an estimate of the power the engine produces when in the car, with the mufflers hooked up and while running all the standard equipment, what is called "at the flywheel." This is not easy to measure because you can't hook up a dynometer to the flywheel so most owners and shops measure it at the rear wheels. There, the car experiences some loses in power consumed by the transmission, U-joints, differential gears, axles bearings, and tires. All in all, most manual transmission cars loss about 11% to 15% from flywheel to drive wheels (GM M-6 cars a a bit better than most here, losing typically about 11%, Fords, about 3%, don't know why). Auto trans cars tend to lose an additional 3-5%: my 320 HP rated Porsche has the Tiptronic auto and did 265 RWHP - 17.2% loses.
You can reduce those loses slightly, very sligthly, by running a more expensive brand of synthetic lubricant in the trans and differential, but you would see only about 2 RWHP gain, at most.
Your Ford was rated at 260 HP flywheel by Ford, following its interpretation of the SAE standard in effect when your car was manufactured. Stock, with a manual trans, it probably dyno tested with about 225-230 RWHP, with an auto 220-225. Your car out to be doing a bit more than that. Have it tested and start keeping a record, then as you add more HP, you'll know what you are getting for your money and work.
SAE (Society of Automotive Engineers) has a way of defining what a car's HP rating means and how it is determined. Over the years they have updated this from time to time, most noteably in the early 70s when the convinced the whole industry to go from gross to net HP ratings -- a '70 427 Vette was rated at 435 HP gross but that same engine would be rated about 310 net.
How this is defined and what it means is pretty technical and takes pages to lay out specifically, but the important point is that it is an estimate of the power the engine produces when in the car, with the mufflers hooked up and while running all the standard equipment, what is called "at the flywheel." This is not easy to measure because you can't hook up a dynometer to the flywheel so most owners and shops measure it at the rear wheels. There, the car experiences some loses in power consumed by the transmission, U-joints, differential gears, axles bearings, and tires. All in all, most manual transmission cars loss about 11% to 15% from flywheel to drive wheels (GM M-6 cars a a bit better than most here, losing typically about 11%, Fords, about 3%, don't know why). Auto trans cars tend to lose an additional 3-5%: my 320 HP rated Porsche has the Tiptronic auto and did 265 RWHP - 17.2% loses.
You can reduce those loses slightly, very sligthly, by running a more expensive brand of synthetic lubricant in the trans and differential, but you would see only about 2 RWHP gain, at most.
Your Ford was rated at 260 HP flywheel by Ford, following its interpretation of the SAE standard in effect when your car was manufactured. Stock, with a manual trans, it probably dyno tested with about 225-230 RWHP, with an auto 220-225. Your car out to be doing a bit more than that. Have it tested and start keeping a record, then as you add more HP, you'll know what you are getting for your money and work.
12-18-2005, 07:38 PM
#10
3rd Gear Member
Join Date: Aug 2005
Location:
Posts: 984
RE: Actual horsepower?
ORIGINAL: Lee Willis
No need to apologize and yes, this is what these forums are supposed to be for - not for beating up on people who ask questions. Everyone has to learn, and there are no dumb questions, only dummies who don't learn the first time and ask them again. You've done a lot of the work yourself, so keep it up.
SAE (Society of Automotive Engineers) has a way of defining what a car's HP rating means and how it is determined. Over the years they have updated this from time to time, most noteably in the early 70s when the convinced the whole industry to go from gross to net HP ratings -- a '70 427 Vette was rated at 435 HP gross but that same engine would be rated about 310 net.
How this is defined and what it means is pretty technical and takes pages to lay out specifically, but the important point is that it is an estimate of the power the engine produces when in the car, with the mufflers hooked up and while running all the standard equipment, what is called "at the flywheel." This is not easy to measure because you can't hook up a dynometer to the flywheel so most owners and shops measure it at the rear wheels. There, the car experiences some loses in power consumed by the transmission, U-joints, differential gears, axles bearings, and tires. All in all, most manual transmission cars loss about 11% to 15% from flywheel to drive wheels (GM M-6 cars a a bit better than most here, losing typically about 11%, Fords, about 3%, don't know why). Auto trans cars tend to lose an additional 3-5%: my 320 HP rated Porsche has the Tiptronic auto and did 265 RWHP - 17.2% loses.
You can reduce those loses slightly, very sligthly, by running a more expensive brand of synthetic lubricant in the trans and differential, but you would see only about 2 RWHP gain, at most.
Your Ford was rated at 260 HP flywheel by Ford, following its interpretation of the SAE standard in effect when your car was manufactured. Stock, with a manual trans, it probably dyno tested with about 225-230 RWHP, with an auto 220-225. Your car out to be doing a bit more than that. Have it tested and start keeping a record, then as you add more HP, you'll know what you are getting for your money and work.
No need to apologize and yes, this is what these forums are supposed to be for - not for beating up on people who ask questions. Everyone has to learn, and there are no dumb questions, only dummies who don't learn the first time and ask them again. You've done a lot of the work yourself, so keep it up.
SAE (Society of Automotive Engineers) has a way of defining what a car's HP rating means and how it is determined. Over the years they have updated this from time to time, most noteably in the early 70s when the convinced the whole industry to go from gross to net HP ratings -- a '70 427 Vette was rated at 435 HP gross but that same engine would be rated about 310 net.
How this is defined and what it means is pretty technical and takes pages to lay out specifically, but the important point is that it is an estimate of the power the engine produces when in the car, with the mufflers hooked up and while running all the standard equipment, what is called "at the flywheel." This is not easy to measure because you can't hook up a dynometer to the flywheel so most owners and shops measure it at the rear wheels. There, the car experiences some loses in power consumed by the transmission, U-joints, differential gears, axles bearings, and tires. All in all, most manual transmission cars loss about 11% to 15% from flywheel to drive wheels (GM M-6 cars a a bit better than most here, losing typically about 11%, Fords, about 3%, don't know why). Auto trans cars tend to lose an additional 3-5%: my 320 HP rated Porsche has the Tiptronic auto and did 265 RWHP - 17.2% loses.
You can reduce those loses slightly, very sligthly, by running a more expensive brand of synthetic lubricant in the trans and differential, but you would see only about 2 RWHP gain, at most.
Your Ford was rated at 260 HP flywheel by Ford, following its interpretation of the SAE standard in effect when your car was manufactured. Stock, with a manual trans, it probably dyno tested with about 225-230 RWHP, with an auto 220-225. Your car out to be doing a bit more than that. Have it tested and start keeping a record, then as you add more HP, you'll know what you are getting for your money and work.