and the bottom line is..... it's all just numbers.... just go drive the car and have fun, and if it's not fast enough, open up the wallet and start modifying!!
Unless of course the manufacturer is misleading the consumer by over rating their motors like the OP was suspicious of. I remember Mazda being sued by Miata owners years back because the motors werent putting out near the claimed power. If I pay for X amount of horsepower, I expect the car to produce it.
Unless of course the manufacturer is misleading the consumer by over rating their motors like the OP was suspicious of. I remember Mazda being sued by Miata owners years back because the motors werent putting out near the claimed power. If I pay for X amount of horsepower, I expect the car to produce it.
The manufacturer was up front and honest on their claim to horsepower produced. The consumer also has some responsibility to understand what they are buying. The horsepower rating standard adopted 30 years ago was to help insure that the consumer was not being misled. Unfortunately, most of us are not going to pull the engine and dyno it to check it.
These engines likely have a Go/No Go test they are put through. I don't know what Ford does exactly but I would imagine each engine goes through a Hot Test and a minimum hp (and many other parameters) has to be reached to be considered a Pass. This would be an automated test and the results recorded against the engine serial number.
It appears that the OP didn't understand that the rating published is at the crank and not the ground. He further claims that he won't buy a car that doesn't deliver as advertised. Based on those two conditions, he will not buy another car from any manufacturer.
You've seen a totally stock GT put 285 at the wheels??? My 2009 GT/AOD is putting down 290rwhp with a C&L CAI, Steeda Pulley, BBK LT's, BBK X-Pipe w/ cats, and a custom 94 octane dyno tune by Lidio at Alternative Auto. If I remember correctly it did 262rwhp totally stock.
I saw a show on how motors are rated by SAE and it is no joke. The motors are set up on the stand EXACTLY like they will be in the car right down to all the accessories and entire exhaust systems. The SAE has a testing regiment that all motors, all manufacturers must go through before they can make claims, advertise, etc. Representatives oversee all aspects of the testing regiment. The feeling I got from the show I watched was that the SAE people were “The Man” and passing the test, getting good numbers, etc was very, very important. The engineers I the show certainly were suffering from some anxiety during the testing process.
I think in this day and age it’s fair to say that the manufacturers are not going to be able to make any outrageous claims and get away with it.
As for comparing crank hp/tq to rwhp hp/tq that will always be a very, very rough calculation. The variables in using the chassis dyno are potentially huge. I know from thousands of hours of dyno testing that it’s very, very hard to get repeatable runs. The smallest thing can affect the run and there are a lot of “smallest things” that can crop up. Then add to that all the parts from the flywheel to the tires and you have a whole new list of variables. I have seen tire pressure change hp readings 5%+/-. Another big factor is the temp of the fluids in the Trans and rear end. There is a big, big difference between hot and cold.
The claimed numbers from the manufacturers, because of oversight are very close to actual outputs. Some will be more, and some will be less due to tolerance stacking during assembly and inconsistencies of the weight of parts, etc. That’s why simply blueprinting a motor can be worth as much as 10% hp. The process of blueprinting eliminates or greatly reduces these variables.
Everyone should always take rwhp numbers with a grain of salt. There are a number of ways of skewing the results to justify claims. It’s easy. And even if someone is not trying to pull a “fast one” it’s still hard to get repeatable runs even for the best operators. Comparing two different cars on two different dyno’s is simply stupid. Comparing dyno runs with the same car and the same dyno but a couple months apart is just as stupid. For the best, and only nearly “scientific” results dyno runs need to be made back to back and if parts are being changed they need to be changed as fast as possible and all engine and drivetrain operating conditions must be identical. And lastly after a parts change a new map must be made to support the change. This is the most prevalent thing I see skipped in magazine tests and that is a big no, no.
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You've seen a totally stock GT put 285 at the wheels??? My 2009 GT/AOD is putting down 290rwhp with a C&L CAI, Steeda Pulley, BBK LT's, BBK X-Pipe w/ cats, and a custom 94 octane dyno tune by Lidio at Alternative Auto. If I remember correctly it did 262rwhp totally stock.
I've heard of one that hit 285. I personally have seen 282.
Thanks for this thread guys. I'm well aware of the difference between numbers at the crank and numbers at the wheels but for some reason I thought bhp (brake hp) was synonymous with rwhp. Thanks for clarifying that STL so I don't make an *ss of myself if it comes up and conversation somewhere and I'm using the wrong terms.
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66 Coupe Tahoe Turq - 200, Pertronix & Flamethrower, 3 Row Rad, Cliff. 6/2 96 GT Vert Laser Red - FMS pulleys, Bullet ProM, BBK CAI, Prof. Prod. Elbow and 70mm TB, MAC Off-Road H, Borla side exhaust, Tokicos, B&M Ripper, 18x10 & 18x9 DD Bulletts 06 GT Tungsten, UIP, Red Leather, Stick, 18" blades, Steeda CAI, SCT XCal 2 w/ MC Racing 91 tune, MACs, BMR SP010 springs, BMR Adj Panhard, CDC ducktail & quarter louvers, Rear louver, painted black stripes
235 w/auto tranny, lower engine combustion chamber compression from looser manufacturing/assembly tolerances on piston rings/cylinders, and higher drivetrain friction from tighter manufacturing and assembly tolerances on crankshaft, tranny, driveshaft, differential, and wheel bearings.
285 w/manual tranny, higher engine combustion chamber compression from tighter manufacturing/assembly tolerances, and lower drivetrain friction from looser manufacturing and assembly tolerances.
Plus, there may also be slight differences in the electronics which govern A/F ratio and timing.
