BHP whats your's??
Discussion
splashback said:
pdd144c If i where you mate I'd check this guy's profile before gobbing off!!!! 
Are you saying he's sexy Splashback? good looking, has nice legs... what?
I thought all dyno's gave at the wheels figures anyway, and the fly figure was calculated on known figures. The only way to get true flywheel figures is to whip the engine out and test it that way, or on a hub thingymajiggy.
Either way, they are impressive figures.
WildCards said:
splashback said:
pdd144c If i where you mate I'd check this guy's profile before gobbing off!!!! Are you saying he's sexy Splashback? good looking, has nice legs... what?
I thought all dyno's gave at the wheels figures anyway, and the fly figure was calculated on known figures. The only way to get true flywheel figures is to whip the engine out and test it that way, or on a hub thingymajiggy.
Either way, they are impressive figures.
I think you get the general idea my friend This has to be 1 of the funniest threads I have ever read.........
The thing with the R1 bike was that the value for money and ptw aspects were always in it's favour. £7000 new in 2004.
Even if you take the weight of a driver out of the equation, for a road car to have 1 bhp per 1 kg is virtually impossible.
Like my Lancer Evolution having 1,400 bhp rather than 340 bhp!
Even if you take the weight of a driver out of the equation, for a road car to have 1 bhp per 1 kg is virtually impossible.
Like my Lancer Evolution having 1,400 bhp rather than 340 bhp!
ferrarispider said:
vixpy1 said:
ferrarispider said:
Not what ya hoped for, WTF!! what were ya hoping for???? 485 BHP, i asume that was at the wheels then. I am going to be brave here and post my weedy Ferrari 355 spider results. It was rated at 328BHP at the wheels, 410ish at the crank. Nothin on your output but there ya go
Hey how about a picture of ya 911 dude. MB:: Hey i just looked at your profile pic and i know your car, you live in the next village to me
A mate of mine had that yellow 993TT in your town last year.
Hey how about a picture of ya 911 dude. MB:: Hey i just looked at your profile pic and i know your car, you live in the next village to me A mate of mine had that yellow 993TT in your town last year. Edited by ferrarispider on Monday 18th December 19:39
Hate to break it to you chap, but those are flywheel graphs, thats 328bhp at the crank. Probably around 280bhp at the wheels.
MB: Even on your own site you say that you can give power at the wheels or crank dyno readings.
And here is another example of the same type dyno that was calibrated to give both flywheel and at the wheel readings. This pair of dyno readings are for a ferrari 348. The 348 is rated at 300 HP which is 100bhp less than a 355. Factory figures. So all dyno readouts i have posted are with in that ball park.
Edited by ferrarispider on Tuesday 19th December 15:11
No chap, Look again at the dyno graphs you have just posted, the top one, which is a crank figure, has S_hp on it.. this is a flywheel graph. The bottom one which is a wheel fig.. just has HP on the scale. Now look at yours, they have S_Hp on them. They are Flywheel graphs! Any graph which is Wheel will have just HP on it! In shootout mode which is what your car was run in this will always be the case. No exceptions! The dyno will record both set of figs and its just up to the dyno operator which set he prints out.
Someone has been telling you porkies i'm afraid.
Edited by vixpy1 on Tuesday 19th December 18:51
ferrarispider said:
Well thats dyno operators cant be trusted. Never heard of the S_hp argument, so what does that mean exactly...S_hp. The F430 has a reading of 420bhp, so that was the crank figure as well then?? Is that what your saying?
. Never heard of the S_hp argument, so what does that mean exactly...S_hp. The F430 has a reading of 420bhp, so that was the crank figure as well then?? Is that what your saying?The S_hp does'nt essentially mean anything, it just signifys a Dyno Dynamics flywheel graph, as does the f infront of the Ftlb's the other side of your graphs.. (it will be just Ftlb on a wheel graph).
As for the F430, without seeing the graphs, there is no way of telling, but it sounds like a wheel fig. I run a thousand cars a year on exactly the same dyno as yours was done on.
ferrarispider said:
Well thats dyno operators cant be trusted. Never heard of the S_hp argument, so what does that mean exactly...S_hp. The F430 has a reading of 420bhp, so that was the crank figure as well then?? Is that what your saying?
. Never heard of the S_hp argument, so what does that mean exactly...S_hp. The F430 has a reading of 420bhp, so that was the crank figure as well then?? Is that what your saying?Ferrari claim 483 bhp so 420 must be wheels no?
Hmmm...
Thats what i thought, also there is no way that my car is the same power as a 348. I have run them and left them for dead. Also the 360 that i use has just a little more power than the 355. And i have run faster times than some 360s at Brunters.This is now a bloody mystery. i will be booking my car into another dyno in January to have another look. Question....how can shaft BHP be read from the rollers under the wheels??
Interesting read.
Tech Stuff: Is Your Dyno Lying?
1 2
Measuring your horsepower depends on whose yardstick you use.
BY AARON ROBINSON
PHOTOGRAPHY BY DAVID DEWHURST
May 2004
Horsepower is like good luck. It can't be seen, touched, or tasted, but you know when the inventory is low. How much do you have? Go measure it. The best place to put your luck to the yardstick is in Las Vegas. The best place to measure your horsepower is on a dynamometer. In both cases, results have been known to vary.
Turns out that different horsepower dynamometers will spit out different results on the same car depending on their design and how carefully the tester manages the variables. When ambient air temperature and pressure were all that yesterday's carburetors cared about, factoring in the variables was easy. But modern cars are gradually becoming too smart for what was once a simple test. Engines trying to squeeze out more horsepower are run by watchful computers with better sensors that are able to differentiate between speeding down a freeway with a cooling headwind and spinning the dyno drums in a stuffy room. The technology of today's cars needs to be factored into your readings along with variations from dyno type to dyno type, or your horsepower numbers may be hazy, too.
Recall that horsepower is a unit measuring the rate at which an engine performs work. By current industry standards, one horsepower equals 550 pounds lifted at the rate of one foot every second. Automakers figure a car's oomph by hitching the engine to a machine that puts a controlled load generated by an electric or hydraulic brake on the flywheel. They plumb the intake and coolant to external fixtures that simulate on-road airflow and then run the engine from idle to redline. The engine dyno measures torque at the crankshaft using a variety of means and then uses a math formula—torque times rpm divided by 5252 (a sort of gearhead's constant, derived by dividing . . . oh, never mind). Horsepower comes after the equal sign. Thousands of hours of testing produce a peak horsepower number that prints in the dealer's brochure.
For the rest of us, rather than unbolt the engine and rent a multimillion-dollar dyno room, it's much easier to simply drive the whole car onto a chassis dyno that measures horsepower where the tires meet the tarmac. Throughout the U.S. are shops with such machines, some even capable of handling four-wheel-drive cars. Ordinary citizens pay anywhere from $35 to $100 to run the car up to redline three or four times, the tires turning rollers monitored by the dyno's computer. Eventually, the computer spits out a horsepower graph that you can take to your next bar-stool drag race.
But before you pop the clutch on your tongue, consider that a chassis dyno doesn't measure horsepower at the flywheel but at the tires after various driveline losses have subtracted their drag. Friction from rubbing gear faces, inertia from heavy shafts, and the stirring of oatmeal-like gear lube all reduce the advertised horsepower reaching the tires and, hence, the dyno.
"There's no really accurate way to get engine horsepower from a chassis dyno," says Matt Harwood, marketing coordinator for Mustang Dynamometer, a major supplier of chassis dynos in Twinsburg, Ohio. Some tuners use the so-called 15/20 rule, which assumes a 15-percent driveline loss for manual transmissions and 20 percent for automatics. But, says Harwood, "I've seen losses as high as 35 percent." So unless it's printed in the brochure or was measured on a true engine dyno or by a tuner with tons of experience with your particular brand of car, any flywheel horsepower number quoted by a hot rodder under the shade tree is most likely just a calculated guess.
More important, did your car run on the dyno as it would on the street? If it's the latest model, chances are good it may not have, says BMW tuning wizard Steve Dinan. An afternoon spent at his Bavarian speed emporium in Morgan Hill, California, convinced us that cars are gradually becoming too computerized for the simple dyno test.
Dinan's cars are wired with a battery of sensors that report when the airflow over the bumper is too little, when the inlet air is too hot, and when the water temperatures in the block and radiator are too close together (most turbocharged and supercharged cars also "know" when their intercoolers aren't cooling enough). The computer reacts by backing off the spark and turning up the richness—and as a result, turning down the power—to prevent catastrophic engine meltdowns.
To prove his point, Dinan bolts to his Dynopack one of his 2003 Dinan M5s, heavily tweaked to make a claimed 470 horsepower at the crank (he expects about 415 at the wheels). With the hood closed and no external fan blowing air into the radiator, the car wheezes out just 334 horsepower at the wheels. An LCD data logger on the dashboard reveals the air-fuel ratio from the engine computer. Approaching redline, the BMW's computer richens the mixture all the way to 9.5:1 as the underhood temperatures soar.
That's one thick mix, practically charcoal briquettes blowing out of the tailpipe. But then, with the M5 running in fifth gear (the 1:1 gear ratio with the least friction, preferred by dyno testers), the computer expects 159 mph worth of cooling wind blast around the horsepower peak. It's getting nothing, and it knows.
Now Dinan opens the hood and turns on a small Home Depot shop fan blowing about 10 mph worth of air. The M5 is allowed to shed some excess heat and then run again. This time the computer finds another 37 horsepower, or 371. Things are looking up, but the M5's output is still nowhere near Dinan's expected number of 415.
"I can't claim something I can't measure," says Dinan, so the crew then wheels out the big gun: a $7000 electric fan that looks like it should be hanging on the wing of a Boeing 737. It blasts 38,000 cubic feet per minute of air at 75 mph down a narrow duct, right into the M5's radiator. The fan roars, the M5 howls, the computer twinkles, and the graph paper ticka-ticks out of the printer. It says 411.4 horsepower, the best run of the day.
"I'd pick up four or five more horsepower if I came back tomorrow morning and ran it at 70-degree room temperature," says Dinan. The room is currently 81 degrees.
"Basically, what horsepower would you like? I can give you anything from 330 to 420 with the same car," Dinan says. "Blowing air with a fan isn't the same as creating a bow-pressure effect over the whole front of the car. BMW can simulate that because it has billions to spend on wind tunnels. We don't, but we can come close by spending $250,000 to $300,000 on a climate-controlled room."
That's Dinan's next step. It's a huge expense for a boutique parts-maker, but BMWs aren't getting any stupider. The trend says the cars rolling into a tuner's shop will have more and smarter sensors with each passing model year. BMW may be at the leading edge of electronic engine controls right now, but the rest of the industry is sure to follow.
When it does, the "brag-ability" of dyno numbers will get even more dubious as dyno printouts become merely a reflection of what a particular car does on a particular dyno under a particular set of conditions. What happens on the street could be another matter altogether. As in Vegas, sure bets are in short supply when you measure horsepower.
Tech Stuff: Is Your Dyno Lying?
1 2
Measuring your horsepower depends on whose yardstick you use.
BY AARON ROBINSON
PHOTOGRAPHY BY DAVID DEWHURST
May 2004
Horsepower is like good luck. It can't be seen, touched, or tasted, but you know when the inventory is low. How much do you have? Go measure it. The best place to put your luck to the yardstick is in Las Vegas. The best place to measure your horsepower is on a dynamometer. In both cases, results have been known to vary.
Turns out that different horsepower dynamometers will spit out different results on the same car depending on their design and how carefully the tester manages the variables. When ambient air temperature and pressure were all that yesterday's carburetors cared about, factoring in the variables was easy. But modern cars are gradually becoming too smart for what was once a simple test. Engines trying to squeeze out more horsepower are run by watchful computers with better sensors that are able to differentiate between speeding down a freeway with a cooling headwind and spinning the dyno drums in a stuffy room. The technology of today's cars needs to be factored into your readings along with variations from dyno type to dyno type, or your horsepower numbers may be hazy, too.
Recall that horsepower is a unit measuring the rate at which an engine performs work. By current industry standards, one horsepower equals 550 pounds lifted at the rate of one foot every second. Automakers figure a car's oomph by hitching the engine to a machine that puts a controlled load generated by an electric or hydraulic brake on the flywheel. They plumb the intake and coolant to external fixtures that simulate on-road airflow and then run the engine from idle to redline. The engine dyno measures torque at the crankshaft using a variety of means and then uses a math formula—torque times rpm divided by 5252 (a sort of gearhead's constant, derived by dividing . . . oh, never mind). Horsepower comes after the equal sign. Thousands of hours of testing produce a peak horsepower number that prints in the dealer's brochure.
For the rest of us, rather than unbolt the engine and rent a multimillion-dollar dyno room, it's much easier to simply drive the whole car onto a chassis dyno that measures horsepower where the tires meet the tarmac. Throughout the U.S. are shops with such machines, some even capable of handling four-wheel-drive cars. Ordinary citizens pay anywhere from $35 to $100 to run the car up to redline three or four times, the tires turning rollers monitored by the dyno's computer. Eventually, the computer spits out a horsepower graph that you can take to your next bar-stool drag race.
But before you pop the clutch on your tongue, consider that a chassis dyno doesn't measure horsepower at the flywheel but at the tires after various driveline losses have subtracted their drag. Friction from rubbing gear faces, inertia from heavy shafts, and the stirring of oatmeal-like gear lube all reduce the advertised horsepower reaching the tires and, hence, the dyno.
"There's no really accurate way to get engine horsepower from a chassis dyno," says Matt Harwood, marketing coordinator for Mustang Dynamometer, a major supplier of chassis dynos in Twinsburg, Ohio. Some tuners use the so-called 15/20 rule, which assumes a 15-percent driveline loss for manual transmissions and 20 percent for automatics. But, says Harwood, "I've seen losses as high as 35 percent." So unless it's printed in the brochure or was measured on a true engine dyno or by a tuner with tons of experience with your particular brand of car, any flywheel horsepower number quoted by a hot rodder under the shade tree is most likely just a calculated guess.
More important, did your car run on the dyno as it would on the street? If it's the latest model, chances are good it may not have, says BMW tuning wizard Steve Dinan. An afternoon spent at his Bavarian speed emporium in Morgan Hill, California, convinced us that cars are gradually becoming too computerized for the simple dyno test.
Dinan's cars are wired with a battery of sensors that report when the airflow over the bumper is too little, when the inlet air is too hot, and when the water temperatures in the block and radiator are too close together (most turbocharged and supercharged cars also "know" when their intercoolers aren't cooling enough). The computer reacts by backing off the spark and turning up the richness—and as a result, turning down the power—to prevent catastrophic engine meltdowns.
To prove his point, Dinan bolts to his Dynopack one of his 2003 Dinan M5s, heavily tweaked to make a claimed 470 horsepower at the crank (he expects about 415 at the wheels). With the hood closed and no external fan blowing air into the radiator, the car wheezes out just 334 horsepower at the wheels. An LCD data logger on the dashboard reveals the air-fuel ratio from the engine computer. Approaching redline, the BMW's computer richens the mixture all the way to 9.5:1 as the underhood temperatures soar.
That's one thick mix, practically charcoal briquettes blowing out of the tailpipe. But then, with the M5 running in fifth gear (the 1:1 gear ratio with the least friction, preferred by dyno testers), the computer expects 159 mph worth of cooling wind blast around the horsepower peak. It's getting nothing, and it knows.
Now Dinan opens the hood and turns on a small Home Depot shop fan blowing about 10 mph worth of air. The M5 is allowed to shed some excess heat and then run again. This time the computer finds another 37 horsepower, or 371. Things are looking up, but the M5's output is still nowhere near Dinan's expected number of 415.
"I can't claim something I can't measure," says Dinan, so the crew then wheels out the big gun: a $7000 electric fan that looks like it should be hanging on the wing of a Boeing 737. It blasts 38,000 cubic feet per minute of air at 75 mph down a narrow duct, right into the M5's radiator. The fan roars, the M5 howls, the computer twinkles, and the graph paper ticka-ticks out of the printer. It says 411.4 horsepower, the best run of the day.
"I'd pick up four or five more horsepower if I came back tomorrow morning and ran it at 70-degree room temperature," says Dinan. The room is currently 81 degrees.
"Basically, what horsepower would you like? I can give you anything from 330 to 420 with the same car," Dinan says. "Blowing air with a fan isn't the same as creating a bow-pressure effect over the whole front of the car. BMW can simulate that because it has billions to spend on wind tunnels. We don't, but we can come close by spending $250,000 to $300,000 on a climate-controlled room."
That's Dinan's next step. It's a huge expense for a boutique parts-maker, but BMWs aren't getting any stupider. The trend says the cars rolling into a tuner's shop will have more and smarter sensors with each passing model year. BMW may be at the leading edge of electronic engine controls right now, but the rest of the industry is sure to follow.
When it does, the "brag-ability" of dyno numbers will get even more dubious as dyno printouts become merely a reflection of what a particular car does on a particular dyno under a particular set of conditions. What happens on the street could be another matter altogether. As in Vegas, sure bets are in short supply when you measure horsepower.
Strangely controversial thread without any reason to be so. I see nothing wrong in talking about one's car, be it power, performance or comfort.
My CSL has 360 at the flywheel going by an identical one tested by Thorney Motorsport.
Regardless of the power the 430 is an awesome machine, that's for certain.
My CSL has 360 at the flywheel going by an identical one tested by Thorney Motorsport.
Regardless of the power the 430 is an awesome machine, that's for certain.
ferrarispider said:
Question....how can shaft BHP be read from the rollers under the wheels??
It can't, it can only be estimated. The Dyno Dynamics rollers tend to be pretty good at doing that though..
The 355 never made what Ferrari claim, but that plot is very low even taking that into account
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