APS has done it again 468 HP
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Originally posted by Silver arrow
They have an engine dyno? Believe it when I see it.
They have an engine dyno? Believe it when I see it.
"APS has fully imported a US specification STI and complete engine for engineering and development purposes."
What do you think they imported a complete engine for?
To mod it and test it while measuring output on their dyno dynamics engine dyno.
It is a fact that engine power estimates taken directly from the engine are inherently more accurate than those taken from the wheels, for obvious reasons. Before and after whp are certainly useful since it is the best you can ordinarily do without removing the engine from the vehicle, but even translating before and after whp to bhp is messy at best. 50 whp increase on one dyno is not equal to 50 whp increase on another.
Ask Shiv at Vishnu if you don't believe.
Whp is inferior to Bhp as a measuring method. That is why NO AUTO MANUFACTURER uses whp. WHP is a 2nd hand (by definition) method, used by tuners ONLY BECAUSE THEY HAVE NO CHOICE.
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Joined: Sep 2003
Posts: 31
From: Bel Air, MD
Car Info: '02 Turbo IS300 660rwhp
If, in fact, APS has an engine dyno then that is great and their flywheel hp #'s will be accurate. The pic on their website shows an STi sitting on an awd chassis dyno. That's why I was inferring they used that to achieve their #'s and then used a "correction" factor to calculate flywheel hp. Also, if they use an engine dyno to achieve all their hp #'s, why have a chassis dyno at all since they're inherently inferior? Maybe they imported the USDM STi motor to tear it apart and find out what Subaru used to build the motor.....and give us nice pics of the coated cast pistons
Next, what did they use to run the 1/4 mile time they quote? Did they do all the installs and tuning on the "spare" motor and then remove the motor from the STi and install the "spare" and run it? Did they use the "spare" motor to achieve the #'s and then install the same parts on the car and run the times? If so, how were they able to achieve the same tune on the car w/out the engine dyno? The chassis dyno will yield different numbers.
These are all questions I have, but don't necessarily need answers to. As I will be doing my own testing....using a chassis dyno and ultimately the 1/4 mile.
Scott
Next, what did they use to run the 1/4 mile time they quote? Did they do all the installs and tuning on the "spare" motor and then remove the motor from the STi and install the "spare" and run it? Did they use the "spare" motor to achieve the #'s and then install the same parts on the car and run the times? If so, how were they able to achieve the same tune on the car w/out the engine dyno? The chassis dyno will yield different numbers.
These are all questions I have, but don't necessarily need answers to. As I will be doing my own testing....using a chassis dyno and ultimately the 1/4 mile.
Scott
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Also, if they use an engine dyno to achieve all their hp #'s, why have a chassis dyno at all since they're inherently inferior?
Obviously they don't use an engine dyno to acheive all their hp #'s. And that is why they have a chassis dyno.
In order to use an engine dyno you need an engine - disconnected from the vehicle.
If you don't have a spare engine for every car you mod, you obviously need a chassis dyno.
They have both: THAT'S WHY THEY IMPORTED A COMPLETE ENGINE FOR TESTING, which would be useless without an engine dyno. I don't know why you find this is so hard to comprehend.
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Originally posted by fledis
[B]Next, what did they use to run the 1/4 mile time they quote?
[B]Next, what did they use to run the 1/4 mile time they quote?
"APS has fully imported a US specification STI" http://www.aps-wrx.com/us_spec/subaru/sti/2004_sti.htm
The significance of the 1/4 mile time of 11.9@118 is that it cross verifies that they have over 400 bhp, as there is no way you are going to achieve 11's with less than that.
So let me ask you. What exactly are you questioning? The horsepower? Good luck getting an STI in to the 11's@118 with less than 400 hp.
Can you tell me what wheel horsepower level will get you into the 11's? No you can't. You can't even generalize or come close. Not without specifying the dyno, the tuner and the methodology as whp numbers are 2nd hand and vary RADICALLY from dyno to dyno, car to car, and tuner to tuner.
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Joined: Sep 2003
Posts: 31
From: Bel Air, MD
Car Info: '02 Turbo IS300 660rwhp
Originally posted by gohan
The question is both illogical and tautalogical.
Obviously they don't use an engine dyno to acheive all their hp #'s. And that is why they have a chassis dyno.
In order to use an engine dyno you need an engine - disconnected from the vehicle.
If you don't have a spare engine for every car you mod, you obviously need a chassis dyno.
They have both: THAT'S WHY THEY IMPORTED A COMPLETE ENGINE FOR TESTING, which would be useless without an engine dyno. I don't know why you find this is so hard to comprehend.
The question is both illogical and tautalogical.
Obviously they don't use an engine dyno to acheive all their hp #'s. And that is why they have a chassis dyno.
In order to use an engine dyno you need an engine - disconnected from the vehicle.
If you don't have a spare engine for every car you mod, you obviously need a chassis dyno.
They have both: THAT'S WHY THEY IMPORTED A COMPLETE ENGINE FOR TESTING, which would be useless without an engine dyno. I don't know why you find this is so hard to comprehend.
That is how they do that, right
Registered User
Joined: Sep 2003
Posts: 31
From: Bel Air, MD
Car Info: '02 Turbo IS300 660rwhp
Originally posted by gohan
Uhm....
"APS has fully imported a US specification STI" http://www.aps-wrx.com/us_spec/subaru/sti/2004_sti.htm
The significance of the 1/4 mile time of 11.9@118 is that it cross verifies that they have over 400 bhp, as there is no way you are going to achieve 11's with less than that.
So let me ask you. What exactly are you questioning? The horsepower? Good luck getting an STI in to the 11's@118 with less than 400 hp.
Can you tell me what wheel horsepower level will get you into the 11's? No you can't. You can't even generalize or come close. Not without specifying the dyno, the tuner and the methodology as whp numbers are 2nd hand and vary RADICALLY from dyno to dyno, car to car, and tuner to tuner.
Uhm....
"APS has fully imported a US specification STI" http://www.aps-wrx.com/us_spec/subaru/sti/2004_sti.htm
The significance of the 1/4 mile time of 11.9@118 is that it cross verifies that they have over 400 bhp, as there is no way you are going to achieve 11's with less than that.
So let me ask you. What exactly are you questioning? The horsepower? Good luck getting an STI in to the 11's@118 with less than 400 hp.
Can you tell me what wheel horsepower level will get you into the 11's? No you can't. You can't even generalize or come close. Not without specifying the dyno, the tuner and the methodology as whp numbers are 2nd hand and vary RADICALLY from dyno to dyno, car to car, and tuner to tuner.
BTW, I think I can tell you what whp level will get you into the 11's. 500whp should do it no prob
450whp should also do it and probably even 400whp, but that's generalizing
The variance btw car to car, dyno to dyno, day to day, etc. will always exist. Can't do anything about that. I guess coming from the Supra world, where rwhp is always used, I'm a little biased toward whp.
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Joined: Aug 2003
Posts: 113
Car Info: Blue STi +Red del Sol VTEC
Did you notice they said the US STi's pistons are cast. They actually showed them too. I'm ****ing pissed the book from subaru plainly says forged molybdenum coated pistons. If this is found out to be true i think something should be done as that is false advertisement and we should get a petition going.
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No way they pulled the motor on either of those cars, they chassis dyno'es and used the standard BS method of adding 25%.
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Okay...first i want to comment on the website, please answer my questions. I hope i am not the only one who noticed this our stock turbo is running at 14-14.5psi peak, and this new turbo is running 21-21.5 psi!!! I dont know about you all but i have been told to lock the boost down well below 20 cause it is a danger to the engine to make any more boost than that. And i was also told by many people that you dont want to exceed 450fwhp without reinforceing the engine, the pistons and cranck arent going to take the power for long. If anyone can correct and know that our engine stock can take 20+psi and 450+fwhp please take me.
And second yes, the more hp you have the more you lose, why do you think that a stock civic SI goes from 160fwhp to 138whp(14%), but then the RSX-S goes from 200hp to 168 a loss of 35whp(16%). Your drive train loss is not a set number it is a percentage, generaly for a awd vehicle you are looking at about 25% loss and in a RWD and FWD you are looking at 13-18% depending on how well the drive train is constructed. As you increase your horsepower you deduct a percentage not a set figure.
And second yes, the more hp you have the more you lose, why do you think that a stock civic SI goes from 160fwhp to 138whp(14%), but then the RSX-S goes from 200hp to 168 a loss of 35whp(16%). Your drive train loss is not a set number it is a percentage, generaly for a awd vehicle you are looking at about 25% loss and in a RWD and FWD you are looking at 13-18% depending on how well the drive train is constructed. As you increase your horsepower you deduct a percentage not a set figure.
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Here is a quote from Joel from Sheehan Motor Racing about driveline loss:
This is one of the least understood issues in the "car guy" world. Not only are driveline losses important, but measurement standards are important, too. The same car will dyno differently on the Vishnu Dyno Dynamics dyno and on a Dynojet dyno. How does that compute? Imagine, 227 hp with 162 to the wheels would be a (227-162)/227 = 65/227 = 28.6% "driveline" loss and in the same car on a different dyno might come out to 191 hp, or (227-191)/227=36/227= 15.8% driveline loss.
So what's the "correct" driveline loss? How much power is actually making it to the wheels? Does it matter?
As someone pointed out, driveline losses cannot be a straight amount of horsepower - then you would never get rolling from a stop. and they really can't be a straight percentage, either, since that would require (say a 25% loss) 250 hp to turn the wheels of a 1000 hp car. Err, I'm guessing the WRX could still tow the 1000 hp car behind it if you used some rope, so obviously, the WRX has the power to move that car... and that 1000 hp car isn't needed 250 hp just to turn the axles.
The answer has to be some combination of the two. But why? Well, what are driveline losses? Where is that power dissappearing to? Pure mechanical systems tend to be pretty efficient, right? Well... there's a host of things that are going on. For example, the transmission has gears that sit in some oil. The gears have to splash through the oil. The front differential has a fat ring gear and a couple of large openings for oil to flow into the open differential unit. These all make a lot of splashing. Think it's not much resistence? Hold your hand out the window at 60 mph. Tell me that's not a lot of resistence. Now imagine if instead of air, it was thick oil that your hand was going through? A lot of resistence? Now what if you were instead smacking several hundred little paddles through the oil at several tens of thousands of smacks per minute? Now you see some possible resistance?
Add to that the fact that there is still some friction between gear teeth. There is some force going into bending and twisting shafts. And some into bending the transmission case (think it doesn't happen? Care to explain the high transmission failure rates?). And that all is just the transmission. The same applies to the diff. And then there's the wheels and wheel bearings. Put the car in the air and spin the wheel. It doesn't spin very freely.
So we see that there are a lot of places for losses, but many of those losses seem more RPM related than power related. Then again, all the bending and twisting type losses seem more power related than RPM related.
It is my opinion that there is some basic amount of power needed to move the driveline. That's a pretty small amount of power (I can turn the input shaft with all the wheels attached and the car in gear but the engine removed, albeit, I turn it very slowly). Accelerating that whole driveline takes an amount of power related to the speed at which you try to accelerate the driveline. To go from one rpm to two rpms in a time of one second takes very little power. But to go from 1000 to 7000 in one second... that's a lot more power. The speed at which you ramp up the RPMs affects the power needed to do that.
So driveline losses are related to some fixed amount of loss from the driveline itself, some amount of loss due to the amount of power you're putting through the system, some loss due to the speed at which you're trying to go through the rpm band, etc. Very complex and not easy to guestimate.
BTW, on a dyno that can create a load for the car to accelerate through, you can see these effects quite plainly. On the dyno dynamics dyno, if you tell the dyno to let the car go from 1500 to 7500 rpms in 5 seconds, you'll see different horsepower readings than if you tell the dyno to force the rampup rate (by modulating the resistence) to drop so that it takes 30 seconds. This is a great way to show how much power your part makes, too, because the speed at which you ramp up the rpms won't show on the dyno chart... The part may even hurt horsepower, but you can make it look like it makes more by slowing down the RPM ramp up rate, which will decrease losses and show a higher horsepower reading.
It's not a simple answer, but it's not a simple question. There is no fixed driveline loss.
Joel
This is one of the least understood issues in the "car guy" world. Not only are driveline losses important, but measurement standards are important, too. The same car will dyno differently on the Vishnu Dyno Dynamics dyno and on a Dynojet dyno. How does that compute? Imagine, 227 hp with 162 to the wheels would be a (227-162)/227 = 65/227 = 28.6% "driveline" loss and in the same car on a different dyno might come out to 191 hp, or (227-191)/227=36/227= 15.8% driveline loss.
So what's the "correct" driveline loss? How much power is actually making it to the wheels? Does it matter?
As someone pointed out, driveline losses cannot be a straight amount of horsepower - then you would never get rolling from a stop. and they really can't be a straight percentage, either, since that would require (say a 25% loss) 250 hp to turn the wheels of a 1000 hp car. Err, I'm guessing the WRX could still tow the 1000 hp car behind it if you used some rope, so obviously, the WRX has the power to move that car... and that 1000 hp car isn't needed 250 hp just to turn the axles.
The answer has to be some combination of the two. But why? Well, what are driveline losses? Where is that power dissappearing to? Pure mechanical systems tend to be pretty efficient, right? Well... there's a host of things that are going on. For example, the transmission has gears that sit in some oil. The gears have to splash through the oil. The front differential has a fat ring gear and a couple of large openings for oil to flow into the open differential unit. These all make a lot of splashing. Think it's not much resistence? Hold your hand out the window at 60 mph. Tell me that's not a lot of resistence. Now imagine if instead of air, it was thick oil that your hand was going through? A lot of resistence? Now what if you were instead smacking several hundred little paddles through the oil at several tens of thousands of smacks per minute? Now you see some possible resistance?
Add to that the fact that there is still some friction between gear teeth. There is some force going into bending and twisting shafts. And some into bending the transmission case (think it doesn't happen? Care to explain the high transmission failure rates?). And that all is just the transmission. The same applies to the diff. And then there's the wheels and wheel bearings. Put the car in the air and spin the wheel. It doesn't spin very freely.
So we see that there are a lot of places for losses, but many of those losses seem more RPM related than power related. Then again, all the bending and twisting type losses seem more power related than RPM related.
It is my opinion that there is some basic amount of power needed to move the driveline. That's a pretty small amount of power (I can turn the input shaft with all the wheels attached and the car in gear but the engine removed, albeit, I turn it very slowly). Accelerating that whole driveline takes an amount of power related to the speed at which you try to accelerate the driveline. To go from one rpm to two rpms in a time of one second takes very little power. But to go from 1000 to 7000 in one second... that's a lot more power. The speed at which you ramp up the RPMs affects the power needed to do that.
So driveline losses are related to some fixed amount of loss from the driveline itself, some amount of loss due to the amount of power you're putting through the system, some loss due to the speed at which you're trying to go through the rpm band, etc. Very complex and not easy to guestimate.
BTW, on a dyno that can create a load for the car to accelerate through, you can see these effects quite plainly. On the dyno dynamics dyno, if you tell the dyno to let the car go from 1500 to 7500 rpms in 5 seconds, you'll see different horsepower readings than if you tell the dyno to force the rampup rate (by modulating the resistence) to drop so that it takes 30 seconds. This is a great way to show how much power your part makes, too, because the speed at which you ramp up the rpms won't show on the dyno chart... The part may even hurt horsepower, but you can make it look like it makes more by slowing down the RPM ramp up rate, which will decrease losses and show a higher horsepower reading.
It's not a simple answer, but it's not a simple question. There is no fixed driveline loss.
Joel
