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Discussion Starter #1
how do we know for sure the real RWHP when we have all these cars with different blowers at different boost levels and different RWHP #'s and different times and trap speeds?
is it simple math to tell the real #'s not taking account for the driver?
 

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Discussion Starter #2 (Edited)
whats with all different ways to read the rwhp on the dnyo it self.
look at these 2 dnyo slips one says uncorrected and one dose'nt
 

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Its one of the problems with dyno's.............they are not consistent from one dyno to another (even same manufacturer type dyno's)

That's why is so important to do your tuning and baselines on the same dyno.

I think it would be awesome to get a mobile dyno out at challengerfest 2011 for cars to get on and do pulls and see what we are all putting down across the forum on the same drums
 

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Dyno's are for tuning.

Best way to compare power is to go to the same track on the same day, like we did at ATCO this weekend.

For example, this showed that Big AL G and Jack SickSRT's Challys were both faster and quicker than SRT5939's challenger :)
 

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Discussion Starter #5
Dyno's are for tuning.

Best way to compare power is to go to the same track on the same day, like we did at ATCO this weekend.

For example, this showed that Big AL G and Jack SickSRT's Challys were both faster and quicker than SRT5939's challenger :)
and a bunch of LX'ers oh I mean all of the LX'ers.
we'll see in bradenton who goes faster i'm not done yet:browsmiley:
 

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last 2 post great points!

I have done 1000s of dyno pulls on all types. They are for a ref point only and do give you a good idea:)

BUT... .

Where did horsepower come from?

James Watt, who did quite a bit of work improving steam engines back in the 1700's, needed a way to measure their output. Watt used a common reference, the horse, as the basis for his calculations (like the inch was based on the width of a man's thumb). The exact process he followed to find out what a horse could do is open to speculation, everyone seems to have their own favorite story, but the end result was: 1 horsepower = 550 foot-pounds per second, which means, in Watt's calculations, a horse can lift 550 pounds one foot in one second.
There are only seven base units of measurement: distance, time, mass, temperature, electric current, amount of substance and luminous intensity. Each unit can be determined by scientifically reproducible results (no more horses and thumbs!) and all units and standards used today can be derived from those basic seven. An international system, SI, maintains the agreed upon standards for all of these basic units.


Something to ponder. What size is the HORSE on a dyno, a pony or a TN Walker?

Horsepower (HP) is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.[1]
Horsepower was originally defined to compare the output of steam engines with the power of draft horses. The unit was widely adopted to measure the output of piston engines, turbines, electric motors, and other machinery. The definition of the unit varied between geographical regions. Most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on January 1, 2010, the use of horsepower in the EU is only permitted as supplementary unit.

The definition of the horsepower also has varied between different applications:
  • The mechanical horsepower also known as imperial horsepower of exactly 550 foot-pounds per second is approximately equivalent to 745.7 watts.
  • The metric horsepower of 75 kgf-m per second is approximately equivalent to 735.499 watts.
  • The boiler horsepower is used for rating steam boilers and is equivalent to 34.5 pounds (≈15.65 kilograms) of water evaporated per hour at 212 degrees Fahrenheit (=100 degrees Celsius, =373.15 Kelvin), or 9,809.5 watts.
  • One imperial horsepower for rating electric motors is equal to 746 watts.
  • Continental European electric motors used to have dual ratings, using conversion rate 0.735 kW for 1 HP
  • The Pferdestärke PS (German translation of horsepower) is a name for a group of similar power measurements used in Germany around the end of the 19th century, all of about one metric horsepower in size.[2][3]
  • The Royal Automobile Club (RAC) horsepower or British tax horsepower is an estimate based on several engine dimensions.
All that said I would kinda have to agree with OLDMAN on this one, I think he is in the ball bark!

If you stuffed an old 318 2 v rated at 230 HP (CrankShaft no accesories except for the TQ value the new V6s run pretty darn well:)
 

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As far as I know they all should be using SAE corrected results. This is used to make sure you are using the same parameters from one dyno to another. I am sure others on here that runs dynos like Mr Norms or Arrington will chime in but that is why I was told you use the SAE numbers only.
 

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Discussion Starter #10
Yup and you are the fastest Chally on this site :)
for now and let me tell you it's not easy being king. a few more goodies and i'll get my 9 also. I'm gonna get it with no juice.
 

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I know everyone has seen this video but look close at the screen. SAE results are 420 hp. Uncorrected numbers are 440 hp and uncorrected can vary alot more than 20hp.
 

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Here is part of the deal, most dyno have a "weather station" module to allow the system to correct to sea level which is what SAE Corrected is when it is selected. The problem comes from where they keep it, if the keep it clean and in free air or in a warn cabinet on a cold day etc.

This information is saved in the dyno files, so you can set the corrections.

Something else you have to watch on a dyno is heat soak or an overly cold run will skew a set and give false numbers.

Think of it this way. At sea level I run 12.7's at -1500 Da i run 12.0's I make 50-60 more Hp in good air.

The differences at tracks are things like rotating mass, sprung mass, weight, traction, rolling resistance and mechanical loss are all going to effect runs also how you stage the car. Cold oil will rob you silly. heat soak will do the same.

Guys that have a plan, and stick to it tend to be very consistent because they don't break the routine and have found what works for their combos.

It took 150 passes to get mine sorted out. Playing will coolant temps, oil temps, trans temps and leave RPM's, staging, and shift points.

The biggest mistake I see people consistently do it to buy stuff install it and spend no time logging, dealing with the tuners and getting the combo right. If it isn't laying down what someone else is running with the same combo they think they have crap parts when its a matter of a tune, or running the car right.

Dynos suck :) they are a tool if used right for seeing changes and getting run data when you can't get to a track.

-Robert
 

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Here is part of the deal, most dyno have a "weather station" module to allow the system to correct to sea level which is what SAE Corrected is when it is selected. The problem comes from where they keep it, if the keep it clean and in free air or in a warn cabinet on a cold day etc.

This information is saved in the dyno files, so you can set the corrections.

Something else you have to watch on a dyno is heat soak or an overly cold run will skew a set and give false numbers.

Think of it this way. At sea level I run 12.7's at -1500 Da i run 12.0's I make 50-60 more Hp in good air.

The differences at tracks are things like rotating mass, sprung mass, weight, traction, rolling resistance and mechanical loss are all going to effect runs also how you stage the car. Cold oil will rob you silly. heat soak will do the same.

Guys that have a plan, and stick to it tend to be very consistent because they don't break the routine and have found what works for their combos.

It took 150 passes to get mine sorted out. Playing will coolant temps, oil temps, trans temps and leave RPM's, staging, and shift points.

The biggest mistake I see people consistently do it to buy stuff install it and spend no time logging, dealing with the tuners and getting the combo right. If it isn't laying down what someone else is running with the same combo they think they have crap parts when its a matter of a tune, or running the car right.

Dynos suck :) they are a tool if used right for seeing changes and getting run data when you can't get to a track.

-Robert
Makes a lot of sense. Like when I am working up a load for a rifle. I will play with the powder and bullet to find a combo that it likes. I shot it though a crony and then try it on some paper. If it does not like the set up I try some thing else. I am shooting for a combination of accuracy and speed of the bullet. This gives me maxinum killing power. I use a crony as a tool to help me tune my cartrige as we use dynos to tune are rides. I am just not looking for killing power in my car, just speed as fast as a bullet.
 

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Its one of the problems with dyno's.............they are not consistent from one dyno to another (even same manufacturer type dyno's)

That's why is so important to do your tuning and baselines on the same dyno.

I think it would be awesome to get a mobile dyno out at challengerfest 2011 for cars to get on and do pulls and see what we are all putting down across the forum on the same drums
Great idea. Hope it happens. It might be interesting
 

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HP is moot unless you can get it to the pavement and hook.
Tout09
 
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