Dyno and Predator tune
3/4/05, 06:58 AM
#41
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Tony, the CARS might not be apples to apples, but I believe the DYNO is. Sure, different parts of the country/altitude cause cars to perform differently, but I would EXPECT my car to perform comparably to yours if I drove it down to AZ, as I would expect yours to if you brought it to Omaha.
Is this a wrong assumption?
As far as my dyno time goes, I got free time on it with the purchase of the tuner and I'm glad I did, as the "numbers" show I got a bum unit and the "sop" might have been swayed by the hype.
For all the bashing I've done on the Predator, I do think it's a good tool. I've gotten into the logging functions and reviewing them on the PC. Just with this you'll be able to tell what impact a stock filter/HC trap has on air flow vs a K&N filter change, or a larger conical type filter by viewing the MAF readings, also has air temp readings.
The bottom line to ME, PERSONALLY, IMO....if someone says I did/swapped out whatever, (kinda like I did with my 4.10!
) and it sounds like bs I'd like to see numbers before I go out and spend 500 bucks on it.
That's just me though.
Peace
This is a blurb from the dyno shop that I went to, which is of course the better than all the rest
The Dynojet Chassis Dynamometer has become the industry standard in chassis dynamometers worldwide because of its revolutionary ability to measure horsepower/torque with repeatability, accuracy and consistency. The dynojet is accurate within 1% from Dynojet to Dynojet anywhere in the world! This enabled the communication and sharing of test data.
How?
Isaac Newton said, (Force=Mass x Acceleration)
Force (horsepower) = Mass (weight of drums) x Acceleration (provided by the vehicle being tested)
A combination of two laws of physics, force equals mass times acceleration and work equals force times distance, gives us this equation: W=m X a X d. "W" is the work, in pounds-feet, the rear wheels are doing, "m" is mass equivalent (the drums), "a" is acceleration (increasing drive wheel speed) and "d" is distance (drum circumference). Once we have the work, we can find horsepower. One horsepower is 550 pounds-feet of work done in one second so, we divide the work number by the length of time measured, then divide the number we get from that by 550. To simplify: we get horsepower by multiplying the mass, acceleration and the distance, then dividing that product by time multiplied by 550. This can be expressed by: hp = (m X a X d) Ă· (t X 550).
Torque can be figured by multiplying the horsepower by a constant, 5252, then dividing that product by the speed at which the thrust force was measured. Generally, with rear wheel numbers, axle ratio is not considered in the torque computation. For comparison purposes, this makes more sense. The computer factors out the axle ratio by using engine speed data in the torque derivation.
Since the only variable in the equation is the vehicle, we can measure the amount of horsepower a vehicle produces at the rear wheels with an extremely high level of accuracy and repeatability. There are up to 4000 sample points in a typical Dynojet horsepower test! Dynojets use the (SAE J1349 rev. June 1990) correction factor, this is the lastest correction factor in use today. Allowing our customers to compare results with each other from over 600 Dynojets worldwide. Test can also be measured using DIN, EEC, and STD correction factors.
The dynojet has become the lie detector of the industry.
An inertia dyno differs from a brake dyno in several ways:
1) it has no active power absorption device
2) it's more accurate
3) it's easier on the vehicles being tested
4) it's easier to use.
Another problem with some brake-type chassis dynos is they lack the accuracy and repeatability demanded by many performance-aftermarket manufacturers and tuners.
Overheating the tires and the tendency of cars to try and jump off the rollers are also eliminated. Also, vehicles do not need to be loaded down against the rollers which also reduces heat build up and increased frictional losses through the tires.
That’s why Dynojet is the chassis dyno of choice for names like:
LINGENFELTER, BORLA, HENNESSEY, ROBERT YATES, KENNY BROWN, STEEDA, HKS, KENNE BELL, PENSKE, Roush, A.J. FOYT, JAVIER GUTIERREZ, NASCAR, ETC. . . .
With Competition Data Systems data acquisition we can simultaneously map and plot RPM, time, and wheel speed.
-Fuel Pressure
-Boost Pressure
-Manifold Pressure
-Air Temp
-Fuel Flow
-Wide Band Air to Fuel
-Horsepower and Torque
Is this a wrong assumption?
As far as my dyno time goes, I got free time on it with the purchase of the tuner and I'm glad I did, as the "numbers" show I got a bum unit and the "sop" might have been swayed by the hype.
For all the bashing I've done on the Predator, I do think it's a good tool. I've gotten into the logging functions and reviewing them on the PC. Just with this you'll be able to tell what impact a stock filter/HC trap has on air flow vs a K&N filter change, or a larger conical type filter by viewing the MAF readings, also has air temp readings.
The bottom line to ME, PERSONALLY, IMO....if someone says I did/swapped out whatever, (kinda like I did with my 4.10!
) and it sounds like bs I'd like to see numbers before I go out and spend 500 bucks on it.That's just me though.
Peace
This is a blurb from the dyno shop that I went to, which is of course the better than all the rest
The Dynojet Chassis Dynamometer has become the industry standard in chassis dynamometers worldwide because of its revolutionary ability to measure horsepower/torque with repeatability, accuracy and consistency. The dynojet is accurate within 1% from Dynojet to Dynojet anywhere in the world! This enabled the communication and sharing of test data.
How?
Isaac Newton said, (Force=Mass x Acceleration)
Force (horsepower) = Mass (weight of drums) x Acceleration (provided by the vehicle being tested)
A combination of two laws of physics, force equals mass times acceleration and work equals force times distance, gives us this equation: W=m X a X d. "W" is the work, in pounds-feet, the rear wheels are doing, "m" is mass equivalent (the drums), "a" is acceleration (increasing drive wheel speed) and "d" is distance (drum circumference). Once we have the work, we can find horsepower. One horsepower is 550 pounds-feet of work done in one second so, we divide the work number by the length of time measured, then divide the number we get from that by 550. To simplify: we get horsepower by multiplying the mass, acceleration and the distance, then dividing that product by time multiplied by 550. This can be expressed by: hp = (m X a X d) Ă· (t X 550).
Torque can be figured by multiplying the horsepower by a constant, 5252, then dividing that product by the speed at which the thrust force was measured. Generally, with rear wheel numbers, axle ratio is not considered in the torque computation. For comparison purposes, this makes more sense. The computer factors out the axle ratio by using engine speed data in the torque derivation.
Since the only variable in the equation is the vehicle, we can measure the amount of horsepower a vehicle produces at the rear wheels with an extremely high level of accuracy and repeatability. There are up to 4000 sample points in a typical Dynojet horsepower test! Dynojets use the (SAE J1349 rev. June 1990) correction factor, this is the lastest correction factor in use today. Allowing our customers to compare results with each other from over 600 Dynojets worldwide. Test can also be measured using DIN, EEC, and STD correction factors.
The dynojet has become the lie detector of the industry.
An inertia dyno differs from a brake dyno in several ways:
1) it has no active power absorption device
2) it's more accurate
3) it's easier on the vehicles being tested
4) it's easier to use.
Another problem with some brake-type chassis dynos is they lack the accuracy and repeatability demanded by many performance-aftermarket manufacturers and tuners.
Overheating the tires and the tendency of cars to try and jump off the rollers are also eliminated. Also, vehicles do not need to be loaded down against the rollers which also reduces heat build up and increased frictional losses through the tires.
That’s why Dynojet is the chassis dyno of choice for names like:
LINGENFELTER, BORLA, HENNESSEY, ROBERT YATES, KENNY BROWN, STEEDA, HKS, KENNE BELL, PENSKE, Roush, A.J. FOYT, JAVIER GUTIERREZ, NASCAR, ETC. . . .
With Competition Data Systems data acquisition we can simultaneously map and plot RPM, time, and wheel speed.
-Fuel Pressure
-Boost Pressure
-Manifold Pressure
-Air Temp
-Fuel Flow
-Wide Band Air to Fuel
-Horsepower and Torque
3/4/05, 07:31 AM
#42
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Good thread 
I hope Diablo gets you straightened out, you obviously got a bum unit/tune.
I'm still pining away. I'm starting to wonder when I'll get around to doing anything. The end of my house remodel is approaching, and that's a BIG drain on finances right now.
I hope Diablo gets you straightened out, you obviously got a bum unit/tune.
I'm still pining away. I'm starting to wonder when I'll get around to doing anything. The end of my house remodel is approaching, and that's a BIG drain on finances right now.
3/4/05, 09:44 AM
#43
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My Blue Heaven
My tech sheet calls it a dynopak, maybe to settle this I will seek out a dynojet. Lee just pm'd me that he thought my numbers were low for a standard, he thought I had an automatic. But this may be the difference in dynos? I was not planning on spending money yet, this may have to wait until my next mod. Who knows when that will happen?
Interesting discussing this though.
My tech sheet calls it a dynopak, maybe to settle this I will seek out a dynojet. Lee just pm'd me that he thought my numbers were low for a standard, he thought I had an automatic. But this may be the difference in dynos? I was not planning on spending money yet, this may have to wait until my next mod. Who knows when that will happen?
Interesting discussing this though.
3/4/05, 09:55 AM
#44
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I have just been informed that my car may have up to 15 less hp reported due to engine temps! This is what I thought at the time. I had just been driving it back from Maryland. And they had their dyno free... and b4 you knew it they had their hands in my pockets!
The place that I used, was near work and will be giving their customers a free pass at a local drag strip in April. They are renting the facility for the day. So I may take advantage of that so that my "investment" was not all wasted.
"Am I feeling better now?"
"Yes I am feeling better now."
"I should stop talking to myself now."
The place that I used, was near work and will be giving their customers a free pass at a local drag strip in April. They are renting the facility for the day. So I may take advantage of that so that my "investment" was not all wasted.
"Am I feeling better now?"
"Yes I am feeling better now."
"I should stop talking to myself now."
3/4/05, 10:29 AM
#45
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Originally posted by 38special@March 4, 2005, 9:58 AM
And they had their dyno free... and b4 you knew it they had their hands in my pockets!
And they had their dyno free... and b4 you knew it they had their hands in my pockets!
3/9/05, 12:52 PM
#46
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Bryan, my dyno's from 3rd gear pulls show less HP than 4th, and if you wanted to know the max you're putting down then yes 4th gear pulls are going to tell you that.
On the OTHER hand, if you're trying to get a decent graph to use to see CHANGES in HP, then I think 3rd gear's the way to go as you'll be rid of the torque converter lock up skewing the graph and numbers. My plan is on my next visit to my dyno/tuner we'll keep it in 3rd gear and see how it goes.
Chris
On the OTHER hand, if you're trying to get a decent graph to use to see CHANGES in HP, then I think 3rd gear's the way to go as you'll be rid of the torque converter lock up skewing the graph and numbers. My plan is on my next visit to my dyno/tuner we'll keep it in 3rd gear and see how it goes.
Chris
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