Who can spot the difference in these Dyno's

[dang]

Yeah i won the highest HP NA 4 cylinder award.

By Stock you mean Intake/Headers/Exhaust and Hondata? Or are you using the Standard Computer?

stock ecu, stock intake, R-crew headers (required for swap) and 2.5 catback.

so yeah pretty much stock.

here's the list results for the day.

note - STocko looking DC2R that was there, so we made some pretty good figures -
8 Fitim Xhemaolaj 43 437FFB 2000 Honda Integra 125.000 126.000 126.000


http://www.boostcruising.com/forums/...p/t156823.html

[Adam]

I just checked my dyno from the same day tony and the "tuner" ran my car in shoot 4

That is after my touch up tune...which was done from scratch for some reason as well....and made exactly the same power as i had before headers etc!

[GoldCoastDC5R]

stock ecu, stock intake, R-crew headers (required for swap) and 2.5 catback.

so yeah pretty much stock.

here's the list results for the day.

note - STocko looking DC2R that was there, so we made some pretty good figures -
8 Fitim Xhemaolaj 43 437FFB 2000 Honda Integra 125.000 126.000 126.000


http://www.boostcruising.com/forums/...p/t156823.html

How do you run stock intake on a swap??? Surely would be using an intake of some sort, i doubt using the stock airbox from a dc5....

And his exhaust is straight through because i have never heard a louder exhaust on a honda in my life, that car is crazy loud...

I'm guessing with hondata or a different ecu the car could make close to the same power as mine, which would make it seem like my car is 10kw down on the power made at Toda....

[dang]

using DC2 ITR intake arm and random pod, just sits in engine bay. exhaust is crazy loud cause it doesn't have a muffler yet. was a good day apart from being defected afterwards :thumbsdown:

[Edw-R]

If using proper intake arm and good pod, it should be more power. Need more cold air and better flow.

[tinkerbell]

APC told me that 4F = 4 Cylinder Forced Induction... Unless their dyno tuner doesn't know wat they are on about???

I don't really think there would be different modes for front and rear wheel drive, never heard of that b4, and i dont think there would be any point, every car has different drive train loss anyways so a setting on the dyno is going to achieve anything...

huh? the whole point of a dyno is to estimate power at the engine, minus drivetrain loss?

it is VITAL for the dyno to know what sort of car is being dyno'd to calculate a drivetrain loss constant?

[tinkerbell]

http://www.bankspower.com/tech_chassisdyno.cfm

read and learn...

(it might help keep your foot out of your mouth )

[tinkerbell]

Chassis Dyno Dynamics

An overview of chassis dynamometer types, how they operate, and how they impact the products you buy.

By C.J. Baker

You'll have to look hard and long to find an automotive aftermarket company that does more testing than Gale Banks Engineering. We test new vehicles and used vehicles. We test for power and emissions. We test for product ease of assembly and use. We test on the road and on engine and chassis dynos. We test before and after our product is installed. We test empty and under maximum load. We test on level ground and in the mountains. We test at sea level and at high altitude. We test in all kinds of weather. We test to find failure points. We test to refine product designs. We put our competitors' products through the same rigorous tests to verify that we offer the best value in terms of performance gains, durability, reliability, economy and safety. Moreover, we religiously test our test equipment to make sure the results are accurate and realistic.

All of our testing is based on accepted scientific and engineering standards, and over the years, one of the things we've learned a lot about is chassis dynamometers. Simply stated, a chassis dynamometer is a device that attempts to evaluate engine and drivetrain performance of a vehicle by dynamically simulating road loads (such as acceleration, grades and wind resistance) on the vehicle's drive wheels. The real purpose of a dynamometer is to measure changes in performance – to tell the user whether modifications helped or hindered performance. In other words, a dyno is like a bathroom scale. It tells you whether you're gaining or losing. Almost any dyno can tell you whether you're gaining or losing, provided you make your comparisons using the same dyno, under identical conditions, or corrected to the same standards. You also need to use the same dyno operator, but that's another story (see "Truth in Testing"). The problem comes when a dynamometer is used to determine a peak power level. Just like bathroom scales, different dynos are likely to yield different results. So, which results are accurate?

Chassis dynamometer types vary, and so do the results. It's well known that no two dynamometers are likely to give exactly equal results, and that even applies to two identical units from the same manufacturer. In such a case, at least the results are likely to be close. However, when you completely change the way the dynamometer gathers data to produce a power rating, the difference in results is likely to be substantial. This is especially true when you compare an acceleration, or inertia chassis dyno to a sustained-load, or power absorption chassis dyno. To simplify things, we'll just refer to the two types as acceleration or sustain-load chassis dynos since those seem to be the most descriptive terms. Technically speaking, you can also do acceleration tests on a power absorption dyno, but again to simplify things, we ignore that form of testing in favor of sustained-load testing, where applicable.

Both acceleration and sustained-load chassis dynos measure power delivered by vehicle's drive wheels. In theory, this makes more "real world" sense than simply measuring the net engine power output on an engine dyno. A chassis dyno measures the actual power at the drive wheels available to propel the vehicle after all parasitic losses have taken their toll on engine power output. Parasitic losses include the engine fan, alternator, air conditioning compressor, power steering pump, exhaust system restrictions, vehicle air intake restrictions (including intake air heating) and drivetrain friction. The drivetrain friction is substantial, including transmission and differential gear and bearing friction. Need proof? Why do you think transmission and differential lubricants get so hot during normal driving? That's power being converted into heat. Unfortunately, this is also an area that is inadequately addressed during most chassis dyno testing since there is no airflow over, around, or under the vehicle to carry away the drivetrain heat. We'll talk more about this later. Just be aware that we're talking about heat dissipation here, not air resistance to the forward movement of the vehicle.

An acceleration chassis dyno really ought to be named a "calculating dyno" since it attempts to measure power output by calculating power based on the amount of time required to accelerate the dyno rollers from one speed to another. This is possible when the weight of the rollers (actually the moment of inertia) is calculated into the equation, and mathematically it sounds good. The problems come with actual application and a number of inconsistent variables that cannot be built into the computation.

By its very design, a power test on an acceleration dyno is a very short test, lasting only a matter of seconds, and during the test, the vehicle's engine and drivetrain are in a constant state of transition. By its nature of transitioning from one speed to another, gear changes are usually required. This creates torque spikes when the shifts occur. At anything other than a direct 1:1 ratio in the transmission, the engine torque (power) is being multiplied, and an acceleration dyno has no way of ascertaining the transmission gear ratios of the vehicle being tested. If the vehicle has a manual transmission, there's the problem of gear changes that momentarily remove the drive force from the rollers, or worse yet, initiate some momentary tire-to-roller slippage. Automatic transmission vehicles also have the problem of the torque converter clutch being unlocked during acceleration. The amount of slippage in the torque converter, being a function of stall speed and load, is another inconsistent variable.

While the weight of the rollers and their resistance to acceleration must be known to calculate the power required to change the speed of rollers on an acceleration dyno, just as important is the mass of the vehicle's drivetrain, especially the drive wheels and tires. Obviously it takes more power to accelerate the wheels and tires on a dually than it does to accelerate single wheel/tire configurations, but an acceleration dyno has no way of accurately computing the moment of inertia of the vehicle's drivetrain. Consequently, the peak power number generated may be inaccurate (and usually lower than the power number generated on a sustained load dyno under similar gearing conditions).

Equally important regarding realistic acceleration chassis dyno results is to have the roller inertia weight closely equal the weight of the vehicle. If the effective weight of the rollers is 4000 pounds and the vehicle weighs 8000 pounds, obviously the vehicle's engine can accelerate the rollers far faster than it can accelerate the vehicle on the road. Calculations can still be made when there are such large variances, but the more unequal the roller moment of inertia and vehicle weights, the more removed from a "real world" simulation the test becomes. If the moment of inertia of the rollers is substantially less than the weight of the vehicle, it is questionable whether the rollers can fully load the engine the way the vehicle would load it. On a turbocharged vehicle, full boost may never be achieved on an acceleration dyno, and that of course, results in lower power output. On an acceleration dyno, you simply can't duplicate the load a truck or motorhome would encounter on a continuous uphill grade.

[tinkerbell]

Exactly where peak power occurs is another problem with an acceleration dyno. Because everything is in transition during a test, the RPM where peak power, or even changes in power, occurs can only be approximated. Still, in apples-to-apples comparative testing, an acceleration dyno can reliably indicate whether changes to the vehicle result in performance gains. Similarly, if multiple vehicles are tested on the same acceleration dyno under similar conditions, that dyno can usually indicate the relative power differences between the vehicles. The reason we say "usually" is that recognizing and quantifying tire slippage on an acceleration dyno is difficult to impossible. The real problem with an acceleration dyno is putting any faith in the calculated peak power number.

Before moving on to sustained-load chassis dynamometers, let's also discuss temperature stabilization of the test vehicle. On an acceleration chassis dyno, the vehicle simply isn't under load long enough for the critical temperatures of the vehicle to maximize or stabilize. These temperatures include: water temperature, cylinder temperature, exhaust temperature or turbine inlet temperature, compressor discharge temperature, intercooler outlet temperature, transmission and differential lubricant temperature, and tire/roller temperature. Each and every one of these temperatures has an impact on the power output of the vehicle and the ability of that power to be transferred to the dyno rollers. Here again, turbocharged vehicles, such as turbo-diesels, never operate long enough on an acceleration dyno to maximize exhaust temperature, and it is the exhaust heat that drives the turbocharger, so maximum boost will not occur.

Some of the above temperatures are significantly impacted by airflow through the front of the vehicle during testing. All chassis dyno testing, whether it's on an acceleration dyno or a sustained-load dyno must be accompanied by radiator/intercooler airflow that is equal in volume and speed to the airflow the vehicle would experience at a road speed matching the chassis dyno roller speed. For example, without such airflow, the intercooler on a turbo-diesel won't be functional. That has a tremendous impact on power and exhaust gas temperature. Banks conducts all of its chassis dyno tests using large, high-speed, high-capacity fans to match radiator/intercooler airflow to roller speed. Any dyno testing without such fans is simply bogus. Similarly, separate high-capacity cooling fans duct cool air onto the dyno rollers and tires on the Banks sustained-load chassis dyno to assure consistent and repeatable results. Without such cooling air, the tires heat up, the inflation pressure increases, and tire slippage is likely to result.

A sustained-load chassis dyno does not calculate the test vehicle's power output. Instead, it measures power output directly by imparting an electrical load or water absorption load on the rollers and measuring torque. It can sustain this load indefinitely to allow conditions to stabilize on the test vehicle. It can take readings at any desired engine speed or roller speed to exactly determine a power curve and the peak power output RPM. The test vehicle can be locked in direct, 1:1 drive with the torque converter clutch (on automatics) locked to eliminate any torque multiplication or slippage. Similarly, engine RPM, wheel speed, and roller RPM can all be monitored simultaneously to immediately identify any tire slippage on the rollers. A sustained-load chassis dyno is simply more accurate.

On a sustained-load chassis dyno, the weight of the rollers has no significance since the load is usually measured at a steady speed with the load imposed on the rollers. This also means the weight of the test vehicle is insignificant. It could be a half-ton pickup or a 45-foot motorhome. It makes no difference.

Perhaps the best way to explain the differences between acceleration and sustained-load chassis dyno operation is to envision the way they load a test vehicle compared to actual road loads. An acceleration dyno is like a drag strip, deriving its power rating from how fast the dyno rollers can be accelerated. A sustained-load dyno is like an unending uphill grade, measuring the power necessary to climb that grade at any given speed.

So why doesn't everyone use sustained-load chassis dynos for performance testing? There are many reasons, but there are two reasons that are important when it comes to testing aftermarket power products for trucks and motorhomes. First, a sustained-load chassis dyno is mechanically more complex and expensive because of the load generators and load-measuring units that must be connected to the rollers. A sustain-load chassis dyno may also have larger diameter rollers than an acceleration dyno. These things, taken together, mean that the sustain-load dyno, and the permanent installation facilities required for it, is substantially more expensive than what's involved for an acceleration dyno. In fact, the total costs of a sustained-load chassis dyno may be more than five times as much as for an acceleration dyno. Second, many of the power products produced by various manufacturers in the aftermarket truck and motorhome industry generate their best results during short tests. Let's put that another way; these manufacturers of quick and dirty power modules and programmers really aren't interested in revealing the problems their products cause under a sustained load. This is especially true for diesel-powered vehicles where simple fuel-enrichment power programmers escalate exhaust gas temperatures into the danger zone under a sustained load (see "Why EGT Is Important").

In all fairness, the fore-going reasons why many manufacturers choose acceleration chassis dynos may reflect the old "chicken and egg" syndrome. If a company is unable or unwilling to invest in a sustained-load chassis dyno, then they also will lack the facilities to more fully develop their products for safe operation under sustained loads. Who knows which came first, an inadequately developed product or the inability to develop a safe, reliable product? Either way, let the buyer beware.

At Gale Banks Engineering, we use a state-of-the-art Mustang sustained-load, eddy-current, chassis dyno, further modified for accuracy and repeatability. We've already mentioned the vehicle and roller cooling fans, but that's just part of it. The Banks chassis dyno uses larger 19-inch diameter rollers as compared to the smaller rollers used on most acceleration dynos, but even more important, both the front and rear rollers are linked together to distribute the vehicle tire load over four contact patches. Most other chassis dynos, both acceleration and sustained-load versions, have a single drive roller and a parallel "coast" roller. Some just have a single, large diameter drive roller. This means the drive load is split between only two contact patches and slippage is much more likely. Moreover, whenever possible, Banks selects research and development vehicles with dual rear wheels to further increase tire-to-roller contact area.

All of these chassis dyno differences and features may seem like little things, but they have a profound influence on the accuracy of the data derived, and the product development process. It's just one more area where we never compromise. When results and reliability are on the line, and you can't afford to make a mistake, you can count on Banks.

http://www.bankspower.com/tech_chassisdyno.cfm

[cldc2]

ooo.. nice one tink...

[GoldCoastDC5R]

Tinks I'm not sure how that is relevant?

Testing has all been done on a dyno dynamics dynometer in shoot out mode 06. When asked APC told me that 4F was for 4 cylinder forced induction. All other NA cars dyno'd at their shop were done in shootout mode 4 as well as my dyno's from Toda and the Dyno Comp. The modes are specific to dyno dynamics dynometer and as such the info you have posted, although very useful in understanding how dyno's work, does not have any bearing on the modes used when my car was dyno'd.

Ok well i have booked in to have the car dyno'd once again at APC in the right mode to find out exactly what power it is making, so i guess my questions will be answered then

[tinkerbell]

tony, it was only (mildly) relevent to clarify:

and i dont think there would be any point, every car has different drive train loss anyways so a setting on the dyno is going to achieve anything...

good luck with APC

[GoldCoastDC5R]

tony, it was only (mildly) relevent to clarify:



good luck with APC

Yeah I get your point tinks and agree with what you're saying, what i was getting at was more the point of drive train loss between my fwd car and say that of a corolla sportivo or whateva. Not so much fwd and rwd which do differ quite substantially. Thanks for the info, always good to widen the basic knowledge

[TODA AU]

Tinks I'm not sure how that is relevant?

Testing has all been done on a dyno dynamics dynometer in shoot out mode 06. When asked APC told me that 4F was for 4 cylinder forced induction. All other NA cars dyno'd at their shop were done in shootout mode 4 as well as my dyno's from Toda and the Dyno Comp. The modes are specific to dyno dynamics dynometer and as such the info you have posted, although very useful in understanding how dyno's work, does not have any bearing on the modes used when my car was dyno'd.

Ok well i have booked in to have the car dyno'd once again at APC in the right mode to find out exactly what power it is making, so i guess my questions will be answered then

We dyno in 5th gear on DC5's so the total torque is less & the tyres are less likley to wheelspin on the dyno (@ 50psi)

Shoot 4 = 100 ramp rate / 80 inertia
Shoot 4F = 150 ramp rate / 80 inertia
Shoot 4F generally reads slightly higher than Shoot 4

As stated previously, Shoot 4 is 4cyl / Shoot 4F is Cyl forced induction

Barometric pressure affects total correction factor.
Lower the number, higher the correction. Higher the number lower the correction.
Default is 101.3

Relative humidity also comes into play.
Dyno Dynamics default is 60%
Less than this adds a negative correction factor, over this is generally positive.
Temperatures affect this also.
Higher intake temps have a positive affect on power shown.
We leave the intake temp sensor away from the engine bay to avoid false power readings with high intake temps.
Hope that helps.

Adrian

[tinkerbell]

i remember we did two dynos on my car in 4F - i assumed it was front, but it is not. i should have asked!

i guess that shows it is upto the dyno operator to determine the best settings, and once ramp rate etc is different - its hard to compare numbers at all...

still, good enough graphs anyway scale on the last one could have been steeper though