Mustang Dynamometer

[wickedstangs]

Here is some good info on a Mustang Dynamometer.. Enjoy

During automotive tuning, a chassis dynamometer is an important tool to
determine whether or not the changes you have made in the ECU are
beneficial. There are two types of dynamometers on the market; an inertia
style and a loading style. A chassis dynamometer that can load the vehicle
will allow for a more accurate tune on the vehicle than one that is an inertia
style. When you are tuning a vehicle on the dynamometer, you want the
amount of load being placed on the vehicle to be as close to the amount of
load the vehicle sees when it is on the street. This includes weight of the
vehicle, wind friction and road friction. The only way you can do this is
with a loading dynamometer.

When using an inertia style dynamometer, the only load the vehicle sees is
the weight of the drums of the dynamometer. This type of dynamometer is
adequate if you are only doing horsepower pulls, but it will not allow you to
do accurate tuning. When tuning a vehicle, you want to be able to tune
every load site in the ECU’s fuel and timing map. This is done by adjusting
how much load is on the vehicle. With an inertia style dynamometer, you
will only be able to do testing in one load column because you can not
adjust the load on the vehicle.

For example let’s tune a late model Chevrolet Camaro. This car weighs
about 3500 pounds. When running this vehicle on an Inertia Dynamometer,
the only load the engine sees is the load created by the rollers. This load is
about 2600 pounds. Now let’s tune this vehicle. You start by leaning out
the air-fuel ratio and advancing timing. The car runs great on the
dynamometer. Now let’s pull the car off the dynamometer and run it on the
street. You will notice that the tune you did on the dynamometer is going
to be to lean and the timing is going to be advanced too much. The reason
for this is because you tuned the motor in a 3500 pound vehicle to push
around 2600 pounds. So when you put the car on the street, the motor is
now pushing around about 1000 pounds more and it has to deal with wind
and road friction. At 100MPH, wind friction can absorb almost 60
horsepower depending on how aerodynamic the vehicle is. This will easily
cause the motor to experience detonation which will eventually damage the
motor. Another issue with the amount of load being to light compared to
what it usually sees is the ability to accurately data-log information. As a
result of the vehicle accelerating so quickly, the computer may not have
enough time to accurately data-log all of the important information (i.e.
temperatures, flows and pressures). This will hinder the tuner’s ability to
analyze all of the vital information needed to accurately tune the vehicle.
Moreover, turbocharged vehicles have a difficult time building full boost on
inertia style dynamometers. Turbochargers run on exhaust gases. When
there isn’t enough load on the motor to produce the proper amount of
exhaust gases, the turbocharger won’t spool up to full boost. For this
reason, you will need to adjust the boost controller to make full boost on
the Inertia Dynamometer. After making adjustments on the Inertia
Dynamometer to build Boost, a tuner will need to adjust the boost
controller again before going on the street - else you will make to much
boost due to the extra load.

Now let’s tune this same car on a Mustang Dynamometer. Before testing,
you input the vehicles weight and HP@50MPH. This allows you to use the
vehicle simulation and accurately load the vehicle. When the car is on the
Mustang, it sees the same amount of load it sees when it is on the street –
weight, wind friction and road friction. It is the closest thing you can get to
performing a road tune on the vehicle. Therefore, when you adjust the fuel
and timing values in the ECU they will be accurate when you take the
vehicle on the road. Having the same amount of load on the dynamometer
as on the street will also allow the vehicle to accelerate at the same rate it
does when on the street. This will allow the computer to accurately datalog
all of the information you will need to properly adjust air-fuel ratios and
timing. Also, because you are applying the proper amount of load,
turbocharged vehicles will spool up at the appropriate time and produce
the desired boost levels.

If you are looking to perform just power pulls, an inertia style dynamometer
will be acceptable. But if you are looking to accurately and SAFELY tune
vehicles to run on the street, a loading dynamometer is the only way to go.

 

[ears]

oh man,,,, this is gonna take a few to read!!!

 

[wickedstangs]

oh man,,,, this is gonna take a few to read!!!

wow, you make me worry about you sometimes....:lol:

 

[ears]

alot of great info,,,, kinda helps to understand what kind of technolegy is actually in one of them fancy roller machine thingies!!

 

[Ford1288]

Yeah I didnt know much about dynos so that was a pretty nice read. Thanks.