Post
by Robou » Sun May 10, 2009 10:06 pm
The diagram and the explanation underneath make me wonder.
First of all, the diagram. The curve for the torque reaches 170 lbs/ft at 4700 rpm in an almost straight line from 100 and than drops from there in a steep line. This is very poor, it should go steep up to 2500 rpm, hold approximatly that value till say 4500 rpm and than gradually go down. The diagram shows this car has no power at lower revs which makes it need a lot of shifting.
Then the absolute values. A dyno measures at the wheels, not the engine. The applied software puts out the figures. The dyno operators can manipulate the software, and almost always do so, in order to please the customer. This is why a dyno is a perfect means to tune a car because one can compare the outputs between changes made, but less than perfect for true values.
What we see here is a claim about a engine power measured. This can not be true, only the wheel power can be measured. For the customer's sake a loss is measured. How? The loss is in the gearbos, the differential and the wheels on the dyno. And the figure is huge, 74 HP. Accepted is a loss between 15% and 20%. Now back to the only value that really can be measured: Wheel power, 94 HP. Assuming a loss of 20% gives a engine power of 118 HP, which is the standard output.
When one looks at the diagram, it shows values "corr", which means corrected. Corrected by what or whom? Air density or -pressure or -temperature? I bet by the operator who manipulated the software.
Now, Brian Ford, don't panic, your car will no doubt put out more than 118 HP, because you are obviously very pleased with it, and you wouldn't if this figure were true. But I think you chose the wrong example to convince people of the benefits of the mod.
I have a incomplete "Richmod" and it brings 220NM between 2500 and 5000 rpm with a top of 250 NM at 4200 rpm and about 150 HP between 4200 rpm and 5400 rpm. For the Enlish: 1 NM equals 0,7376 footpound. Assuming 15% loss this means a little over 175 HP engine power.
My "Richmod" is incomplete, because no changes were made to the microprocessor and the bin for the eprom is slightly different, but I trust the original "Richmod" will bring at least the figures mentioned.
Too old to bother
480 Turbo midst '91
)
