Originally Posted by ilia@industry
I'm sorry that you misunderstood.
It's not possible to be honest with the customer and give dyno graphs for mods with small power gains.
If a modification's power gain is smaller than the margin of error inherent in the dyno you're using, the measured gain from that modification is not repeatable.
In order to be as honest with the customer as possible, we do not list measurements that are not verifiable, either by the customer, or even by us from run to run.
If your exhaust is claimed to have a 10hp gain, and the dyno results vary by 20-30hp from run to run, that 10hp gain will not be consistent. One run might show a 400hp car, while the next can show a 415hp car, and the run after that will show the car making 390hp.
As I said, a repeatable measure of performance is backpressure. A reduction in backpressure, while keeping the same tubing sizes, will yield an increase in flow, and therefore performance. Backpressure measurements are a much more repeatable, honest way of telling the customer how a system performs.
what kinda dyno are you using thats so inconsistent?
We have a DynoJet and see variances of only 1 to 2 hp.... with a extremely consistent car in the same day.... i would put the M3 in the "extremely consistent" category..