Dyno
Have a look at my car | Why even bother spending money and putting it on the dyno. Well that’s an easy answer. You should know where your car delivers most of the performance. Most manufactures give you in the brochure some information on this. Some even give you a dyno chart, however this is not your car, but a similar one and after you made any modifications to it, this chart is not correct anyway. I did the first time the dyno when the car was completely unmodified. This way I could see what kind of performance it had. This is what came out of it: WHP 198,8 @ 5776 EHP 225,4 @ 5904 NM 331,4 @ 3894
So this meant that I had about 5 HP less on the engine than Subaru says it has. This can have many reasons, and could be as simple as a different temperature in the room. In this case the reason was that the dyno air cooling was not quite right. For a Subaru there has to be a separate fan that directly blows in the top mount intercooler. The way it was done however was without the additional fan. So the engine measured that it did not get the needed cooling and did not release the full power. When you have a look at the dyno chart, you will notice a quite obvious peak around 3400 rpm. This is normal for Subarus, because at this rpm the turbo starts spooling up. Now that I knew that my NM drop quite a bit around 6000 rpm I could change gears at 6000 rpm. Depending on the gear I would then end up at around 3500 rpm. This way I never had a loss of torque after gear changes. Now that I have done quite some modifications to it, I have to go back on the dyno. One thing to remember is also that a dyno is not quite as accurate as you might think. Basically as a tip, always use the same dyno if you want to compare results. I have read of cases where the same car was tested on two different dynos without modifying anything and still there was a difference of up to 20-25 HP. So the dyno result is an insight into the performance but will not give you a totally realistic picture. But who cares if you have 10 hp more or less. After all its more important what you can do with it on the road. Also have a look at the videos to see the car in action. First they calculated the losses. Then the real run in 3rd gear. Here are some dyno pictures of my Subaru as it was untuned. |
