I always liked the Remus exhaust I put on my previous 1.9 Z3, but I regretted not doing "before" and "after" dynos on the car to see how much of a performance gain the aftermarket Remus exhaust gave me. I didn't make that mistake this time, a "before" dyno was recorded with the M roadster in stock condition after it was broken it (click on the graph for a larger view).

After the installation the car felt quicker and it seemed to run through the upper RPM range faster. In fact I even bounced it off the rev-limiter a few times on accident until I got use to the new tach speed. But all this was just non-scientific (what some people call the "butt-dyno") data. I knew the car felt quicker but what I needed was a real dyno to prove it. I returned to the same place where I had my M roadster dynoed before to see just how much of a gain the Remus exhaust gave me (click on the graph portion to the right for a full screen view).

What the dyno did was prove what I was feeling, the Remus exhaust boosted the torque across nearly the entire RPM range. The biggest gains were found in the range between 3500 and 5100 with a peak gain of 13 ft/lbs of torque at 3800 RPM. The only exception was the RPM range between 2300 and 2500 which showed no gain. A few skeptics said that an aftermarket exhaust might gain power in one area but then loose it in another. What the dyno showed me was that the Remus exhaust never hurt performance, improved the performance across most of the RPM range, and even smoothed out some of the torque curve where dips in power occurred on the stock dyno.

I was hoping to back up the dyno data with performance timing, so I purchased a GTechPro which measures 0 to 60 and quarter miles times. I took several measurements before the exhaust upgrade and several measurements afterwards. However I don't think that data can be trusted because what the GTechPro really did was teach me how to drive the car faster. In between the before and after testing I had improved my driving skills enough to make those tests invalid. I also didn't pay much attention to the temperature variations which might also explain the gains I was seeing. So really the only thing I got out of the timing tests for this article is this fairly cool real video.

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