Wednesday, August 8, 2012

First dyno numbers

Now that the painful 1000-mile break-in is done, I feel comfortable wringing the car out, so that means a trip to our Dynojet dyno.  I did runs with the car in all-stock configuration, and then I also removed the rear muffler section and replaced it with a little stubby pipe that we fabricated.  We observed the same horsepower with and without that muffler section.  The power is about on par with other BRZ / FR-S dyno results we've seen.  The weird semi-circle of low torque between 3000 and 4000 RPM is common across every dyno graph.

I tried one run where we removed the intake filer completely.  That resulted in no benefit.

159 horsepower to the rear wheels is pretty low.  We usually see a 15% loss from the engine to the dyno, so we'd expect 170 rear-wheel horsepower from a 200-hp-rated car.  159 at the wheels would indicate more like 187 at the engine.  Perhaps the power will go up after the car has been run in some more.  We'll check back.

The modest result on the dyno brings to mind our current vanity plate for the car, pictured at right.  (Vanity plates cost next to nothing in Virginia, so we'll probably end up changing these a few times.)

We got some decent video footage of the dyno runs with the muffler on:

I also did a little bit of outside recording of the sound with the muffler delete installed.  To my surprise, the noise was pretty moderate -- I wouldn't really mind living with that on a daily basis.  Although there's no increase in horsepower, taking off the muffler does drop about 25 pounds from the car -- almost 1% - so that's a plus.  We haven't decided yet if we're going to mass-produce the muffler delete.  Let us know if you'd be interested in purchasing one.


  1. dan, why not make a delete with massive tips but a dual setup? i know its ment to save weight but i think a lot would buy it more if it looked more appealing.

    well done!

    1. We'll have something like that soon. Gotta build it first.