Friday, August 17, 2012

More driving impressions, and prototype parts

I've been commuting back and forth to work in the BRZ, and the more I drive it, the more I just love this car.  I am afraid I'm turning into a less-polite driver, because every time I'm in the car I just want to grab it by the scruff of the neck and toss it around.  I find myself using full throttle more than in my other cars, and challenging myself to see if I can get past slow cars in traffic.  I feel like I'm reverting to a teenager.  On the plus side, full-throttle driving doesn't actually make the car go very fast, nor does it make much noise with the stock exhaust, so a lot of times I think I'm the only one who knows I'm flogging the car.  The rest of the world just cruises along in their tall, sound-isolated, luxury barges.  Which happen to be faster than my car, but that just makes it all the more challenging to keep up.

The car is very, very low.  It was low to start with, and the Mach V springs have lowered it about another inch.  Either way, I noticed that a lot of drivers don't even see the car -- I've had a couple of somewhat close calls with bigger vehicles changing lanes and not seeing me.  Maybe I need a little orange flag to stick up off the top like on a bicycle.

Getting in the car and driving it, I have these weird flashbacks to other cars I've owned or driven in my past. Today I had a memory of driving a 1988 Honda CRX Si, back when that car was new.  The Subaru has some of the same sensory triggers: Short-throw gearbox, taut handling, naturally-aspirated engine that only makes power up top, and light weight.  I remember revving that CRX to redline at any and every opportunity, and I'm driving the BRZ that way, too.  It's refreshing and pleasant to be able to use every bit of the car's performance, and not have to worry so much about breaking the sound barrier (or my driver's license).

The handling is forgiving and exploitable in the same way.  Other cars I have, or have had recently, have such high limits, I could never, ever approach the limits on any public road.  It just wouldn't be safe or sane.  The BRZ has pretty good grip, but the limits are very progressive and approachable.  I feel comfortable playing around with the car in a corner, exploring a little bit of oversteer or understeer, and I don't have to be going 100 mph to do it.  A simple cloverleaf becomes my own little section of race track banking, and I'm only going 35 mph.

In other news, parts development for the car continues.  Our muffler delete pipes are in production now and should be ready in a couple of weeks.  We recently test-fit a prototype front license plate mount that bolts into the tow hook location (so you don't have to screw it directly into the bumper), and we should have those in 2-3 weeks as well.  Our Mach V rear differential cover, billet aluminum with big cooling fins, is also in development.

We also got in some aftermarket silicone radiator hoses from Fuku Works, and we'll be test-fitting those sometime soon.

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.