NAC: how to test gas ?

[Taka Mizutani]

Comments interspersed below:

On 8/2/07, Roy Wendell <erwendell at mac.com> wrote:
>
>
> [snip]
>
> As for some first hand info, if I recall correctly doesn't the Spec B have
> essentially an STI motor? I ask because my friend's '06 STI used to do the
> exact same thing when new but it eventually went away. It's almost like it
> was running some sort of learning routine that took a while to optimize. I
> remember being incredulous when I first rode in it that Subaru could have
> stuffed up the tuning so badly on their highest performance model. The
> hesitation was obvious from the passenger seat. When I drove it a month or
> so later and every time since including in a couple of autocross
> competitions it's been smooth as glass.


No, Legacy Spec Bs don't have anything special done to the engine- it's a
Legacy GT, essentially. 2.5L, 250hp. However, they do have basically a
non-DCCD version of the STI 6-speed transmission and STI-tuned Bilstein
struts and Alcantara interior and standard nav.


I can't say as the mileage is all that surprising either. Big sticky tires,
> awd, and power add up and my friend has to work very hard to get his milage
> into the 20s with a smaller car. I'm also not sure at your current milage
> (or would that be kilometerage?) that the engine is completely broken in.


Spec Bs don't use any seriously extreme tires (IIRC, they're still using
crappy Potenza RE-92s on them!). Mileage should be similar to the standard
Legacy GT. My STi does about 12-14mpg with me using full acceleration quite
often and the A/C on; it gets about a max of 22-24mpg on the highway with
the cruise set to 70 on a 110mi drive. The '06 with the underbody panels and
diffuser should get a couple more mpg on the highway due to better
aerodynamics.


As a side note, the temperatures that you are currently enduring can't be
> helping the performance much. There are very good reasons why Subaru mounts
> the intercooler up on top of the engine where they do but heat soak in
> traffic on a hot day causes a noticable performance drop.


I really don't know why Subaru does a top-mount other than that it's easy to
get air across it w/o putting in a place where it would be hard pressed to
pass the 2.5mph Federal crash testing. Putting it right nearly on top of the
turbo isn't a good idea, although the packaging also keeps the intake tract
short, which may be the reason why they packaged it that way- with the flat
four, there's plenty of space on top of the engine.

The rally cars use a V-mount setup for the radiator and intercooler, allows
for a lot more air and a shorter intake tract than a FMIC. If I had a larger
budget for mods, I'd do an ARC V-mount on my car along with a bigger turbo,
but then I'd want a built motor, etc. Slippery slope indeed.

Taka