08-20-2001, 08:33 PM
I am possibly going to buy a late model SVX next year and, from researching the car, it seems to be the general opinion that the performance of post-93 cars was down compared with the 92/93 versions (although I've seen posts which appear to contradict this). The general opinion seems to be that Subaru "de-tuned" the tranny for post 93s, however, I recently came across a theory which I had not heard before (maybe it's common knowledge and I'm just not aware of it - if so, sorry for wasting everyone's time).
My source was the Shop Foreman at a local Toyota dealership where they also service Subarus (two dealerships both owned by the same person). He was quite adamant that Subaru had modified the exhaust system to make it more restrictive to increase backpressure and allow them to lean out the engine to F/A ratios of 15 or 16 (maybe to help mileage or help pass emissions??). He cited the case of an SVX owner whose exhaust system they had replaced with a "conventional" system (ie. not a performance exhaust, but not too restrictive). The tone was much more aggressive as the car drove away and, when the owner returned a few days later he was ecstatic and swore that the car had gained 25 or 30 HP.
I'll admit that this is purely anecdotal evidence, but my experience is that putting a performance exhaust on a normally aspirated engine does not make much of a difference to the perceived power (a turbo, though, is a different story :) . I remember reading that most people cannot perceive anything less than a 5% power increase.
To a first approximation you'd have to drop HP from 230 to about 195 to give the sort of change which Motor Trend saw in 0 to 60 time and 1/4 mile speed between the 94 and the 92. This seems to fit with what the SVX owner reported.
Has anyone else come across this theory?
My source was the Shop Foreman at a local Toyota dealership where they also service Subarus (two dealerships both owned by the same person). He was quite adamant that Subaru had modified the exhaust system to make it more restrictive to increase backpressure and allow them to lean out the engine to F/A ratios of 15 or 16 (maybe to help mileage or help pass emissions??). He cited the case of an SVX owner whose exhaust system they had replaced with a "conventional" system (ie. not a performance exhaust, but not too restrictive). The tone was much more aggressive as the car drove away and, when the owner returned a few days later he was ecstatic and swore that the car had gained 25 or 30 HP.
I'll admit that this is purely anecdotal evidence, but my experience is that putting a performance exhaust on a normally aspirated engine does not make much of a difference to the perceived power (a turbo, though, is a different story :) . I remember reading that most people cannot perceive anything less than a 5% power increase.
To a first approximation you'd have to drop HP from 230 to about 195 to give the sort of change which Motor Trend saw in 0 to 60 time and 1/4 mile speed between the 94 and the 92. This seems to fit with what the SVX owner reported.
Has anyone else come across this theory?