legacycentral bbs

OK, so I want to get 15 pounds (1 bar) of boost into my engine.
Anyone know a definite answer on what I need?

1. fuel pump, regulator? I've always heard I need a larger fuel pump
to to cure the full throttle, half throttle feel, but I think Adam
pointed out that a 1991 turbo fuel pump will flow more lph than a WRX
pump. Does this mean I don't need an upgraded pump? As for the
regulator what can I purchase to serve my needs? Injectors, do I need
bigger?

2. Intercooler, Saab 900? Is this a little small? Or should I get a
Early generation WRC Air/AIR? Topmount sound OK, with a bigger
hoodscoop?

3. Turbo, Is the stock turbo rated high enough for 15 psi of boost?
Or will it be in afterburner mode by then?

4. Exhaust, I Plan to put in a 3 inch system all the way through.

An the norms, boost controller, guages etc

Do you know an approximate cost for all these things? Any horsepower
figures?

Thanks,
Mark

Im not trying to be a hater so don’t take this the wrong way.

I think you should NOT try to get 15 psi of boost. Instead choose to
have xxx hp and tune until you do. I have seen and rode in a couple cars
with high boost that were just cool and rode in a couple more with more
moderate boost levels that were WOW.

No reason to set a boost level and tune around it.

Exactly....you always want top actually run the least amount of the boost that is within the turbos efficiency range and still produces the hp levels you desire.

As for components, the fuel pump in stock form is slightly higher flowing than a new age WRX, but that does not mean it can be overlooked as power levels increase. The WRX has a much nicer head(s) design, and breathes better than a Legacy does. As such, it takes a bit more effort to get the power increases that you can get with the WRX, though the same general rules applies.

I don't see why the stock turbo won;'t spin to 15 psi..though if yours has high mileage, it might not be happy there...you would probably be better served with a better turbo in the long run. As a general rule, we like to stretch the stock components to their realistic, reliable maximum level of performance, and from there, replace only those componenets that need to be replaced. This ensures you tune each part to their max, which not only allows you to budget things a bit better, but actually realize the benefits each mod makes.

Adam

Hi Adam,

I hear there are many Legacy Turbo's running 12-13 pounds of boost.
At this rate will I need such things as a new fuel pump and
regulator? I know an intercooler is mandartory at this rate, Should I
get a first gen WRX Air-air IC or will the some-what smallish Saab
900 provide enough cooling at 13 Pounds? I plan on an improved
exhaust too.

Thanks,
Mark