ScoobyNet.com - Subaru Enthusiast Forum - Dawes on MY01

I watched the boost gauge at different throttle openings on Paul's MY01 tonight with a Dawes set to 16.5-17 PSI as it had been installed with the standard bleed hole. It made about 15 PSI at 1/4 throttle. Paul did not have an AFR gauge in his car.

We drilled out the bleed hole on the Dawes to 1.5mm, and turned back the Dawes 1 3/4 turns and it consistently made 16 PSI. It is subjective, but we thought it pulled better at the top end with the bleed hole and slightly lower boost. Perhaps it was less retard - perhaps the midrange was less strong making it feel like it was pulling relatively harder at the top end. This car has a decat DP, but still the original uppipe cat.

Certainly the boost held on quite well at the top end - about 14 PSI at 6000 RPM.

However, although the part throttle was boosting much more sensibly, it still felt a lot friskier than a MY00 for part throttle boost which I can't explain satisfactorily. We did not drill out to 2mm, but I was tempted to, but did not want to dumb down the Dawes spool up speed. It seemed to produce 15 PSI at 1/2 rather than 1/4 throttle. From watching the AFR in the MY00 it seems to fuel quite well if you boost a lot above 1/2 throttle but not between 1/4 and 1/2, so maybe we have a good compromise. It still seems like a good idea to get rid of the uppipe cat though, which I think is on Paul's list now, and overall the car actually felt quicker with the bleed at 16 rather than just set to 16.5-17. Certainly you could perceive the extra weight over a MY00 though, but we were three peeps, and my car was running 2 extra PSI and full decat and is a bit rawer.

I wish I had some G readings, and data logging of ignition and boost, TPS and RPM, but sadly all I can do is share my subjective impressions. Hope this helps.