Boost Curve

[R33vit]

After the SAU Dyno Day at UAS, I noticed that boost was all over the place using the Autospeed boost controller.

Boost was bleeding off up top, but this is to be expected from a pneumatic boost control system.

I decided to see if I could get the curve to sit a bit flatter than what it was. After sourcing a wastegate actuator from an R32 GTS-T, which is, I believe spring rated to 10 PSI and is a direct fit we ran the car back on the Dyno to compare the difference.

Boost was sitting pretty flat though the Rev range but the dreaded bleed off was still present. I have plotted the result on a XLS spread sheet and created this chart. Hope this helps anyone who is thinking of performing this cheap and easy mode.

The part was picked up from SSS performance for $30 and was about 15-20 min to fit. I did have to reset the boost controller after the fit as boost was hitting 20 PSI with the original setting for the R33 wastegate actuator.

Sam

Yellow is the R32 actuator

Red = R33

[Guest Robo's]

That's a terrific little exercise. Although it comes to suspicion that you may had problems with your R33 Actuator. I have got similiar graph to your R32 actuator with the stock actuator with no dips, but it may fall of more sharply than the R32 actuator.

Ive installed the HKS actuator and to tell the truth it drops at high revs too. Whether it drops off the same as the R33 one, i dont know. Its going on the dyno next week too see if we can pick up any boost up high but i think it might be marginal.

[R33vit]

The old actuator was ok just the boost settings may have been a little different. The drop off is less with the R32. Bleeding off up top is common with bleed valves, may have to do with heat, restriction or something along that line. I think SK had a post about why it bleeds. In any case I am trying to source a APEXi boost control kit for the PFC.

Keep us posted with your results Rob

Chers