PFC stock soleniod, boost control
PFC stock soleniod, boost control
Has anyone been able to make the stock wastegate control solenoid and pfc work together and control boost on a single turboed car with an external WG. I've read on this fourm that it doesn't work well but I figured I'd ask.
Would hooking up my external like an internal make it work using this idea or is this just a useless quest.
Would hooking up my external like an internal make it work using this idea or is this just a useless quest.
WWFSMD
Joined: Jun 2001
Posts: 5,035
Likes: 4
From: SoCal
I tried that but it didn't work very well so I gave up and got an AVC-R. I didn't really spend much time trying to make it work, though, so perhaps I just gave up too soon.
You MUST understand how boost control systems work in general (stock setup, and external setups -- there's more than one way to do it), so do some homework first if you don't already have that knowledge. Ultimately, you may find that the stock solenoid doesn't flow enough to work well, or that the PFC doesn't adjust the solenoid duty cycle actively enough to get good control. Keep in mind that depending on how you set it up, you may need to incorporate (and tune) a vent in the system.
The way I did it was to have full boost pressure go to the side port on the wastegate and one of the nipples on the solenoid. Then I connected the other nipple on the solenoid to the top port on the wastegate, and I had a vent in that line (so it would bleed pressure out of the top of the wastegate when the solenoid was closed). The boost pattern I got after playing with the vent size a bit (I had a small vent at first and it would overboost quickly) was that it would rise to my target boost quickly and then taper off significantly. Maybe just using the solenoid to bleed boost from the side port (and leave the top port open) would give you more stable boost as you rev out, at the expense of some spool up. Relocating the stock solenoid in the ABS area to reduce the volume of the wastegate top port + line might help, too (since the solenoid wouldn't have to flow as much to pressurize the top of the wastegate). Or perhaps using both the stock WG and PC solenoids in parallel, both connected to the WG electrical lines, would allow the solenoid (now two solenoids) to flow more for better control. Hard lines (aluminum tubing, available from the hardware store) might help, too, since the volume will be fixed rather than variable as the lines expand. Rubber rather than silicone lines offer a similar advantage.
-Max
You MUST understand how boost control systems work in general (stock setup, and external setups -- there's more than one way to do it), so do some homework first if you don't already have that knowledge. Ultimately, you may find that the stock solenoid doesn't flow enough to work well, or that the PFC doesn't adjust the solenoid duty cycle actively enough to get good control. Keep in mind that depending on how you set it up, you may need to incorporate (and tune) a vent in the system.
The way I did it was to have full boost pressure go to the side port on the wastegate and one of the nipples on the solenoid. Then I connected the other nipple on the solenoid to the top port on the wastegate, and I had a vent in that line (so it would bleed pressure out of the top of the wastegate when the solenoid was closed). The boost pattern I got after playing with the vent size a bit (I had a small vent at first and it would overboost quickly) was that it would rise to my target boost quickly and then taper off significantly. Maybe just using the solenoid to bleed boost from the side port (and leave the top port open) would give you more stable boost as you rev out, at the expense of some spool up. Relocating the stock solenoid in the ABS area to reduce the volume of the wastegate top port + line might help, too (since the solenoid wouldn't have to flow as much to pressurize the top of the wastegate). Or perhaps using both the stock WG and PC solenoids in parallel, both connected to the WG electrical lines, would allow the solenoid (now two solenoids) to flow more for better control. Hard lines (aluminum tubing, available from the hardware store) might help, too, since the volume will be fixed rather than variable as the lines expand. Rubber rather than silicone lines offer a similar advantage.
-Max
Last edited by maxcooper; Jan 13, 2005 at 11:28 PM.
