BCS and adjustable wastegate questions

[Beerplease]

Have a few questions regarding a nagging issue I have had for years with my SVO. I currently am running the following engine mods to the car done about 6 years ago:
6K on rebuild, stock pistons, crank, etc. 70K on motor
Every nut, bolt, component in the entire engine bay was also cleaned, and/or blasted and repainted at this time
Ported/polished iron head with big valves 2.02/1.68 I think
Ranger Roller cam
Garret GT25/40R turbo
SS Rod's header/3" downpipe/Dynomax Turbo's
Tial 38mm Wastegate with open dump
Greddy BOV
Greddy Profec B electronic WG controller
Spearco FMIC
Custom Moates chip running 190lph pump and 55lb injectors

I orginally ran the stock turbo with the wastegate controlled by a cheapie manual controller, and left the BCS wiring and hoses intact. I then upgraded about 6-7 years ago to the above setup. I guess I did not think/know to remove the stock BCS and hoses when I put everything else in. I have never really gotten the wastegate to work, it never seems to really control the turbo(i.e. limit boost at set levels) and it seems almost as if there is no wastegate control at times. It will easily go to 20psi and I have always limited it by my right foot, to mean I have always have to lift way before the 5K rpm mark under hard accel. I have gotten the overboost light more times than I can remember and backfires/pops and high boost can occur. While killing time at work today I started looking into the BCS and am I correct that it should be diconnected? If so do I remove it entirely? Or do I just unplug it? And what about the vacuum lines? Is my car in effect not controlled at all by the wastegate and has that explained why is runs the way it has all these years. I have chased what I thought was improper WG springs and BOV settings for some time with no real change. I am finally able to devote some time to proper tuning of this car and it has been in the garage more in the past 4 years than not. I can try and send some pics of the setup if anyone would like to see them.

[mrzw70]

What year is your car?

[MikeFleming]

It would help greatly to know exacty how things are connected now - maybe some pics of all the hoses?

If you bypass and block off the BCS solenoid(s) and assorted manual valve(s), does that limit boost pressure?

[Stinger]

You should be able to connect a hose from the outlet of the turbo to the lower port on the wastegate and get whatever minimum boost pressure the wastegate spring is designed for.

Then, if you want more boost, you hook up the Profec B like this: http://www.mkiv.com/techarticles/greddy_profec_b/05.jpg and you should be able to raise boost above the wastegate spring controlled limit.

At no point does the stock BCS need to be used with the Profec B. You can unhook all lines to it, unplug the electrical connection, and store it away for future use (if desired).

[Beerplease]

Sorry it's a '86, and I am working today but I will get the wife to take some photos of the area and post them. And big thanks to Stinger for the Profec link, I was a little confused when I orginally installed the WG and the controller and even called Greddy but they were not much help. I am really excited to sort this out now, it's seems that BCS needs to go and I need to go through the connections again to make her work.

[Beerplease]

Took some pics today and I am working on a photoshop drawing to illustrate it so that it is easier to follow, it was really bright out today.

[scenario]

Are you sure the wastegate is not stuck in the closed position. It could be seized up and if that is the case it would allow you to run way off the scale.

Confirm it is not seized before you do anything. If it seized up years ago, it would still be stuck now. It is possible this has been the case and you did not realize it.

[Beerplease]

Ok, a few discoveries mad in the last couple of days. Went through the plumbing with a fine tooth comb, all appears to be 100% correct. BCS vacuum lines were disconnected but the electrical connection was not, so I disconnected that. Turned off the Greddy and sure enough the WG works fine with the 15LB spring setup, that is it opened fine. Puzzled by the continued lack of response to any adjustment by the WG controller I read the instructions again and again. There is a setting for start boost, Hi/Lo boost, gain, boost warning, and peak boost,warning, and limiter. So there are a few ways to set her up!! Anyway I never really played with the gain setting and on a whim I turned it all the way up last night and that was it! Now she boosts happily to my setting and stays there without surging and popping by 4K rpm. I can't seem to attach anything yet so here is a link to the Greddy instruction manual if you want to see the setup, etc. http://www.jdmlegion.com/Assets/PROFEC_B_SPEC2.pdf

[Stinger]

Good to hear you got it working.

[Beerplease]

Well a few updates:
It was really not working as advertised, I think I just got a fluke response for a run or two. I did check the plug gap after talking meeting with another local SVO owner(quikup) and they were .036-.400" so that was way off. I put in a set of Autolite 764's(I know Motorcraft but I was in a bind after breaking one of my Motorcraft ones) and gapped them to .028" That completly eliminated the breakup issue I was having at high RPM, turns out it was not a WG problem at high RPM after all. So then I turned off the Greddy and the WG is opening at the 12LB spring limit and makes a easily identifiable sound due to a open dump through a 1'' dia. pipe to atomosphere I also found a great tech article on how to set up the Greddy and followed it to a T. The wastegate still refuses to open via the Greddy control no matter what I setting is on the control head. The limit warning, last boost, current boost/vacuum setting works on the unit but no matter the boost setting either LO/HI I select it will not open the gate. The gain setting and start boost seem to make some changes but that is kinda hard to tell while driving. Attached is the schematic of the current setup and also a Tial diagram as well as the above mentioned article. If any body wants to take a crack at it this I would appreciate it. I am ready to vacuum check all the hoses/fittings as well as the wiring next. I am leaning to a malfuncting solenoid but I could have a error in my plumbing too.

http://www.jdmlegion.com/Assets/PROFEC_B_SPEC2.pdf

http://www.tialmedia.com/documents/w3_tial_wginstall.pdf

http://www.sr20forum.com/archive/index.php/t-86098.html
1408

[Beerplease]

Did some troubleshooting and found that the solenoid valves can be failure prone. Going to apply some shop air to the control solenoid and test it to determine if it is opening properly. It seems to fit the symptoms that I am having of no boost control but many of the other controller functions appear to be working.

[Beerplease]

OK here are some pics with the routing, I hope this makes it easier to understand.146414651466

[Beerplease]

Did a test of the Solenoid Valve per a few videos and posts I found on the web of the solenoid valve. Here is a video of mine, it sounded really weak compared to the You Tube video I have attached. I found the direct replacement MAC valve for 100 bucks less on Ebay and bought one of those. In the mean time I re-installed a old Ric Gillis valve I had laying around so I can at least limit the boost reliably.

Bench Test Vid:
http://www.youtube.com/watch?v=9cqlWnFK5PA

Mine:
http://www.youtube.com/watch?v=EnZM-SNB9U4

MAC valve:
http://www.ebay.com/itm/Boost-Control-Solenoid-valve-BCS-MAC-35A-AAA-DDBA-1BA-turbo-PWM-EMS-ECU-/330734891233?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d0155f0e1&vxp=mtr

[MikeFleming]

OK here are some pics with the routing, I hope this makes it easier to understand.1464 Note that the picture shows a BPV/BOV - a device that limits pressure in the intake, genarally on throttle closing. It does nothing for limiting the airflow/pressure that the turbo sees.

It will do nothing to keep the turbo from over-revving. To do those things one needs something that bypasses exhaust gases around the turbine wheel.

[Beerplease]

Umm, you mean the Tial WG directly under the BOV right? You can only see half of it under the BOV.

[MikeFleming]

Umm, you mean the Tial WG directly under the BOV right? You can only see half of it under the BOV. Umm, could be.
:3stooges: