wrcwannabe

iTrader: (1)

/\/\ That seems to make more sense. John Banks could test this theory by disabling one or more of the solenoids on his UK FQ. I think disabling the activate on solenoid two by raising it to 7500 would do the trick. i predict that the additional air signal unable to vent will reduce his boost above 4000 rpm

If this is the case, and the USDM ROM supports the 2 solenoid setup , AND the UK and USDM pin out is available then we gotta try this. Sounds better than using 3 ports or taking out pills . It may be as simple as buy , plug , play with settings

John: are the twin solenoids the same part?
Can you post that part number so we can see if the part is the same as the usdm one?
Lastly has anyone got a pinout of the UK FQ to match up against the USDM 8 or 9 ROM ECU

Doesnt explain the extra 2% though :-)


Milburn

mchuang

iTrader: (11)

I found this in google, and I think it is a pretty good explanation of what the wastegate solenoid does.

How does a bleed increase your performance? Easy--it directly determines what level of boost is generated in your intake manifold. Our cars run a vacuum/pressure "feed line" from the intake to the wastegate actuator. If you were to run full boost pressure to the actuator, your boost would always stay low (about 6 psi max) because this pressure would blow open the wastegate and prevent higher boost levels. Your car's stock computer raises the boost above this minimum by "bleeding" some of the air pressure out of this feed line through the opening and closing of the wastegate solenoid; cycling the solenoid reduces the amount of boost pressure in the feed line which then reduces the opening of the wastegate. If you manually bleed more air out of the feed line than the computer does, your boost level will go higher than the computer lets it go. That's all there is to it.

Here's the procedure:

1. Remove the hose coming out of the wastegate actuator can and plug the hose. Find a source of manifold pressure/vacuum (at the turbo's output barb if your turbo has one, or else from the intake manifold itself) and run a new short rubber vacuum line directly from this source of manifold pressure to your wastegate actuator can's barb.

2. Now you have to find the factory restrictor. It's in the wastegate solenoid vacuum lines that you just rendered useless when you unplugged the hose from your turbo OR it might be in a tube that comes straight out of your turbo.

3. Cut your new rubber line in half, then reconnect it using the restrictor.

4. Prepare your bleed valve by closing it all the way and then opening it very slightly. You should just barely be able to blow through it at all.

5. Cut your new rubber line in half again between the restrictor and the wastegate actuator. Get a vacuum line tee and push the two tubing halves you just cut onto the tee. That leaves one barb of the tee open. Mount a check valve to that open barb so that it lets air blow out but won't let air get sucked in. (Make sure you point it the right way!) Now get your bleed valve and, with short rubber tubing, connect it to the open end of the check valve.


Here's what it looks like:



Now you dial it in. Take a ride and nail it in a higher gear (so that you can stay in full boost for a little while). Note where the boost levels out. If it isn't quite 2 psi more than stock then pull over, crack it open ever so slightly more and try again. If the boost level is too high then close the valve slightly. Go back and forth until you get it set just where you want it; after that you're done.

NOTE: You can directly control the size of the boost spike with your restrictor: the bigger the restrictor's hole, the smaller the spike; the smaller the restrictor's hole, the bigger the spike. Be careful, though; if your restrictor is too small you may spike all the way to cutout.


Turbo performance pages Dempsey's home Page Email me.

mchuang

iTrader: (11)

Picture of a wastegate solenoid, which looks just like what we call our boost control solenoid.

mchuang

iTrader: (11)

More info and what it does.

BCS/boost control solenoid:
Boost control solenoid, also called the wastegate solenoid. The BCS is controlled by the ECU, (engine control unit). This unit activates vacuum for the wastegate actuator; it has a limited range of control over the wastegate by changing the pressure signal to the actuator. The ECU input tells the BCS to open, and approximately 4 PSE of pressure is bled from the actuator’s control signal, allowing the boost to build to an increased amount. If there is knock (or similar problems) the ECU closes the BCS—causing the wastegate to open more quickly, lowering the total boost level. The BCS is a critical component which allows a car to drive with low octane gasoline. If you have removed the BCS by installing an aftermarket boost controller, you should only be running premium (92+) octane gasoline, or risk engine failure

jcsbanks

Twin solenoids are the same part (connected to the ECU through their own channel and plug each), but on the ROMs I've looked at with them there isn't this approx 3250 RPM point, it is about 1900/2000 and then 7500/7500.

juyanith

iTrader: (7)

I tried the DIY pill and had some success. I'll try to get around to posting details about making the pill itself in the other thread to keep this one about WGDC. Anyway, after I made the changes I took the car out for a spin. I had already set the max WGDC to 50% and with the stock restrictor I would boost to about 15 PSI. With the new pill, I hit about 17 PSI. I then raised the WGDC to 75% and hit 22 PSI, which is right about where I wanted it to be. I spent some time raising the WGDC before 3500 and after 5000 RPM to help increase spool and reduce boost taper. My boost currently hits about 22 PSI and tapers to about 19 PSI at 7500 RPM.

What was odd is that I can't seem to keep the ECU from adding 10% to the WGDC. At one point I tried setting the WGDC to 85% but the ECU simply scaled it up to 95% even though my 2-byte load was a good 10-15 points above BDEL. I wanted to do some more tests reducing the boost offset, but ran out of time. (It also didn't help that the bicyclists were out on Sunday afternoon and seem to like riding on the same flat rural roads I use for testing.)

So, my boost is pretty much where I wanted it but I also wanted to ECU to compensate downward when the weather changes. I guess it will take more testing but I don't know when I'll get the time.

mrfred

iTrader: (50)

Its not just BDEL that matters. I like to use the term target load = BDEL + offset. What is your target load and your 2-byte load where the ECU is adding 10% on the WGDC?

juyanith

iTrader: (7)

Sorry, you're right. I meant that 2-byte load was 10+ higher than target load (BDEL + offset). I even switched back to my 75% WGDC map and reducing offset by 10 but it didn't seem to matter. I would have tried reducing offset more, but ran out of time.

Here's a graph showing what I'm talking about.


The first WGDC (shown in yellow) was what I based my D(esired) WGDC on. DWGDC in that run was 75% tapering up to 100% (not shown). The desired load was based on the 2-byte load (in orange) and as you can see I was hoping to eliminate the "dip" at about 4300 RPM. The WGDC from the second run initially follows DWGDC until the ECU adds its 8-10% which I expect under 3000 RPM. However it never stops adding to the DWGDC even when the load jumps above the desired load.

mrfred

iTrader: (50)

Couple of thoughts:

1) It should have definitely pulled back the WGDC after that dip.

2) What gear did you do that pull? If you did it in 2nd gear, there may not have been enough time for the ECU to adjust the WGDC.

3) I used to try to make my baseline WGDC curve smooth. Eventually, I realized that I had to make a kinked curve to get a smooth boost profile. Also, feel free to rescale the BWGDC RPM axis to get more definition points around the dip that you're seeing.

4) I've found that the tendency for the ECU to correct the WGDC is sensitive to the values in the error correction table. I haven't got it figure out yet, but that's what I've seen. Could you post up a screen shot of your error correction table?

5) Did you adjust all the WGDC and BDEL tables? On a IX there are three of each.

juyanith

iTrader: (7)

Or at any other point where load was above target. At least that's what I thought.
Both are 3rd gear pulls. The ECU seems to react quick enough when increasing WGDC.
Yeah, I noticed that in your graphs. These were really starting points (and maybe a bit optimistic). I've adjusted my current WGDC with a bit of a spike right where that dip in the load is, but it's not very well tested yet. I'm not quite sure how to rescale the table, but I thought I'd rather have more resolution between 3 and 4k than 2 and 3k RPM. So how do you rescale a table anyway? I looked under the edit menu but wasn't sure if I was changing the scale for the map or for the ROM definition.
Sure, I haven't edited this table yet (see the attachment). I still don't understand where that additional +2% is coming from though...
On my VIII there are four (and they're all identical).

juyanith

iTrader: (7)

Ah, it was too simple. Just edit the RPM values the same way I edited the WGDC values. I guess I was thinking I had to change the definitions of the tables or something.

wrcwannabe

iTrader: (1)

Thank you John. So not so easy to add in the factory duals then. We would need to identify the correct request and table, then identify the pin used for the second solenoid.

The posts above are using a secondary port with manual bleed valve. I think I might try this but use a second factory solenoid, tied into the BCS harness and activated in parallel. Control would be via the tables for WGDC and error correction. I will start with halving the WGDC at control boost onset but allowing it to go to max to try to get better control at 5k up. The factory pill at the BCS will need to be removed to help out.

So essentially you would have the air source from the turbo, going through a pill then teed to the WGA and then going to both BCS solenoids that vent into the turbo inlet again.

ECU control and a more sustained boost sounds good to me.

Milburn

wrcwannabe

iTrader: (1)

In preparation for the dual solenoid I am testing the system with stock pill sizes, although not stock WGA or DV. I anticipate having to bleed a lot more air. Or divert some air to the backside of the WGA to help keep it closed more? Any one know of a WGA with nipples on both sides of the diaphragm?

racer135

iTrader: (2)

Anyone knows how the Wastegate Solenoid Activation RPM table works on EVO VIII? I have a Def 96420008 ROM and got the same values as described above. I have been searching but have found no info on the VIIIs. Looks like EVO VIIIs uses different stock values comparee to the IXs.

mrfred

iTrader: (50)

The "Deactivate On" value looks wrong. That setting is the upper rpm where the BCS turns off (and thus boost will drop). It should be something like 7500 rpm. The "Deactivate Off" should also be set to something like 7500 rpm.