Full DIY: GM solenoid install (56k warning)

[Chapel]

Originally Posted by WR^2X

Yep. This is where I bought them. Even cheaper if you use their discount code!

anyone have the latest discount code?

*edit: found it on fatwallet

* Registered users of the site do not see these ads.

[Freon]

Just a quick write up for running a 4 port with your 2-port EWG. I'm going to be brief and assume you've read post #1 thoroughly.

Grainger PN 6JJ40
ARO Premair 4 port pneumatic solenoid with speed control
There's another one that is otherwise identical but without speed control. I don't think it is needed, but I got it to play with.


Basic principles of using a 4 port with EWG are the same as running a 3 port with a single port IWG.

The point of the 3 port is to be able to get a wider pressure range to the wastegate. From vacuum from the intake up to full boost out of the compressor.

(Quick aside: You can certainly run a 3 port with your EWG just like an IWG. Just use the bottom wastegate port. Leave the top port open to air. It works just fine.)

Running a 4 port on an EWG allows you to get the same range on both the upper and lower control port. You get full intake vacuum to full boost, and vice versa, on both ports. When the solenoid clicks on, it swaps which port gets the vacuum and which gets the boost.

Here's how the lines run. The blue lines represent how the ports are connected when the solenoid is at rest (0% WGDC, or low side of the PWM cycle). The red lines show how the ports are connected when 12VDC is applied to the solenoid (100% WGDC, or high side of PWM).



Here's a basic 3 port "bleed" setup on EWG vs. a 4 port "dual interrupt" (what I'm talking about):


Since this setup not only releases pressure from the push-open side, but also moves that pressure to the push-closed side, it is very reactive. In addition, most EWG come with much stiffer springs (~1bar instead of 0.5-0.6bar like a stock TD04 or VF--). This means it takes less duty cycle to reach boost, and small changes in duty cycle have a large effect.

When replacing a 2 port stock to a 3 port, I generally recommend multiplying your Initial WGD, Max WGD, Turbo Proportional, and Turbo Integral by about 0.7 (i.e. reduce by about 30%) as a starting point. Your actual WGD might drop from say 80 to about 55.

With an EWG, you might only need 20-30% total WGD to reach 20 psi Remember, you'd hit 15 just on the WG spring by itself, and the 4 port. Thus, you need to reduce your initial, max, and turbo closed loop controls by even more than a 3 port on a 8psi-sprung stock type turbo.

Here are some example maps to give you an idea of what kind of changes to make. (FWIW, a 3 port only running bottom EWG port is not too far from this, at least it is way closer than stock mapping).



The initial maps here are just alittle lower than what it takes to hit target boost. Since I know I can't hit 18psi at 3200rpm, I don't ask the car to try. I still have the WGD really high. Basically following the boost threshold of this car's setup (Perrin GT30 STI).



Notice how low the values are in the proportional and integral maps. This is important. The stock map has values about 2-4 times as large and will cause spiking and oscillation.

You may not recognize some of these maps, but they're there and are useful. Merchgod has put them in the Enguinity definitions. I'll talk about each of the odd ball maps briefly.

With a large rotated turbo and 1 bar spring in the WG, the WGD is going to matter much at low rpm or when desired boost is way less than the spring pressure. I don't want the car trying to think too hard trying to hit boost at a rpm so low it's not going to matter. Or, more technically, I do not want the car to evaluate the integral term, because it can wind up or down (look up integral windup on Google, wikipedia or buy a control theory book). Basically, if you know the control won't affect the output, you don't want your loop evaluating!

I changed the RPM to enable turbo closed loop control up from about 1600rpm to 2200rpm.

I also increase the desired boost threshold 1D map (on this car it is like 0.3 bar default). It just doesn't matter what the solenoid is doing if you're only trying to hit +0psiG, so I set it to not even worry about it until 1.1 bar (about +1.5psi). The stock mapping on most of the DBW cars seems to set this map to about 1/2 the spring pressure in absolute. I.e. if the stock IWG spring is ~8psiG, that's about 22.5psiA, and the stock map turns on the PID control loop at about 10psiA desired boost. So with a 15psiG spring, that's about 30psiA, or 2 bar, so I set the ECU to not even bother trying to effect output when its effect is so minor. You could probably go as far as to set this to about 5psi less than the spring. Might be messing with this on your setup.

There is also a revolving integral min/max that defaults to -20 and +15 on this car. To keep it from running away on me, and since small changes have a big effect, I cap it at only +4.5. This means integral can only be able to pull up the initial WGDC map by 4.5%. Again, this is to avoid integral windup issues. It's just about as effective to change this cap as it is to use the Max WG duty map to limit WGD. Perhaps even better in some respects.

[Freon]

I just realized I made an error in the hookup picture and replaced it.

[img]http://freon.shackspace.com/car/ecu***37;20and%20tuning/gmbcs/4portsolenoid-hookup.jpg[/img]
This is the correct explanation of how the lines are hooked up. This correctly represents the diagram posted above as well, and it was always correct.

I do not suggest this setup for 16bit ECU. It really needs the initial wastegate map to work right.

[dudical26]

I have done this mod, and I am sure that I hooked up all the lines properly.

I was doing a boost leak test and I have noticed that I have boost leaking out of the port that goes back to the intake. I have this port not connected to anything as I am venting it to the atmosphere.

This is with the car turned off. Should air be coming out of this port?

[KAX]

edit: nvm

[06rexwagon]

Originally Posted by dudical26

I have done this mod, and I am sure that I hooked up all the lines properly.

I was doing a boost leak test and I have noticed that I have boost leaking out of the port that goes back to the intake. I have this port not connected to anything as I am venting it to the atmosphere.

This is with the car turned off. Should air be coming out of this port?

Yes, when the solenoid isn't energized, which is why it bypasses the pressure from getting to the wastegate actuator. When you are actually under boost, the solenoid will be closed. You should route it back to the intake though.

[dudical26]

Are you sure about that. I thought that when the solenoid is not energized it allows air to pass from the turbo to the WG. (normally open).

This is why energizing the solenoid increases boost as it blocks air from getting to the WG.

[06rexwagon]

Originally Posted by dudical26

Are you sure about that. I thought that when the solenoid is not energized it allows air to pass from the turbo to the WG. (normally open).

This is why energizing the solenoid increases boost as it blocks air from getting to the WG.

You're right. Sorry, it's been a long day already.

[dudical26]

so does that mean this is not normal.

[06rexwagon]

Originally Posted by dudical26

so does that mean this is not normal.

Not normal. Post a pic.

[dudical26]

[IMG]http://www.skidmore.edu/~a_blaker/Car/Boost***37;20Solenoid/GM%20BC.jpg[/IMG]

Bottom line to turbo, top line to WG

Dont get confused, this is on an EVo.

[Freon]

That's hooked up right. It shouldn't be leaking. Take the turbo line off and try to blow through that port (literally, with your mouth).

If it seems like you can blow a bit, take the solenoid out completely and blow on the turbo port with your finger on the wastegate port. Or use a short piece of hose with a large screw in the end to seal that port. It's possible there is a leak in the lines, or your wastegate actuator is leaky. I suppose the solenoid could be failing as well, never know...

[dudical26]

leaking lines or a leaky WG would not make the disconnected port have air come out. I am not saying there is a boost leak but specifically there is air coming out of the 3rd port

[Freon]

Ah, then sounds like the solenoid is busted. There should be no air coming out of the third port (the one you showed disconnected, just open to air) when the solenoid is not energized. It should be blocked altogether.

Seems odd the solenoid would bust. Maybe pick up a Grainger/ARO Premair piece. They're rated to 125psi use a billet aluminum body.

[Wrx_Fan_0717]

Originally Posted by fmowry

$34.73 shipped from Rockauto. Search on part numbers below

ACDELCO solenoid part # 214474
ACDELCO ABS modulator pigtale part # PT374



Frank

If anyone wanted to know.
Just used Rock Auto and this still works if anyone is interested. 37 and change shipped. Good deal IMO.

[Thug Nasty]

Originally Posted by Wrx_Fan_0717

If anyone wanted to know.
Just used Rock Auto and this still works if anyone is interested. 37 and change shipped. Good deal IMO.

I did the same thing a few weeks ago. I went to fatwallet.com and got a discount code for like 10% off or something. Every little bit helps.

[Wrx_Fan_0717]

Originally Posted by Thug Nasty

I did the same thing a few weeks ago. I went to fatwallet.com and got a discount code for like 10% off or something. Every little bit helps.

Dang it dude. I always figure this crap out late.

[Superorb]

I'll be running an XPT Stage 2 with GM BCS map. Resistor for this setup? I'm not sure if that map is tuned for the resistor or without it. Also, restrictor pill need to be used for this map?

[Thormix]

Originally Posted by Superorb

I'll be running an XPT Stage 2 with GM BCS map. Resistor for this setup? I'm not sure if that map is tuned for the resistor or without it. Also, restrictor pill need to be used for this map?

This map was tuned without the restrictor pill and should be run with all new matching hoses w/ out the restrcitor pill or "T".
You do not need to add the 20ohm resistor. The XPT map deletes that CEL code when you flash the map to your ECU.

Enjoy your XPT Power

[Superorb]

Originally Posted by Thormix

This map was tuned without the restrictor pill and should be run with all new matching hoses w/ out the restrcitor pill or "T".
You do not need to add the 20ohm resistor. The XPT map deletes that CEL code when you flash the map to your ECU.

Enjoy your XPT Power

Thanks. I'm on a stage 2 OTS map and only boost right under 14psi. Will the XPT map plus the extra 3.5psi and the GM BCS make that much of a difference?

[KAX]

extra psi will make a pretty big difference. the bcs, you probably wont notice.

[Thormix]

Originally Posted by Superorb

Thanks. I'm on a stage 2 OTS map and only boost right under 14psi. Will the XPT map plus the extra 3.5psi and the GM BCS make that much of a difference?

The boost maps are different for the OSEcu (OTS) maps and the XPT maps. The higher target boost of the XPT maps will deliver a noticeable difference. However the main difference with the XPT maps is the Throttle Response and overall feel of the Tune is much more refined. Most WRX's require a manual tightening of the Wastegate Arm with the XPT map. This can be done very easily; it is required in most cases to reach the target boost levels for the map. Here is a link to the XPT instructions - Click Me
Here's a Picture I borrowed from ScoobyMods:

Originally Posted by KAX

extra psi will make a pretty big difference. the bcs, you probably wont notice.

You are 100% correct sir.
BCS allows you to sustain boost longer and in the higher rpm areas, and if tuned correctly can lower your spool up time (in rpm's). The three way GM BCS is much more contol'able (reads - responds faster) to whatever the ECU tell it to do with the Wastegate. That being said it is only as good as the tuner. With the right tune/map the GM BCS is a great upgrade for the Stock Turbo or a larger Snail.

[Superorb]

I'll have to shorten the arm even WITH the GM BCS?

[Thormix]

Originally Posted by Superorb

I'll have to shorten the arm even WITH the GM BCS?

Yes and no.

Yes - you can shorten/tighten the Wastegate arm if you are not reaching target boost in 3rd & 4th gear.
No (there is no need to tighten) - if you want to go into the ECU Maps (via Enginuity or other Editing software) and use the greater overhead that the GM BCS gives you to adjust the Wastegate duty via software to dial in your boost map.

*There are many tuning approaches and the above are just two options.

The XPT GM BCS map is designed to run with the Wastegate as is (not tightened). That being said most TD04's will not hit the maps 17PSi target boost with out being tightened about a turn and a half. If you have the ability to log your car you can really dial in your Boost with this map and your newly added GM BCS.

[Superorb]

Originally Posted by Thormix

Yes and no.

Yes - you can shorten/tighten the Wastegate arm if you are not reaching target boost in 3rd & 4th gear.
No (there is no need to tighten) - if you want to go into the ECU Maps (via Enginuity or other Editing software) and use the greater overhead that the GM BCS gives you to adjust the Wastegate duty via software to dial in your boost map.

*There are many tuning approaches and the above are just two options.

The XPT GM BCS map is designed to run with the Wastegate as is (not tightened). That being said most TD04's will not hit the maps 17PSi target boost with out being tightened about a turn and a half. If you have the ability to log your car you can really dial in your Boost with this map and your newly added GM BCS.

Ok. Would it help if I were to post a log of 3rd gear if, after I flash to XPT map, it doesn't reach target boost?