new hybrid mbc/ebc method of boost control

[NSFW]

I was thinking more about 3-port solenoids though - if they work fine with the third port capped off, then does anyone bother with a third hose at all? Other than tradition, of course.

Seems like it ought to be possible to hook up the OEM BCS in an interrupt configuration, too. Or use it in place of the 3-port in a hybrid setup.

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[ride5000]

Originally Posted by NSFW

Seems like it ought to be possible to hook up the OEM BCS in an interrupt configuration, too. Or use it in place of the 3-port in a hybrid setup.

it is possible, IF you flip the electrical/pneumatic phase.

to interrupt we need closed when energized, not open, as in the oem bcs.

if you wanted to, you could rig up a state inverter with a transistor... flip the electrical phase. then use the oem.

the 3 port solenoids are easier because they allow you to pick which pneumatic phase you want.

[NSFW]

Oh yeah, it works backwards... good point.

[02RexWI]

^P&L told me they use the stock BCS in interupt fashion all the time with only ECU tuning...

[ride5000]

Originally Posted by 02RexWI

^P&L told me they use the stock BCS in interupt fashion all the time with only ECU tuning...

P&L is full of **** then.

[ride5000]

actually, i take that back: it IS possible to invert the electrical phase in the ecu code itself (ie, by reflashing) and thus you COULD use the oem bcs in interrupt mode.

however, one of the crucial aspects of the way the system is designed is that boost is limited to wastegate by default, and the ecu must pass current through the coil to RAISE boost. inverting the electrical state in the ecu itself in order to use the oem bcs would lose that failsafe.

you also need someone with enough ROM chops to change the correct register, and do it for every version of ecu code you tune.

so, i'll change my answer to "not likely, and a bad idea if they do."

[NSFW]

You wouldn't need to change the code, you could just do it in the WGDC table by changing every cell from "N" to "100-N" to get the same effect. And then think inverted when you make any changes - decrease WGDC to increase boost. Probably a good idea to leave it at 0% for everything below 1/3 throttle too, to keep it from cooking itself while you're driving out of boost.

So yeah, I'll go with a proper aftermarket BCS...

[ride5000]

Originally Posted by NSFW

You wouldn't need to change the code, you could just do it in the WGDC table by changing every cell from "N" to "100-N" to get the same effect. And then think inverted when you make any changes - decrease WGDC to increase boost. Probably a good idea to leave it at 0% for everything below 1/3 throttle too, to keep it from cooking itself while you're driving out of boost.

So yeah, I'll go with a proper aftermarket BCS...

i'd be concerned about some aspect of the ecu logic that hasn't been "inverted."

ie. limp mode (or high det mode) suddenly runs totally unrestricted boost because it defaults to (what it thinks is) 0% wgdc

[medamullet]

I made some improvements to my setup. I ran a 1 way valve at the end of my MBC so air doesn't come back up from the "T" and out the bleader hole on the MBC. I also want to run a stiffer spring in my EWG. no matter how you hook it up you are loosing the good quality of the EBC holding the wastegate shut, so a stiffer spring is in order. Mine opens at 14.7 psi no matter what, considering how you have to hook it up.

[medamullet]

the bottom most is an idea I haven't tried yet....

[02RexWI]

The bottom one could be done by simply plugging the bleed hole, RTV sealant works well
I'm kind of cheap if you couldn't tell

[medamullet]

I actually used a $3,000.00 1 way valve. My wife had some samples from work she brought home for me to use. She is an medical device engineer. Probably the most expensive part on my car

[02RexWI]

^ OMG you better be kidding

[SurfWagon]

Med supplies are always outrageously priced...

[NSFW]

Originally Posted by ride5000

i'd be concerned about some aspect of the ecu logic that hasn't been "inverted."

ie. limp mode (or high det mode) suddenly runs totally unrestricted boost because it defaults to (what it thinks is) 0% wgdc

Very good point.

[SurfWagon]

Medamullet-
Let us know how that setup works out for you. I'm interested in being able to use boost pressure to keep the valve closed right up until the last moment.

The design looks sound and I like the use of the one way valve. I might have to go find one and give it a shot.

[medamullet]

Originally Posted by 02RexWI

^ OMG you better be kidding

no joke

Originally Posted by SurfWagon

Med supplies are always outrageously priced...

That's because it take a staff of engineer's who all make 60+ an hour to design, test, market, build. With all the government regulations it takes. I would rather pay 3k for a valve that I know works vs 1 from china that "may" work when your life is on the line.

I am super busy putting my car back together. Hopefull next week I will will reroute things and give it a go.

[SurfWagon]

I didn't say over-priced. Sometimes they are because of the current pay system. We'll see how the price of things change soon.

(we were talking about the one-way valve used after a tracheotomy that allows the patient to apply external force and create sound...350 a pop and they need replacing every 3-5 months....a little piece of silicone. But they have the patent and went through the trials.)

Good luck when you get it put back together.

[xsnapshot]

Ok this is the setup I just put together today. Each of these parts is exactly what I'm using too. (I.E. I'm actually using a perrin)

Anyway, here's the deal. At <80% throttle, the boost runs through the normally open port on the 3-port thus opening the IWG. Currently that runs at about 12 psi IWG spring pressure (i've adjusted the arm).

At >80% throttle, duty cycle is maxed, closing off the normally open port. This forces air pressure to the MBC. When this is happening the air in the IWG diaphragm is being let out through the normally closed port.

I'm having some issues though with WOT throttle. At lower than 80% it functions as it should, but when I step on it boost builds very slow, and barely manages to even open the EWG at all. It seems as though the IWG is being blown open, but I can't imagine how! I have the IWG arm adjusted so that its 12 psi, and that's quite a lot of tension in the arm.


EDIT: perhaps my 3-port is faulty? Or maybe the air in the IWG diaphragm can't escape fast enough and keeps the IWG open? The normally closed port is completely unobstructed, so it should let air out quickly. Also I have very minimal vacuum tubing, so there shouldn't be an issue there.

[ride5000]

what are you using to control the solenoid? the oem ecu? if so, capture a datalog of the actual duty cycle. i suspect it isn't locked at 100%.

[xsnapshot]

I'm on my phone so I cant post up a log, but yes you would be right. I logged this morning and only reached 13% duty cycle, with it usually staying @ zero. How do you your ecu to request 100% duty cycle?

[ride5000]

you'd have to ask someone who uses the oem ecu to control the BCS.

wasting time ****ing around with this issue is why i use the utec to run it, open loop style.

[02RexWI]

You've probably got the maximum wastegate duty cycle set below 100%

[xsnapshot]

Originally Posted by JSarv

Just so absolutely everyone knows/does their own tuning - DO NOT clear your Turbo Dynamics tables - this will cause your WGDC to stick and do crazy things....

Otherwise 24psi by 3450 @90*F on a 2.0/18g/110k miles.


-Jerod

Found this little gem...

Jerod, can you elaborate on this? I cleared my Turbo dynamics tables and am wondering if this is the cause of NOT getting 100% duty cycle. If your not supposed to clear it, then what values do you use? I was thinking 100's in every cell, such that any correction the ECU would attempt to make would always be positive and 100%.

For those OEM ECU users, how did you go about getting your ECU command 100% WGDC at WOT conditions?

I'll be playing with this more and will report back.

[xsnapshot]

Originally Posted by 02RexWI

You've probably got the maximum wastegate duty cycle set below 100%

well its set at 99.6% which is the highest I can set in romraider. That's clearly not the issue though, as the ECU is rarely, if ever, increasing my WGDC.

I'll post up the tables I've modified once I get home later.