Okay, I threw together a lame tune to work on the revised GM BCS setup I'm playing with.. Its running open loop boost, and I found it to be a bit lean for my taste (and had a bit of knock at 6000rpm so I shut down at 6200)
As you can see, the GM BCS Holds boost better at upper RPM (stayed at around 22psi where the stock bleed system would drop to 19psi on my car) but it spikes quite a bit.. anyway, its no supercar HP numbers, but its nice for what it is, and the mods I have..

 

sorry, my forum shrunk the image slightly.. but you get the point.. 320whp/302wtq on pump 93 octane gas (No WI or Race gas runs any time soon) this was at sea level @ 23 degrees C (70 degrees F I think) with 89% humidity.

 

One thing I noticed is the boost ramps slower, if I were to use closed loop boost control, and set the target duty and a better gain setting, It would ramp very quickly (Like an MBC) and then open when I hit my target... Only without a current limiting resistor on the BCS, it gets VERY VERY hot and I don't want to burn it or anything else up.. Once I figure out how much current is needed to actuate the solenoid, I can put the resistor on and then I can operate it completely closed loop at all times, and get real stable and fast boost..

 

What did you get all those graphs from? I assume an OBD-II logger? It looks pretty nice.

Dont be lazy and just get yourself a MBC and make scratch marks for your different boost levels you want. It works great you just need to get out to screw with it but if you dont run race gas alot who cares? I just dont really see a point in electronic boost control unless you have a rear/front wheel drive car and you can electronically control it depending on gear. Then it makes sense but otherwise I dont understand the point. Is there any advantage that I am missing?

 

Nah, I've never been an MBC fan, have one I can swap in quickly if I need it.. Its easy to get this thing where I want it after I get a knack for what its response looks like.

 

Oh.. Data Log Lab generates these graphs from UTEC shift-1 logs..

 

Jack

I had the same slow ramping issue in my other post. This is why I decided to use wastegate spring pressure. As for the closed loop control, I have yet to figure this out with the gm bcs. I tried several variations, but it ramped way way to fast. I tried to even run straight 100's across the board (lowest setting I believe) and still had major issues. I found that the gm bcs really seems in its element in OL and not in CL. Just my thoughts.

 

One other note, is that I didn't find the bcs any higher in temp than 'usual'. I am in Texas and we do have some pretty hot weather here, espically lately, but the bcs wasn't unbearably hot. More to the effect of engine bay heatsoak type of hot. I will double check this at night sometime this week, when the weather is cooler (85 F )

 

That's the dreamiest dyno presentation EVAR did you use CS2 for those effects?!? How many others have integrated the gm solenoid into their UTEC setup?

 

Wow that grapher thing is bad @ss! I got something new to play with now :P

 

LOL actually you need to set the o% column to 1% BCS Duty, otherwise it'll burn out the solenoid with the ECU setting wanting it to be on all the time.. In the 10% column, you'd set it for 10% to keep the duty pretty low under most driving.. 100% will completely close off airflow, basically if you set it up as a bleed system, it seems to respond very slow and therefore explains why your situation was different.. In my situation, I can set it for 90% or 80% to get it to ramp very quickly, then hit the 70% target (whcih gives me 22psi) In closed loop, its some arbitrary value to represent the boost level you want, and then you set the gain to determine how long it hits 100% duty to ramp the boost.. ITs pretty straightforward, but I had an easier time since I'm using an internal wastegate and the solenoid as a restrictor system.

And yes, my dyno sheet is done with a template on Adobe photoshop.. It grabs the two saved files, lays it out with the modification list and generates that..

 

one small advantage is the fact my boost is low 19 in first gear and 20 in 3rd. i am able to switch to a second set of settings to get 20 in all gears. the big advantage to me is the humidity and temprature changes mess with boost. so i don't have to pop the hood to change boost at least three times a day. once on the way to work, once at lunch, and once on the way home. i also can run low boost when i get on the highway if i want to save gas, then when i see that subie flying up i can switch boost and go, instead of trying to explain at 80 mph that i would have to pull over to race him. then there there no threads of "how i smoked an evo and he blew his engine and had to pull over" threads.

 

My solenoid is mounted "Inline", with an external wastegate, I think it needs to be mounted as a bleed system.. Otherwise the solenoid will do the opposite of what you'd expect.. the higher the duty, the lower the boost might get.. and that would actually wreak havoc with the closed loop boost control since it will do the opposite of what it needs to slow down the ramping of the boost..

 

Yeah, what he said... Actually you answered the question Exactly the way I would have..

 

Still dont see the point but maybe thats me being old school :P

I try to set my boost on a cooler night in the summer (70ish outside) and then leave it alone... if it is off by .5psi or even 1 psi I could care less :P But yes.. I do see the point now but it just seems like another thing to make me try to 'tune' to get working right. Mine just works

And the boost settings at different gears doesnt matter to me because 2nd and up are all the same and 1st is too retardedly quick for me to care on race gas and it spools so slow unless i launch it so it doesnt matter really. but yes, I do see the point now