I have no problem reaching my target boost with my current stock bcs. Does the gm bcs help spool up quicker? Will I really notice a difference? I don't want to change if its not going to benefit me in some way.
Yeah, your wastegate duty cycle numbers are way lower with the GM solenoid than with the stock one, so you need to tune for it before you even drive out of the driveway.
My wgdc right now are 42% at 100% tp. If mine is set at 90% like most, i'm over boosting by at least 3psi. My wg arm could probably be loosened up a full turn.
Just a little info on the gmbcs. The stocker is a bleed system. That means you get full boost to the wastegate right away, and the extra is bled off to keep you at the target pressure. At a point, the stocker just can't keep up anymore. With my 18g i was having some issues, but other have run larger turbo's and it has worked. The gm bcs is a interupt style system. That means that boost will not get to the wastegate until you hit target pressure. The will give you a bit quicker spool (similar to a mbc), but it is also more prone to spiking. Once you are at pressure, the bcs will bypass the extra pressure to keep you at target pressure. The gmbcs will need a custom tune. Like what was said before, the wgdc will go way down, and you will also have to make some other minor tweeking to get the boost curve smooth. If you can do the tuning and make the chenges, the gm bcs is a cheap mod, but if you have to pay to get it tuned, might as well wait till you have other mods. Russ
^^ Thanks for the explanation, thats what I was wondering, how it worked. so your saying its more prone to spiking than the stocker?
PSH, I'll be there, don't worry Wifey schedule changing alot, I told ray that, but I'll just pay up soon, geez
haha...I think that is a good idea...For all the handrasiers that didn't pay yet...can't reply to any post or thread...lol Nuke, u didn't say anything to me, dunno what your talk'in about...
There are a few other compensation tables that NEED to be adjusted if you want the thing to work correctly. If this is not done that it is very likely that you will encounter spiking when conditions change.
Hopefully you have read this, but if not here's some good info.... http://forums.nasioc.com/forums/showthread.php?t=870619
More info, same thread... http://forums.nasioc.com/forums/showthread.php?t=870619&page=3 Good info if you are wondering how the setup works.
I see how it is ray...i see back to the topic I've been reading more about gmbc tuning..and tom did explain some of it to me (on nabisco) and I'm starting to get the hang of it (kinda)
Yeah I saw the nabisco thread, easy easy install...I just don't have time to read 25+ pages of junk I just ordered mine
How do you have the plumbing set up for the GM BCS? I'm getting boost overrun to 21psi before it settles to 15. This annoys me because I only have a 2.5bar MAP sensor and this turbo really likes 20+psi. Also, will running the top fitting on my wastegate to pre-turbo vaccum help? This overrun is really getting on my nerves.
