How exactly does MBC work? - Saab NG900 & OG9-3 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
7/1: Members: Log In to See Fewer Ads! |
5/28: SAAB Evolutions/TSN T-Shirts $14
[General |
Members |
C900 |
9000 |
NG900 & OG93 |
93 |
95 |
NG95 |
99 |
Sonett |
Vintage Models |
Clubs |
Other Cars |
FAQs |
Gifts |
Member Photo Galleries |
Member Directory |
Classifieds |
Manuals |
*Buddy Registry |
*Mileage Registry |
Polls |
What's New |
Raffle |
Photo of the Month |
Sponsors]
[Main NG900 & OG93 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
How exactly does MBC work?
Posted by Nemo (more from Nemo) on Wed, 12 Jun 2002 15:31:37
Members do not see ads below this line. - Help Keep This Site Online - Signup
I know there's been lots of discussion on this, but I thought I'd try and flesh out a bit more. Here's my understanding of what's going on. Please feel free to correct:
Normally, the BPC monitors boost pressure from the turbo, then opens the wastegate when it wants to cut off turbo boost. The ECU can control when this happens by talking to the BPC. A necessary fallout from the mechanism is some pressure bleeding and turbo spoolup lag.
With the MBC, this process is circumvented somewhat. The MBC delays "boost reading" to the wastegate. So while the turbo is cranking out 12psi, the "mechanism" or whatever is left of it, thinks it's less (eg., 10psi). So the wastegate doesn't open as early, hence we get stronger boost. Also, eliminating the BPC results in no turbo pressure bleeding / spoolup lag.
Am I on the right track here?
I ask this in part because the thing I don't really understand is driving the MBC from someplace else to avoid the alleged top-end power reduction.
Thanks all,
Nemo
posted by 128.143.140...
Posts in this Thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
StateOfNine.com
|
SaabClub.com
|
Jak Stoll Performance
|
M Car Covers
|
Ad Available
|
Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!