No dumb questions... - Saab 9000 Bulletin Board - Saabnet.com
Click Banner for Details on this Saabnet.com Classified
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 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
No dumb questions...
Posted by BillJ (more from BillJ) on Mon, 29 Apr 2002 09:27:47
In Reply to: A dumb question., TonyB, Mon, 29 Apr 2002 08:44:36
Members do not see ads below this line. - Help Keep This Site Online - Signup
... only dumb answers. Hopefully, this answer won't be too dumb.
The lever operates the wastegate, which is a valve inside the turbo (simply a plate that covers a hole) which allows exhaust gasses to bypass the turbine instead of passing through it, lowering the amount of power available to drive the turbine and so lowering the boost pressure. The "damper" you mention is known as the "wastegate actuator" and contains a diaphragm. Boost pressure from the manifold moves the diaphragm, which moves the lever to open the wastegate, which reduces the pressure. More pressure will make the wastegate open more, which will tend to reduce the pressure again. As you can see, this will reach a balance where the boost pressure is exactly right to hold the wastegate open exactly the right amount to maintain that boost pressure.
This is how a basic turbocharger system limits the boost pressure, and is how the Saab light-pressure turbo system works. In Saab full-pressure turbos there is the added complication of an electronically controlled valve that plays with the pressure that the diaphragm sees, and can fool it into allowing a higher pressure than it normally would allow. Apart from the interference of this extra valve, though, the basic mechanical wastgate system is still there in these cars.
Does this help, or am I talking in circles? :)
posted by 161.71.171...
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
![](/tsn/xyz/stateofninebutton.gif) |
SaabClub.com
![](/tsn/xyz/scnabutton.gif) |
Jak Stoll Performance
![](/tsn/xyz/jakstollbutton.gif) |
M Car Covers
![](/tsn/xyz/mcarcoversbutton.gif) |
Ad Available
![](/tsn/xyz/buttonavailable.gif) |
![](/tsn/images/tsnmap.gif)
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!