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]
The Aero and Arc require premium fuel. If boost is going towards 12, then settling back, that *could* be a sign that the Trionic is pulling back the boost because if detects knocking (pinging), which can happen with less-than-premium fuels.
As for the "overboost", if I understand that correctly, what it does is enable you to maintain the maximum manifold pressure, regardless of your altitude. Normally (and this is the mode on pre-T7 Trionic systems), the turbo is set up to allow you XX psi of boost over your ambient pressure. As your altitude increases, that pressure drops, and so does your maximum manifold pressure. T7 maintains the sea level max manifold pressure at altitude.
Example: at sea level, you get 10 PSI of max boost (remember, this is just an example, I'm not quoting actual spec). Add this to the nominal 15 PSI of atmospheric pressure, you get 25 PSI of absolute manifold pressure (pressure in the manifold relative to a complete vacuum). Now, take your 9-5 up to the mountains of Colorado, at a bit above 10,000 feet, and the atmospheric pressure is about 10 PSI. Normally on T-5 and earlier Trionic systems (NG 900, some early 9-3s, 9000), all you could expect is an absolute pressure of 20 PSI (10+10). But Trionic T7 (9-5, later Classic 9-3 & Viggens) will still allow you the maximum sea-level absolute manifold pressure of 25 PSI, and that "extra" 5 PSI is considered "overboost".
_______________________________________
Current:
2002 9-5 Aero Kombi Cosmic Blue
2000 9-5 SE sedan, Imola Red
1990 900S Rose Quartz, Auto
Past:
1999 9-5 LPT Combi
1999 9-5 LPT sedan
2002 9-5 Arc
1990 900 5-speed
1986 900 turbo Convertible
1991 9000 turbo
1980 99 GLi
1986 900 turbo
1986 900 S
1991 900 turbo
1984 900 turbo
1976 99 GL
Posts in this Thread:
- No Overboost? 2000 Aero, Dave F., Sun, 14 Sep 2008 18:22:46
- Clean your BPC valve, Finch, Wed, 17 Sep 2008 13:01:58
- Re: No Overboost? 2000 Aero, Dave F., Mon, 15 Sep 2008 13:37:08
- What gas are you running?, Larry West , Mon, 15 Sep 2008 13:04:46 <-- Viewing This Message
- Re: No Overboost? 2000 Aero, jgARC03SW , Mon, 15 Sep 2008 07:13:24
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!