9k Aero BOV question (diaphragm vs spring) - Saab Performance Bulletin Board - Saabnet.com
NG900 & OG93 |
Vintage Models |
Clubs & SOC |
Other Cars |
Books Movies & Music |
Member Photo Galleries |
Member Directory |
*Buddy Registry |
*Mileage Registry |
What's New |
Photo of the Month |
[Main Performance Bulletin Board | Post Followup | BBFAQ ]
[ Prev by Date ] [ Next by Date ] Member Login / Signup [Most Recently Edited Saabnet.com Photo Galleries]
9k Aero BOV question (diaphragm vs spring)
Posted by SMP (more from SMP) on Tue, 31 May 2016 08:05:43
I've done a lot of searching with very mixed answers.
I have had an original, "bosch" brand diaphragm type BOV valve on my 1993 9k Aero (has a stg1 tune and a K&N drop in filter but otherwise stock motor) for the longest time. The boost was decent and pretty solid on the needle and I would always get a consistent, singular "whoosh" sound when the throttle would snap close during shifting or letting off under boost.
I recently installed the later "viggen" style BOV (with the spring) after hearing some whistling noise that sounded like boost leak and suspected an old, weak BOV valve. I could not find a "new" Bosch style diaphragm valve...
The throttle response is better and the boost builds a bit quicker and holds higher with the newer, spring style valve installed. This I like.
The problem is that now I get an obviously choppy "whoosh" sound when the throttle plate gets snapped close. This I don't like as much...
Instead of the smooth PSHHHhhhh noise its more like PSHhh SHhhh Shhh.
I have read people say "Oh nice I love that sound" and others say "Oh that's bad the air isn't dumping all the way and its hitting your turbo blades which will cause premature wear.
Can someone please give me a straight, educated answer? :P
Or maybe one based on experience? I'm honestly not that worried about how it sounds. I just want better performance and not to worry about "turbo surge" or "compressor stall" or any of that negative stuff.
posted by 24.104....
Posts in this Thread:
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.
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 -
Your address is: 220.127.116.11 - Using CCBot/2.0 (https://commoncrawl.org/faq/) - Logged.
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!