Anyone installed a blow off valve? [Archive] - SaabCentral Forums

: Anyone installed a blow off valve?

25th June 2004, 11:00 PM
I am looking for an aftermarket blow-off valve to install instead of the stock unit. (one of those noisy ones, i aint a ricer, i just like the sound). I cant find much info on which product to buy that will fit my 99 Saab 9-5 2.3l 4cylinder. Any help would be good.


26th June 2004, 04:13 AM
Won't work with the 9-5, it will upset your ECU...

26th June 2004, 10:10 AM
You can install an aftermarket bypass valve but as Simon noted not a blow off valve. You will not get any different sound by going this route. The only way to hear the bypass valve is to open up the intake by removing the stock air box and installing a cone filter at the plastic tube coming off the air mass sensor. This will provide a nice increase in throttle response as well as the whoosh sound you are after (sounds slightly different than a blow off valve but same concept).

26th June 2004, 11:21 AM
If in installed the cone filter where you say, what about the moisture? There has been talk about re-routing the stock air box to pick up from a different direction, but its been said that if that happened you would get moisture in the intake. What would be the difference in doing that and installing a cone filter?

26th June 2004, 12:17 PM
I don't think moisture is a problem. The problem is if the intake "drinks" water which can cause serious engine damage. There are certain designs which make it easier to suck water into the intake (Abbott most notably) where all of the air is sucked through a small opening at the very bottom of the car. :nono; Putting a filter on the end of this pipe is going to raise the point where the air enters the intake by approx. 6 inches and since it is a cone it is pulling air in from 360 degrees not just at one point. In other words, you don't have as strong of a vacuum. I ran the open intake with care to not drive through deep puddles and taking it easy on the throttle during heavy rain. I never had a problem. I have considered putting a K&N drycharger over the filter for further protection. The drycharger is a bag that fits over the filter which has been treated with silicon to repel water. They are common in jetski and ATV applications.

The difference between rerouting the airbox and removing it completely are that you have much improved air flow (better throttle response and more power), slightly increased intake noise and the bypass valve will be heard and not muffled by the airbox.

26th June 2004, 01:46 PM
anyone got a pic of this setup? Will i need to have a pipe coming from the throttle body to the filter at all? And i have noticed there isnt a whole bunch of room under that hood, where does the cone filter go exactly?

26th June 2004, 03:14 PM
The cone will not be under the hood and it does not connect to the throttle body. It connects to the tube coming off the air mass sensor which is on the left side of the engine bay. You need a 4" (approx) long x 3" (exact) diameter piece of aluminum tubing (any hard plastic or other type of metal will work fine as well) and a 3" intake cone filter. The tube coming from the air mass sensor has a 3" inlet which is the same as the 3" cone filter otherwise you could just connect the filter directly to the tube. After you remove the stock air box and the snorkel pipe, you will need to remove the turn signal and headlight to get to the clamps for tightening. Slide the aluminum tube into the pipe coming from the air mass sensor and clamp. Then slide the cone filter on to the tube and clamp. Speedparts makes a kit which will attach to the mounting point used by the stock air box. This will keep things tidy and secure the filter from hanging loose but it really is not necessary if you want to save a little money.

26th June 2004, 03:28 PM
Correction: Insert the aluminum pipe into the cone filter and clamp before inserting into the pipe coming from the air mass sensor. Take the pipe and the filter as one piece and then insert into the pipe coming from the air mass sensor. This will make things easier on your knuckles.

26th June 2004, 03:52 PM
what about moisture and debris and stuff. I really dont want to have to only take the car out on sunny days and stuff, its my daily driver. I had any problems with water and such on this setup yet?

26th June 2004, 03:55 PM
I went over that in this thread in a prior post.

26th June 2004, 10:12 PM
i just installed a boost/vacuum gauge in my car. Lemmy know if this is correct, it pulls a maximum of 8lbs boost and around a max of 24lbs of vacuum. That normal?