1999 9-3 Boost, BOV help [Archive] - SaabCentral Forums

: 1999 9-3 Boost, BOV help

1st October 2002, 02:38 AM
Hey guys I just got a 1999 Saab 9-3 5spd with the 185hp turbo engine. A couple of questions, in 3rd and 4th gear the car doesnt boost fully, like it will go to the end of the orange for a second then settle at the middle part. Once in a while it'll stay at the end of the orange for most of the gear, when it does that it is also faster :) Why is the boost so inconsistent? Im not sure of the octane of the gas used by the previous owner, I just put in a full tank of 92, how do I go about resetting the ecu?

2nd question: Is it safe to vent the bov or bypass valve to the atmosphere? I just took off the tube from the bov and that cycles it back into the intake and just completely removed it, is this safe? Any performance gains or losses?

3rd) I have a Manual Boost Controller from my old talon, ive been trying to find out if i can boost this saab with it or not, havent had much luck finding any info except on one guy's site he gives instructions on how to hook it up. If it can be done this way, what is the max boost that can be run assuming I am running an intake and the turbo silencer removed?

Lastly, how much hp can i expect with a modified intake box, turbo silencer removed and max boost from an mbc?? 200? 215??

Thanx Guys

1st October 2002, 11:15 PM
1) your stock diverter valve is probably leaking, resulting in the boost to drop over time. i installed a GFB hybrid valve on my 900se and it fixed the problem completely, and reduced turbo lag. i think that you, however, need to run a complete diverter valve. i would recommend the HyperBoost valve from Stratmosphere: http://www.stratmosphere.com/hyperboost.htm

2) no i don't think atmospheric valves would work with your car.

3) removing the turbo silencer yeilds no performance gains, at least from what i've heard. the intake isnt going to add more than 5hp. it all depends on how much psi you run using your MBC. i recently ordered a MBC from DawesDevices that i heard worked well with my car. there's a nice diagram of how to install it, but i don't know if it applies to your MBC as well:

hope i helped you out...

4th October 2002, 03:07 PM
2) You got a T5 computer, so you can vent your boost, Just make sure to use a proper BOV, not just disconnect the hose from the stock BPV, cus' it's just not designed to work like that, It will let air be drawn back inside and that will mess stuff up.

3) 15Psi is the max boost your Computer will allow before it cuts fuel. It's should be pretty obvious when you hit that.