Hey all, I was wondering if a MBC would work on my 86 9000T B202.

Right now, i have a calibrated boost guage.
Base Boost at 5 PSI. I have a modded APC awaiting to be installed and a 3.0 Bar FPR.

Does my car have a LPT?
How far can I adjust my base boost with a modded APC. My APC has new resistors installed and is tweaked to SPG spec.

Thanx!

I don't see why you should use a MBC if you already have a modded APC. Anyway, it would work.

No,your car isn't an LPT.

As far as I know, base boost doesn't need to be adjusted when tweaking a APC. Maybe you could lower it a bit to, say, 3.5 psi to have more safety against knock, but a higher base boost would geve a better throttle response (faster spool up).

jack up the base boost to around 5.5. it will get you better overall performance. Also, what mods have you done to the APC?

Remember increasing the “boost” on a older car with mileage also increases engine wear.
Unless you are 100% sure of the engines condition I would recommend only moderate tweeking

My car's engine condition is top notch. had it compression tested, and its all good. I noticed a small prob. At base boost 5 psi, when she spools up, she hits around 9 psi, then seems to jump as if she hit knock. Never exceeds 10 psi. Any advice on this?

MBC would be useful for giving you a quick spool up but increasing base boost would give you bascially the same effect. I suggest that you up the base boost a bit and make sure that the APC is modded to Tweakers specs.

Alanb

Hey guys, I got a new prob.

Seems like my APC is failing to kick on.

Sometimes on acceleration i hit around 5 psi and then the apc takes over to around 8-9 PSI then it goes back down to base and stays there. Any reflections on this? Seems like a controller is failing and not the APC. thnx.

Seems like you're in base boost mode, or that you go into it after a second you're boosting.
Search the forum for base boost, you'll find tons of info.

But if you suspect the controller (aka BPC valve), try to squirt some WD40 into it: I heard this isn't a permanent fix, but it should help for a while if the problem is there.

If you want to change it because WD40 is't enough, search scrapeyards-junkyards because Saab prices for that are silly.

I found the problem. The wiring harness for the APC wasn't pushed in all the way! LOL

Must have happened when i changed my brake light switch! :D

Ah well my 375,500 kms 9000 will keep on running strong!