Has anyone successfully installed a SAAB APC wastegate control on an Audi? I converted my 84 4KQS to turbo power and am hoping to get more boost than the wastegate spring allows. I'm not using the later MC motor with knock sensors. So far the SAAB knock sensor activates at 2700 rpm regardless of what gear its in. So it appears a harmonic in the 5 cylinder engine is setting off the knock sensor. Anyone had this issue and figured out a solution?

Don M

Knock sensing controllers are only good for a certain engine, there is no universal knock sensing device. The "microphones" themselves can be universal, but the device controlling them (rather, listening to them and using them to control something else) cannot be universal.

Not sure why you wouldn't just get a manual boost controller, or an electronic boost controller and pair it with a WB O2 and/or EGT setup (if you know what EGT is safe and what is unsafe).

I have an EGT installed and am wondering what the upper limit should be before getting concerned. I've only had the turbo on for a week and the highest temp around town (lots of hills) is 1050. I have 10 lbs of boost, but have only run max boost for 20 or 30 seconds continuously. The probe is in the port just downstream of the turbo outlet. It seems to run fine on mid grade fuel, but on regular I heard a few knocks so that is why I'm trying the APC box knowing that summer temps will change the situation.

Any help is surely appreciated.

Ramp
Colorado Springs

hook up the RPM reference, or you will get all kinds of noise. I honestly would not be running my motor the way it is without that damn thing. I can't hear knock till it gets really bad, the little APC knock light let's me know when it just starts to set in.

The turbo sucks so much heat out that you never really have a goods idea of what's really happening. I see 1650 F about 6" away from the port outlet on the head. That's at 25 psi of boost, 6000 rpms. 1650 is as far as I'm willing to go, and it's still a little warm for sustained temps. Being as I'm usually only there for a few seconds, I'm OK with it.

Jim,

What wire did you connect to on the SAAB box to get the LED light? The posts I read said to use pin 19 where a ground can be obtained upon knock. There was no wire coming from that pin so I connected one and put a hot lead to the other wire on the LED, but still don't get any light when I hear the solenoid clicking. Also I'm running off the - terminal on the coil to get rpm to the APC box. Is that the wrong location? How did you get yours to work correctly? I would like mine to be functional too even though I'm only running 10 psi boost.

What does your EGT read just cruising down the highway at 70 mph off boost?

Thanks for any help,

Don

I'm not sure right off hand which terminal it is for the knock light, whatever all the internet sites say. For the RPM ref, you might need a pullup resistor on it. A 10k should work, connect that to +12v, and then feed that into the wire that is coming from the green wire on the coil, this way the box sees +12, then when the ign fires, it goes -12 and you get the proper signal.

For cruizing EGT's at stoich I get about 1450-1500 on the highway in the header.

as long as you only want to use it as a boost controller