Turbo Project Problems/ my turbo update

[Michael Gough]

Hello
I'm not completely sure about the Audis, but I know for a fact that at WOT in the turbo Dodge cars you want it to run at 9 lights on the A/F guage corresponding to a .9V reading from the O2 sensor. Also, this crosses over into my project. I filled the tank with 92 octane today and took it out ripping through the gears. I got my APC knock light working and with the good fuel I don't get any knock at all. Speaking of leaning out at 6psi or whatever it is, I hypothesize that if my fuel system is good enough for my engine at 6000 rpm, I should be able to run 1 bar (~15psi) at 3000 rpm and have enough fuel. It is twice as much air as normally aspirated but at half the rpm so ~half the fuel is used. I took off in full throttle at a light a few times and here is what I found. In first I gave it full throttle and shifted at 4k rpm, engine got up to 4k so quickly that it only got to 6psi. In second, it got up to 8psi because there was more time for it to spool up. So someone answer me this— 15psi @3k is roughly equal to N/A at 6k, so should I have enough fuel for 4k @10psi. Thanks everyone.
BTW, when I got up to 8 psi I didn't have any flash from my knock light so the premium fuel seems to have done the trick.
Mike


> I do have boost alright, feels wicked even at lower boost levels, much
> faster car.  I ran at 0.43bar (~6psi) and my air/fuel read one bar above
> stoich, which pleased me.  Though other times I pushed it to .40bar and the
> gauge dips to full lean and then hops up to stoich and rich again after a
> second.  I am thinking that on the onset of boost the mixture is leaning out
> and when the ECU finds out it's hitting the DPR with more current to richen
> things up, anyone?  Dangerous?
> 
> When I hit full throttle, no matter what, the air/fuel gauge drops to full
> lean and doesn't hop back up until I let go.  The WOT switch is the same one
> that was in the car before the conversion and I know it works.  I can hit
> full boost slowly and everything is fine, but if I try to jump on it a bit
> it goes lean.
> 
> I will have to get a new seal for that leaky flange at the rear of the
> cylinderhead.  I'm not loosing that much coolant at all but it is real
> smelly and sometimes there is a tiny bit of smoke from it.  I can't find any
> secret oil leaks that would be causing low pressure, but I want to get it
> higher for sure.  I am going to fiddle with the base mixture and timing to
> get the idle a tiny bit higher so the oil pressure is higher as well, plus
> when I slow down to idle the engine wants to drop to 0.5k rpm and then kick
> back to regular idle.
> 
> Thanks and soon she'll be ready!
> 
> Alexander van Gerbig -- '88 80
> 
> The Audi  80 Pages-----------------
> http://surf.to/the80pages.com
> 
> North Ferrisburg, VT 05473


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