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mark houghton mark houghton is offline
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Join Date: Jul 2008
Location: Central Washington State
Posts: 3,776
Ok fellow Porschaholics, just to put closure to this thread I started awhile back. We made the maiden voyage today...52 degrees and sunny ouside, just a perfect test day.

Fired the beast up...and she ran like dog doo. Missing something terrible. I would recommend that nobody follow the plans I've laid out for this modification.

Oh...but WAIT!!!.....further diagnostics showed the coil wire pulled loose from the cap (it was arching at least two inches through the air and into the cap somehow; surprised she ran at all!!). Plugged that bad dog back in and....she idled at around 1800 stone cold. Much higher than my normal 1200 or so pre-modification.

Well, it turned out that the AAR just hadn't heated up enough, but still idling high after warm. Why, you might ask? Well, because I upped my static timing from 8 degrees to 12-13. A quick air correction/idle screw adjustment took care of that.

Now for the ride. First, the extra timing advance made a noticeable difference (for your MSD BTM dudes, I have the retard onset set at 5 psi, with 2 degrees per psi being shaved off. Safe setting, will actually put me at less advance once full boost is achieved than stock settings. May play with that later....).

Peformance perceptions? Low end power curve is improved with the extra timing. Nothing doggy about the pre-boost performance, boost lag between gears is almost non-existent and boost onset is quicker (full boost by3600, vs. 3800 prior), and that with a 7006 turbo. And with the AAV disconnected from the intake manifold and venting to atmosphere instead, rpms drop instantly when shifting. AFR's have changed (drop to around 10.5 momentarily when expected) since no additional air is being injected via the AAV. None of this is bad stuff. The only other weird thing I noticed is that when abruptly getting off a steady 2500 rpm cruise, the AFR's lean way out to about 16.5. Back on the gas, and they settle back into the normal 14.2. AFR's on full boost haven't changed any (still in the high 11's low 12's, just where I want them. All this at .8 bar, since I haven't hooked up my new boost controller yet.

All is good, about peed my pants with the first ride of the year. Happy with the mods so far. One final picture attached to show the bracket I fabricated to stiffen up the left hand IC mount.
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 02-21-2010, 01:28 PM
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