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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
Originally Posted by 9dreizig View Post
Beautiful day here so took the tracdog out for a ride. Since I've not really had a chance to fine tune the DWUR I had my computer hooked up.

Well I hit it hard and watched as the boost guage climbed past 1 bar and pegged.. I naturally lifted immediately. In looking at the graph on the DWUR it looks like it it 1.5 bar. I repeated this to make a few more observations.
Also it appears that my guage is screwing up but that's another issue...

So here are my questions..

What's the fail mode of the wastegate ? is it typical for them to stick ??

Where does the overboost switch kick in ? I'm pretty sure it did on the second or third try on my part to see what was going on.

How is the stock boost guage tied into the overboost relay ?? I can see from the wiring diagram that it is but I'm not sure how..

If your overboost switch worked at all, you would know it. "Dash in the face" syndrome....can't miss it. You go from 2 G's pressed against the seat to an abrupt catastrophic decelleration. Old switchs often trip earlier in the boost (or not at all), but still it should have shut you down well before 1.5 bar if it's still working.
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 03-26-2010, 08:56 PM
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