I have a 7.2lb spring in my wastegate and have ben runing non ethanol pump 91 in my sled for aproximatly 13 rides or more now. No timeing changes. I ride from 4500' up to 9,500'. of course no really long pulls have ben made untill about 6,500' or higher. I have made some really long pulls the last week with the deep snow we have now. I have held it pretty long playing around on the lake at around 4800' though.
Compresion is still exactly the same as before I put the turbo on, pistons look perfect, never any signs of detonation on plugs, etc. Never any problems on the sled other then cracking pipe, and oil tank. Building a new oil tank today. Doing something so it will not leak any more, and will not backup into the turbo when you roll it. Tired of getting oil in the turbo and charge pipes.
I ordered a mbc, and the boot reinforcment plates yesturday and going to be turning the boost up to 10lbs soon and plan on putting in 2 gallons of 105 motor octane sunoco. I can get it for $5.75 a gallon out of the pump so it will not cost much extra. I got like 4 empty vp c16 and q16 pails I can fill or a empty vp 55 I can take and have filled up to keep at my house to save the hassel of going to get race fuel.
Still undecided if I want to keep the power valves or eliminate them when I turn the boost up.
check out my thread for pics and info.
http://www.snowestonline.com/forum/showthread.php?t=191751
I have some ideas for a fail proof meth setup I may try later this year or next. Also got some ideas on a water to air intercooler I may try.