Just got off the phone with Silber. He said in midwest run it at 3 lbs of boost and change clutch weights only if it's over revving. which makes sense. no need to change springs in clutches. the boost as stated above is changed with a simple change of the waste gate spring. at home in the midwest running 3lbs of boost you can use pump gas. it gives you about 185 hp.
you can switch it to 7 lbs out west and run pump gas, just need to change the clutch weights to prevent over revving. this puts out 200+ hp.
anything higher than 7 lbs of boost out west you need higher octane fuel, anything higher than 3 lbs in the midwest and you need higher octane fuel.
their electronics changes everything based on elevation and conditions. no changing anything except for clutch weights and waste gate springs.
Silber prices: $4,000 during the season. $3,600 spring price. $3,300 spring price if you buy 2 or more turbo set ups, so get a buddy to buy with you too.