My car is boosted on stock internals. I'm about to hit the dyno in a few days. I don't have a boost controller yet and my spring is suppose to boost 7 lbs. but only boosts 5 lbs. I'm about to buy a mbc but it won't get here until after the dyno tuning session. Can I borrow my friends mbc and set it at say 7 lbs. and when my comes in, just set it at 7 lbs? Since I dyno tune it at 7 lbs. with the borrow mbc, when I put mine in, it would be the same, right?

 

just set it properly both at 7psi, on the dyno it shouldn't matter since it measures power throughout the powerband, the only difference you may see different is one may spool to 7psi faster or slower, just make sure you don't spike to 20psi or something...