my mods are in my sig, but my vf30 was having some problems, so i got a really good deal on a brand new vf30. now the tune hasnt been touched. and it was previously tuned for 18.5 lbs with ecutek. now this new turbo is spiking to 21 lbs, how could this happen if my tune is no different?

 

wastegate could be calabrated differently (but i dont think those are adjustable).

the old vf30 could have been shot when you got it tuned.

check all of the vaccum lines on the turbo, wastegate, and boost controller.

 

does your old turbo have cracks?

 

cracks, difference in spring pressure (lighter new wastegate spring), shot or worn bushing/bearing, wheel(s) rubbing on the houseing(s)...

 

His old turbo didn't look like it had cracks or very much shaft play. When he bought the car it had an ECUTEK tune for a VF-30 to hit 18.5 lbs and now the new one is surging up to 21ish lbs. We datalogged it on my comp. and it the boost graph had numerous defined peaks and valleys. I'm thinking he might need a helper spring but I'm not sure. Also, it has the stock BCS and I'm thinking a GM solenoid would help out a little.

 

thats really weird.

 

the old vf30 has the infamous crack by the wastegate