So i just put on my 4 inch ets intercooler and went from 25 psi dropping to 21. to 21 psi dropping to 16 psi. Can i turn the boost back up to where it was without tuning it?

 

Did you have a stock intercooler before? You either developed a boost leak, or removed a heck of a restriction.

 

Yes had stock intercooler before. It basically dropped 5 psi from what I can tell. I have a manual boost controller

 

I have heard of bigger intercoolers causing a drop but 5 psi seems like a lot

 

it might be 4 psi its kinda hard to tell exact amount as im using my MR gauge that is in bar but it defiantly dropped

 

You should do a boost leak test before turning the boost back up.

 

I'm going to just want to make sure it's safe to turn it back up

 

Bigger IC should cause a boost build delay and not a drop....those are two different symptoms.
Since you have more volume to fill, then it will take longer (depending on size difference) to achieve the target.
Do a boost leak test and my guess is you have leak!
GL!

 

I will check for a boost leak tomorrow.

 

Did you only swap out the IC and not change anything else, i.e. IC piping? If you only changed the IC then I seriously doubt you that you have a BL. If you had not connected and securely fasrened the IC couplers properly then it would be obvious....big time.

Just raise your boost pressure back up 4# via your MBC, man. Also, get a real boost gauge. This is EvoM not the Mickey Mouse Club.

 

that's how I would understand it to. Unless you're some weirdo who measures boost pre-intercooler

 

There could be some pressure drop. You should do a boost leak test. Its a good idea to do one whenever the charge pipes, or anything that see boost pressure, is taken apart..

 

doesn't make sense. do a boost leak test.

 

I would recommend a boost leak test as well.