I have a 9 MR with just an MBC and TBE. I was wondering what safe boost would be on 93oct. I am currently set at 21psi. I was hoping 22.5 to 23 would be safe. I plan on getting the fuel pump and other mods soon, 02 housing, mani, etc. Thanks.

 

You should get a Tune with the Fuel Pump and should be able to get 24 psi.

 

yea a fuel pump and u should be able to run 24psi dropping off to 21psi.... thats what mine does altho i have alot more mods... but i have done that from day one... but make sure u have a tune on it before u do it cuz of knock and what not

 

Does having a wastegate actuator effect any of this? I was told this will help hold boost pressure. If I set the mbc to say 23psi and it holds to 21 to 22, I should be ok, right?

 

+1 on the fuel pump. Tuned on a stock pump and all depending on the tuner you could get up to 23 psi safely. Add a walbro and you can get 24 psi safely no problem.

 

The turbo can only push a certain amount of air efficiently...At high RPMs (7K +) it will be very hard to hold more than 20 psi and not have knock issues on 93 octane...I currently can hold 19.5 psi at redline, but that took a bit or work...