How much boost is safe??

volvee850glt · Post by **volvee850glt** » 14 Feb 2010, 23:47

I'm pushing about 7psi right now but Iv'e seen places on the internet where people say 850's push 10psi stock. I recently had the head rebuilt and the guy that did it said he wouldn't go over about 7psi with the standard valves. How much boost would be safe with the standard valves??

Post by **JDS60R** » 15 Feb 2010, 00:45

Call IPD and talk to Lucky.
Tell him which engine , miles etc and he will let you know. If Lucky is not available than most others can help.

rbodor3 · Post by **rbodor3** » 01 Mar 2010, 16:35

you're leaving out a lot of information
what all was rebuilt on the head? did you get an angle valve job done? Has the block been rebuilt?
What turbo are you running, stock? How much mileage on the engine? What ECU are you running, stock?

There really is no answer to this question - it's not really the quantity of boost that will bend your rods, it's when you get it, how much at that time, what gas you're running, etc. etc. etc. etc. etc.

The easy answer is 15psi
but if you build more than 7 below 3000 rpms you're looking at detonation.
If you run bad gas you're looking at detonation.
If you boost spike you could get detonation, blow out, crap out your rings, etc.