ghag_S4racing

Before I get flamed...I already check the archives...

What is the max boost a stock 2.7 block can take before the unspeakable takes place?...

I am seeing numbers up to 1.9 ...anyone really know?

Thanks
ghag_S4
'01 S4
'01 S2k
'81 CJ-7

Mods?...can anyone really leave anything stock these days?

Mike2kS4

I sometimes peak in the 17's with my XChip and I doubt I'm anywhere close to exceeding the mechanical limits of the long block. Though the head gaskets may be quite vulnerable to something north of 20 PSI...

This is based on the fact that 1.8T's can handle ~27psi with no internal mods and share key cylinder-level design features with the 2.7T. There may be some other weaknesses/strenths of the 2.7 of which I am unaware.

Mirror|rorriM

Well before that, of course, you'll be pinging like a ****.

I personally have seen 27psi on an S4 with no ill-effects.

You do know that there is more to making power than just increasing boost, right?

ghag_S4racing

Yeah...I know...my current config has me at about 27psi peak...a buddy of mine in the Toyota world was telling me that is too high for a stock block...just wanted to make sure

Thanks
ghag_S4

SmokinS4™

thanks to drive by wire...Unless you are looking at some custom programming or standalone management.

Mirror|rorriM

It is too high for you to be running sustained - you're well out of the K03's (and k04's) efficiency range there. You're going to be faster if you lower the boost and increase timing instead.

VerrÜckt

Yep, I can make this happen at will with XR programming.

SmokinS4™

make the throttle cut? or get more than 1.55 bar?

VerrÜckt

Both.

ghag_S4racing

I can't keep one eye on the boost gauge and the other on the road at the same time...(boost gauge is a secondary funtion of my turbo timer)
it appears that 27psi is spiking...have not had this configuration very long so I don't have much of a history yet...I am running K04's as of late...turbo lady did a wonder on me