Many have been tuning the stock appearing turbos to 28-30 psi and have had good results. It might be more difficult to hold 26 psi with a 28 psi spike though. Depends on how efficient your setup is along with other factors. Get a solid tune for what you want and I'm sure the tuner will have a good idea of where the turbo should fall off safely. You don't want to generate too much heat either.

 

Im at 27psi on 91 and tapering to 24. I cant see y u cant do around 29-30 on 93!

 

i made decent power at ~26 psi

 

You should tune the car to where your making good power and don't need high boost.

Example, 24psi making 400whp or 27psi making 410whp. Really no point in those 3 extra psi. Thats why a dyno or DLL is good, so you can measure your power to monitor gains and know when to cut off.

 

I think you got a very good point here. Its all about the output vs boost. How good is DLL for that? Are the HP readings of EvoScan any good?

 

now 30psi (26-27psi before). well according to my defi boost gauge which i have read do not read all that accurately

 

It depends on the dyno. I ran a 305whp DLL and a week later on a dynojet with a correction of 1 I think, it was 312whp. This was a conservative tune without adjusting the AFR. (no wideband at the time of the tune)

 

and dont forget the fpgreen is a little more efficient than a stock IX turbo. stock IX turbos on 93 octane are good to go at 24psi. running a green at 26-27 psi is the same threashold. larger turbos generate less heat/backpressure allowing more boost safely. i run 28psi daily w no knock, on 93 pump. Tuning the green on pump has come a long way since they first came out.

 

Tell me about it. I'm surprised at what the Green can do. I stopped adding boost at 28psi because I wasn't making enough gains to raise boost higher. Then dropped it down to 26psi as a daily driver. Now I gotta tune for meth, I'd say 31psi dropping to 27psi is fair enough for me.

 

im tuned to 24 and I have usually around 22psi. When I was tuned in the middle of the summer on 93 pump, 24psi, no knock at all. I used 93 from shell and ever since my tune, I have been pretty regimented about using shell.

 

updated my response before but 30psi on the green pump 93 only