Hey guys. I have a question about how much boost I can "Safely" run om my Z setup. This isn't my first FI build, Ive had 240sx with sr20det with Gt35 on it all done myself except tuning. I will be installing my parts which I already have and i am thinking of turning up the boost a little. I guess the proper question I am trying to ask is what amount of boost can I run before the compression ratio becomes to high for 91 or 93 octane to not be enough in a VQ35de. I am planing to run 12psi and getting a really good tune,(Race MRC).

03 350z VQ35de 40k

Ati pro charger
30% larger Inter cooler than the original. Bar and Plate
rc 550cc Injectors
Large AMS Aluminum Radiator
Large Custom Oil Cooler
Walbro 255
Fuel return kit with Rising Rate Fuel Pressure Requlator
Turbo XSUtec with Map Sensor
1 Step cooler Plugs
pump gas- 91 or 93
Motordyne 5/16 Isothermal.
Nismo Low Temp Thermostat
CF hood w vents to help with ENgine Bay Temp
All necesary gauges including Wideband 02
Turbo XS exhaust with Test Pipes

I am located in NY so I am at sea level. I am aiming for 400RWHP. I have seen people with 9psi almost hitting 380. I called ati and they said for 240bucks they can make any pulley setup for any desired PSI so I was thinking 12psi should be correct. Not a daily driver and i will be tracking it and Drifting it. Any info would be much appreciated.
Thank you.

 

You'd be running the ragged edge, but with a good tune, might last you awhile. No way to know for sure with those wimpy DE rods...

 

im not too well informed but my understanding was anything exceedng 10-11 was in high risk territory. On a positive, centrifugal builds boost with rpm so you would only max at 12, and would be running less at say 5k rpm. Unless you redline frequently could make it work with proper timing i would think.

 

also since its a supercharger you wont be making the torque that turbo guys would at that PSI, so you might still be safe, since its the tq that kills rods

 

Since supercharger build boost I think you would be ok at 12psi. The life of your motor will be cut more then half. I would run Water/Meth and 93 octane. When I had my procharger I loved it. I started spraying at 2psi to red line never any knock with the meth.

 

maybe u should IDK search........ Huge thread on it

 

Thanks for the info guys. I think ill stay with 9 because im dont care to much abot how fast i can go in a straight line, but its so addicting. The high 300s is still plenty.

 

you keep adding boost til you reach your horsepower goals.

not sure why you are worried about boost pressure? my vortech runs 15 psi at 6700 rpms.

 

what size pulley are you using to get 15 psi? DO you have any internal work done?!?

 

ITS all in the tune,just stick with 91 93 octane.