Confused as to Factory boost.

[Gonthrax]

Ok, I'm confused and disturbed... I was searching around trying to find out what the factory boost on the US WRX is and I found the following.

The WRX's turbo feeds 14.2 pounds of maximum boost up to 3000 rpm, and then tapers it off with a waste gate at higher rpm, making for a peak output of 227 hp at 6000 rpm and 217 lb-ft of torque at 4000 rpm.

Please tell me that this is the pressure at the manti., not the boost the turbo is producing 'cause the factory boost on a R34 is like 7psi and the max safe boost for the factory turbo is 13psi.... Please don't tell me our beloved turbos are being shamed by some Mitsu made turbo

The article is at http://www.thecarconnection.com/index.asp?article=3146 if you want to check it out.

[RazorGTR]

Factory boost on the R34 GTR is just under 1 bar ( 14.6 psi). One of our club members has a Vspec ll which is the only one driving around New Zealand at the time.

The WRX does not come from the factory running 1 bar. I have yet to see an EVO, WRX, or GTR come from the facotry running that sort of boost. Most generally speaking they are set up pretty conservitive, say around the 10 - 13 psi range. The skylines use a ceramic exhaust wheel on their turbos to promote quicker spool up time and they are also quite a bit bigger than the others. Since the GTR uses a twin turbo set up, on that is not sequencial but in parallel, quicker spooling turbos meen less lag.

Have no fear dude there is nothing made on this planet with under 3 liters that can be modified to touch the GTR's RB26DETT motor when it is also modified by the top guns in Japan.

[Gonthrax]

Ok then tell me this, when one speaks of how much boost he (Or she ) is running, do they mean how much the turbo is producing or total pressure including atmospheric? Or does that even figure into it sense it has to go through the turbine anyway? Kinda sad that I don't know this Just don't get to play with many turbos here in the my area.

[Gtr2.7L]

1 bar is above atmospheric (1 bar PSIG). Easiest way to verify this in your mind without going into an assload of fluid dynamics is to turn your car to the "on" without starting it....read your boost guage. Mine reads zero. At this point, all pressures have to be equalized because your car has been off (the only exceptions being a two cylinders that hadn't had their valves open on their way to BDC when you turned the car off.)
Another verification is to drive a steady speed at about 2400 RPM. Your boost gauge shows -.3 to -.5 This is an impossibility if you were reading PSIA as you can't have a -PSIA. No air is no air.....period, you can't get any lower than that!

[Gonthrax]

I understand that, what I am getting at is this. If I say that I am running 14psi boost, do I mean that my turbo is adding 14psi of pressure on top of the 14psi of atmospheric pressure thus my manifold pressure is 28psi?

[WraithR32]

when people say "I am running .... boost" they are talking about what is showing on their boost gauge which is the boost that the turbo is adding to the inlet manifold.

[Gonthrax]

Ok, thanks for clearing that up for me I was pretty sure thats what it ment but wasn't sure. I guess the web site I was reading about eh Scoob was just plain wrong, 'cause I know that little turbo isn't boosting 1bat STOCK. Hell, isn't 1bar about as high as the stock turbos on a GTR can take safely?

[WraithR32]

I think the R34 can handle 1.1 or 1.2 bar, not sure about the others..