what is the stock boost pressure on a 2002 wrx. When i had my boost gauge installed a year ago i was reading peak at 10 psi. Then i got a boost controller and put it up to 11 thinking it was 1 pound over. Now i have people telling me that stock boost is 14 pounds. Does this mean there is a problem with my car? I think that the person that installed my gauge did not tap into the line next to the bov he did it somewhere else. Would this make a difference? It is a cheap gauge and the only mod i had was a ram intake.

 

i know that stock boost is 13.8 psi the question was really about why my meter is reading 10psi. Anyone else ever have problems like this?

 

I think stock psi is 14.5

 

i think 14.5 is for the STI for the wrx its 13.5.... or it is for mine anways

 

Stock boost for the WRX is 13.8, but boost varies according to what gear you are in. I can only hit 12.5 or 13.1 PSI in 1st and 2nd, but in 3rd I hit 13.8 and 14.1 for 4rth and 5th. I've got a digital gauge with peak hold, which is how I can take accurate readings without crashing.

If your boost gauge was reading incorrectly (which it may not be -- you might have a more serious problem) then it is simply broken or you have a leak somewhere in the line that has been tapped. There is no way for one part of the system to be at 10psi while other parts are at 14psi; pressure is equalized throughout the system unless you are tapped into a vacuum line.

 

thanks for the help meilers. i am going to get this sorted out imediatly.

 

Well, I told you that boost for the stock WRX is 13.8 PSI.

HOWEVER, I just got an accurate boost gauge, and I found out that I am boosting to 14.4 PSI...

...in second gear!

This is with a totally stock 02 WRX; only "mod" is a Perrin foam air filter. I thought boost was locked at 12psi in 1st and 2nd, but that doesn't seem to be the case in my situation! This is measured using an ECU monitor, so I am readin the car's own boost sensor, not a 3rd-party gauge...

14.4 PSI on a stock TD-04; does that seem risky to anyone here?

 

i'm running 14.5psi on all of my gears when i floor it and my car is all stock ....but because maybe i have an 03

 

it also depends what elevation you're at too, because here in colorado, we dont actually get the stock rated boost, sucks!

 

the dealership people say it 13.1 psi

 

Considering I just hit 14.8 yesterday in 3rd gear, I'd say 13.1 for a stock EJ20 is not the correct number

 

Stock is 13.5 on a WRX and 14.5 on a STI.

 

is every car different??

 

See, that information is useless with out specifying what gear and under what conditions.

My 2002 WRX, totally stock except for a Perrin panel filter and synthetic oil:

Gear 1: 13.6 PSI
Gear 2: 13.8-14.1 PSI (one freak boost to 14.4, couldn't reproduce)
Gear 3: 14.1-14.8 PSI (range in 3 runs)
Gear 4: 14.4-14.8 PSI (same)
Gear 5: never maxed this one, don't have a track nearby

Those totals were recorded by an ECU monitor, reading directly from the car's own telemetry (not from a possibly incorrectly-installed boost gauge) that records absolute peaks. The higher numbers (14.8) were just a few seconds and there was an immediate falloff; however, the ECU monitor keeps track of spark timing and knock sensors, and I had NO knock and the car did not pull timing when I hit that peak.

Altitude, which of course affects air pressure, is also a factor. Here in Phoenix I am at about 1100 feet above sea level; lower air presure means more PSI = less effect on the engine.

I have mixed feelings about the results. The fact that I am able to boost to 14.8 on a stock TD04/EJ20 and get no knock and no pulled timing (and ignition temp, EGT and oil pressure were within totally safe margins) means I have a solid and reliable engine setup; however, if I am already boosting to 14.8, I probably won't see dramatic results from tuning the engine (ECUTek ECU reflash) without doing a turbo swap. I have an EARLY 02 WRX (I bought it 4 weeks after the cars became available in the US; it was the third to arrive in the state) so it might be possible that the later WRX models have been "dialed back" a bit since then due to feedback from consumers or shops.

 

Absolutely correct. And there are many, many conditions that will affect peak boost readings in a given gear. Among them are how much weight is in the car, whether the road is level, uphill, or downhill, intake air temp, intercooler temp, and car-to-car manufacturing variations in the boost control hardware.

For instance, using an "orifice" (Subaru p/n 22326KA120) with a diameter of .046" instead of the correct .0472" will result in another pound or so of peak boost, and will cause the boost to waver up and down by about a pound when the ECU is trying to hold peak boost. (Ask me how I know...).

My point is that anywhere between 13.5 and 14.5 or so peak boost, in the higher gears, should be considered "normal".