Boost

[Drifter To Be]

hey, anybody know how much boost the WRX runs on stock? (PSI please)
and as for adding more boost, should i just go for a higher boost wastegate? adding a cheaper manual boost controller? or one of those more expensive electronic boost controllers?
thanks all

[Alldar]

13.5 stock

[scottb2004]

electronic w/o custom engine tuning, manual with custom engine tuning (i.e. unichip)

[Drifter To Be]

thanks,
have u had any experience with electronic boost controller?
which one would u recommend? electronic or manual w/chip?
which type of electronic boost controllers are easier to install and use for a good price?
thanks again

[Drifter To Be]

Originally Posted by Alldar

13.5 stock

r u sure??
it sounds to be a little to high for me
because isnt it 2L turbo engine?
wouldnt it make more than 227hp with 13.5 psi?
sorry just skeptical

[LjasonL]

Manual boost controllers:

Manual boost controllers are pretty basic. They raise the boost, but don't do anything else. They work if you're strapped for cash though. They come in 2 basic types, ball and spring, or screw. A ball and spring controller has a spring with a ball on the end, and once there is enough boost, it compresses the spring, opening the wastegate. The advantage to this type is it opens the wastegate instantly once boost is completely built, so the car will spool up faster than with a screw type and in the end be quicker at the same boost level. Even adding a ball and spring controller to a stock car, without raising the boost at all, can make it quicker because it spools faster, since the stock wastegate opens slowly a little at a time, and the full force of the exhaust isn't used to spool the turbo. The disadvantage to this type is it will be spooled more and boosting more during part throttle driving, and you may get higher than recommended cylinder temps when driving normal. An EGT guage would be recommended so you know if things start to get too hot, though even that isn't instantaneous readout. A screw type is pretty much the opposite, slower spool up, but safer with no part-throttle boosting. This type is generally more accurate too.

The biggest disadvantage to all manual controllers is you can't adjust the boost on the fly. You have to make a pass, watch your boost guage, pull over, get out, adjust the controller, get back in, make another pass and check the guage again, and keep doing this till you get it right. Then if you want to turn it down cuz you're done racing and time to drive home, you have to start the process all over again. Come back to the track next weekend you gotta set it back to high boost. It's a pain in the ass. Some, like the TurboXS controller (I forget what it's called) allow you to switch between 2 different boost levels with the flip of a switch, one for low boost daily driving, and one for high boost racing. This is certainly a lot easier once it's set, but still the same old process to get it set, and it's not near the adjustability of an electronic one. Also, manual boost controllers can be affected by the weather conditions. You might set it during the afternoon to get ready for the race that night, then nightfall comes it could be off again, and you have to go through the same old deal again. The biggest advantage of manual boost controllers is they are cheap.



Electronic and electric boost controllers:

Electronic and electric mean the same thing when taken literally, but this is a catch phrase used to distinguish between 2 different types of electronic controllers. Actually I don't even know if this is a common phrase, or just local slang, but that's beside the point.



Electric boost controllers:

Electric boost controllers are a lot like manual boost controllers, but with a motor or solonoid to do the adjusting for you. You generally have a dial of some sort, and you need a boost guage of some kind too. You make a pass and watch the guage, if it's too much boost, just turn the dial down some, if it's not enough, turn it up some. No getting out and turning the little wrench hassle of the manual controller, and you can actually do it without pulling over and stopping every time if you have a long stretch of road to test on. Much easier. However, they are also affected by the weather problem the manual controllers have, although it's not nearly as big of a problem here because you can adjust it with a simple turn of a dial/push of a button. They come in 2 types, Solonoid and screw. The screw type is just a screw that opens and closes in the path of the air. This kind is more accurate, but less resposive as it may take a moment for the screw to turn to it's new position after you turn the knob. The solonoid type has a solonoid that opens and closes, letting more and less air through to the wastegate. This type is instant response, but generally less accurate.



Electronic "learning" boost controllers:

These are pretty much the same as regular electrics, but they have a built in boost guage and a computer that attempts to "learn" your cars boost characteristics so it can make all adjustments automatically. They can be time consuming to set as you need to make several passes to give them time to learn, but once they're programmed themselves everything else is a breeze. If you want 15 psi, just dial it to 15 psi and it does the rest, no watching the boost guage as you fine tune the dial. This type also compensates for the weather conditions automatically. However, they can be confused with cars that have boost creep or other strange boost characteristics, causing them not to perform up to par. They are also the most expensive type.

Both electric and electronic controllers usually come with other features you can't get on a manual, such as push button instant preset boost levels, integrated timing controllers, etc... This depends on the model.



Here is a test from several of the more popular controllers on the market to help see how they perform - http://www.arimport.com/forum/index.php?showtopic=490


I'm totally putting this in the FAQ

[Alldar]

thats what it says on this page... which is put up by a dealer

http://www.cars101.com/subaru/imprez...ew%20for%20WRX