turbo boost q

[negular]

i tried searching but my computer is being retarded.

what is turbo boost? is it the air pressure the turbo is exerting?
i read that the stock boost for an SR is 7psi and it is safe to have it up to 13-15psi... how do u alter boost?


did i post in the wrong place?

[Jeff240sx]

Ok.
First off, this is definatly the wrong forum to post in.  Only answers to common questions should be here, and since you're new, don't get upset if this post gets deleted.
Second, the entire search function on Ikonboard is F'd up, and little bugs like that is why we are switching to a different board company.
Now... on to the answers.
Yeah, turbo boost, or boost, is pressure the air is exerting, either psi, or bar in the US.  1 bar is 1 atmosphere, or 14.7psi.
The stock boost on a sr is dependant on the engine.  The s15 has a higher pressure and a larger turbo.  Different engines have different "maximum boosts" and it all depends.  Sport Compact Car claims the sr20 is capable of 20psi on racegas.  Thats kinda iffy, but...
To alter boost, there are 2 ways, one is more dependable, and the other is easier.
The dependable way is to alter it with a different wastegate.  The wastegate does just what it sounds like.  Past a certain pressure, it opens and dumps the excess exhaust gasses out before it hits the turbo.  And different models have different springs.  And TiAL, and some others can have their springs swapped out.  Stiffer spring = hard to open, and hard to open = more exhaust gasses to spin the turbine, and more boost on the compressor side.
The easier way, without getting your hands dirty every time you wanna change your pressure, is with a boost controller.  Basically an overglorified bleeder valve, and can be had from HKS for $100, or a aquarium shop for $5.  It just vents air out of the wastegate so it takes that much more exhaust to open the wastegate, and more air = more psi.  The electronic boost controllers are nice... but I digress.
-Jeff

[DSC]

Some additional reading...
http://www.howstuffworks.com/turbo.htm
http://www.gt-turbo.freeserve.co.uk/article_turbocharger.htm

and yes, this post will most likely be moved to tech talk...
but I dono, it is almost faq material.

[wherezmytofu]

the stock sr turbo uses an interal waste gate...so u got 2 take the acualtor off a similar turbo (t3 from t3) i think it uses t28?!?...so find a t28 that is stock boosted 2 12psi......i know ther eis an audi t3 that is 12.5psi stock...2 bad uc ant use it.....anyway....or u can get a booste controler &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>