Whats the limit to PSI i can run with my 7lb spring?? I searched, and am sure there is a general rule for spring rates and PSI, i am just not aware of it...

 

anything above 7psi, springs only limit the least you can run, a boost controller can run anything above that

 

well now that i just found it, im seeing you can only double the spring rate. i.e. with a 7lb spring i can only hold about 14 lbs of boost.


Im looking to get tuned at around 22 lbs so i guess i need a 10lb spring.

 

not true, dont waste your time with springs, just get a boost controller.

 

The wastegate spring is just that, a spring. A 7 psi spring just means that at 7psi, the spring compresses, and the wastegate opens. It's really that simple. Thus, anything more than 7 psi will have the wastegate open. All a boost controller does is prevent boost/vacuum from getting to the wastegate until a set psi, and then it essentially opens a valve and boom, the wastegate opens limiting boost. A 7lb spring is fine for higher levels of boost, just use a cheap manual boost controller or whatever.

 

I have a good electric boost controller, but i dont think a 7lb spring can hold 30lbs of boost even with a controller.

 

not true.. i have a 6lb spring in my tial, with AEM boost solenoid we were able to hit 18psi on the dyno

 

u can hit more then double, but the wastegate might leak at triple the spring. effecting spool and top end power. personally, i would pick a 10-12 psi spring. the spring will be the lowest boost you would ever run. your never gonna run just 7, so thats a waste in my book.

 

I have a 6lb spring and easily hit 25lbs, Evans said it would have no problem hitting 30 either..............

 

dont use a cheap manual boost controller they suck. Also what a boost controller does correct me if im wrong. Is puts air into the top of the wastegate thus making it hard to push the spring/platform up witch essentually gives you more boost till the wastegate opens. you cant stop air from entering the wastegate. it will enter no matter what just the vacuum will help the spring push the platform down. id recommend getting a 10-12 psi spring.