# BoOst not holding to 12psi **URL:** \ **Category:** SON240sx Automotive\ **Created:** [June 30, 2011, 6:03pm UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077 "2011-06-30T18:03:18Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![RED\_LINE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/red_line/32/5656_2.png) [@RED\_LINE](https://forums.speedlife.net/u/RED_LINE)\ **Post date:** [June 30, 2011, 6:03pm UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/1 "2011-06-30T18:03:18Z")
Hey guys, so after my second oil change I decided to up the BoOst on my t25 to 12psi using my Trust TVVC manual boost controller by clicking it and doing a few runs around town to check where it’s at. I’ve noticed that it’ll hit about 12psi(0.8bar) but then drop and settle to (0.6bar), or as tested going into full bOost while crusing on the highway in 4th gear it just sits at 0.6bar. Not sure what could be causing this, otherwise it’s all good. Could it be the actuator, the boost controller, the exhaust?(since I’ve banged it a few times from it hanging too low when the car was lower, it’s a 3" catback and piping is full 3" turbo back with megan manifold) and all the other bolton goodies…etc. Thanks for any input, Gurpreet ---
**Author:** ![RED\_LINE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/red_line/32/5656_2.png) [@RED\_LINE](https://forums.speedlife.net/u/RED_LINE)\ **Post date:** [June 30, 2011, 11:20pm UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/2 "2011-06-30T23:20:49Z")
friend said it may be the related turbo lines kinking…I’ll give it a look through tomorrow… ---
**Author:** ![renegade141](https://avatars.discourse-cdn.com/v4/letter/r/ba8739/32.png) [@renegade141](https://forums.speedlife.net/u/renegade141)\ **Post date:** [July 1, 2011, 6:54am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/3 "2011-07-01T06:54:35Z")
Wastegate actuator will contribute to that problem. Its probably as old as the engine. ---
**Author:** ![RED\_LINE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/red_line/32/5656_2.png) [@RED\_LINE](https://forums.speedlife.net/u/RED_LINE)\ **Post date:** [July 1, 2011, 10:01am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/4 "2011-07-01T10:01:04Z")
That’s a good probability it’s the wastegate actuator maybe loose, its as minty as the 98’ sr motor lol. ---
**Author:** ![Mr\_Phonso](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@Mr\_Phonso](https://forums.speedlife.net/u/Mr_Phonso)\ **Post date:** [July 1, 2011, 10:23am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/5 "2011-07-01T10:23:40Z")
could be a manifold to turbo leak, after years those bolts will back off. Check them because I remember when I swapped in my T28, 3/4 bolts were hand tight. ---
**Author:** ![RED\_LINE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/red_line/32/5656_2.png) [@RED\_LINE](https://forums.speedlife.net/u/RED_LINE)\ **Post date:** [December 5, 2012, 10:33am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/6 "2012-12-05T10:33:14Z")
**SOLVED** I fixed it a lil while back, but it ended up being my boOst controller. A Hallman fixed it right up to redline as it should be lol. ---
**Author:** ![Singh](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@Singh](https://forums.speedlife.net/u/Singh)\ **Post date:** [December 5, 2012, 12:00pm UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/7 "2012-12-05T12:00:14Z")
yea was gonna say, manual boost controllers are crap. ---
**Author:** ![sharpe\_corners](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sharpe_corners/32/5767_2.png) [@sharpe\_corners](https://forums.speedlife.net/u/sharpe_corners)\ **Post date:** [December 6, 2012, 7:22am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/8 "2012-12-06T07:22:15Z")
TVVC are good too, thats suprising! ---
**Author:** ![RED\_LINE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/red_line/32/5656_2.png) [@RED\_LINE](https://forums.speedlife.net/u/RED_LINE)\ **Post date:** [December 6, 2012, 7:47am UTC](https://forums.speedlife.net/t/boost-not-holding-to-12psi/214077/9 "2012-12-06T07:47:39Z")
> [@sharpe\_corners](#): > > TVVC are good too, thats suprising! Ya dude, they are no doubt. Lots of Supra guys use those, but I guess mine wasn’t in good shape no more, I got it used so maybe needed some rebuild or something. Hallman is a great brand, great bang for the buck, so far so good 🙂