The reason you MUST do a "boost leak test"!! Don't pass go. Read this.
Newbie
Joined: Jun 2011
Posts: 9
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So long as the TB is closed, the small IAC passage allows only a trickle of air into the manifold (didn't I say this already?). Your boost gauge is probably connected to the intake manifold. If you want to pressurize the manifold fully, hold the TB open as pressure is applied.
I read this whole thread and not once did I see it mentioned that not only are u losing power with a boost leak but your also shortening the life of your turbo as it is working harder to try to achieve max boost since its bleeding out. So theoretically if you have a massive boost leak, at 25 psi your turbo could be spinning fast enough to actually be making over 40 psi but its being let out because of a leak.
I can tell I have a leak usually by the sound of my turbo. If it sounds like its spooling ridiculously loud then I know I prob have a leak. I also do test every oil change or so while the oil drains.
I can tell I have a leak usually by the sound of my turbo. If it sounds like its spooling ridiculously loud then I know I prob have a leak. I also do test every oil change or so while the oil drains.
Newbie
Joined: Jun 2011
Posts: 9
Likes: 0
I read this whole thread and not once did I see it mentioned that not only are u losing power with a boost leak but your also shortening the life of your turbo as it is working harder to try to achieve max boost since its bleeding out. So theoretically if you have a massive boost leak, at 25 psi your turbo could be spinning fast enough to actually be making over 40 psi but its being let out because of a leak.
I can tell I have a leak usually by the sound of my turbo. If it sounds like its spooling ridiculously loud then I know I prob have a leak. I also do test every oil change or so while the oil drains.
I can tell I have a leak usually by the sound of my turbo. If it sounds like its spooling ridiculously loud then I know I prob have a leak. I also do test every oil change or so while the oil drains.
im spiking at 25psi and dropping boost down to 20psi by the time i reach 7500 rpms. the car was tuned with the mods i have on my sig on 93oct and it ONLY MADE 340whp and 317wtq! 
could this be a good sign of a boost leak?? i feel that the numbers i got are extremely low for an evo 9 with stock turbo any advice and inputs will be highly appreciated. thanks in advanced
could this be a good sign of a boost leak?? i feel that the numbers i got are extremely low for an evo 9 with stock turbo any advice and inputs will be highly appreciated. thanks in advanced
excuse my language but how the hell are other guys making more power with less mods than me? ive seen up to 360whp 350wtq @25psi. compering these numbers to mine is a real eye opener. im sorry im just venting i just want the motor/car to be healthy and make the power it should.
And I saw 370whp on 93 octane using an EVO VIII turbo with 19psi at the hp peak, but with a different set of upgrades.
FWIW, your exhaust is the most effective upgrade you've made. Those others shouldn't deliver more than a few peanuts at your power level. Right now, you are potentially leaving 20-30whp on the table with the factory cams. And of course, the tuning is always a substantial variable.
Nevertheless, every turbo car on the street should be periodically checked for pressure leaks.
FWIW, your exhaust is the most effective upgrade you've made. Those others shouldn't deliver more than a few peanuts at your power level. Right now, you are potentially leaving 20-30whp on the table with the factory cams. And of course, the tuning is always a substantial variable.
Nevertheless, every turbo car on the street should be periodically checked for pressure leaks.
And I saw 370whp on 93 octane using an EVO VIII turbo with 19psi at the hp peak, but with a different set of upgrades.
FWIW, your exhaust is the most effective upgrade you've made. Those others shouldn't deliver more than a few peanuts at your power level. Right now, you are potentially leaving 20-30whp on the table with the factory cams. And of course, the tuning is always a substantial variable.
Nevertheless, every turbo car on the street should be periodically checked for pressure leaks.
FWIW, your exhaust is the most effective upgrade you've made. Those others shouldn't deliver more than a few peanuts at your power level. Right now, you are potentially leaving 20-30whp on the table with the factory cams. And of course, the tuning is always a substantial variable.
Nevertheless, every turbo car on the street should be periodically checked for pressure leaks.
