Help Boost Leak

[Ginglingston11]

hey guys, my friends got a gst with like the minor upgrades(intake, boost contoller)
so he had a used turboxs boost contoller in and he would spike at 15 and creep down to about 10. i asked him why he had a boost controller even in there if he had a t25. he told me that they boost at 10 and i laughed. my stock t25 was boosting at 16 w/o a boost controller, now everyday driving im at 22. i think he has a 14b in there and doesnt even know it. his wastegate is right on top and mines on the bottom. so anyways we thought it was possibly his boost controller and we went to my house and grabbed mine and swapped em. same thing now but mines set at 22 so it spiked at 22 and it droppped immediately to 15 and started creeping to 10. can someone tell me what you think it is? thanks

 

[1993eclipseGS]

Do you know what you're talking about? Not trying to sound rude or anything. Why do you have your boost set at 22psi when you don't have basically any supporting mods, Even worse, You're doing it on a stock t25(According to your profile.)

Anyways, To answer your question.. Boost spike is when the boost level initially "spikes" up to higher than the preset boost setting, and then quickly settles back down to where it should be. As most people with turbos know, once the boost pressure in the intake starts to rise, the rate at which it rises quickly increases until the pressure is increasing at a phenomenal rate. This means that, if your boost is set at 12 psi, when it reaches that point it will be increasing so quickly that it will go higher than 12 psi and then drop back down once the boost control system can correct it, which is within a half second or so.

Some causes of spike are bad boost controllers (only ball-and spring type MBC's should be used, and only proven electronic boost controllers should be used), long boost source or wastegate activation hoses(You can try making your hoses shorter) and the lack of any boost controller at all. It's basicially an effect a t slow response time of the boost control system.

Good luck fixing the problem.

 

[doug]

Other factors to consider:

1) Stock 2G BOV: starts leaking boost anywhere over 12 or so.
2) T-25: Boost falls off at higher RPMs 'cuz it's so tiny.
3) 2G Upgrade Path: doesn't seem like you or your friend are familiar with it.