From 13 to 18 PSI With a 1G BOV

[Chrisgys]

Hi I have a question for you guys. I have a Mitsubishi GSX 99 I removed the selonoid and I have a Injen hard pipe with an Apexi power intake filter and I hited 13-14 PSI with this setup on my aftermarket boost gauge. So the question I have is today I recived my 1G BOV i bought on e-bay and I intstalled this BOV and after i tried the car. Its not the same car. Its like a rocket and I hit 17-18 PSI but how can that be I only changed the BOV and I think 17-18 PSI is not good for the car with this setup right ? so please someone can help me. Thanks

[joemathews]

You removed your stock BCS solenoid aparently, and installed a better bov that will hold more pressure. Don't run more than 16 psi on the stock turbo, or you will be severly shortening the life of your turbo.

[kjewer1]

It is pretty common to see spikes to 16-17 psi after changing to a 1g BOV, but it should still settle down at set boost, and drop to 15 psi or less over 5500 rpm. This is all within the capacity of the 2g fuel system, and I would not be concerned about. The turbo also spins slow enough even at 17 psi becuase the rpm is low at the point it spikes.

Nothing to be worried about, unless that spike at peak torque causes some knock that lasts throughout the whole pull, or its trying to hold that 17 psi to redline.

[Chrisgys]

Thanks Yes it is only a spike like 1/2 seconden and after that its going down to 15-16 psi. So to be safe do I have to change my fuel pump or rewire it or can I leave it like this ?

[scottsee]

i turned my boost upto 18psi on my t-25 last year. but i never rev higher then 5000rpms, there just isnt any pull. on the other hand, if its destroying my turbocharger so be it. i welcome its replacement!

[kjewer1]

The stock fuel system can handle the spike, since RPM (and airflow) is low. But that doesnt mean it wont hurt performance. It usually doesnt.

[JoeWagon]

I had some adventures at 20+psi on the t25, and had it mostly spike to 19psi and settle at 16-17 for the life of it (14,000 miles). The turbo burns oil now and needs a rebuild if I can get the warranty people to pay for it. On another note, as I get close to fuel cut (over 18psi near 3k) the car will misfire. Maybe it's the heat, but it seems to happen when it's colder outside as well. I suspect something having to do with being close to the g/rev limit for the stock ECU to cut fuel. Who knows.

[Chrisgys]

Ok but i only changed the BOV to a 1Gen I never touched the boost and I have now 16 PSI with spike to 18 PSI and sometimes it stays at 18 PSI I would like to know why it goes to 16 or 18 because I never touched the boost I have no boost controller.

[sganc4life_4]

I would say because either you dont have a boost controller and you took out the solnoid or just because the fact that your plastic bov leaks at 14psi

[JoeWagon]

I thought we already mentioned this. You had a leak known as the stock 2g BOV. You fixed it, so you make more boost.