Boost Valve Trick Pros & Cons?

[Brutal04]

So I did the vac line switch-a-roo thats on the RPM website. What are the pros (if any) & cons?

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[Wiked03]

I have been wondering this for a long time.

Never really heard any concrete info for it or against it.

Maybe someone on here can explain it for us?

 

[ILLINI-SVT]

It has no known-of cons. In an over-boost situation, which on stock vehicles could be caused by quickly revving up to the redline (read - when doing a burnout), the PCM senses boost exceeding the 8 stock psi, and sends the command to open the boost dump valve, which stays open until the vehicle is restarted. Rerouting the vacuum lines as rpmoutlet lays out disables the physical mechanism for opening the valve. The same result can be obtained by your tuner on your chip/flashtuner by turning off the function in the PCM. In fact if you're running a pulley it has to be disabled or you'll never hit full boost.

Hope this helps.

 

[Brutal04]

Thanks ILLINI-SVT.. :biggthump

 

[Wiked03]

Yeah, thanks Kevin.

I will probably give a try this weekend at MSC.

 

[Racerx66]

So I did the vac line switch-a-roo thats on the RPM website. What are the pros (if any) & cons?

I did it a couple of weeks ago and can honestly say no cons so far. My testing method was unscientific (doing blasts down Linconln Ave.) but you can tell the difference, especially if your not always speed shifting. I think it's a helpful and obviously free :biggthump mod.

 

[ILLINI-SVT]

I guess there is theoretically a con. Ford is assuming that putting more than 8 psi of boost is damaging to your engine. So to that effect, I guess it ha(d) a purpose?????

I did it before I went to the track, so as not to look like an idiot running the strip with no boost after a burnout. In Lightnings, I was always led to believe that it's only function was to fully dump boost if you exceeded a certain point. Then you had no boost unless you restarted the engine. Lately I've heard that it's also used to bleed off excess boost beyond the 8 psi while at WOT (the boost normally increases with throttle). I never really noticed that part of it before I did it, although now I've seen stock boost levels climb as high as 10 in really cold weather. So maybe someone without the mod can tell us if they notice it bleeding boost toward the upper portion of the rpm range.