I had an hks drop in filter, used to boost 21 and hold it mostly all the way to redline( or atleast I believe I usually dont pay attention). Installed K&N drop in today, now it spikes 21 and drops down to about 19/20 in higher rpms. Sound right? Sounds weird if you ask me.

 

do you have a mbc. Sounds like you need a good mbc. or if you have one it sounds like you need to buy a better one. Boost can differ from alot of things. You just need to controll it. By the way i have a mbc for sale if you want to stop all that

 

Nah I got a hallman pro.

 

Ok just got to work. In 3rd gear, its holding 21 to about 4k-4300 rpms, and then its tapers to about 18/19. Last week it was holding 21 to redline. I dont see how an air filter can do that. Anyone else think my stock bypass valve is taking a crap? my mods are full tbe, hallman boost controller, afcII tuned for mods.

 

Has the weather gotten warmer on you also?
I have trouble holding 20.5 now that the weather is warmer.
My Greddy e-01 is pegging at 19.8 now that the weather has warmed up here in Michigan. I will probably crank up the numbers to achieve 20.5 again.

 

I set the controller 2 weeks ago when it was in the 70's. Yesterday it was in the 60's, doing same thing. Today its in the 70's also and its doing the same thing, so im pretty sure its not weather related.

 

ANyone else ?

 

you should not be having troubles holding boost with the hallman. Take it some where and have a boost leak test. Or just turn the boost up a hair and see if that helps. I would get some iradium spark plugs also. Not that its hurting you but its safer from detonation.

 

Why don't you put your old filter in and see if it changes back? That way you know for sure whether it's the filter or something else.