vac leak or boost leak?

[rwp096]

hey guys i own an rb20 s14 with some bolt ons,the other day i was doing some spirited driving and when i got past 10lbs of boost my bov started to shutter and open and close at a fast rate. I popped the hood and couldn't vissualy find any couplers loose, but i did notice my vac line going from my wastgate to my boost control that the heat shield had some how fallen further down the line and the line was right up aganist the turbo manifold. Would a leak in the vac line cause my bov to open and close really quickly like that?

[virus77]

is the same line tee'd off to the bov? Either way replace it and test it rather than posting on the forum lol. The wastegate line being disconnected is a recipe for disaster.

[rwp096]

yea it is connected to a t fitting to the boost controler and the line looks like has been burnt and more than likely is the problem

[virus77]

Sure is, replace and report back for debriefing.

[rwp096]

the night before me and my friend did some data logging with nistune with the old vac line on and got a boost spike to 26lbs on a run but nothing was damaged. so today we put the line on and fixed the boost spike issue but my bov still sometimes chutters when underload in 4th or th gear like on a hill when wotm, so what does this mean?

[rb25det250sx]

what kind of bov do you have? what do you pull for VAC? is your BOV crushed. and you might have crushed it during the boost spike. most stock BOVs are made to take no more than 14lbs. then crushing occurs, which is nothin bad. just makes your bov sound diff.

[rwp096]

hks ssqv and how can you tell its crushed? nad at idle i pull like 25 on vac i think
Modified by rwp096 at 8:02 AM 10/25/2009

[rb25det250sx]

oh..not sure about those bovs. i figured mayb you still had a stock one. lol

but 25 is a little much i would think. most people pull 18-20.

[rwp096]

so should i test to see if the bov is the problem by unplugging the vac line and going wotm and seeing if the car still shutters? and does the ssqv need to be lubed