i bought a used blitz dd bov but it seems like its not working. any ideas what could be wrong? or what i should to make sure its working correctly. i hear a fluttering noise but i dunno what it is. what does a dumptube sound like?

 

thats compressor surge. is it doing that at WOT or when your cruising? its semi-normal to do that at part-throttle, but if it does that at full or almost full throttle that could kill your compressor. a dumptube just sounds like a jet taking off thats not what your hearing. ive never used a blitz dual-drive...does it have an adjustment screw like a GReddy Type S? if so it might be too tight.

 

it does have a screw. but i just had it tuned yesterday and my thing held boost at 10psi. oh yeah it flutters at partial throttle does that mean i need to tighten the nut more?

 

mine does the same thing....I have a dual sequential BOV...how much boost are u running...the lower the boost I think the harder it is for the BOV to release

 

what are u using for a vacuum source?

 

nvm it works. just had to loosen it more

 

if your using the high out put fitting...the large hole. that fitting just sounds like air, if you have loud exhaust or lots of engine noise you want hear it...unless your running 10 lbs or more. the low out put...the filter has a pop sound to it, but still if your racing you want realy hear it unless you have a quiet setup. to check if its working rev the engine and hold your hand around the filter...if air comes out it works, for the high out put fitting you can watch the valve open. as for the fluttering sound if your running low boost levels 10 and below you will hear the waste gate actuator flutter as it is bleeding of excess pressure...this is not compressor surge as stated earlier. compressor surge mainly takes place between shifts or feathering your accelartor at high rpms...besides that you would smell it. it smells kinda like rubber and oil burning. The fluttering is more apparent on low boost levels because the boost peaks earlier in the rpm band than lets say 15 and up psi which would peak closer to the redline. so you wouldnt hear the actuator fluttering since by the time it peaks your shifting.

 

nice explanation thanks!

 

awesome explanation

 

glad to help