ok, my friends dad has a sandrail with a built v-dub motor in it. it is turbocharged, and he claims to have a "mercedes t3" turbo. he also said it has an internal blowoff valve and wastegate. i understand the wastegate, but how the hell can it have an internal bov? i checked his setup and there is no bov present, but it makes the sound between shifts. can someone explain?

 

The sound you can hear is compesser surge, it is where the pressure in the charge pipes is still there and the preesurized air goes back into the blades of the compresser making a chattering sound, This is BAD! for the turbo and this is why a BOV is important, it releases the pressure in the charge pipes and keeps the compresser surge away!

As for the internal BOV! I don't know!

Matt


Edited because i got PWN3D!

 

I have seen some turbos with some sort of "relief valve" on the compressor housing. I guess you could call it a blow off valve.
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Hes not fuul of ----.They did make t3s with relief valves built onto the compressor housing.I have seen manny of these on Volvos.I dont know if benz used anny of these turbos seeing that most there turbo cars are diesel.Ive never seen a bov on a diesel car.

 

There are no BOV's on diesels just for the fact that there is no throttle plate in a diesiel, so there is no chance of compressor surge. When you let off the 'gas' in a diesel, you are actually controlling the amount of fuel injected directly, as opposed to controlling the amount of air a gasonline engine injests. A BOV is not needed since there is no throttle plate to slam shut.

I have also seen the turbo's with built in bypass / blow off valves. They do exist, so he probably isn't full of ----.

Matt

 

"internal BOV"??

I think he's referring to the divertor valve. Same damn thing as a BOV but the air is being recirculated into the turbo intake plumbing instead of vented into the atmosphere.

Don't call it a BOV in front of him though. A VW enthusiast will ---- a brick if you utter the words "blow off valve"