GhostSpooLrTK
20+ Year Contributor
- 521
- 0
- Sep 17, 2002
-
El Paso,
Texas
BOV Return / Dump Tube Reduction
There is a tube which extends deep into the turbo intake after the MAS which blocks a significant portion of the turbo's inlet. This is the Blow Off Valve (BOV) dump tube. This tube carries the air purged by the BOV during shifting back into the turbo. The problem however, is that it blocks off so much of the intake that it posses a serious restriction to an already intake limited engine. The fix is the cut or replace this tube with something shorter to open the intake a little more.
There have been some theories about the utility of this tube. A few people have suggested that it is located where it is to use the out rushing air to help keep the turbo spooled (like blowing into a pin wheel). Though this has some merit theoretically, I haven't noticed any reduction in boost response between shifts, nor has anyone else. Further more, the improved flow of the intake from removing this restriction seems to have helped hold boost at the higher RPMs and appears to have even helped throttle response. The theory for that being that the improved flow helps the turbo suck in air easier.
There haven't been any definitive (read: time / dyno tests) but the theoretical negatives have not been observed just like there is no hard proof of the benefits. However, there is one effect which I have personally noted, and is the basis for my theory as to the tubes existence. Upon removal of the tube I noted a significant change in the BOV sound. Not really louder just deeper; less whistly. So my theory is simple: The tube is there, like many other seemingly silly designs, to reduce noise. Why you ask? Elementary my dear Watson, most people, like Mr. Jon Q. Public) don't appreciate or understand, and are afraid of the noises made by most turbo vehicles. Hell, one of my ex's even commented, "Wow I would be worried if my car made a noise like that," and no amount of explaining would convince her that it was OK. I bet you wonder why she is an ex.
Anyone ever done this? I tried looking it up in the FAQ/How Tos, but it wouldnt load, he says it will incearse throttle response, is that true? or anyone know where i can find a guide on doing this????
There is a tube which extends deep into the turbo intake after the MAS which blocks a significant portion of the turbo's inlet. This is the Blow Off Valve (BOV) dump tube. This tube carries the air purged by the BOV during shifting back into the turbo. The problem however, is that it blocks off so much of the intake that it posses a serious restriction to an already intake limited engine. The fix is the cut or replace this tube with something shorter to open the intake a little more.
There have been some theories about the utility of this tube. A few people have suggested that it is located where it is to use the out rushing air to help keep the turbo spooled (like blowing into a pin wheel). Though this has some merit theoretically, I haven't noticed any reduction in boost response between shifts, nor has anyone else. Further more, the improved flow of the intake from removing this restriction seems to have helped hold boost at the higher RPMs and appears to have even helped throttle response. The theory for that being that the improved flow helps the turbo suck in air easier.
There haven't been any definitive (read: time / dyno tests) but the theoretical negatives have not been observed just like there is no hard proof of the benefits. However, there is one effect which I have personally noted, and is the basis for my theory as to the tubes existence. Upon removal of the tube I noted a significant change in the BOV sound. Not really louder just deeper; less whistly. So my theory is simple: The tube is there, like many other seemingly silly designs, to reduce noise. Why you ask? Elementary my dear Watson, most people, like Mr. Jon Q. Public) don't appreciate or understand, and are afraid of the noises made by most turbo vehicles. Hell, one of my ex's even commented, "Wow I would be worried if my car made a noise like that," and no amount of explaining would convince her that it was OK. I bet you wonder why she is an ex.
Anyone ever done this? I tried looking it up in the FAQ/How Tos, but it wouldnt load, he says it will incearse throttle response, is that true? or anyone know where i can find a guide on doing this????
What?
