I'm with Kosij, not a chance it spins backwards that's serious momentum chaguing and it would definitely damage a turbo. Think about what the air is doing, your pushing whatever boost ( say 10psi ) through the induction system. A BOV releases this remaining pressurised air when the throttle is snapped shut, via a tube back into your air intake. that's why it is called recirculating.

When no BOV is present, There is no where for the air to escape when the throttle is shut. So where does it go? back through the only opening, the turbo. Because this turbo is still spinning at X RPM, as the air passes back through it and out the air filter until it reaches atmospheric pressure, you get the tu tu tu tu sound.

Does it damage the turbo? dont know, im not a turbo and I cant talk to it to ask him. But theory suggests it puts extra force on the shaft and bearings. At 10psi? probably wont. At 40PSI throught a GT45 on a drag car? possibly, but its a drag car as if they care. I can garuntee youll be sick of it before it does any noticeable damage, I ran mine without a BOV for a couple months, put one back on now though I was sick of it.

Don't bring seriousness into this FFS!^^^^

gotta do something or people will start bringing up changing of diff bush!

on a less serious note, having flutter for cops is like wearing pants half way down your arse in jail, you have verrrryyyy limited time before your phuked

I love it. I get so much fan from dosing it past women, they wet themselves.

I find the best solution is stock BOV but 15 pounds. At light boost levels it is quietly vented. If I want flutter I can have it easily though just by boosting a bit and getting off throttle fast. I do this many times a day. Not too fast off throttle now as I did read that can cause timing chain to jump teeth. I do it at lower RPM the I did indeed have a skipped timing chain recently diagnosed.

Also my turbo is 100,000 km old and has had 15 PSI with my fluttering its entire life, still works.

my car flutters & there is NOTHING wrong with that setup.. I have an account with MTQ and I thought to myself why not ring and ask them if when you have a warranty claim when you fill out there paperwork does it ask IF YOU RUN A BOV OR NOT.. nope not a mention of it. So I dont see how its an issue having flutter when the people who sell the turbos dont even ask if you run a bov or not at any stage, if it doesnt concern them well it sure as hell doesnt concern me

reverse turbo spinning helps with braking too...

I love it. I get so much fan from dosing it past women, they wet themselves.

This guy haha

To make the car make that sound you can remove the vac hose that goes in front of the BOV, then block the hose off with a tight fitting bolt.

I'm not sure if the factory valve can still hold itself shut all the time without this vac hose on so another way to make the car make that sound is to put a rubber stopper in the hose that connects the valve to the Crossover pipe that runs across the engine head. Clark rubber has a perfect fitting rubber stopper to fit the hose

While it would cause more wear to the turbo, I don't think it would decrease the life that much noticeably as a lot of people do it and don't get sudden turbo failures, many cars come without a bypass valve from factory too.

Edited September 10, 201313 yr by Z2TT

Personal preference really, and the jury has been out on if it damages turbos since the 80's. I don't think the question will ever be answered.

One fact is though cops hear that flutter from kms away and they will leave murder scenes to get their defect books out all because the fact that you run a pod filter and intercooler together is a worse sin then being a murderer according to them.