Was reading this thread in the RX7 forum about the pro's and con's of not using a blow-off-valve. As far as I see, they make a pretty compelling case for not using one. I am currently not running one was was starting to get a little worried.

Any thoughts from here?

http://www.rx7club.com/showthread.php?t=884695

 

every stock car has a blow off valve to relieve pressure properly, so every turbo car should have one!

 

Wow, you're right! My Civic totally came with one stock!

 

He means to say every factory turbocharged has a BOV, so yes, there needs to be one.

OP, I'm going to let you go ahead and try and run without one for a while. Let's see how long that turbo lasts at higher pressures. This "poll" makes no sense.

 

if you asked bov or bypass valve, you may have received some different answers.

 

amazing how some people turn into an engineer overnite and decide to not use a device that 99% of OEM boosted cars have standard. That alone should be proof enough.

 

Overnight. But, did you actually read the link?

I, not at any point, claimed it was a good idea, was merely proposing the thought...

 

it was the link i was referring to.. not you in general

 

i run dual bov

 

I got a 50mm rs one. I run one because its needed.
It releases the pressure and stops the turbo from stalling.

 

Not true. The Neon SRT-4 has no stock BOV at all nor does the Caliber SRT-4 or the PT Cruiser GT Turbo, no diesel turbo vehicles run a BOV, no VW turbo cars run a stock BOV just to name off a few. Some turbo cars come with a BOV or bypass valve but some dont. Should you run one? Yes for the life of the turbo run a BOV. Only diesel motors dont need a BOV because there is no throttle plate so no chance for compressor surge.

 

Right on the diesel, and i havent really found oem turbo without bov or bypass. Some even build it into the compressor housing. And thought the pt has bypass

 

I don't get the poll part. Not necessary. If we're talking about the pros and cons or running without a BOV then the poll is useless. I run one because I'd rather be safe than sorry. But back in the day the turbo LeBaron didn't seem to have either BOV nor IC. I'm just an entry level turbo dude so what do I know?

 

Let's start a poll for whether or not this is the worst poll ever!

 

I feel like from friends and things I have read most of the time people trying to get away without running a BOV are trying to be cheep. They use the excuse of running under a certain pressure and it not being necessary, and who knows what else. Bottom line for me a BOV means less stress on the turbo and that's good in my book.

 

They are diverted valves that route back to the intake system. Different look same principle as a bov. Marcus McCallum was chief engineer for the SRT-4 and caliber projects back in 03. Yes they use a valve

 

I know of more than a few supra guys who run no bov - but they have anti surge housings on their turbo's... They swear by no bov.

 

Sorry man but you are just wrong.

The cars you mentioned ALL have bypass valves bolted to the compressor covers.

Also, more and more diesels are putting them on because they do indeed run into compressor surge.

 

the anti surge or inducer bleed groove is to stabalize the wheel at high rotational speeds. it does not release the pressure a BOV does.

for example. http://www.youtube.com/watch?v=9_DbyD3Px5s

no BOV. you can hear the surge even when let off at light throttle. and after the pull it dumps smoke out the compressor inlet.

 

^^Exactly...Anti-surge housings, don't protect from BOV compressor surge. It helps keep the wheel from overspinning past the surge point of rotational speed. Wrong kind of surge definition is used....

This thread needs to DIE already. But before it does... Enjoy

http://www.youtube.com/watch?v=Z_fG_...eature=related

 

just stating something i noticed... my friends 03 gti 1.8t didnt have a stock bov, we actually had to open a hole in his charge piping to put an hks one

 

Bypass=blowoff. Again. Same principle, same purpose, different name. Relax a bit.

 

it does have one. it's a plastic diverter valve. (bypass valve in vw terms)

 

I always thought it was people seeing pure race cars without them thinking they can do the same on the street and have long term success. Many purpose built race cars don't have them. Many of those cars run the turbos for a few miles and thats all it needs to do.

I will always use one as I don't see myself having limitless funds.

 

Perfect demonstration of why they are needed.
That turbo is getting its guts hammered at every lift.