Blow Off Valves 101: What they do, and why you need them! Tech Tip Tuesday

Blow Off Valves (or BOV for short) are a topic we get a lot of questions about. They are actually very simple, and way easier to size than a wastegate. Simply put, you cannot OVER blow off valve a combo, you can't put too big of one on (that we have every been aware of, someone will prove us wrong with a 160mm bov on a 4 cylinder some day).
For our full list of Blow Off Valves click below. We stock and carry PTE Precision Turbo, JGS, & Turbosmart
www.motionraceworks.com/colle...
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[@Trialnerror]

I developed shaft play at an early age.

[@darrentylor5473]

Eww tmi

[@Parkway808]

Definitely suffering from premature shaft wear

[@LoneStarStinger]

😶

[@jamisonderek1607]

You probably dont care but if you guys are bored like me atm you can watch all the new movies and series on InstaFlixxer. I've been binge watching with my brother during the lockdown :)

[@tuckerlangston8528]

@Jamison Derek Definitely, been using instaflixxer for since november myself =)

[@tim6913]

Thank you, after watching mini different videos, you’re the only one that has mentioned anything about superchargers and how to regulate boost

[@bobby_hills_outdoors5227]

Great Informative video ! 👍

[@jonathan7744]

I agree that you need a BOV. But I feel like you only need the BOV near your throttle bodies. If you think about it closing the throttle creates a pressure wave starting there, if you have the BOV right there it kills the wave there. That means there should be no pressure build up in the intercooler or elsewhere. I may be wrong on this but it's what makes sense to me.

[@abundantcat7448]

noob

[@JWP1990]

Can you explain the spring pressures on bov’s?

[@mattsiev1]

Turbo Buicks never had them and plenty of stock turbos and even upgraded ones last 100k plus like that. It's an old argument but I agree they help in the right application. Larger ones need them more. I run a 6465 at 30+psi without one but that's still tiny compared to what y'all are doin'. You loose that signature turbo Buick sneeze when you go to a bov too. ;) Keep up the great videos! I love 'em.

[@davepalmer4125]

Have you done a video on plumbing the oiling system for a turbo?

[@JeLifeCoach]

This was awesome. Thank you so much. Could you do a video over BOV w/ cars that are MAP Sensored and not MAF sensored? I dont think there is any problem in a MAP sensored car w venting full to amtmosphere, but some people stay recirculating/atmosphere BOV on a MAP car will help will throttle response. I feel like it is being argued both way and Im not so sure. Thanks

[@jasperpipes4222]

2:00 Pulling boost into cylinders ? You should change from Tech Tuesday to Fabricated info Friday !

[@shawng7902]

still undecided on a blow-off valve for mine. Heard so many arguments both ways. This does sound reasonable though. What I don't like is it being open at idle. I watched a kid install one on his turbo mustang and they were all so pumped. Then I watched it as they drove. They put theirs right down at the intercooler. Driving around at normal speed with vacuum they had a 2" open valve right down at street level in the dirt. Then I heard that they spring them to engine vacuum. I thought that would keep it closed until boost overcomes the spring pressure. No here you say that they are open and floating back and forth at idle. So once again I'm lost and don't know what to do. I think I will still go ahead and run one at the TB just to save the intake and intercooler just in case.

[@jonathanmoore5112]

I’d like to see more information on how to select the correct blow off valve for your vehicle (-6,-8,-10)

[@adrianberryhill]

@3:01 My new Freedom Motion Raceworks hat has been a major contributor to this issue 🇺🇸

[@MotionRaceworksOfficial]

🤣🤣🤣🇺🇸🇺🇸🇺🇸

[@mcssmostwanted]

Some GTO love ❤❤❤❤

[@adamkelleyrealestate6976]

Looking for advice on tuning a single cylinder motor cycle with a blow in carburetor setup

[@UnknownDevice.]

Can you explain the purpose of soft & hard on a blow off valve.

[@ImTheBOSSRoundHere]

Well my boost gauge goes down when I slam the throttle shut as you also unload the turbine wheel. Ill take my chances for that sound thoooo. 1700 miles currently with no bov but granted I'm not running a 1000+ dollar turbo

[@roscoadventures2194]

Hi Doug got question I hooked up Yamaha blow up valve V2 works I'm confident I did it right hooked vacuum line to map senser do U no why my blow up valve will not open and close at all brand new in box can I ajust aleen key and screw nut on top maybe?

[@freddyrosenberg9288]

5:15 And that's how you know the blow off valve is not adjusted to suit the engine. A properly adjusted working blow off valve is shut at idle and it should take very little force to open it.

[@BOSS-jf7on]

Would you explain how and why of springs , CO2. Also the strategies of their use. Thanks for sharing!

[@BOSS-jf7on]

Ok, I got it. I watched it again.

[@tammypapa1]

What size would you need for a 80mm turbo on a sbc . New build

[@1moderntalking1]

Can u please do a video on superchargers and blow off valves? On say 9 to 12psi boost , would I still need that?

[@NoferTrunions]

Yes, maybe be completely different strategy since supercharger is always 100% connected to crankshaft, not like turbo with turbine waste gate.

[@jonathanmoore5112]

Should the bov be closed at idle?

[@snuggleseal]

Might sound like a dumb question, but I want a BOV that is loud, is there one that is the loudest? I am looking at the PRECISION TURBO PB64MM but the price is almost double others like the TurboSmart or HKS BOVs and I dont know why it costs so much more... :-\ thx!

[@LoneStarStinger]

Don’t get a trumpet 🎺 with your BOV... imo those are trying to hard.

[@pigspleen]

I have my bov vacuum line t'd into my turbo to waste gate vacuum line. Should I tie the bov vacuum line into the intake manifold instead?

[@MotionRaceworksOfficial]

Yes sir separate them

[@attzelonvenus]

if the car has 900-1000 hp is it okay to put on a low budget blow off valve ?

[@chriscastillo3851]

What's the deal with the side ports on the pte 64mm bov any one know?!

[@tomscobra2003]

Would two pt65 mm bov be overkill on a 1300hp turbo car

[@MotionRaceworksOfficial]

Never hurts to have to much BOV but you could definitely get away with 2 50s.

[@freshweezyboy1733]

Lemme do this to my truck lol. Probably void the warranty tho

[@halozeus3844]

Do not watch at family event uncles wanted to know about shaft play

[@dennisbanks706]

The 11 people that disliked the video have no idea what you're talking about lol.

[@FryGuy65]

But, but, that flutter noise...

[@terrywilson581]

👍👍👍👍👍🎄🎄🎄🎄😎

[@MarcTavX]

WASTEGATES OR BLOW OFF VALVES U SAY THE WRONG THINGS AND FIX YOUR BRACES OR DONT DO SPEAKING ROLES