Jump to content
SAU Community

BOV position

mattysaidso

By mattysaidso,
in Engines & Forced Induction

 Share

Recommended Posts

  • Replies 93
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

R33vit Experienced

R33vit

Posted
Posted

Roy is correct.

A Pop off valve is fitted by the governing body in motor sports and is compulsory, where a BOV valve is not.

Two totally different operations.

POV's are to stop race teams running more than a pre-set amount of boost as defined by the governing body.

A BOV is fitted to help reduce turbo spool up time after a throttle close.

pnblight Mentor

pnblight

Posted
Posted

yes i know and they are all bov and proform the same task .whether a car use a vacuvm operated or spring set pressure unit. I personal know of no performance car that didnt run one or the other the WINFIELD GTR ran at 1.5bar bov and FORLUMA 1 IN 1988 were resisted to 2.3bar from memory they blow off valve service the same role as the vacuvm operate and you would gain no advanage to run both thats why you dont see this style on some race car but so say races dont use bov could be a bigger crock of shit

R33vit Experienced

R33vit

Posted
Posted

A POV will not vent on throttle liftoff. A BOV will.

They’re not the same thing.

As for racecars not using BOV may be correct. If you think about it, a champ car uses SWOL (Shift With Out Lift) so a BOV is not really needed here, but if the driver tries to turn up the boost to far in a race the POV will stop him exceeding the regulation limits.

As for a road car with the constant lifting of the throttle in everyday driving conditions a BOV will assist in a quicker spool up of the turbo.

doridori32 Rising Star

doridori32

Posted
Posted
A POV will not vent on throttle liftoff. A BOV will.  

They’re not the same thing.

As for racecars not using BOV may be correct. If you think about it, a champ car uses SWOL (Shift With Out Lift) so a BOV is not really needed here, but if the driver tries to turn up the boost to far in a race the POV will stop him exceeding the regulation limits.

As for a road car with the constant lifting of the throttle in everyday driving conditions a BOV will assist in a quicker spool up of the turbo.

It will not give you faster throttle response(boost response)in between gears... if it does on your car then your car is setup very shocking.

Doesnt help me spool up quicker in between shifts.. your wrong .. show me some proof it does.

pnblight Mentor

pnblight

Posted
Posted
A POV will not vent on throttle liftoff. A BOV will.  

They’re not the same thing.

As for racecars not using BOV may be correct. If you think about it, a champ car uses SWOL (Shift With Out Lift) so a BOV is not really needed here, but if the driver tries to turn up the boost to far in a race the POV will stop him exceeding the regulation limits.

As for a road car with the constant lifting of the throttle in everyday driving conditions a BOV will assist in a quicker spool up of the turbo.

i didnt say they were the same thing but they perform the same task and champ had blow off valve not pop off valve i can quote published documentation but for any interested parties have a read off FORCED INDUCTION PERFORMANCE TUNING by Graham Bell .This guy is a legend and has lived and breathed race all his life and it is well worth the read.

And someone tell me how a bov is for emissions is has no benefits for emission at all

R33vit Experienced

R33vit

Posted
Posted
i didnt say they were the same thing but they perform the same task and champ had blow off valve not pop off valve i can quote published documentation but for any interested parties have a read off FORCED INDUCTION PERFORMANCE TUNING by Graham Bell .This guy is a legend and has lived and breathed race all his life and it is well worth the read.

And someone tell me how a bov is for emissions is has no benefits for emission at all

I will give it a read, thanX for that.

As for now Im off to bed

Sydneykid Grand Master

Sydneykid

Posted
Posted
Sydneykid i would like to tell you your wrong.... very very wrong.

My Engineer told me to tell you that you don't know nothing and suck balls.

If you want his email let me know!

Im not being a smart ass but just giving you some real fact's. Stating BOV"s are useless pieces of shit.

HANG ON, have you got the posters wrong? All of my cars, race and road have BOV's?

Imagine your average joe driving this brand new series 6 RX-7 off the factory floor with the flutter noise every gear change. He would be straight back to the Mazda dealership asking if he has piston slip or has done a head gasket. Laughing

Just in case you are picking on the right poster, since when have rotary engines had pistons or heads? Headgasket? What's a "slip"?

:cheers:

Oosh Veteran

Oosh

Posted
Posted

I've read bits and pieces of Graham Bells FIPT, this isn't exactly on topic (and could start another sh!t fight), and i seem to remember it mentioning a race team who set their engines up to run no wastegates and instead use pop-off valves to regulate boost...

...i guess my point is (if i have one): just because race team X swears by method Y, it might'd be the greatest thing out there, and it sure as hell doesn't mean it translates well to the street.

Porsche make some awesome machines but you can't hold up what they do (or did years ago) and preach it to be gospel.

I think it's safe to say F1 is the pinnacle of N/A engine development and if only they'd bring back the turbos we could add those teams to the discussion. Which leaves WRC and Indy at the top of the current Turbo field (shame there's no more Pikes Peak or Group N) so i'd be interested to hear what those RACE teams run BOV-wise. Please, and i'm sure someone will, correct me if there are higher level race categories out there... we've already discussed LeMans 24Hr and to be fair that's a single race not a category IMHO.

Edit: Shows how much i follow Indy, looks like they run N/A V8's now, when did that happen?

doridori32 Rising Star

doridori32

Posted
Posted
I've read bits and pieces of Graham Bells FIPT, this isn't exactly on topic (and could start another sh!t fight), and i seem to remember it mentioning a race team who set their engines up to run no wastegates and instead use pop-off valves to regulate boost...

...i guess my point is (if i have one): just because race team X swears by method Y, it might'd be the greatest thing out there, and it sure as hell doesn't mean it translates well to the street.

Porsche make some awesome machines but you can't hold up what they do (or did years ago) and preach it to be gospel.  

I think it's safe to say F1 is the pinnacle of N/A engine development and if only they'd bring back the turbos we could add those teams to the discussion. Which  leaves WRC and Indy at the top of the current Turbo field (shame there's no more Pikes Peak or Group N) so i'd be interested to hear what those RACE teams run BOV-wise. Please, and i'm sure someone will, correct me if there are higher level race categories out there... we've already discussed LeMans 24Hr and to be fair that's a single race not a category IMHO.

Edit: Shows how much i follow Indy, looks like they run N/A V8's now, when did that happen?

F1 car's didnt have BOV's. Because they dont help your car in ANY WAY. Not even throttle off and on boost repsonse, and especially not turbo life.

WRC's car's dont run BOV's they run pop-off valves, just to regulate them in boost.. nothing else.

BOV"s are JIBBERISH!

doridori32 Rising Star

doridori32

Posted
Posted
point of thread: doridori32 doesnt like BOVs, so neither should you

Thread close

No, many people dont use BOV. Spend the money on something that is going to give you performance for your dollar.

with the 500$ or so you spend on a BOV you could buy yourself sticky tyre's or something else!!

Oosh Veteran

Oosh

Posted
Posted
F1 car's didnt have BOV's. Because they dont help your car in ANY WAY. Not even throttle off and on boost repsonse, and especially not turbo life.

WRC's car's dont run BOV's they run pop-off valves, just to regulate them in boost.. nothing else.

I've done a fair bit of searching on WRC cars and found very little info. on their engines, care to point me in the direction of some info. sources to back your claims?

Roy Grand Master

Roy

Posted
Posted

I have some articles on rally cars, they never mention specifics of ancillaries though...manily drivetrain and aero changes etc etc. Plenty of pics of engines though, and i have found it tough to find what may look lik e a BOV...i know the Grp N rally cars do.

LOL...someone will freak when i install a 2nd BOV on my car:)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • MBS206
      Starting again

      By MBS206 · Posted

      The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
    • MBS206
      What brakes on R34 GTT(Europe)

      By MBS206 · Posted

      Just like in being 14mm too small (296mm) makes it not fit, being 14mm too big (324mm) it also won't fit. You want to find the correct rotor.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      @GTSBoy Ok so that was the shops problem...they showed R33 rotors on R34 page and i did not know 296 do not fit(and are for R33) Yes i bought "kit" with rotors and pads. Pads are ok(i have GTT calipers front and rear). They have some 324mm but no 310mm. So i dont know if they would fit. I have 17inch LMGT4s So another question. Can i fit those in the rear or they are just "too" big for that?
×
×
  • Create New...