BOV's

[R33-JET]

do u really need them

i got a r33 skyline

im making ova 200rwkw

will the original bov do the same job as say a greddy bov

and im talking about perfomance not pssht sounds

[inark]

u mean BOVs actually improve performance?

lol i was under the impression they were more of a "i wanna hear a psssht sound" mod

[R33-JET]

well if they are

anyone wanna buy a greddy bov

bcz im putting the stock one back in

not worth the hassle

first things dumb cops look for is bov

and i had enough of there crap

and if bov is just games and noises i rather the stock one

[2rismo]

what model and how much?

Cheers.

[XrSiSt]

R33-Jet, how much boost are you running.

[cynider]

With 12psi at the throttle my turbz was pushing 15 psi (Got 2 boost readings). Problem was the standard BOV was bleeding the boost. I'm now looking for a aftermarket BOV plumbback.

[R33-JET]

my turbo runs standard at 1bar and i sometimes run boost up to 25psi

aftermarket BOV plumbback.. that is like a turbosmart one that makes all the noises and is illegal

will putting the standard bov effect the performance of my car??

[rev210]

Originally posted by R33-JET

my turbo runs standard at 1bar and i sometimes run boost up to 25psi

aftermarket BOV plumbback.. that is like a turbosmart one that makes all the noises and is illegal

will putting the standard bov effect the performance of my car??

Shouldn't lose power if it doesn't leak boost , most don't, though at 25psi you might have to see.

I think turbosmart actually make a non-venting aftermarket BOV, try that if you have no joy with the stockie.

[R33-JET]

i rang epa today

and actually spoke to someone that didnt keep saying illegal illegal

and i found out that u can have any bov u want as long as its not open to the atsomphere

and i got some sort of hose that can be ran into the opening of the bov sitting next to the bov but was never connected

so i going to connect that

and it should be ok

[Guest Butters_99]

Hey,

I been wondering the same thing ......

Does a BOV increase performance in Any way ?

The only place it could is in the gear changes ..

But if your drag racing, dont you change gears quick enough to keep it on boost ?

Any one run a 1/4 with a BOV and then Without ?

[PranK]

A BOV gives no performance increases.

They are only for if you are running over 15-ish psi... your turbo will be fine with boost around 12ish with No BOV at all... but once you start running more than that, you are risking damage to the turbo from the pressure hitting the turb's..

hope this clears it up for you guys... altho, by reading over it... it probably confuses things more than clear them up.

Christian

[Guest | hype^ |]

i though not having a bov, not matter the boost, will stuff up the turbine coz the air coming back through it on shifts will make it spin the other way..

what iv been told anyway...

[TTT]

BOV thread yet again.

Lets make it simple.

If NISSAN decided that this car needed a BOV as standard then I guess that they would have done some reserach to back this up.

They would not have placed a BOV on your car if they didn't think that it needed it.

The standard BOV is fine unless it leaks.

My standard one on the R32 GTST does leak and therfore I have an aftermarket one that vents to atmosphere.

The crap thing about this BOV is that all the mixtures are wrong and the car feels like it will stall when coming to a halt.

But I have run the car with the standard BOV and the SARD one and with the SARD, boost comes on much quicker and stronger and holds better as the revs go up.

If you don't experience any (or very little) boost loss as the revs build up, then I wouldn't bother changing the standard BOV.

Also, I hear a lot of people that are installing aftermarket BOVs but also keeping the standard one on there and still in use.. This will be crap.

Unless you have put the new ATMO valve before the standard one, it won't even open cause the original valve is doing the job.

You can buy after market BOV's that are plumback. GFB (Go Fast Bits) and Turbo smart both make plumback ones.. These will be better than the stock on if you are running more than 15psi..

As for not needing a BOV unless you are boosting more than 12 psi or whatever, I would rather follow in the foot steps of the company that made my car (NISSAN) and have a BOV of some sort.

I hope this helps.

[Guest Butters_99]

Quote

-------------

If NISSAN decided that this car needed a BOV as standard then I guess that they would have done some reserach to back this up.

They would not have placed a BOV on your car if they didn't think that it needed it.

-------------

Amm actually dude i heard bovs were put in place to meet Emmison rules. Suggesting Nissan had no chioce to put them on. As far as I know all factory bovs are plumb back.

A lot of factory stuff is done for better emissions / economy.

Us performance types remove as much emmisions stuff as possible .... hehehe

Hence my question.

[Jay95R33]

I'm pretty sure that my standard BOV is leaking, although it doesn't really bother me that much.

Just accelerating slowly, the boost needle doesn't even get into 'boost' and I can hear the BOV open and start circulating air.

When I bought the car the standard BOV was blocked off, I think there was a after market one on there. Now whether is was blocked off cause it was leaking, or because they were running a another one, I don't really know.

Is there any other way of telling if your BOV is leaking?

When I had it off it was pretty easy to push in.

J

[Guest MaVeRiC]

just a lil info i picked up

The function of the blow-off valve is to vent the "excess" compressed air entering the throttle-body when the throttle plate closes. Consider the case of the car running with high boost in second gear. In order to shift to third, the driver lets off the accelerator, momentarily closing the throttle plate. All of the sudden, the compressed air from the turbo (which was rushing into the engine) has no place to go. Instead the air "bounces" off of the throttle-body plate and begins travelling backward through the intercooler and into the turbo. This "backpressure" causes the turbo to slow down and produce less boost during a shift. This backpressure not only reduces the boost level, it is also potentially dangerous to the turbo, and is referred to as compressor surge.

To avert this problem, vacuum opens the BOV (mounted in the upper intercooler pipe) when the throttle plate closes. This diverts the compressed, intercooled air back into the intake stream, and allows the turbo to continue to run normally "across" shifts.

[GTR-80Y]

All turbo cars have a BOV as standard for one reason......If they didn't there would be a loud noise being made from the back flow of air (the process maveric just mentioned). The standard plumb back system reduces this noise. Having a plumb back system will, in most cases, cause no noticable turbo lag or turbo damage. The turbo in most cases will slow by itself off throttle especially if it isn't ball bearing. I have yet to see someone prove a venting bov brings boost on earlier and reduces turbo lag. As for having an aftermarket bov positioned after the standard OEM bov, you will find that most people will have sealed up the factory bov.

I strongly recomend a book called 21st Century Performance by Julian Edgar (i think). He seems to know wat hes on about and has all the evidence in testing to back it up. Also it really relates to our type of cars, even has GTR's in it.

[TTT]

Just wanted to clarify one thing.

NOT all cars come with BOVs.

Mitsubishi Cordia

Holden Commodore VL turbo just to name 2, never came with standard BOVs.

There are others but I just can't remember at the moment.

[GTR-80Y]

Thats why the VL goes "woop woop woop" all the time. Sounds pretty cool actually.

[GOTRICE]

early liberty turbos do it 2