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I just put a turbosmart bov type2 on my r32 and was shocked with the results

first of all the car DOES NOT stall while driving, the only time it stalls is when 2nd gear is revved out and i put it back into neutral n let the car roll the revs just die n the car stalls but i have tried this with every other gear and it is fine, have no idea why this happens

car runs alot better, pulls harder

the car is drinkin alot more fuel (maybe coz i've been goin sick)

and it sounds good

overall was worth it

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Hi guys, let me get this right, there is a line of thought that says you don't need a BOV at all?

Or is it that the standard BOV is better recirculating rather than venting to atmosphere?

Or is it that an aftermarket BOV offers nothing over the standard BOV?

So let's investigate...

No BOV = stalling the turbo is OK? I don't think so.

Recirculating BOV = all that hot air going around and back through the turbo again to get even hotter. Doesn't affect the performance, I don't think so.

No matter how big a turbo you put on, the standard BOV is always big enough to vent all the air fast enough to prevent the turbo stalling. Once again, I don't think so.

Anyone who has driven a car without a BOV will know that there is a noticeable delay before the turbo regathers the 70,000 or so rpm it looses on gear changes. In a circuit race car with 20 or so gear changes per lap that is enough to loose a race by a lot. Even the three or so gearchanges down the 1/4 will have a noticeable affect on the time.

So next time someone tells you a BOV is not a performance device, you can say .......................

Guest INASNT
Originally posted by Sydneykid

Hi guys, let me get this right, there is a line of thought that says you don't need a BOV at all?

Or is it that the standard BOV is better recirculating rather than venting to atmosphere?

Or is it that an aftermarket BOV offers nothing over the standard BOV?

So let's investigate...

No BOV = stalling the turbo is OK?  I don't think so.

Recirculating BOV = all that hot air going around and back through the turbo again to get even hotter.  Doesn't affect the performance, I don't think so.

No matter how big a turbo you put on, the standard BOV is always big enough to vent all the air fast enough to prevent the turbo stalling.  Once again, I don't think so.

Anyone who has driven a car without a BOV will know that there is a noticeable delay before the turbo regathers the 70,000 or so rpm it looses on gear changes.  In a circuit race car with 20 or so gear changes per lap that is enough to loose a race by a lot.  Even the three or so gearchanges down the 1/4 will have a noticeable affect on the time.

So next time someone tells you a BOV is not a performance device, you can say .......................

so after all that u r saying its a performance enhancement??

I would rather have minimal semi hot air recirculating rather than none at all! I had a blitz supersonic and it sucked balls

Old BOVs, as all things old age and CAN start to leak. I was always happy running std BOV, but recently installed an Apexi for the following reasons.

1. Car was starting to run a little doughy and didnt boost as hard as it used to.. .was it me getting use to hp, mech prob such as plugs or was the BOV leaking?

So i blanked off where it circulates back to behind filter, and tapped in a pressure gauge, (cheapy from work) and went for a drive, the valve was definitley leaking as the gauge was reading a pressure as i gassed it gear after gear.

2. For track days wanted to see if there was any truth to intermittent rich mixture cooling piston crowns, and may delay onset of water/engine temp probs at track.

3. As Sydneykid said, air being vented back to inlet tract has already been compressed (heated) once and despite intercooler will never be as cool as ambient air. My car pings so in additon with point 2, cooler air & cooler piston crown, well wont stop pinging but every little bit helps

... with some playing under the bonnet, starting with softest spring setting, kept tightening the pre-load screw until car no longer stalls...

As for performance gain, if the original (or an old BOV) is leaking then it will be costing you power, funny how 1 year ago everyone was saying BOVs are the go, these days everyone is sworn off them! Cycles i suppose.

Guest INASNT
Originally posted by Sydneykid

Hi INASNT, me, I'd rather have no hot air recirculation.  Remembering that every 8 degrees is worth 5% in horsepower.  We find it worth the effort to tune out the problems.

Each to his own.

how do u tune out the stalling problem with atmo venting blow of valves when u r running around 450-500hp?

Hi INASNT, you asked "how do u tune out the stalling problem with atmo venting blow of valves when u r running around 450-500hp?"

Horsepower is pretty irrelevant really, the tuning methodology is the same regardless. I will assume that you know the causes of the stalling and move straight to resolution. If the following doesn't make sense, just ask and I will try to fill in any blanks.....

When you snap off the throttle the TPS reads 0%, the engine RPM is way above idle and excess fuel is delivered because of the AFM reading. It is also most likely running on a TPS vs rpm driven ignition advance (depending on the ECU) . What we do is lean out the mixture at those points on the fuel map and advance the ignition timing. We resume normal parameters at slightly above idle rpm (say 1400 rpm). You may have to fiddle with the exact fuel and ignition values until you eliminate the problem. It is sometime necessary to raise the idle RPM, 100 to 150 rpm seems to work OK.

We also find it helps if the lambda sensor is in good condition, a dirty one slows down the response and exacerbates the problem.

Hope that helps.

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