Will POP Sound Harm Engine?

[Peter_hii]

Hi, i just installed HKS BOV into my car and when release the clutch to 2nd and 3rd gear the 'POP' :Bang: sounds always coming out from my exhaust. Just want to ask someone have this kind of experience and how can i avoid it cause it is annoying sometime. thank you.

[Doctor]

To stop it either get rid of the atmo BOV or get a SAFC to lean of mixtures. All it will really do is foul your plugs a bit and stuff your cat over time.

[Tosh]

put the stock BOV back on your car and it'll fix it

[Peter_hii]

can you please explain more Doctor? what else can i avoid it? what you just mention is to purchase the SAFC and change the plug? is that what you mean?

[Doctor]

Sorry mate, allow me to explain.

You car has been tuned for a re-circulating BOV. When you have a BOV that vents to the atmosphere (opposite to your stock one) your car will run rich when you change gears and your exhaust/gases are hot enough to ignite the extra fuel that is not being used, hence the reason you will get a pop or explosion in your exhaust. There are two causes of this.

1. A BOV that is tighter than the stock one will usually makes the turbo flutter, which is called reversion. Reversion is where air bounces off the butterfly (throttle body) back through your piping and out of your airfilter past your AFM (Air flow meter) which cools the sensor and therefore making your fuel mixtures rich. This happens as the BOV is too tight to allow small boost pressures to make it open.

The other is

2. When the BOV opens to the atmosphere the ECU has already recorded this air passing through the AFM and thinks the engine has used this air when really it hasnt there for the fuel for this air has been added to the mixture but the air has escaped = rich condition.

A SAFC is a Super Air Flow Converter made by APEXi which taps into your AFM which enables you to alter the fuel maps at different RPM/Load levels.

Fouling your plugs means your spark plugs are coated with unburnt fuel and carbon which makes it harder to get a clean ignition spark.

Hopw that helps,

Ben

[R33vit]

What they are saying is. With a non standard BOV which vents to atmosphere your engine runs rich when you lift off the throttle. Replacing the standard BOV or fitting a BOV which recirculates back into the inlet will stop the popping/backfire

[Doctor]

And to answer your initial question "Will it harm your engine" the short answer is No.

[Doctor]

Yes you are correct.

[Peter_hii]

thank you for all.. it helps alot .. thnx .. guyz ..

[Zebbie]

This my seem like a silly question, but.........

I'm getting pops when i'm using the engine for braking, and I *know* it's running rich, as it's currently using a mines ECU.

(It's popping, mabee once or twice in 20-50km's of driving with roundabouts etc)

I'm seriously looking at changing to a PFC asap, with the retune - will it get rid of the pops etc?

TIA - Zeb

[B-Man]

I would have thought a mines ECU leaned out the inherant richness that Skylines display.

Has anything else been changed on your car ?

[Peter_hii]

Can the PFC avoid the sounds of "POP" sounds?

[R33vit]

I have a PFC and still get the occasional pop. Not as bad as with the stock ECU

[Guilty]

ummm when i had my stock BOV on, i actually had the "pop" sound from the exhaust occasionally, like not all the time. ONly when i rev harder, there would be the occasional pop. What does that mean? since i wasnt using a atmo bov

[pooski]

i have a SAFC and an atmosphere BOV and i still get the pop, it happens quite often, but i think its kind of cool. I also have a gutted cat, so when the air is cold and its dark you can see about a 30 burst of flame every now and then.... if it doesnt do any damage to the engine, i cant see any reason to change it

[Doctor]

ummm when i had my stock BOV on, i actually had the "pop" sound from the exhaust occasionally, like not all the time. ONly when i rev harder, there would be the occasional pop. What does that mean? since i wasnt using a atmo bov

It just means that your exhaust is hot enough to burn the unburnt fuel.

[Peter_hii]

everyone think the Sounds POP is cool .. but lets think another way, for example when the COP is behind of your vehicle and the pop sound coming out, wat will it happen next?

And one more question is that, will the POP sound come out with the flame?

[wilch]

My old car was a 1990 Honda Integra (non vtec) but with cams, exhaust, etc...(no bodykit, just lowered with big sticky rubber). It popped and crackled louder than any car I've ever driven. I owned that car for 7 years, drove it every day and not once did I get pulled over by the cops because it was popping and crakling on the overrun. I did get pulled over once for doing 70+km/h WOT around a really tight corner though. I was let off with a warning. The policeman said he heard me coming.

no defect.

If you drive stupid, and act like a smartarse you'll get done. Drive normally, and treat cops with respect and you'll be fine.

RE: "...will the pop sound come out with flame?"

If you get rid of your catalytic converter or gut it you'll get flames. The fine for having no cat though is $10,000 last I heard.

wil..

[smok74]

In my R33 series II '97, I have a 'Stealth' BOV from Go Fast Bits which has a plumb-back as well as a trumpet outlet, it has two type of settings, spring tension and outlet, it allows you to set the ratio between full dump to the plumb-back or trumpet and everything in between, so what I did was started with full trumpet and gradually tried settings (all 17 of them) until the 'pop' or backfire goes away, by doing this, you are allowing just enough air back into the inlet to stop the 'running rich' condition. Believe me, I paid AUS$550 for the Stealth with the extension trumpet and it's worth every cent ! ALSO, I got pulled over once and this cop tried to defect me for my BOV and I jarded him by turning it off !! now, how many BOV are there that lets you turn the sound off right there n then without having to pull the damn thing off?? I think Go Fast Bits now have a new version that just came out not that long ago that has a electric servo built into the BOV so that you can make the setting from inside the cockpit. Now Try that sucker !

[smok74]

Next to the Turbosmart EBoost, I think the Stealth is one of the better 'bits' that was ever invented for boosted cars