turbo 240

[phatsx]

I have a 240sx with the nsport turbo kit.  The blow off valve that came with the kit returns to the engine.  I want a bov that will wake the neighbors up.  What can I do.

[nrcooled]

I'm not to good w/ the instalations of turbos but just run an external from blitz or HKS and bypass the internal.

BTW internal wastegates are much more reliable and I got sick of the sound real quick but its was still cool when you roll up on a civic <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=''>

[Jeff240sx]

Sorry. &nbsp;Here is more of that "Flaming for misposting" that you complained about in the Chat section.
I will not flame you, but ask you to read through the post before replying.
A Wastegate and BOV are not the same. &nbsp;A wastegate controls the boost pressure that the turbo CAN make. &nbsp;A blow off valve releases pent up pressure in the intake tubing during shifts or any other time the throttle body snaps shut... thereby saving your turbo.
As far as a noisy BOV. &nbsp;Boosteds14 said his recirculating BOV can be heard from 1/4 mile away. &nbsp;It is just the type of BOV that decides how much / what kind of noise it makes. &nbsp;Get a better aftermarket one. &nbsp;TurboXS (I think thats their name) has REALLY loud bovs, and a lot a Blitz are pretty loud too. &nbsp;You will lose power due to the engine bogging down, and you will quite possibly get a fireball out your exhaust if you go with a open atmosphere BOV.
-Jeff

[JSR]

A fireball!?!?! &nbsp;Thats cool! &nbsp;How does an open atmophere BOV work? &nbsp;And the loudest BOV i have heard is on my friends MR2 its a blitz one, can't remember the name... &nbsp;But that thing is LOUD! sounds like a semi when he rolls by and shifts. &nbsp;But please explain how to get a fireball when shifting. &nbsp;And does a fireball harm anything?

peaCe,
Jesse

[Jeff240sx]

Your exhaust is 600+ degrees. &nbsp;Think about that for a second.
And the MAF sensor, hereby known as MAF, tells the ecu how much air is comming in to the engine. The ecu dumps gas into the engine based on the airflow the maf measures. &nbsp;If you shift, the maf has already read the airflow and dumped the gas into the engine, but you are shifting, so the BOV is opening. &nbsp;This gets all the pre-measured air out of the tubing. &nbsp;Since there is no air there, and an excess of gas, only the gas that can be burned (very little) is burned, and the rest is shot down the exhaust pipe. &nbsp;Since the metal is 600+ degrees, it post-ignites the gas, which expands and sends a fireball out the tailpipe.
The harm this causes is little holes get created in your (expensive?) exhaust system. &nbsp;No Good. &nbsp;Also, your car will bog down due to the flooding of the cylinders.
-Jeff

[phatsx]

Thanks for all the help.

[9591]

BoostedS14 was apparently confused by the word "recirculating". Recirculating BOVs don't make any significant noise, unless they aren't set up to be recirculating, in which case they obviously aren't recirculating BOVs.

"Can you recirculate the word 'recirculate' one more time, please?"

Sure. A recirculating BOV returns the blown-off air back into the intake system, instead of directly into the atmosphere. While there might be some noise associated with this action, it surely wouldn't be audible over the noise of just about every other noise that an internal combustion engine in a road-driven vehicle makes. An atmospheric BOV, on the other hand ...

... will totally screw up the driveability of any engine not designed for one, unless appropriate changes are made to the system. If somebody thinks that such a BOV is a "better aftermarket one", then, well, more power to 'em.

[luey02]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Jeff240sx @ May 05 2002,11:17)</td></tr><tr><td id="QUOTE">Your exhaust is 600+ degrees. Think about that for a second.
And the MAF sensor, hereby known as MAF, tells the ecu how much air is comming in to the engine. The ecu dumps gas into the engine based on the airflow the maf measures. If you shift, the maf has already read the airflow and dumped the gas into the engine, but you are shifting, so the BOV is opening. This gets all the pre-measured air out of the tubing. Since there is no air there, and an excess of gas, only the gas that can be burned (very little) is burned, and the rest is shot down the exhaust pipe. Since the metal is 600+ degrees, it post-ignites the gas, which expands and sends a fireball out the tailpipe.
The harm this causes is little holes get created in your (expensive?) exhaust system. No Good. Also, your car will bog down due to the flooding of the cylinders.
-Jeff</td></tr></table><span id='postcolor'>
according to what you said, then wouldn't recirculation valve also cause fireballs? &nbsp;Since both bov's and rec. valve both relief the pressure? &nbsp;

Also are bov's loud all the time? &nbsp;or just during high rpm shifts where there's higher boost??

ya know

[s14boi]

also jeff... whether or not u have a blow-off valve venting the excess pressurized air, wouldn't u be closing the throttle plate and no air is getting thru anyways?
like when u shift, the MAF already read the airflow, but w/ the throttle plate closed, no air goes into the cylinder so there is still excess fuel?
i'm just asking coz ur explanation doesn't make sense... i've driven cars w/ blow-off valves and don't see this bogging that you mention.
and a blow-off valve doesn't let ALL of the air out of the intake tube, it jus relieves the excess pressure so it doesn't harm your turbo.

[sykikchimp]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (luey02 @ May 06 2002,12:47)</td></tr><tr><td id="QUOTE">according to what you said, then wouldn't recirculation valve also cause fireballs? Since both bov's and rec. valve both relief the pressure?

Also are bov's loud all the time? or just during high rpm shifts where there's higher boost??

ya know</td></tr></table><span id='postcolor'>
Recirculating will not cause a fireball b/c the same amount of air is going into the TB that the MAF measured. &nbsp;So the A/F ratio is still good.

BOV are only loud when they are releasing pressure. &nbsp;such as shiffting gears at high boost.

[sykikchimp]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (s14boi @ May 06 2002,12:59)</td></tr><tr><td id="QUOTE">also jeff... whether or not u have a blow-off valve venting the excess pressurized air, wouldn't u be closing the throttle plate and no air is getting thru anyways?
like when u shift, the MAF already read the airflow, but w/ the throttle plate closed, no air goes into the cylinder so there is still excess fuel?
i'm just asking coz ur explanation doesn't make sense... i've driven cars w/ blow-off valves and don't see this bogging that you mention.
and a blow-off valve doesn't let ALL of the air out of the intake tube, it jus relieves the excess pressure so it doesn't harm your turbo.</td></tr></table><span id='postcolor'>

useless info.. &nbsp;that has already been stated:
It is a Safety feature for your Turbo. When pressure is raised in the Intake, and you close the Throttle butterfly (let off gas) the charged air hits a wall, and has to go somewhere. Without a BOV it will go back through the turbo. Problem. Turbo is still spinning due to inertia in the direction to compress air. When the charged air bounces back, it slams the breaks on the compressor wheel, and can actually make it spin backwards. This is VERY hard on a turbo, and causes a LOT of lag b/w shifts. With the BOV, when pressure gets to a pre-specified point (specified by a spring, the same way as a wastegate) it will open a valve and release the excess pressure. Thus, allowing for the charged air to go somewhere besides the back thru the turbo.

Now, if you recirculate the carged air, into the non charged part of the intake (before turbo) and after the MAF, then the Volume of air in the intake will remain the same, and your A/F ratio's will still be in reasonable levels.

your question:
When Venting the air, you loose some of the Volume of Air that the MAF already sent the signal to the ECU for. How open the Butterfly is, does not affect the amount of fuel the injectors are going to pump. What the MAF reads does. It wouldn't bog when accelerating b/c your immediately re-opening the accelorator. Now if you are ppushing a lot of boost, and suddenly close the butterfly, say to stop at a red light, you have just created a very RICH situation, and could cause the engine to bog. You could adjust for this with an AFC.
Does that help?

-Charles

[Jeff240sx]

Gee, thanks Charles. &nbsp;You saved me a lot of typing.
And when did you start putting your name in the bottom of the post with a dash. &nbsp;I think I started all this.
Back to the quesiton at hand.
I wondered how boosteds14's recirculating BOV would make a lot of noise, and I just compared it to my intake. &nbsp;It is a hollow metal tube that will amplify and reverberate any noises inside it. &nbsp;Then it goes into another metal tube (air inlet tube) and shou be audible. &nbsp;Highly.
But, then again, this is my theory. &nbsp;If Boosted would like to come in here and defend himself against your onslaught.
-Jeff

[s14boi]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (sykikchimp @ May 05 2002,1:09)</td></tr><tr><td id="QUOTE">your question:
When Venting the air, you loose some of the Volume of Air that the MAF already sent the signal to the ECU for. How open the Butterfly is, does not affect the amount of fuel the injectors are going to pump. What the MAF reads does. It wouldn't bog when accelerating b/c your immediately re-opening the accelorator. Now if you are ppushing a lot of boost, and suddenly close the butterfly, say to stop at a red light, you have just created a very RICH situation, and could cause the engine to bog. You could adjust for this with an AFC.
Does that help?

-Charles</td></tr></table><span id='postcolor'>
yup helps alot, thanks for the info <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>

[phatsx]

Ok, so if I do want to use an open atmosphere bov, I should install either the apexi safc or the hks afr to correct the a/f. &nbsp;Is this correct?

Thanks

[Jeff240sx]

As I have had no experience in these electronics, I feel somewhat incompetant in answering this question. &nbsp;But I will try, none the less.
The S-AFC is, as far as I know, a computer that will adjust the mixtures of your fuel based on its own readings of the car, and is totally independant of your ecu. &nbsp;But it should override your ecu and tell it to do different things, rather than what it thinks is best.
That said, I think the afc will learn how your car runs and will react faster than the ecu and not dump excess gas in your car during shifts, if you set it up right. &nbsp;I won't even try to answer if you ask how to set it up.
If I mis-informed someone here, let me know!
-Jeff

[IceTekGuy]

if you don't want your car to bog down, and even out the exhaust pressure, so it does'nt blow flames get an APEXi AFC (air fuel controller)
its will remap your air flwo so that way it doesn't &nbsp;bog down and try to stall out from over flooding...

[sykikchimp]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Jeff240sx @ May 06 2002,1:58)</td></tr><tr><td id="QUOTE">Gee, thanks Charles. You saved me a lot of typing.
And when did you start putting your name in the bottom of the post with a dash. I think I started all this.</td></tr></table><span id='postcolor'>
actually, It's out of habit, thats how I sign my emails at work.. &nbsp; <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''>