ok, guys... I now possess 2 forge motorsport BOV, 1 to the atmosphere and the other the recerculating...anyways could someone that really knows their evos in general explain one thing to me..
Its now afact that the atmospheric blow off valve causes idling and all other BS idle issues ( from running rich) but what I want to know if it actually does hurt the pistons and rings or any internal parts of any kind, short term or long term? I have the SAFC2 on my car and I set the knocking sensor and it shows it knocking between 10-25 at idle and 5-15 during shifts, what does that mean? is it bad? is it related to the BOV dumping excess fuel? or is it simply a missreading by the SAFC 2, I am tunning on Wednesday but I want to put my atmospherical one on for good cause lets face it the recirculating one sound like crap...but I need to know potential cause and effects...
thanks

 

i don't have idle issues

 

Why would you want to risk potential problems with your car for a sound? BOVs are not meant to sound good or "to get you laid" as another one said. You really should do what is best for the car and not worry about the sound. I would stick with the recirculating.

 

believe me the sound is well worth it

 

LOL...well I would have to disagree. If anything you put on your car is causing it to idle rough, there is a 99.9% chance it is BAD for the car to continue in that state. It's your car so do as you wish but you should always put longevity and reliability before sound. Just my .02

 

once again that is a matter of opinion but I really need an expert opinion on this as far as damage to internals and such

 

Advan,

VTA BOV should not affect idle since at I dle the car would not know if it had a VTA or recirc. The SAFC2 has a setting to help adjust for the rich conditions between shifts. The knock sensor is not really a useful tool on the SAFC2 (This taken from many posts on the feature by tuners). As far as internals, you are in control of the fate for those, not an VTA BOV. FYI, there are probably 10,000 people out ther with VTA BOV running fine on various different makes and models.

 

ok, mrdecible...
FYI, the car does know since it thinks the air is going back in the intake, it therefore compensates by giving it enough fuel making it run rich every time the VTA bov opens... So u see it does technically affect
your idle but what I am asking I guess are 2 things...What is that knock sensor and would someone explain it to me? but also when the car is dumping so much raw fuel without it being nessessary into the motor, wont that eventually fry the rings?

 

Answer to your first question: Octane is not a measure of the amount of energy in gasoline - rather, it is a measure of how well the fuel resists preignition, also known as detonation or 'knock'. Detonation is very hard on the engine, and must be avoided. The DSM cars incorporate a knock sensor specifically for the purpose of detecting knock. Higher-octane gasoline resists knock better than lower octane gasoline.

During normal operation, the engine control unit (ECU) adjusts the engine timing as far forward as it will go. This provides maximum power, but also increases the possibility of knock. This is especially true for turbocharged or supercharged engines, such as the 2.0L turbo 4-cylinder found in the upper model DSMs. Note that the ECU hears knock all the time - the problem has to be persistent to generate a reaction from the computer.

If the ECU detects excessive, continuous knock via the knock sensor, the engine timing is retarded until the knock goes away. This results in a power loss, but saves the engine from damage. So, if you fill up with 87 octane gas, your ECU will be forced to retard the timing quite a bit, and you will not get the rated power from the engine. Not only that, but the ECU may also be forced to limit turbo boost levels to accommodate the lesser quality gasoline, which again means a significant power loss.

Answer to your second question: I doubt you have an issue to worry about. As I said in my post earlier, there are thousands of people running VTA with no "Fried Rings, Chicken or even Egg Plant. And I said before if you are worried, tune around it, you have the tools there.

Also, the blow off valve has no need to open while idling. Hope this helps.

 

now thats a much better and more understanding explanation, thanks mr decibel but one final ? for U ....
if the engine always detects knock then will I be able to tell in the way the car reacts if I am knocking too hard?

 

You have to identify what normal noise is and anything higher is knock. The SAFC2 has the ability to learn regular noise

 

yes if you have serious knock you will definatly know it. it sounds like rapid gunfire coming out of your exhaust and you loose all power pretty much.

just to add a few statements. having a VTA BOV will of couse as we all know already make you run a little rich when the air is released(unless your car is set up perfectly or you have a MAP sensor instead of a MAF sensor) the problems this will cause is your spark plugs might foul quicker and you might build up some extra carbon deposits in the long run. nothing serious should happen though.

StriktlyBidness..with your idle comment...adding some 272 cams will greatly affect your idle...but there is nothing bad about using them.

umm..in general actually the more power you make the shorter life your engine will have basically. thats a general statement tho...i kno someone will have a stupid comment to say about that.

 

i wasn't aware of any vta bovs opening during idle? unless u rev up the engine during idle.. only time ur bov opens is when u shift or let off the gas pedal.

kent