One day the rest of the US may be like California but it is not yet. Even where full smog tests are required there is more than one way to skin a cat. I know of cars that could not pass a smog test sitting unstarted that are driven regularly on the street. It takes some innovation to get a inspection sticker and they must take action around roadside sniffers (shutdown and roll a couple hundred yards) but many manage. Here is Texas where radar traps seem to be legal they are too busy harassing the public writing moving violations to fool around with inspections right now.

 

Hey guys, I'm new just looking on. I just wanted to let you know that some people don't really know what a Blow-Off Vavle (BOV) really is. Stock cars that come with turbos (like my Eclipses) do NOT technically come with a BOV, they come with what is called a Compressor Bypass Valve. This stays legal because it vents back to intake, and techincally a BOV vents to ATMOSPHERE, which is illegal. You will know when a car vents to atmosphere, it is a sweet sound, but it's a LOUD PPFSSSSHHHHHHHHHHHHH gush of air, and if you are somewhere where a cop will know that sound, you'll be busted. A compressor bypass valve that can be vented back to intake (such as the Greddy Type-S, which can also be used as a BOV) makes a more quiet chirp sound. I personally don't think it sounds that bad, but there are people that just LOVE the BOV sound and don't want anything less. Anyway, there seemed to be some confusion on that topic. But regardless, unless the turbo kit is CARB approved it will techinically not be a legal street car anymore.

 

Unless you have a 'special' Eclipse turbo then it does have a BOV.

 

[QUOTE]Originally posted by Sparky
[B]

Uhh... Unless something has changed since I went to school, there are 50 states in the union....

 

That's the thing. It's not technically called a BOV, it's called a compressor bypass valve. Technically a BOV vents to atmosphere, which is illegal.

 

Everyplace that I looked said that a BOV is the same as a CBV. Either one can vent to atmosphere and either one can vent to the intake.

If you dump high pressure air to the intake (by definition your car can't use that air, since it is being dumped) , it will exit from the intake to the atmosphere, right?

 

Not true, some cannot vent into the atmosphere. At least they were not designed to. Take a look at the two most popular Greddy BOV's, the type R and the type S. One vents into the atmosphere, (or at least is capable of) and the other does not.

 

The BOV isn't the same as the CBV. The Greddy Type-S can do both, and some true BOVs cannot be routed back to intake. That TIAL BOV that comes with this kit I'm pretty sure can only vent to atmosphere. In my turbocharged cars, venting to atmosphere actually turns out to be detrimental. The stock air/fuel ratio sensors on the stock computer setup (Karman MAS) get real screwy when the cars vents to atmosphere, and you pretty much need a completely different setup like an HKS VPC to handle it (the car runs too rich between shifts mainly with the stock setup), that on top of the fact that venting back to intake keeps the turbo spooled up faster between shifts as all the air is shot back in. So basically without serious modifications of the stock computer setup on my cars you can't vent to atmosphere anyway. Due to the way the airflow works in a turbocharged car, if anything escapes back to atmosphere through the intake it's probably in a MUCH smaller amount than when the BOV spits all of the air into the atmosphere.

 

[QUOTE]Originally posted by Puckman
[B]The BOV isn't the same as the CBV.

 

Well, mainly I'm not arguing with that, I'm just showing how a TRUE BOV becomes illegal for street use. There are some BOVs that cannot my routed back to intake however, or at least aren't built with it's capability in mind. I was mainly just saying that the true BOV vents to atmosphere, and specifically the TIAL one in that kit, which would then techinically be illegal.

The problem with my car running to rich when the BOV vents is due to the Karman MAS on my car, this might only be specific to my car, however (in fact I think it might only be an issue on the 1G DSM). Basically, as I understand it, the ECU expects the air to be coming back into the engine leaning out the mixture, when you vent to atmosphere you stop this from happening, and the only way to run a correct mixture is to run a complete unit for controlling a/f like the VPC, which can control the mixture across the board (including between shifts, which is where this problem occurs). So, the ECU compensates the mixture by seeing the air that comes through the MAS, when you shoot the air out that is supposed to come back in and the ECU doesn't know about it, you run too rich without that air. If this is not a problem on your car, or other cars that get turbocharged, more power to you! I was just stating a reason why on my car I can't vent without buying a $1000 a/f control computer courtesy of HK$, and specifically with cars running the Karman MAS that I have. I have seen this in person though, my friend ran his Greddy Type-S vented for a VERY short while just to hear it and he fouled one of his plugs pretty bad. Whether or not this was the cause is one thing, but for sure it slowed down his car running that rich.

Ok, this is more of a rumor, I bet the effects of the turbo spooling faster vs the running rich problem I discussed above is negligible. But the air that is shot back into the intake does go into the pipe that conencts to the turbo. However, exhaust gases are what spool the turbo up, so who knows I would think that it's probably theory that the 15 PSI (or whatever you are running) of air being slammed into the intake has some effect on keeping the turbine wheel spinning, will it make a HUGE difference in your ETs? Doubtful, and definately not as major a difference as a rich condition in the cylinders.