For all u SC maxima owners!

Is it possible to put a BOV ( blow off valve) in a Stillen SC Maxima ?? Does it matter if the car is manual or Auto?? Is it better than the wastegate the kit comes with ? Or are BOV's supposed to be just for Turbocharged cars?? I have a 2000 SC MAX and I was wondering if that was even possible cuz if I can put one on, I'll do it cuz I like that PSSHHHHH sound that Turbocharged cars have. If any one can help me out here, it'll be greatly appreciated!! Thanx in advance!!

 

Some of the SC Maxima owners here have a BOV. Y2KevSE convinced me I should get one. It's been sitting on my desk for about a month now, no time to get it installed yet. It doesn't matter if you're auto or manual. The Stillen SC uses a Bosch recirculation valve to cycle the boosted air back to the intake pipe. The BOV replaces that to release the boost out of the system. As far as I can tell, since the SC doesn't make that much boost, a BOV is kind of useless. But... I often gun it from the light, then let off quickly if the other guy isn't racing, or sometimes I will boost to close the gap between me and the car in front of me, but as soon as I get close, I have to let up on the accelerator, in effect, producing more boost than the system needs. I'm guessing the BOV will help there. Do a search, Y2KevSE has a video clip of the BOV on his car (kind of hard to hear, but it's there).

 

Here's the link to the movie clip.

BOV clip

 

It sounds different in real life. I'm not sure why, but cameras can't pick up the sound very well. This video is the best out of all the sound clips I have though.

 

Well, your engine is pretty beefy sounding, and your friends were making a lot of noise. I heard the woosh once or twice, sounds nice.

Of course, it depends on which BOV you get. I'm hoping the Blitz Supersound with air horn that I got sounds good.

Also, I've heard Brian V's BOV in person, sounds great. The woosh is not as pronounced as on a big turbo'd car, but it's still cool.

 

Okay thanx guys!! I was asking cuz I put the the SS blitz blow off valve and something seems to not be running right!! Before I put the BOV, I was running fine. Once I put the BOV in, the engine would die after revving it or even after putting the car into neutral durng the drive. I have a manual and sometimes when I change gears, the car seems to almost turn off on me. I took it to go get it looked at and get it tuned but the problem still persists. When the RPM's go back down after revving the engine, they go too far down like the car is dying...sometimes it does dies. I checked all the lines and evrything seems fine. I got this BOV cuz I saw it on one of Kev's pages and it seemed hella cool to get one. I like that PSSHHHH sound but it doesn't make too much of that sound anyways. Does any one here know what could be happening?? Help please!
Thanx in advance.

 

Your BOV screw might still be too loose.

How far down does the RPMs go if you give the car a quick rev... say up to about 2.5K?

 

I had the same problem occuring with my car as well. The issue is with the MAF sensor. You MAF sensor is unable to adjust for the air that is being released, even ig you get a APEXI S-AFC you are not able to adjust for this issue like other cars are able to (at least I was not able to do it). You would have to remount the BOV to be placed before the MAF sensor. I had remove my BOV becuause I had this same issue, and it became too dangerous to drive.

I may remount the BOV since I really love the sound and its better than the POS bosch plastic recirculating one.

 

Why don't I stall in my auto when I rev?

 

This only appies to fast cars, for slow cars you don't need to worry about it.

I am not sure why that is happening, but even with the screw all the way down it was still happening. The explanation I gave was from my shop and what others told me here.

Didn't you do something with your maf sensor, keving?

 

That's why I have the Slow Car badge.


Maybe you used the wrong hose.


Nope, I didn't do anything with the MAF sensor. I actually had to try different vacuum hoses because the car did stall when TurtleMax and I first installed the SC.

 

Wow, glad this was posted. I'm close to getting my BOV installed and I never expected a problem like this occurring.

So the BOV should be mounted between the SC and the MAF, or between the MAF and the throttle valve?

 

For the setup you have, it has to be after the MAF (between SC and throttle plate).

 

That's the same place the Bosch recirculation valve is located right? I plan to have the installer hack saw the valve stem off the pipe, then weld a 2" flange at the same location for the BOV.

 

Wow, u guys are quick with your responses!! Thanx for info again guys!! Well, the thing that bothers me is that I did install the BOV where the bosch valve was located at, between the charger and the throttle body, and the RPM's would go less than 2500 and sometimes stall the engine. I really want to keep the BOV but I don't want to be driving with a car that will be turning off in the middle of my drivng. Should I put the BOV closer to the charger than to the throttle body? The reason y I put the BOV by the throttle body was cuz the hole from the bosche location was already there. It's more easier to weld an install in this location. your comments will help out a lot!! Thanx again!!

 

As I understand it, your MAF reads the amount of air going to the engine, then the A\F ratio is adjusted to compensate for that amount of air. That amount of air is expected to go into the throttle body, but with the BOV, you lose some of the air, so less is going in than the system expected. Thus, too much fuel is burned and unused and that causes the engine to shut down.

So how do we prevent this? According to Kevin, the BOV should go between the MAF sensor and the throttle body, but according to The New Climax, it should go between the SC and the MAF?

 

Same location.

 

Huh? I don't remember saying between the MAF and TB.

You asked where you can put it, and the only place is between the SC and TB (which is going to be after the MAF with the stock SC setup).

If you put it after the MAF, the BOV won't work correctly (it will be between the MAF and SC).

 

Hehe sorry, I thought the MAF was between the SC and the TB. I keep getting confused between the V1 and the V2 SC. I'm going to put it where the Bosch recirculation valve is currently connected. Sorry for the confusion .

 

Yeah, I have a 2000 SC max and I put the BOV where the Bosch valve was located ( btwn the SC and the TB) and that's how the problem began? That's why I asked in the first place if SC maximas can have a BOV instead of that POS bosch valve ( i guess it's not a POS cuz my car was working fine with it ). But anyways, I asked cuz my car would not run right after I put it. The RPM's go too low after revving. My vaccuum lines are setup correctly but the problem still persists. hey KEV, U said that u had the same problem but when u changed the vaccuum lines, the problem went away, right? Were your lines bigger or smaller or did u use a different vaccuum line to connect the BOV?? I have the SS Blitz BOV and I was wondering if I should cover up the bottom clearance of the valve so that the air doesn't escape too easily. U know how there are two openings of that BOV for air to be realeased? I'm talking 'bout the really thin opening, the one that u can feel air coming out of when idling. Do u think that might fix the problem, if I cover that part up?? cuz it seems like a lot of air is escaping thru there. If any one has fixed this problem, please let us know. Thanx again!!!

 

I just tried different hoses from different locations. If they worked, I cut the hose and added a tee.

How much air is a lot of air? You shouldn't be releasing air during idle. Is your idle rough?

 

My bad, it's not a large amount of air that is being released at idle. U can feel the air with your hand, like 3-5 inches near the horn of the BOV. My idling seems fine as long as I don't rev. I tried adjusting the BOV but the results are the same. I will try the different vaccuum lines to see if that works out or not. If any one has had any experience with this problem and has repaired it, let us know....THANX again!!!!

 

If you zoom in on my sig-pic or go to my site and enlarge the picture, you can see the BOV I have. Its an HKS Super-Sequential and it gives that stuttered PSSSSHHHH sound and I love it! The stock plastic BOV was crap so since we wanted to upgrade, we went w/the HKS. I've never had a problem w/stalling from day one...not even close!!! BOV's are more efficient for use w/Turbo'd cars but it does help on SC's as well...more than the stock one but not as much as it would on a Turbo app because of the amount of boost from an SC is less.

Deac

 

maxboost did you try changing the vacuum lines as Kev mentioned, I am interested in the outcome since I would like to reinstall my Blitz BOV?

 

Hey guys,

As I understood the purpose of a BOV, was in a turbo setup. As you let off the gas inbetween shifts (man) you slam shut the throttle body. That sudden slam shut slows the turbo blades down, and you essentially stall the turbo. So you have let off the gas, shifted, closed the throttle plate, now that pressure slows the turbo down, now you slam the throttle open, and crap, you have induced more turbo lag. Now you SC guys have a belt running your turbo, no exhaust gas to propel your impeller, just engine RPM. If you add a BOV, I am thinking you are just letting the pressure out of that long pipe of yours, and thus slowing your car.
Does this help? Just my .02-Wish I had a turbo though, My bro had a 87' GN, 18lbs boost, 3" exhaust, and 12.8 QTR mile. Sounded so awesome!

We need a turbo smilie.

 

but in a turbo setup, isn't the function of the BOV to release excess boost (a PSI calibration is made to a certain value so that the engine doesn't go boom after that PSI boost is reached).

So it seems for our SC setup we would have to provide more boost than is actually needed (at a fast charge rate) so that the BOV could release the excess boost. This reinforces the havoc with the MAF that u guys are seeing.

ie. One state in the cycle, the MAF will compute one A/F ratio just before a release, then it releases just after the computed value, now the PSI boost that the MAF had calculated for has drastically changed, problem.

my 0.02c

 

That is the job of the wastegate. If you are running say 14psi, the faster you go, the faster your exhaust pulses. now this makes the turbos blades spin faster, causing more pressure. The wastgate will open at a set pressure and "leak" out some pressure so you do not blow up your engine by allowing 25 pounds boost to go through it. The older cars were a manual setting on it, like the buick, we used a fish tank bleed regulator to adjust the boost from inside the car as we ran down the track. Now you have electronic boost controllers and turbo timers. The blow off valve is for the manual crowd, as with an auto and SC you would run with your foot on the gas wide open, and the trans shifts for you, so your throttle plate does not close, and you have a rise in pressre in a closed system, that would slow down a turbo. The turbo slows because there is no other force spinning the blades other than exhaust gas. The SC has a physical belt driving it. Hope this helps!

 

Has anyone figured this out yet? I just got my BOV installed and I'm having this problem .

 

Turn the screw toward the closed postion till it is closed, then work it back up to the proper point.

 

I've had the screw bolted down all the way, then loosened it. When loosened (by hand), nothing seems to happen with the BOV. Is something visibly supposed to happen with the BOV when I tighten or loosen the bolt, because nothing seems to happen.

 

Your never realy gonna see anything major... Under boost after the throttle comes off, you will hear it open and blow it out, turn it just enough to allow this to happen but to the point where the car dont' stall.

 

Well, I checked the BOV, and it's releasing air all the time, through the main air outlet. I tried to tighten down the screw, but then the entire screw came loose:



You can tighten down this screw with an allen wrench, but on this Greddy, it won't tighten at all. I think I stripped the hole, even though I didn't do anything out of the ordinary. I just tightened the nut, then tightened the screw. Now the screw won't catch at all and can't go down at all. POS greddy cheap materials!



Right now, the BOV is turned off (disconnected the vacuum line), so it's always closed. This is ok until I get the problem solved, but I can't boost without risking damage to the blower. Of course, now I might have to get a new BOV .

 

Here's the main problem now, I can't tighten down the pressure screw because the thread has been ruined:



What's weird is that the pressure screw will only go down so far, then you can see that the opening is too small for the screw to go any further. I tried to push down on the opening with a small rod, and it doesn't move. So I guess the pressure rod only goes down half an inch, and no more?



It doesn't really matter, since the pressure bolt won't stay in place because the thread has been stripped in the hole. Now what should I do?

 

I got a suggestion from members of the local import car club:

Tap new grooves and use a bigger screw. As far as I can tell, the pressure release adjustment for the BOV is completely controlled by moving that screw up or down the 1/2" tall hole. Is that correct, or does the screw press down on something further inside the BOV to adjust the pressure release point?

 

Bump.