That all depends I guess. If you can recirc enough air around and around to someplace after the maf, it would probably work ok. OR another thought is to bleed off air BEFORE it gets read by the maf. Then you can just vent it to the atmosphere no problem. You just have to make sure it snaps shut right off idle. I do believe more than one oem sc systems use bypass air to correct idle problems.

 

That is what I currently am doing. Look at the pics in my first post, my BOV is before the MAF, and it sits open at idle, so essentially it is bleeding off the air. There is such an exess of air though, that it isn't enough.

 

Hmmm. ok. I think maybe the BOV is bleeding off not enough air or too much air. You might be right that the bov might be creating turbulance that the idle air control can't deal with well. A recirc valve will really cut down on the noise. At least in general recirc valves are much quieter than BOVs.

 

dont waste your time. Move the TB. Its not about that the eaton has higher pressure at idle than the vortech, it is that you are dealing with two completely different blowers. Comparing the vortech and the eaton is like comparing an electric motor to a gas engine. You may be able to bypass, but it really is a half assed solution. Prostock cars have those butterflies on the intake for a reason. You may be able to simulate that however and add a second TB, it would function in the same manner as the butterflies. Moving the TB isnt really that hard anyway.

If you want to do a bypass valve it has to be big. Bigger than any BOV. Think about this, lets say you shift at 6500 roms. You release your foot, and it draws a vacuum, you Bypass valve opens. Keep in mind that you have to bleed off almost all the air that is coming through the blower. Think about how many CFM's of air that is. It would actually should be equivalent to the size of the intake piping if you wanted to avoid putting strain on the blower which i imagine you dont.

Now, do you REALLY want to come up with a bleed valve that has a quick response time and can open to 2.5" in diameter? Moving the TB would be so much easier.

I am a mechanical engineer, and I work with pumps all day. Just trust me on this one...

 

I have to agree with on_alert. Like I said it would be a half measured solution. Thanks for letting me chime in even though im not a member here
Brian

 

If I relocated my TB, what would I do about my throttle cable wires and all that stuff? It seems like a big PITA. Room is scarce on the intake side of the blower, too, but the TB is pretty small so I don't think I have to worry about that, just what to do with all the crap, especially the throttle cables!

 

Also, are my problems effecting my power output for sure? B/C acceleration seemed akward at points, even at WOT.

And what would make my FP shoot up to mid-high 90's in psi? I never saw that much FP with 10psi on my V1 setup. Could that be sapping a lot of power as well?

Whats weird is that it would shoot to mid-high 90's, and gradually decrease as my RPMs rose.

 

The BOV could be effecting the sound of the blower when I revv it too, right? Like, would bypassing the air and moving the TB act like a big muffler, filtering the sound at idle AND when revving? Becuase my blower is REALLY REALLY loud when you revv it. REALLY high pitched, more high pitched and "untame" sounding then in the vids of GTP's with normal setups.

BTW, my car revvs MUCH faster with the eaton then with the vortech. When I first drove the car home, I usually revv to about 1800 to engage into first smoothly, but when I looked down I was at 2800rpm! This thing revvs like a champ now.

 

What kind of boost are you seeing?

 

Craig -

MOST of the sound is probably coming from the BOV releasing air. However, you also need to realize the GTPs are running an airbox which acts as a silencer. Unless you're referring to a non-stock GTP?

Also, once the car has warmed up, has your idle RPM changed?

 

It could possibly be that when the TB first opens up and the motor gets a surge of air and your ecu tells it to run rich to compensate for the sudden burst of air, then as it becomes more stable the fuel pressure drops to a normal rate. Does this happen when you switch gears too?

 

I bet your fuel pressure is high because the FMU is seeing boost(at idle) and is upping the pressure accordingly.

 

Your very right. The GTP's blowers are also in the motors valley, and with all that silencing crap, they should run almost silent. The only reason I was caught off gaurd at first is becuase Eaton claims a near silent operation for their blowers. It's definately audible though, about as audible as the Vortech but with a more mellow "zipper" tone.

My idle RPMs shoot up to ~1500rpm like normal on a cold start, and gradually settle down to ~900 with the a/c on. The RPMs go crazy though, shooting anywhere from 200rpm to 1000rpm spurraticly (sp?). It's died twice on me, and has almost died even with the freakin a/c on.

 

Danget, I didn't really pay attention to the gauge during shifts. The shifts have an akward jerk to them though, almost like im going to stall for a split millisecond, similer to what Jer was describing earlier.

IcEy: I'm seeing ~6.5psi by 2000rpm, and I know i'm seeing a lot of boost at idle b/c of how loud my BOV is. I see 7-8 by 2500rpm. It could have kept rising, but I was too busy keeping myself from crashing with the intense acceleration.

 

Ackwardly enough, the car only seemed to pull HARDER and HARDER as the rpms rose. If my boost dropped off, I sure as hell didn't feel it. It seems as if my motor has responded positively to this type of boost, hopefully that will continue to be the case.

 

I hope moving the maf sensor will help you fix your problem. I know throwing out that kind of money you would want something to work right away. I hope it works out on Monday.

 

Thanks bro

 

Craig, heres some encouragement to get your car fixed up took this video yeasterday...

http://www.we-todd-did-racing.com/we...ZmQzMXk1NDE%3D

(don't watch the vid just listen )

 

Link doesn't work.

*Update*

Took the car in tonight to drop it off (sunday). We are first going to relocate the BOV further away from the MAF. (somewhere underneath the blower) Secondly, we are going to bypass that air to the intake before the blower. Moving the throttle body would make the system quieter, but this should work just as well. We are not bypassing the air into the valve in the blower because there is no room, but the valve is not big at all, so we surely won't be damaging the blower by running a simple hose. The blower would get really hot if it was being overworked, and as of now, it doesn'te even heat up nearly as much as my V1 did. Obviously the turbulent air created by the BOV was messing everything up, and the BOV itself was magnifying all the sound.

I am still running way too rich. Looking at the gauge more closely, it appears that i'm only hitting 5.5psi by 2000rpm, my bad. I don't reach 7psi until ~2600rpm. I'll have to get a friend to keep an eye on it to see what I peak out at. Anyways, an 8:1 disc is obviously overkill for this much boost, so tommorow i'm going to drop in the 6:1 FMU disc. Hopefully that will clean things up and i'll see a lot more power.

There are a couple things that i'm still not getting. One is my FP. I hit ~96psi, and as the RPMs rise, the FP will decrease, settling in the 80's near redline. My fuel pump is a Walbro Hi flow, so it's not that. This is very weird. Secondly, is my acceleration at full throttle. Sometimes it seems slower then others. Noticeably around 4000rpm, it will really slow down, and pick back up, like my air readings are off or something. But, if i'm out of vaccum and the BOV isn't making a difference, what could be causing this? My MAF should be fine handling the amount of boost. Maybe i'm just running insanely rich there for some reason?

The car will be done tommorow afternoon, so i'll post more then. Until then, please give me your feedback...

 

Craig, have you read what anybody in this thread has said?

 

haha!..............

 

Yes, just restating the obvious and repeating myself.

 

Obvious?

Craig, the BOV isn't your problem.....

 

It is the MAF sensor, haha again. J/k

 

There are soo many different opinions in this thread. The MAF can obviously handle the boost, so it's more then likely fine. Moving the TB would solve the issues most definately, but it also requires a custom mounting bracket to be made, and new cables, ect. The plan is, for now, to relocate the BOV and bypass that air before the blower. Under vacuum most the air is being surged out the BOV, while some is being sent through the MAF. This is definately causing a lot of turbulence, and can very much be accredited to my driveability and idle. It only makes sense to relocate the BOV and recirculate the air. Besides, i'm pretty sure the Ford Probe guys didn't move their throttle bodies.

 

not trying to be a smartass here, but why dont you referance the comptech supercharged V6 accords? they run an almost identical setup.
also on turbulance, i agree with whomever said that the air hasnt "calmed down" by the time it reaches the MAF. the recommendation by that person was like 18" away from the blower is the closest the MAF should be. that'll probably help too, if that idea is correct.

 

recirculating the BOV isnt going to solve the problem your going to have to move the MAF or move the TB and the MAF and eliminate the BOV and since this is the method that has been proven youll proboly end up doing it sooner or later so why not just bite the bullet and do it tommarow and forget about all this

 

Craig, the issue is not turbulence, turbulence at the MAF would screw it up a little, but not totally make it run like crap. And if you are going to try to run a bypass valve, it better be one huge *** valve, or else you are just wasting your time.

what kind of bypais valve are you going to use?

If you arent going to listen, then I am not going to help

 

1/2static+(FMU ratio X psi) = 21.75+(8 X 10)=101.75psi

Either you're seeing 9psi to get mid 90's or your AEM FPR has raised the base fuel pressure past 43psi.

That's a sign of a weak fuel pump or possibly injector leakage due to excessive fuel rail pressure.

 

Turbulence/an improper MAF reading can make your car stall. I'd say that would even outdo "run like crap" Smash your MAF with a hammer and start your car - same effect.

 

Alright, here is the NEW issue. His car is no more...so any and every part of the roots discussion is useless. I personally doubt any1 else will do it so...yeah I guess its time we just...let it go. Once again sorry about your ride Craig.

http://forums.maxima.org/showthread.php?t=262781