2g bov reversing [merged 1-8] backward

[MC-97-GSX]

I was recently messing around with my 97-gsx, and i flipped the bov around, the end that the dump tube is normally mounted on, i put to the upper I/C piping, and the other end to the dump tube. As a result, the BOV now flutters isntead of the squeek, and it seems to be holding all the boost (14psi) that my turbo is putting out, it sure seems like it too, and it sounds sweet, if only it was a little louder... try it!

 

[polarmoment]

you don't want to plug that or it wont' want to open right, it will flutter and most likely get compressor surge more than anything

it will respond the same as a greddy type S with the lower boost port plugged- since it's the same basic design.

 

[BluemeanieTSi]

it will respond the same as a greddy type S with the lower boost port plugged- since it's the same basic design.

you don't want to plug the lower nipple on a types either

you want it open to the atm or boost source somewhere after the boost controller

 

[19gale2gGST]

I didnt see these anywhere on the web. Except another forum I run I posted it in. Anyways I am broke and like most DSMers want to get more for less. So I have done every free mod to my car and was curious what was really going on as the gains were still miniamal. Thats when I said oh duh the stock BOV leaks at 9psi so I can only get that much so in looking for a cheap fix to that a friend of mine(who shall remain nameless unless he wants you to know) had an idea will lookin at I believe a HKS SSQV and noticed that the stock BOV was being pushed open under boost while the other BOV was being held shut by the boost and opened by the vacuum. So here was the idea: Flip the BOV upside down. Make the piece that recircs go into the UICP and the UICP part go to the recirc tube. Had to very careful with the little line that goes to the TB. But it worked. I am unsure how much it will hold. I would still suggest a new BOV ASAP, but until then I do not see a problem with doing this until then provided you have a MBC and a Gauge to keep an eye on everything. If this is somewhere else on DSMtuners I am sorry but I didnt see it.





Will post a pic of it here shortly.

 

[Artago]

Why not just get a used 1G bov for $30? It'll hold 18 PSI.... which is more that you need.

 

[tlikethedrink]

or find a evo bov. you can pick up a plastic one that looks almost exactly like the 2g but holds way more boost for cheap. try ebay or evo forums...

 

[kenamond]

I didnt see these anywhere on the web. Except another forum I run I posted it in. Anyways I am broke and like most DSMers want to get more for less. So I have done every free mod to my car and was curious what was really going on as the gains were still miniamal. Thats when I said oh duh the stock BOV leaks at 9psi so I can only get that much so in looking for a cheap fix to that a friend of mine(who shall remain nameless unless he wants you to know) had an idea will lookin at I believe a HKS SSQV and noticed that the stock BOV was being pushed open under boost while the other BOV was being held shut by the boost and opened by the vacuum. So here was the idea: Flip the BOV upside down. Make the piece that recircs go into the UICP and the UICP part go to the recirc tube. Had to very careful with the little line that goes to the TB. But it worked. I am unsure how much it will hold. I would still suggest a new BOV ASAP, but until then I do not see a problem with doing this until then provided you have a MBC and a Gauge to keep an eye on everything. If this is somewhere else on DSMtuners I am sorry but I didnt see it.

Will post a pic of it here shortly.

Although I agree with the other two responders, you *can* test how much boost it will hold as follows:

Disconnect the recirc tube from the BOV.
Do a boost leak test to 20psi at the turbo compressor inlet. Have someone listen to the BOV recirc outlet to see what boost it stops leaking at. If it leaks at 20psi, but stops leaking at 15psi, then you know it will hold 15psi boost.

Anyway, if this actually helps the BOV, it might be worth knowing for folks on limited budgets. And if this is the case, you might want to post a tech article (why not?).

 

[sd_ff22]

What ever happened to the pic Billy?

-Dan

 

[19gale2gGST]

Once I get the car back together(I had to rebuild my F4A33..they suck..stock) I will get Dan to help me with that check. Iwould have gotten a used 1g but I am a poor navy guy. With a wife and 1.5 kids and a house payment, so the cheaper the better. I will eventually get a good BOV but if this works for now than I like it ### its free. Anywayz here is the pic from before disassembling the engine bay of what it looked like.

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[PitBullDsm]

Anyone know if this holds more than stock?

 

[19gale2gGST]

I dont have hard proof of it holding more than stock, but I can tell you as soon as I did this I felt an increase in power immediatly. I dont know what I am at right now but I will find out here shortly when I get my car back together(just got put everything back and hookup all the hoses-wires-lines) and I will tell you what boost I am pushing compared to the stock 9lbs. and when I do the check that kenamond said to do I will know exactly what it will hold. As soon as I find out I will post it up. But even without paper work I can promise it holds more this way then it does stock. I really have alot more pull especially through 1 & 2( it is an A/T).

 

[rich3389]

That BOV is mounted backwards.

 

[silver bullit]

Just get a 1g bov with a stock pipe bolted to it for 40 or so.

 

[19gale2gGST]

Either repeative comments intentionally or didnt read the rest of the thread. 1 It is supposed to be backwards. 2 I didnt have the money to buy someone elses BOV hat I dont know anything about except what they say. Also if these ends up holding a good amount of boost (maybe close to a 1g) than why spend the money when I have it for nothing? What is a better way to do something then for free? I feel like I am at times explaining why, or how come I ddint buy a 1g BOV. I dont care I will post back in this thread once I find out how much pressure it will hold. And yes it does hold. I had it like this for a little bit (like 2 weeks) than my tranny went out. I am about to put it back onthe road and will have pressure tests done before the end of the month(DSM willing).

 

[PitBullDsm]

Also if these ends up holding a good amount of boost (maybe close to a 1g) than why spend the money when I have it for nothing? What is a better way to do something then for free?

I agree.

I am about to put it back onthe road and will have pressure tests done before the end of the month(DSM willing).

I'll try this mod out tomorrow, pressure test it and post results...

 

[eddied118]

Well this is probably the best free mod out there But I have a concern because now it sounds like it might be getting surge.... sounds like shhh shhh shhh kinda like a hks maybe the springs too strong for it to be used this way but im no wiseman.

On the other hand the car felt stronger and pulled a whole lot better and the vacuum created by the motor is enough at idle to open the valve to recirculate.

:edit: oh and about leaking, I don't think it should leak at all since the pressure is pushing the valve closed and the vacuum created by the turbo is pulling on it at the same time when boost is made

 

[sd_ff22]

I'm an evil genius.

-Dan

 

[Spades]

Hmm, I just stared at that picture for a couple minutes and gave it some thought, and I can actually see it working as intended, in fact i see it holding infinite boost, you have the diaphragm pushing on the valve as well as the actual boost pushing down on the valve shut. Im curious about its "release" point though, it will probably be delayed when the diaphragm sees vacuum since the top part of the valve still has pressure, therefore you should be experiencing some surge. Only way to tell is by you letting us know the results. Im not interested in this mod im just looking at it from a physics or theoretical standpoint. But again, this looks like it DOES work

 

[MrBoxx]

If I remember right, Kevin Jewer did this a few years ago with his stock Evo BOV on his Evo, but I believe he only did this "mod" at the track to hold boost. I don't think he ran it on the street in this configuration.

 

[eddied118]

So my question... Could the valve opening and closing rapidly like it does (because I tried it) cause surge or is it safe for the turbo? It does it at any amount of boost wot or crusing

 

[19gale2gGST]

I'm an evil genius.

-Dan

Yes you are.




And Pitbull I am glad you can find out how much it will hold. When Dan thought ofit I was really intrigued.





And yes I have the flutterin when it blows. I can see that causing a problem with the diaprghram at high boost pressures but I think for low levelboost(under 14psi) I think it would be ok as a way to keep the boost until you can get a good quality BOV. As I stated earlier I wouldnt leave this on as a way to get away from buyin a BOV but a way to save some money and get the boost untillyou do have the money. And thank-you to the guys that have already tried this and agree that it definitly holds more boost than the stock position.. When I get mine done and tested I will try my hand at a tech article for it. I dont want to use someone elses results, no offence. If I write it I want it to be what I got.

 

[eddied118]

Here's my paint drawing on it the red is the valve and the blue is the pressure from boost.

first bov is regular and the second is the reversed way and from what I see it would not open at all under boost since the boost is keeping it closed

 

[19gale2gGST]

If I remember right, Kevin Jewer did this a few years ago with his stock Evo BOV on his Evo, but I believe he only did this "mod" at the track to hold boost. I don't think he ran it on the street in this configuration.

I would be worried about street use with the evo since the spring is stronger(the stock evo doesnt leak at 9lbs and thats do to a couple things but one is a stronger spring) is can hold more so the vacuum wold have to get higher to open it. However the 2g one is a weaker spring. So I wouldnt run an evo like this on the street but the 2g I havent had a problem with......yet.





I cant wait for Pitbull to post what his held up to.

 

[PitBullDsm]

I did the "mod" and all I can say is...HOLY CRAP! I didn't realize how much of a difference this would make. The car pulls a hell of a lot stronger and it held sucessfully up to 20 psi. Although, I am sure it can hold a lot more. I'm definately noticing surge, but nothing to make me too worried. If you are planning to do this, make sure to get a boost controller considering the limitations of the stock fuel system. Thanks a lot guys!

 

[whitetsi95]

for a completly stock engine whats the most amount of boost you can run?

 

[PitBullDsm]

for a completly stock engine whats the most amount of boost you can run?

about 15-16 psi.