BOV help

Devil Dog · Post by **Devil Dog** » Thu Apr 20, 2006 8:27 pm

With my XR's engine being stock, can I put a BOV on it without having a IC?? Where do I purchase one? Is it hard to install?

turboplz · Post by **turboplz** » Thu Apr 20, 2006 8:33 pm

yes you can, you'll have to put it on the turbo-throttle body section of pipe. Make sure the flange you make or have welded on is aluminum, otherwise it won't work out. You can make any bov, bpv work, ebay is where i've always bought mine. Good luck!

Devil Dog · Post by **Devil Dog** » Thu Apr 20, 2006 9:11 pm

I went to Ebay and they have 20 different types. What would be the best for the XR?

Maurice S · Post by **Maurice S** » Thu Apr 20, 2006 9:12 pm

You might have an easier time putting one of those E-Bay sleeved bov's into the compressor to TB hose...though I have no experiance with them...all the $#!* I've bought off of ebay has worked as promised, but I've been careful.

Post by **John Brennan** » Thu Apr 20, 2006 9:14 pm

You should get a dual-piston model, like the Bailey or the Forge. I don't know if there are any other makers of this type, but the Forge one is available at Bob Lee's site:

http://www.40bob.com

From what everyone says on this and related sites, don't get one that's not of this type.

Post by **anglin** » Thu Apr 20, 2006 10:45 pm

John Brennan wrote:From what everyone says on this and related sites, don't get one that's not [dual piston].

I certainly think this information is FAQ worthy. I know Ed (of Utah fame, not of disappearing-act fame) had requested a BOV FAQ, or something along those lines. He's started two solid threads on BOVs and intercoolers (though it looks like he might be leaving us), which have some good, solid information in them. They could really be pared down and have the BS removed to build a good FAQ from them.

Anyway, information that is FAQ bound, based on MCAF user agreement:

- if you choose to run a BOV, it has to be of dual-piston type if you are keeping the VAM or a MAF conversion.
- Any BPV should work

Is it agreeable to keep out the debate about brands and whether a BPV is incorrect, or whatever? Feel free to weigh in, Brad.

Post by **DPDISXR4Ti** » Sat Apr 22, 2006 10:27 am

anglin wrote: Feel free to weigh in, Brad.

I guess I'm contractually obligated to respond now, huh?

I'll try to keep this short, even though it can be a somewhat complex subject.

I used to think that a BPV was the only "right" way to go. After all, dumping metered air "overboard" (as you would with a BOV), had to be a bad thing, right? Well, I've come to find out that dumping metered air overboard on throttle tip-out is mostly irrelavant. During this short time period, the injectors shut off and the meter input is ignored. Furthermore, dumping a bunch of air back between the air meter and turbo can cause a variety of different issues, depending on whether you're using a VAM or MAF to meter your air.

So bottom line, I believe that a BOV is better than a BPV, but especially so if you're running a MAF conversion of any type. I'm actually running a Mitsubishi valve designed to be BPV, but plumbed as a BOV. To avoid sucking in any unmetered air through the valve outlet, I simply have a check valve attached so it can only release air, not inhale it. It is surprisingly quiet, but that might be a function of the small outlet I have plumbed off the throttle body. It's really pathetically tiny (3/8" maybe?), but it was readily obvious to me when I added it, so perhaps size isn't as important here as some might think.

That's my 3 cents on the topic...

turbofan · Post by **turbofan** » Sat Apr 22, 2006 1:27 pm

anglin wrote:
John Brennan wrote:From what everyone says on this and related sites, don't get one that's not [dual piston].
I certainly think this information is FAQ worthy. I know Ed (of Utah fame, not of disappearing-act fame) had requested a BOV FAQ, or something along those lines. He's started two solid threads on BOVs and intercoolers (though it looks like he might be leaving us), which have some good, solid information in them. They could really be pared down and have the BS removed to build a good FAQ from them.

Anyway, information that is FAQ bound, based on MCAF user agreement:

- if you choose to run a BOV, it has to be of dual-piston type if you are keeping the VAM or a MAF conversion.
- Any BPV should work

Is it agreeable to keep out the debate about brands and whether a BPV is incorrect, or whatever? Feel free to weigh in, Brad.

Hey look, it's Ed (of Utah fame, not of disappearing-act fame)! Hey, if you guys wanna donate a good turbo, i'll stick around! anyway, i've got a simple dump valve on my car that i bought brand new off ebay for $40 and it works great, i'm really satisfied with it, and it sounds awesome. not too loud, but the car sounds like it's snorting when it shifts. bad awesome.

check out the BOV thread for more pics and info here: http://www.merkurclub.com/forum/viewtopic.php?t=6384

Frag · Post by **Frag** » Sat Apr 22, 2006 8:46 pm

I'm running a POS single piston (if thats what you want to call it) BOV I bought off ebay. I mounted it on the 90* elbow that leads to the throttle body. It allows for some adjustment by twisting the top but I had to shim it with a nickel because it seemed to be opening a little early. I'm sure if you hooked up an AFM it might show the mixture going rich between shifts but the butt meter barely notices anything, I can get the car to make a light popping backfire every once in awhile that you couldent hear if you had the radio on or were talking to someone in the vehicle if I pourposefuly made the bov vent 3x within a 10 second period of time. On the birght side it doesnt have a diaphram so no need to worry about it going bad over time. For the low price of $25.00 i'm happy with it's perfomance.

YMMV

worked_xr · Post by **worked_xr** » Sun Apr 23, 2006 12:42 am

What is the issue/difference between a single and dual piston BOV in our application?

Frag · Post by **Frag** » Sun Apr 23, 2006 1:55 am

Read DPDISXR4Ti post it explains the (non?) issue somewhat.

Devil Dog · Post by **Devil Dog** » Sun Apr 23, 2006 9:53 am

Does anybody have any pics of a BOV on a non IC XR?

turbofan · Post by **turbofan** » Sun Apr 23, 2006 12:19 pm

Frag wrote:I'm running a POS single piston (if thats what you want to call it) BOV I bought off ebay. I mounted it on the 90* elbow that leads to the throttle body. It allows for some adjustment by twisting the top but I had to shim it with a nickel because it seemed to be opening a little early.
YMMV

that's exactly what i'm running. i need to shim it a bit as well, methinks. hmm....

Frag · Post by **Frag** » Sun Apr 23, 2006 2:40 pm

I may try a second nickel as well, though this may be too much so I may have to find some washers or something a bit thinner.

turbofan · Post by **turbofan** » Sun Apr 23, 2006 2:52 pm

you're using them as a spacer sitting under the spring right on top of the piston, right?

did yours make a little air leaky sound before you shimmed it?