Enlarge holes? Alien births? Chopped yours up? Whats all this?

Sounds like my Friday night. I can't wait.

https://www.miataturbo.net/attachmen...ine=1411792862

https://www.miataturbo.net/attachmen...ine=1411792862

https://www.miataturbo.net/attachmen...ine=1411792862

Stock

http://i205.photobucket.com/albums/b...r/complete.jpg

My local supplier gets better discount for turbosmart than for forge. Anyone see any glaring problems with Turbosmart Vee Port Pro? It sounds ok on youtube...

Vee Port PRO BOVs

And comments on this: leaking under partial boost?
SI #10

Cruise leaks is not uncommon. My forge leaks between 60-80kpa however once i get to 80kpa it shuts closed again while under that the secondary white valve keeps it from leaking.

Cruise is a bit different though, since you really aren't using the turbo at all. My issue is that the eBay BOV won't close until like 4,000RPM's even at WOT most times.

Forge will be here Thursday. Stoked.

Kinda sorta related. I have this old FM Bov. Anyone know much about it? It seems to work well for all the different setups I've had on it but I haven't tried anything else and can't tell if it leaks because it's currently in my fender. I prefer little spring pressure so it vents as much as possible therefore open at idle but I run a filter on the open at idle side. Should I buy something new? Am I loosing 100 hp running this?! it's so quiet.

I've taken it apart a few times and rehoned the ID so it still slides smoooooth as butter.

http://rs192.pbsrc.com/albums/z146/f...e40c1.jpg~c200

https://www.miataturbo.net/attachmen...ve-fm-bov1-jpg

https://www.miataturbo.net/attachmen...ine=1325715660

Isn't that just an FM-badged GFB?

It very well could be, I still don't know if it's 'bad' or why. Seems to be fine but I'm missing something, like:

Huh? If you had a maf you'd want that shit closed so you aren't venting the MAF'ed air out.

On our man cars you'd want it open at idle, no? This is why I like my FM with it's filter and why I haven't gone with a tial Q.

I use a Vee-Port Pro. I had the model before it as well. Think it was just called a Vee-Port. And I used one on my WRX awhile back too. I have really liked turbosmart products. I have a 38mm UltraGate that I will be using on the new setup.

So I got my Forge today. STOKED. Put it on. Massive compressor surge.... Opened it up... sent me the yellow spring instead of lighter green one. Ugh. Called. New one is on its way.

This brings me to the question: what spring do you guys use on the idle side, to keep it closed during idle? I have red, yellow, blue, green, and the stock one in it which is very light. Idle did seem to be much different as soon as I installed the new valve over the old China one so I'm assuming its either sealing a lot better or leaking a lot better, but don't know how to test it hahaha.

you're not venting it out, it goes back to the inlet after the maf and right before the turbo. the stocker actually opens at idle a little too, I think its to keep the car happy and not surging when letting off (that roughness for a split second right after easing off the throttle when the bov goes between open/closed a few times)


TEST:
1-put in softest spring
2-observe if its open at idle
3-replace spring with stiffer one until it doesn't, without making it surge like crazy
4-????
5-Profit

On MS controlled miata's I've actually had much better luck maintaining a rock solid idle with the bov not open at idle. I don't think there's a drastic difference either way, just my preference. I know some people swear by having it closed at idle.

Umm you want the main valve to be open at idle.

I cannot imagine that there would be very much differnece if the BOV is or is not open at idle (filtered). Very little air acutally flows as there is very little pressure diffence. On one side (at the outlet port) there is atmosphere +/- whatever the fan might be inducing. On the other side (charge pipe) there is atmosphere +/- filter drop +/- idleing compressor - charge pipe drop (at idle).

On my Mitsubishi BOV, open at idle, I put a plastic bag on it at idle and it neither inflated nor pulled into the filter.

AND all of this is occurring upstream of the throttle and AIC valve.

At idle you want maximum vacuum. with it closed you get maximum vacuum.

Its likely not a big difference, I'm just sharing what worked for me.

Interesting. I would think logically it should be closed. I've never used a 2 stage BOV so I didn't know if there was a process like "tune this then that" or anything, thats all. I'll just screw with it.

its not two stage
its just dual piston. so even with the softest piston it should still remain closed at idle.

so you will likely be ok even with the softest spring

+1 to closed BOVs, :party:

In my case using the MAF still, anything not through the MAF is air not accounted for. Once I got my greddy fv, I re-tuned the idle and its butta at 14.7 afr & no more crap idle.

Follow 18's test recommendation, you'll be set in no time.

Not AFAIK.

I had that FM valve on my original kit (2002-vintage 2-cat 99 CARB-approved kit w/ Link Piggyback). It's huge, much bigger than the GFB valve that came when I upgraded to the modern FM2 hardware a couple years ago.

The old FM valve was dual port -- if the piston moved a little bit, then it opened the recirculation port (the one with a flange on it), but if it moved a lot then it opened up a second port on the other side that did VTA. It didn't leak through the VTA port at idle, so didn't piss off cars that still had the stock ECU with the MAF hooked up (like with the Link Piggy).

Aside from being huge and comparatively heavy, the main downside was that the recirc port flange was not retained very well and had a tendency to come off. It was basically pressed into the housing with a few punched retaining points around the circumference, but mine kept coming apart. I eventually JB welded it on.

--Ian